CN103581094B

CN103581094B - The transmission method of downlink user dedicated demodulation reference signal and equipment

Info

Publication number: CN103581094B
Application number: CN201310055541.XA
Authority: CN
Inventors: 高雪娟; 林亚男; 丁昱
Original assignee: China Academy of Telecommunications Technology CATT
Current assignee: China Academy of Telecommunications Technology CATT; Datang Mobile Communications Equipment Co Ltd
Priority date: 2012-07-24
Filing date: 2013-02-21
Publication date: 2016-12-28
Anticipated expiration: 2033-02-21
Also published as: CN103581094A; CN103581095A; CN103581095B

Abstract

The embodiment of the invention discloses transmission method and the equipment of a kind of downlink user dedicated demodulation reference signal DM RS, relate to wireless communication field, for improving the data demodulation performance on new carrier type NCT carrier wave.In the present invention, base station determines DM RS mapping resource in present sub-frame according to DM RS resource mapping method, resource is mapped according to the DM RS determined, DM RS is mapped in present sub-frame and is transmitted, terminal determines DM RS mapping resource in present sub-frame according to DM RS resource mapping method, map resource according to the DM RS determined, obtain the DM RS of transmission in present sub-frame.DM RS mapping resource at least includes that Resource Unit RE, N at least one OFDM symbol in the top n orthogonal frequency division multiplex OFDM symbol of present sub-frame are the integer not less than 1.Use the present invention, it is possible to increase the data demodulation performance on NCT carrier wave.

Description

Transmission method and equipment of demodulation reference signal special for downlink user

Technical Field

The present invention relates to the field of wireless communications, and in particular, to a method and an apparatus for transmitting a demodulation reference signal dedicated for a downlink user.

Background

On a Legacy (Legacy) carrier of a Long Term Evolution-advanced (LTE-a) system, an Orthogonal Frequency Division Multiplexing (OFDM) symbol in a downlink subframe is divided into two parts, namely a control region and a data region, where the control region is the first N OFDM symbols of the downlink subframe, as shown in fig. 1. Where N may take values of 1,2,3,4, and N =4 is only applicable to carriers with a system bandwidth of 1.4 MHz. A legacy Downlink Channel for carrying Downlink Control information, such as a Physical Downlink Control Channel (PDCCH), a Physical Control Format Indicator Channel (PCFICH), and a Physical HARQ Indicator Channel (PHICH), is transmitted in a Control region; downlink channels carrying Downlink data, such as a Physical Downlink Shared Channel (PDSCH), can only be transmitted in a data region. I.e., PDCCH and PDSCH time division multiplexed transmission.

Downlink Reference signals for DeModulation in the LTE-a system mainly include Cell-specific Reference signals (CRS) and DeModulation Reference signals (DM-RS) dedicated to User Equipment (UE, also called terminal Equipment). In the LTE-a system, 9 downlink transmission modes are defined, and which transmission mode is specifically used by the UE is preconfigured by higher layer signaling. Different downlink reference signals are suitable for different transmission modes.

The CRS is used for signal demodulation in transmission modes 1 to 6, and may support single antenna port transmission (antenna port number p is 0), two-antenna port transmission (antenna port number p is 0, 1), or four-antenna port transmission (antenna port number p is 0,1,2, 3). A mapping manner of CRS resources with one PRB pair as a unit is shown in fig. 2a and fig. 2b, where fig. 2a is a mapping manner under a conventional Cyclic Prefix (CP), and fig. 2b is a mapping manner under an extended CP. The CRS is transmitted over the full bandwidth of the carrier and in every subframe.

The DM-RS is used for signal demodulation of transmission modes 7-9, can support transmission of 1-8 antenna ports, and is respectively configured at the antenna ports p-5, p-7, p-8 orp-7, 8. DM-RS is only sent on PRBs where PDSCH with a transmission mode of 7-9 is transmitted, so that the overhead of reference symbols is reduced, energy is saved, and interference between adjacent cells is reduced. Fig. 3a (under the normal CP) and fig. 3b (under the extended CP) show resource mapping manners of DM-RS in units of one PRB pair, where the mapping resources of DM-RS on antenna port 7/8/11/13 are the same, and the mapping resources on antenna port 9/10/12/14 are the same. By tables 1 and 2Time domain orthogonal sequences are shown to ensure orthogonality between DM-RSs on different antenna ports using the same mapping resources. Under the extended CP, the DM-RS does not support transmission at antenna ports 9-14. In addition, for a special subframe with a Downlink Pilot Time Slot (DwPTS) length of 3 OFDM symbols in a Time Division Duplex (TDD) system (i.e., under a Downlink normal CP, the DwPTS is 6592 · T ·_SIn the special subframe of (1), DwPTS is 7680. T under the downlink extended CP_SOf special subframes, wherein T_STime intervals are adopted for the system), namely special subframes using downlink normal CP under special subframe configuration 0 and 5 and special subframes using downlink extended CP under special subframe configuration 0 and 4 do not support DM-RS transmission.

Table 1: DM-RS orthogonal sequences of different antenna ports under normal CP

Table 2: DM-RS orthogonal sequences of different antenna ports under extended CP

In order to further improve the utilization rate of system resources, Release-11 (Rel-11, Release 11) of the LTE-a system determines to introduce a New Carrier Type (NCT) into a Carrier Aggregation (CA) system, so as to enhance the system spectrum utilization rate, better support a heterogeneous network, and reduce power consumption. Currently on NCT: in order to improve the utilization rate of NCT resources, the PDSCH may be transmitted on the first N OFDM symbols (i.e., a control region in one subframe defined on a legacy carrier), that is, the PDSCH may be transmitted on all OFDM symbols in one subframe; the NCT only supports PDSCH transmission using the transmission mode 9, and may be scheduled across carriers by a PDCCH on a legacy carrier aggregated with the NCT, or scheduled by an Enhanced Physical Downlink Control Channel (E-PDCCH) on the NCT; the main difference between the E-PDCCH and the legacy PDCCH is that the E-PDCCH is transmitted in frequency division multiplexing with the PDSCH, so the E-PDCCH can also be transmitted on all OFDM symbols; NCT supports only CRS transmission with 5ms period on a single antenna port (antenna port p = 0), and CRS is only used for measurement and tracking, not for demodulation; and E-PDCCH, PDSCH and other downlink channels on the NCT need to be demodulated based on DM-RS.

In summary, in the DM-RS resource mapping mode defined by Rel-10, DM-RS is not transmitted on OFDM symbols in a control region, and when E-PDCCH and PDSCH on NCT are mapped on all OFDM symbols in a subframe in the time domain for transmission, channel estimation information on at least the first N OFDM symbols needs to be obtained by performing an extrapolation algorithm through a limited column of DM-RS, thereby reducing the data demodulation performance on NCT; and the DM-RS does not support the transmission in the special subframe with 3 OFDM symbols in DwPTS, so that the downlink data can not be transmitted based on the DM-RS in the special subframe only containing 3 OFDM symbols, and the resource utilization rate of NCT is reduced.

Disclosure of Invention

The embodiment of the invention provides a method and equipment for transmitting a demodulation reference signal special for a downlink user, which are used for improving the data demodulation performance on an NCT carrier.

A method for transmitting a demodulation reference signal DM-RS special for a downlink user comprises the following steps:

the terminal determines the mapping resource of DM-RS in the current subframe according to the DM-RS resource mapping mode, wherein the DM-RS mapping resource at least comprises resource units RE on at least one OFDM symbol in the first N OFDM symbols of the current subframe, and N is an integer not less than 1;

and the terminal acquires the DM-RS transmitted in the current subframe according to the determined DM-RS mapping resource.

the base station determines the mapping resources of DM-RS in the current subframe according to the DM-RS resource mapping mode, wherein the DM-RS mapping resources at least comprise resource units RE on at least one OFDM symbol in the first N OFDM symbols of the current subframe, and N is an integer not less than 1;

and the base station maps the DM-RS to the current subframe for transmission according to the determined DM-RS mapping resource.

A terminal, the terminal comprising:

the resource mapping unit is used for determining the mapping resources of the DM-RS in the current subframe according to a DM-RS resource mapping mode, wherein the DM-RS mapping resources at least comprise resource units RE on at least one OFDM symbol in the first N OFDM symbols of the current subframe, and N is an integer not less than 1;

and the signal acquisition unit is used for acquiring the DM-RS transmitted in the current subframe according to the determined DM-RS mapping resource.

A base station, the base station comprising:

and the data transmission unit is used for mapping the DM-RS to the current subframe for transmission according to the determined DM-RS mapping resource.

In the scheme provided by the embodiment of the invention, the mapping resources of the DM-RS exist in the control region of the subframe, namely the first N OFDM symbols, so that the channel estimation information on the first N OFDM symbols can be obtained by carrying out interpolation calculation on the DM-RS transmitted on the N OFDM symbols, and the channel estimation information is prevented from being obtained by carrying out an extrapolation algorithm on a limited array of DM-RSs which are far away from the N symbols in the time domain, thereby improving the data demodulation performance of the NCT, ensuring that DM-RS transmission also exists in special subframes of which the DwPTS only comprises 3 OFDM symbols, further enabling the special subframes to transmit downlink data, and further improving the transmission efficiency and the spectrum utilization rate of the NCT.

Drawings

Fig. 1 is a schematic diagram illustrating a multiplexing relationship between a control region and a data region in a downlink subframe in the prior art;

fig. 2a is a schematic diagram of a CRS resource mapping manner under a conventional CP in the prior art;

fig. 2b is a schematic diagram of a CRS resource mapping manner under an extended CP in the prior art;

FIG. 3a is a diagram illustrating a DM-RS resource mapping method under a conventional CP in the prior art;

FIG. 3b is a diagram illustrating a DM-RS resource mapping method under an extended CP in the prior art;

FIG. 4 is a schematic flow chart of a method provided by an embodiment of the present invention;

FIG. 5 is a schematic flow chart of another method provided by the embodiment of the present invention;

FIGS. 6a to 6j are schematic diagrams of DM-RS resource mapping according to a first embodiment of the invention;

FIGS. 7a to 7i are schematic diagrams of DM-RS resource mapping according to a second embodiment of the invention;

FIGS. 8a to 8c are schematic diagrams of DM-RS resource mapping according to a third embodiment of the invention;

FIGS. 9a to 9c are schematic diagrams of DM-RS resource mapping according to a fourth embodiment of the invention;

FIGS. 10a to 10e are schematic diagrams of DM-RS resource mapping according to a fifth embodiment of the invention;

FIGS. 11a to 11d are schematic diagrams of DM-RS resource mapping according to a sixth embodiment of the invention;

FIGS. 12a to 12d are schematic diagrams of DM-RS resource mapping according to a seventh embodiment of the invention;

FIG. 13 is a schematic structural diagram of an apparatus according to an embodiment of the present invention;

fig. 14 is a schematic structural diagram of another apparatus according to an embodiment of the present invention.

Detailed Description

The embodiment of the invention provides a DM-RS transmission method suitable for an NCT carrier, in the method, a DM-RS mapping resource exists in a control region of a subframe, namely the first N OFDM symbols, so that channel estimation information on the first N OFDM symbols can be obtained by carrying out interpolation calculation on the DM-RS transmitted on the N OFDM symbols, and the channel estimation information is prevented from being obtained by carrying out an extrapolation algorithm on a limited column of DM-RSs which are far away from the N symbols in a time domain, thereby improving the data demodulation performance of the NCT, ensuring that DM-RS transmission also exists in special subframes of which DwPTS only comprises 3 OFDM symbols, further ensuring that downlink data can be transmitted in the special subframes, and further improving the transmission efficiency and the spectrum utilization rate of the NCT.

Referring to fig. 4, a DM-RS transmission method for a terminal side according to an embodiment of the present invention includes the following steps:

step 40: the terminal determines the mapping resource of the DM-RS in the current subframe according to the DM-RS resource mapping mode, wherein the DM-RS mapping resource at least comprises a resource unit (RE) on at least one OFDM symbol in the first N OFDM symbols of the current subframe, and N is an integer not less than 1;

step 41: and the terminal acquires the DM-RS transmitted in the current subframe according to the determined mapping resource of the DM-RS in the current subframe, namely acquires the DM-RS received on the determined mapping resource.

In step 40, the terminal determines the mapping resource of the DM-RS in the current subframe according to the DM-RS resource mapping method, and the specific implementation may adopt one of the following four methods:

the method comprises the following steps: the terminal moves part of REs in an RE set corresponding to DM-RS on a DM-RS antenna port defined in LTE system version 10 to at least one OFDM symbol in the first N OFDM symbols of a subframe on the antenna port where the DM-RS is transmitted in the current subframe through translation in a time domain and/or a frequency domain based on a preset rule and a DM-RS resource mapping mode defined in LTE system version 10, and takes the moved REs and the rest of the non-moved REs as mapping resources of the DM-RS on the antenna port in the current subframe;

based on a DM-RS resource mapping mode corresponding to each DM-RS antenna port in Rel-10, on the basis of not changing DM-RS resource overhead (not increasing DM-RS mapping resources), by moving the position of the existing DM-RS mapping resources, such as time domain and/or frequency domain translation, moving part of DM-RS mapping resources in one subframe determined by the DM-RS resource mapping mode to at least 1 OFDM symbol in the first N OFDM symbols of the subframe; the above process may be regarded as a process in which the UE obtains a DM-RS resource mapping manner that needs to be used currently, and determines the DM-RS mapping resource according to the RE position corresponding to the DM-RS in the DM-RS resource mapping manner, or may also be regarded as a process in which the UE directly obtains the DM-RS mapping resource through a predetermined translation operation based on a DM-RS resource mapping method defined in RE-10; the DM-RS mapping resource is embodied as RE corresponding to the DM-RS;

preferably, the DM-RS mapping resources on a part of OFDM in OFDM, which includes the DM-RS mapping resources, in one subframe determined by the Rel-10DM-RS resource mapping manner are moved to 1 or 2 OFDM symbols in the first N OFDM symbols in the subframe through time domain and/or translation, wherein the DM-RS mapping resources on different OFDM symbols are moved to different OFDM symbols in the first N OFDM symbols.

The second method comprises the following steps: the terminal increases REs used for transmitting the DM-RS on at least one OFDM symbol in the first N OFDM symbols on the antenna port where the DM-RS is transmitted in the current subframe based on a preset rule and a DM-RS resource mapping mode defined in LTE system version 10, and takes the increased REs and REs corresponding to the DM-RS on the DM-RS antenna port defined in LTE system version 10 as mapping resources of the DM-RS on the antenna port in the current subframe;

based on a DM-RS resource mapping mode corresponding to each DM-RS antenna port in Rel-10, increasing DM-RS mapping resources on at least 1 OFDM symbol in the first N OFDM symbols of a subframe; the above process can be regarded as a process in which the UE obtains a DM-RS resource mapping mode that needs to be used currently, and determines a DM-RS mapping resource according to a RE position corresponding to a DM-RS in the DM-RS resource mapping mode; or the process itself can be regarded as that the UE directly obtains the DM-RS mapping resource by increasing the DM-RS resource operation based on the DM-RS resource mapping method defined in Re-10;

preferably, based on the Rel-10DM-RS resource mapping manner, the DM-RS mapping resources are added to 1 or 2 adjacent OFDM symbols in the first N OFDM symbols of a subframe according to the subcarrier positions where all or part of the DM-RS mapping resources are located in the DM-RS resource mapping manner.

The third method comprises the following steps: the terminal determines a DM-RS resource mapping mode according to configuration information carried in a high-level signaling or a Physical Downlink Control Channel (PDCCH), and determines a mapping resource on an antenna port where DM-RS is transmitted in a current subframe according to the determined DM-RS resource mapping mode, wherein the configuration information indicates a DM-RS resource mapping mode or indicates whether DM-RS mapping resources exist in the first N OFDM symbols of one subframe or not;

the terminal receives the configuration information through a high-level signaling or a PDCCH, and determines the practically used DM-RS resource mapping mode according to the specific indication of the configuration information; the configuration information may indicate a specific DM-RS resource mapping manner, where the DM-RS resource mapping manner is predefined in the system, and the UE determines to use one of multiple predefined DM-RS resource mapping manners in the system indicated by the configuration information; or, the configuration information may further indicate whether DM-RS mapping resources exist in the first N OFDM symbols, the UE may select one satisfying the configuration indication from a plurality of DM-RS resource mapping manners predefined in the system according to the configuration information, or when the configuration information indicates the existence, the UE performs the operation according to a predetermined mobility scheme (as in the above method 1) or a scheme of increasing DM-RS resources (as in the above method 2), forming a DM-RS resource mapping mode currently used on the basis of the DM-RS resource mapping mode defined by Rel-10, and determining DM-RS mapping resources according to the RE position corresponding to the DM-RS in the DM-RS resource mapping mode, or directly determining DM-RS mapping resources on the basis of a DM-RS resource mapping mode defined by Rel-10; and when the configuration information indicates that the DM-RS resource mapping mode defined by Rel-10 is not existed, the UE determines to use.

The method four comprises the following steps: the terminal determines the mapping resource of the antenna port where the DM-RS is transmitted in the current subframe according to a predefined DM-RS resource mapping mode, wherein the predefined DM-RS resource mapping mode at least meets the following requirements: there is a DM-RS mapping resource on at least 1 OFDM symbol among the first N OFDM symbols of one subframe.

That is, the terminal does not need to further form a needed DM-RS resource mapping mode, and can directly use the DM-RS resource mapping mode that has been defined in the system and satisfies the above conditions, and determine the DM-RS mapping resource according to the RE position corresponding to the DM-RS in the DM-RS resource mapping mode.

Specifically, the terminal determines a DM-RS resource mapping manner according to configuration information carried in a high layer signaling or a PDCCH, and determines a mapping resource of the DM-RS in a current subframe according to the determined DM-RS resource mapping manner, which may be implemented by one of the following four schemes:

the first scheme is as follows: the terminal determines whether DM-RS mapping resources exist in the first N OFDM symbols of the current subframe according to configuration information carried in a high-level signaling or a PDCCH, when the DM-RS mapping resources exist, based on a predetermined rule and a DM-RS resource mapping mode defined in LTE system version 10, on an antenna port where DM-RS in the current subframe is transmitted, partial REs in an RE set corresponding to DM-RS on the DM-RS antenna port defined in LTE system version 10 are moved to at least one OFDM symbol in the first N OFDM symbols of the subframe through translation in a time domain and/or a frequency domain, and the moved REs and the un-moved residual REs are used as mapping resources of the DM-RS on the antenna port in the current subframe;

scheme II: the terminal determines whether DM-RS mapping resources exist in the first N OFDM symbols of the current subframe according to configuration information carried in a high-level signaling or a PDCCH, when the DM-RS mapping resources exist, based on a predetermined rule and a DM-RS resource mapping mode defined in LTE system version 10, REs used for transmitting DM-RS are added to at least one OFDM symbol in the first N OFDM symbols on an antenna port where the DM-RS is transmitted in the current subframe, and the added REs and REs corresponding to the DM-RS on the DM-RS antenna port defined in LTE system version 10 are used as the mapping resources of the DM-RS on the antenna port in the current subframe;

the third scheme is as follows: the terminal selects a predefined DM-RS resource mapping mode indicated by the configuration information from a plurality of predefined DM-RS resource mapping modes according to the configuration information carried in a high-level signaling or a PDCCH, and determines the mapping resource of an antenna port where the DM-RS is transmitted in the current subframe according to the selected predefined DM-RS resource mapping mode;

and the scheme is as follows: the terminal determines whether DM-RS mapping resources exist in the first N OFDM symbols of the current subframe according to configuration information carried in a high-level signaling or a PDCCH, when the DM-RS mapping resources exist, one predefined DM-RS resource mapping mode in which the DM-RS mapping resources exist in the first N OFDM symbols of one subframe is selected from multiple predefined DM-RS resource mapping modes, and the mapping resources of the DM-RS on an antenna port where the DM-RS is transmitted in the current subframe are determined according to the selected predefined DM-RS resource mapping mode;

specifically, in the fourth method, the third scheme, or the fourth scheme, when the terminal determines the mapping resource of the DM-RS in the current subframe according to the predefined DM-RS resource mapping manner, the predefined DM-RS resource mapping manner is specifically one of the following three manners:

the first method is as follows: moving part of REs in an RE set corresponding to DM-RS on each DM-RS antenna port defined in LTE system release 10 in a subframe to at least one OFDM symbol in the first N OFDM symbols on the antenna port in the subframe through translation in a time domain and/or a frequency domain to obtain a DM-RS resource mapping mode;

in the second mode, based on the DM-RS resource mapping mode corresponding to each DM-RS antenna port defined in the LTE system version 10, REs corresponding to the DM-RS are added to at least one OFDM symbol in the first N OFDM symbols on the antenna port in one subframe to obtain the DM-RS resource mapping mode;

and in a third mode, on each DM-RS antenna port in one subframe, the OFDM symbols with the DM-RS mapping resources are not adjacent, at least 1 group of DM-RS mapping resources exist on the OFDM symbols with the DM-RS mapping resources, and each group of DM-RS mapping resources consists of REs corresponding to at least 2 adjacent subcarrier numbers.

Specifically, when the above method one or scheme one or mode one is adopted, the terminal in step 41 obtains the DM-RS transmitted in the current subframe according to the determined DM-RS mapping resource, and may reuse the time domain orthogonal spreading sequence corresponding to the corresponding DM-RS antenna port defined by Rel-10 to despread the DM-RS, so as to ensure the orthogonality between the antenna ports using the same resource mapping mode, and the specific implementation may be as follows:

for the conventional CP, on each antenna port where the DM-RS is transmitted in the current subframe, 4 REs corresponding to the same subcarrier number in the REs used for transmitting the DM-RS are taken as a group, and the DM-RS transmitted on each group of REs is subjected to despreading by using a time domain orthogonal spreading sequence with the length of 4 corresponding to the current DM-RS antenna port and defined by the LTE system version 10 so as to obtain the DM-RS transmitted on the current antenna port.

Specifically, in the first method or scheme, in step 41, the terminal obtains the DM-RS transmitted in the current subframe according to the determined DM-RS mapping resource, and may reuse the time domain orthogonal spreading sequence corresponding to the corresponding DM-RS antenna port defined by Rel-10 to despread the DM-RS, so as to ensure the orthogonality between the antenna ports using the same resource mapping method, which may be specifically implemented as follows:

for the extended CP, on each antenna port where the DM-RS is transmitted in the current subframe, on the first two OFDM symbols containing REs used for transmitting the DM-RS, 2 REs used for transmitting the DM-RS corresponding to the same subcarrier number are used as a group, on the last two OFDM symbols containing REs used for transmitting the DM-RS, 2 REs used for transmitting the DM-RS corresponding to the same subcarrier number are used as a group, and the DM-RS transmitted on each group of REs is subjected to despreading by using a time domain orthogonal spreading sequence with the length of 2, which is defined by the LTE system version 10 and corresponds to the current DM-RS antenna port, so as to obtain the DM-RS transmitted on the current antenna port; or,

for the extended CP, on each antenna port where the DM-RS is transmitted in the current subframe, on the former two OFDM symbols containing REs used for transmitting the DM-RS, 2 REs used for transmitting the DM-RS corresponding to the adjacent subcarrier numbers are used as a group, on the latter two OFDM symbols containing REs used for transmitting the DM-RS, 2 REs used for transmitting the DM-RS corresponding to the adjacent subcarrier numbers are used as a group, and the DM-RS transmitted on each group of REs is subjected to despreading by using a time domain orthogonal spreading sequence with the length of 2, which is defined by the LTE system version 10 and corresponds to the current DM-RS antenna port, so as to obtain the DM-RS transmitted on the current antenna port; or,

for the extended CP, on each antenna port where the DM-RS is transmitted in the current subframe, taking 2 REs used for transmitting the DM-RS corresponding to the same subcarrier number as a group, and performing despreading on the DM-RS transmitted on each group of REs by using a time domain orthogonal spreading sequence with the length of 2 corresponding to the current DM-RS antenna port, which is defined by the LTE system version 10, so as to obtain the DM-RS transmitted on the current antenna port; or,

for the extended CP, on each antenna port where the DM-RS is transmitted in the current subframe, two REs which are used for transmitting the DM-RS on each OFDM and are most adjacent to each other in a frequency domain and contain DM-RS mapping resources are used as a group, and the DM-RS transmitted on each group of REs is subjected to despreading by using a time domain orthogonal spreading sequence which is defined by LTE system version 10 and has the length of 2 and corresponds to the current DM-RS antenna port, so that the DM-RS transmitted on the current antenna port is obtained.

Specifically, when the method two, the scheme two, or the mode two is adopted, in step 41, the terminal obtains the DM-RS transmitted in the current subframe according to the determined DM-RS mapping resource, and the specific implementation may be as follows:

for the conventional CP, on each antenna port where the DM-RS is transmitted in the current subframe, taking 4 REs used for transmitting the DM-RS corresponding to the same subcarrier number on the first four OFDM symbols containing the REs used for transmitting the DM-RS as a group, and taking 4 REs used for transmitting the DM-RS corresponding to the same subcarrier number on the last four OFDM symbols containing the REs used for transmitting the DM-RS (namely, corresponding to the DM-RS of the original Rel-10 resource mapping mode) as a group;

and the DM-RS transmitted on one group of REs uses a time domain orthogonal spread spectrum sequence which is defined by the LTE system version 10 and has the length of 4 and corresponding to the current DM-RS antenna port to perform despreading, and the DM-RS transmitted on the other group of REs uses a time domain orthogonal spread spectrum sequence which is obtained by transforming the time domain orthogonal spread spectrum sequence which is defined by the LTE system version 10 and has the length of 4 and corresponding to the current DM-RS antenna port to perform despreading, so that the DM-RS transmitted on the current antenna port is obtained.

Preferably, the orthogonal sequence in the original Rel-10 is used for 1 group of DM-RS in the original Rel-10 resource mapping mode, and the transformed orthogonal sequence is used for 1 group of DM-RS only partially containing DM-RS in the original Rel-10 resource mapping mode, so as to ensure the compatibility with legacy terminals.

Preferably, if REs used for transmitting DM-RS are added to two OFDM symbols in the first N OFDM symbols of the current subframe, the time domain orthogonal spreading sequence obtained after the transformation is: exchanging the first two spreading factors and the second two spreading factors of a time domain orthogonal spreading sequence with the length of 4, which is defined by the LTE system version 10, to obtain a time domain orthogonal spreading sequence; or,

if RE used for transmitting DM-RS is added to one OFDM symbol in the first N OFDM symbols of the current subframe, the time domain orthogonal spread spectrum sequence obtained after transformation is as follows: the method comprises the steps of taking the last spreading factor in a time domain orthogonal spreading sequence with the length of 4 defined by the LTE system release 10 as a first spreading factor and sequentially shifting back other spreading factors to obtain a time domain orthogonal spreading sequence, or taking the first spreading factor in the time domain orthogonal spreading sequence with the length of 4 defined by the LTE system release 10 as a last spreading factor and sequentially shifting forward other spreading factors to obtain a time domain orthogonal spreading sequence.

Specifically, in the second method, the second scheme, or the second mode, in step 41, the terminal obtains the DM-RS transmitted in the current subframe according to the determined DM-RS mapping resource, which may be specifically implemented as follows:

for the extended CP, if REs used for transmitting the DM-RS are added to two OFDM symbols in the first N OFDM symbols of the current subframe, on each antenna port where the DM-RS is transmitted in the current subframe, 2 REs used for transmitting the DM-RS corresponding to the same subcarrier number on each two adjacent OFDM symbols in the multiple OFDM symbols including the REs used for transmitting the DM-RS are used as a group, and the DM-RS transmitted on each group of REs is despread using a time domain orthogonal spreading sequence with a length of 2 corresponding to the current DM-RS antenna port defined by the LTE system version 10, so as to obtain the DM-RS transmitted on the current antenna port; or,

for the extended CP, if the RE used for transmitting the DM-RS is added on one OFDM symbol in the first N OFDM symbols of the current subframe, on each antenna port where the DM-RS is transmitted in the current subframe, performing despreading on the DM-RS transmitted on the RE used for transmitting the DM-RS on the current DM-RS antenna port defined in the LTE system version 10 according to the mode defined by the LTE system version 10 to obtain the DM-RS transmitted on the antenna port; and the number of the first and second groups,

taking 2 REs used by two closest transmission DM-RSs on the frequency domain on an OFDM symbol added with REs used for transmitting the DM-RSs as a group, wherein the DM-RSs transmitted on each group of REs use a time domain orthogonal spread spectrum sequence which is defined by an LTE system version 10 and has the length of 2 and corresponds to a current DM-RS antenna port; or, the OFDM symbol added with the RE used for transmitting the DM-RS and the first OFDM symbol defined in the LTE system release 10 and including the RE used for transmitting the DM-RS are used as a group of 2 REs corresponding to the same subcarrier number, and the DM-RS transmitted on each group of REs is despread by using the time domain orthogonal spreading sequence obtained by transforming the time domain orthogonal spreading sequence defined in the LTE system release 10 and having the length of 2 corresponding to the current DM-RS antenna port, so as to obtain the DM-RS transmitted on the antenna port.

Preferably, the time domain orthogonal spreading sequence obtained after the transformation may be: and after two spreading factors in the time domain orthogonal spreading sequence with the length of 2 defined by the LTE system release 10 are exchanged, obtaining the time domain orthogonal spreading sequence with the length of 2.

Specifically, when the third method is adopted, in step 41, the terminal obtains the DM-RS transmitted in the current subframe according to the determined DM-RS mapping resource, and the specific implementation may be as follows:

for a conventional CP, on each antenna port where a DM-RS is transmitted in a current subframe, 4 REs corresponding to two adjacent subcarrier numbers on a plurality of OFDM symbols including REs used for transmitting the DM-RS are taken as a group, and a time domain orthogonal spreading sequence with a length of 4 corresponding to the DM-RS antenna port defined by LTE system release 10 is used for despreading the DM-RS transmitted on each group of REs to obtain the DM-RS transmitted on the antenna port.

for the extended CP, on each antenna port where the DM-RS is transmitted in the current subframe, 2 REs corresponding to two adjacent subcarrier numbers on each OFDM symbol containing the REs used for transmitting the DM-RS are taken as a group, and the DM-RS transmitted on each group of REs is subjected to despreading by using a time domain orthogonal spreading sequence with the length of 2 corresponding to the current DM-RS antenna port and defined by the LTE system version 10 so as to obtain the DM-RS transmitted on the antenna port.

In the method, the current subframe is a conventional downlink subframe or a special subframe configured corresponding to any TDD special subframe.

When the current subframe is a conventional downlink subframe, N is a positive integer not more than 4; and/or when the current subframe is the special subframe, N is a positive integer not exceeding 2 or 3.

The overall method flow of the interaction between the terminal and the base station is as follows:

the method comprises the following steps: the base station determines the mapping resources of the DM-RS in the current subframe according to the DM-RS resource mapping mode, the DM-RS mapping resources at least comprise REs on at least one OFDM symbol in the first N OFDM symbols of the current subframe, and N is an integer not less than 1;

step two: the base station maps the DM-RS to the current subframe for transmission according to the determined DM-RS mapping resource;

step three: the terminal determines the mapping resource of the DM-RS in the current subframe according to the DM-RS resource mapping mode, the DM-RS mapping resource at least comprises the RE on at least one OFDM symbol in the first N OFDM symbols of the current subframe, and N is an integer not less than 1;

step four: and the terminal acquires the DM-RS transmitted in the current subframe according to the determined DM-RS mapping resource.

It needs to ensure that the DM-RS resource mapping mode used by the base station is consistent with the DM-RS resource mapping mode used by the terminal.

Referring to fig. 5, a DM-RS transmission method for a base station side according to an embodiment of the present invention includes the following steps:

step 50: the base station determines the mapping resources of the DM-RS in the current subframe according to the DM-RS resource mapping mode, the DM-RS mapping resources at least comprise REs on at least one OFDM symbol in the first N OFDM symbols of the current subframe, and N is an integer not less than 1;

step 51: and the base station maps the DM-RS to the current subframe for transmission according to the determined DM-RS mapping resource, namely, the DM-RS is transmitted on the determined DM-RS mapping resource.

In step 50, the base station determines the mapping resource of the DM-RS in the current subframe according to the DM-RS resource mapping method, and the specific implementation may adopt one of the following four methods:

the method comprises the following steps: a base station moves part of REs in an RE set corresponding to DM-RS on a DM-RS antenna port defined in LTE system version 10 to at least one OFDM symbol in the first N OFDM symbols of a subframe on the antenna port where the DM-RS is transmitted in the current subframe through translation in a time domain and/or a frequency domain based on a preset rule and a DM-RS resource mapping mode defined in LTE system version 10, and takes the moved REs and the rest of the non-moved REs as mapping resources of the DM-RS on the antenna port in the current subframe;

the second method comprises the following steps: based on a preset rule and a DM-RS resource mapping mode defined in LTE system version 10, a base station increases REs used for transmitting DM-RS on at least one OFDM symbol in the first N OFDM symbols on an antenna port where DM-RS is transmitted in the current subframe, and takes the increased REs and REs corresponding to the DM-RS on the DM-RS antenna port defined in LTE system version 10 as mapping resources of the DM-RS on the antenna port in the current subframe;

the third method comprises the following steps: a base station determines a DM-RS resource mapping mode according to actual needs, determines mapping resources on an antenna port where DM-RS is transmitted in a current subframe according to the DM-RS resource mapping mode, and sends configuration information to a terminal through a high-level signaling or a Physical Downlink Control Channel (PDCCH), wherein the configuration information indicates the DM-RS resource mapping mode or indicates whether DM-RS mapping resources exist in the first N Orthogonal Frequency Division Multiplexing (OFDM) symbols of one subframe;

the method four comprises the following steps: the base station determines mapping resources on an antenna port where the DM-RS is transmitted in the current subframe according to a predefined DM-RS resource mapping mode, wherein the predefined DM-RS resource mapping mode at least meets the following requirements: there is a DM-RS mapping resource on at least 1 OFDM symbol among the first N OFDM symbols of one subframe.

Specifically, the base station determines a DM-RS resource mapping manner according to actual needs, determines mapping resources on an antenna port where the DM-RS is transmitted in a current subframe according to the DM-RS resource mapping manner, and sends configuration information to the terminal through a high-level signaling or a PDCCH, and may specifically implement one of the following three schemes:

the first scheme is as follows: the base station determines whether DM-RS mapping resources exist in the first N OFDM symbols of the current subframe according to actual needs, when the existence is determined, based on the pre-agreed rule and the DM-RS resource mapping mode defined in the LTE system release 10, through the translation on the time domain and/or the frequency domain, on an antenna port where the DM-RS is transmitted in the current subframe, moving a part of REs in an RE set corresponding to the DM-RS on the DM-RS antenna port defined in LTE system release 10 to at least one OFDM symbol in the first N OFDM symbols of the subframe, taking the moved REs and the rest of the non-moved REs as mapping resources of the DM-RS on the antenna port in the current subframe, sending configuration information (specifically indicating that the DM-RS mapping resources exist) for indicating whether the DM-RS mapping resources exist in the first N OFDM symbols of one subframe to a terminal through a high-layer signaling or a PDCCH;

scheme II: a base station determines whether DM-RS mapping resources exist in the first N OFDM symbols of a current subframe according to actual needs, when the DM-RS mapping resources exist, based on a predetermined rule and a DM-RS resource mapping mode defined in LTE system version 10, the RE used for transmitting DM-RS is added to at least one OFDM symbol in the first N OFDM symbols on an antenna port where DM-RS is transmitted in the current subframe, the added RE and the RE corresponding to the DM-RS on the DM-RS antenna port defined in LTE system version 10 are used as the mapping resources of DM-RS on the antenna port in the current subframe, and configuration information (specifically indicating the existence) for indicating whether DM-RS mapping resources exist in the first N OFDM symbols of one subframe is sent to a terminal through a high-level signaling or a PDCCH;

the third scheme is as follows: the base station selects a predefined DM-RS resource mapping mode from a plurality of predefined DM-RS resource mapping modes according to actual needs, determines mapping resources on an antenna port where DM-RS is transmitted in a current subframe according to the selected predefined DM-RS resource mapping mode, and sends configuration information for indicating the selected predefined DM-RS resource mapping mode to a terminal through a high-level signaling or a PDCCH, or sends configuration information for indicating whether DM-RS mapping resources exist in the first N OFDM symbols of a subframe (specifically indicating that the DM-RS mapping resources exist) to the terminal through the high-level signaling or the PDCCH.

Specifically, when the base station determines the mapping resource of the DM-RS in the current subframe according to the predefined DM-RS resource mapping manner, the predefined DM-RS resource mapping manner is defined according to one of the following manners:

the second method comprises the following steps: based on a DM-RS resource mapping mode corresponding to each DM-RS antenna port defined in LTE system version 10, increasing REs corresponding to DM-RS on at least one OFDM symbol in the first N OFDM symbols on the antenna port in a subframe to obtain the DM-RS resource mapping mode;

the third method comprises the following steps: the OFDM symbols with DM-RS mapping resources are not adjacent on each DM-RS antenna port in a subframe, and at least 1 group of DM-RS mapping resources consisting of REs corresponding to at least 2 adjacent subcarrier numbers exist on the OFDM symbols.

Specifically, in the first method or the first scheme or the first mode, in step 51, the base station maps the DM-RS to the current subframe for transmission according to the determined DM-RS mapping resource, which may be specifically implemented as follows:

for a conventional CP, on each antenna port where DM-RS is transmitted in a current subframe, 4 REs corresponding to the same subcarrier number in the REs used for transmitting the DM-RS are taken as a group, and the DM-RS transmitted on each group of REs is spread by using a time domain orthogonal spreading sequence with the length of 4 corresponding to the current DM-RS antenna port and defined by LTE system version 10, so as to transmit the DM-RS on the antenna port.

for the extended CP, on each antenna port where the DM-RS is transmitted in the current subframe, on the first two OFDM symbols containing REs used for transmitting the DM-RS, 2 REs used for transmitting the DM-RS corresponding to the same subcarrier number are used as a group, on the last two OFDM symbols containing REs used for transmitting the DM-RS, 2 REs used for transmitting the DM-RS corresponding to the same subcarrier number are used as a group, and the DM-RS transmitted on each group of REs is spread by using a time domain orthogonal spreading sequence with the length of 2, which is defined by the LTE system version 10 and corresponds to the current DM-RS antenna port, so as to transmit the DM-RS on the antenna port; or,

for the extended CP, on each antenna port where the DM-RS is transmitted in the current subframe, on the former two OFDM symbols containing REs used for transmitting the DM-RS, 2 REs used for transmitting the DM-RS corresponding to the adjacent subcarrier numbers are used as a group, on the latter two OFDM symbols containing REs used for transmitting the DM-RS, 2 REs used for transmitting the DM-RS corresponding to the adjacent subcarrier numbers are used as a group, and the DM-RS transmitted on each group of REs is spread by using a time domain orthogonal spreading sequence with the length of 2, which is defined by the LTE system version 10 and corresponds to the current DM-RS antenna port, so as to transmit the DM-RS on the antenna port; or,

for the extended CP, on each antenna port where the DM-RS is transmitted in the current subframe, taking 2 REs used for transmitting the DM-RS corresponding to the same subcarrier number as a group, and spreading the DM-RS transmitted on each group of REs by using a time domain orthogonal spreading sequence with the length of 2 corresponding to the current DM-RS antenna port defined by the LTE system version 10 so as to transmit the DM-RS on the antenna port; or,

for the extended CP, on each antenna port where the DM-RS is transmitted in the current subframe, two REs that are used for transmitting the DM-RS on each OFDM and include the DM-RS mapping resource and are most adjacent in the frequency domain are taken as a group, and the DM-RS transmitted on each group of REs is spread by using a time domain orthogonal spreading sequence with a length of 2 corresponding to the current DM-RS antenna port, which is defined by LTE system release 10, to transmit the DM-RS on the antenna port.

Specifically, when the method two or the scheme two or the mode two is adopted, in step 51, the base station maps the DM-RS to the current subframe for transmission according to the determined DM-RS mapping resource, which may be specifically implemented as follows:

for a conventional CP, on each antenna port where a DM-RS is transmitted in a current subframe, taking 4 REs used for transmitting the DM-RS corresponding to the same subcarrier number on the first four OFDM symbols containing the REs used for transmitting the DM-RS as a group, and taking 4 REs used for transmitting the DM-RS corresponding to the same subcarrier number on the last four OFDM symbols containing the REs used for transmitting the DM-RS as a group;

and spreading the time domain orthogonal spread spectrum sequence with the length of 4 corresponding to the DM-RS antenna port defined by the LTE system version 10 for the DM-RS transmitted on one group of REs, and spreading the time domain orthogonal spread spectrum sequence obtained by transforming the time domain orthogonal spread spectrum sequence with the length of 4 corresponding to the current DM-RS antenna port defined by the LTE system version 10 for the DM-RS transmitted on the other group of REs so as to transmit the DM-RS on the antenna port.

if RE used for transmitting DM-RS is added to one OFDM symbol in the first N OFDM symbols of the current subframe, the time domain orthogonal spread spectrum sequence obtained after the transformation is as follows: the method comprises the steps of taking the last spreading factor in a time domain orthogonal spreading sequence with the length of 4 defined by the LTE system release 10 as a first spreading factor and sequentially shifting back other spreading factors to obtain a time domain orthogonal spreading sequence, or taking the first spreading factor in the time domain orthogonal spreading sequence with the length of 4 defined by the LTE system release 10 as a last spreading factor and sequentially shifting forward other spreading factors to obtain a time domain orthogonal spreading sequence.

Specifically, when the second method, the second scheme, or the second manner is adopted, in step 51, the base station maps the DM-RS to the current subframe for transmission according to the determined DM-RS mapping resource, which may be specifically implemented as follows:

for the extended CP, if REs used for transmitting the DM-RS are added to two OFDM symbols in the first N OFDM symbols of the current subframe, on each antenna port where the DM-RS is transmitted in the current subframe, 2 REs used for transmitting the DM-RS corresponding to the same subcarrier number on every two adjacent OFDM symbols in the multiple OFDM symbols including the REs used for transmitting the DM-RS are used as a group, and the DM-RS transmitted on each group of REs is spread by using a time domain orthogonal spreading sequence with a length of 2 corresponding to the current DM-RS antenna port, which is defined by LTE system version 10, to transmit the DM-RS on the antenna port; or,

for the extended CP, if an RE used for transmitting the DM-RS is added to one of the first N OFDM symbols of the current subframe, on each antenna port where the DM-RS is transmitted in the current subframe, spreading the DM-RS transmitted on the RE used for transmitting the DM-RS on the current DM-RS antenna port defined in LTE system release 10 in a manner defined in LTE system release 10 to transmit the DM-RS on the antenna port; and the number of the first and second groups,

taking 2 REs used by two closest transmission DM-RSs on the frequency domain on an OFDM symbol added with REs used for transmitting the DM-RSs as a group, wherein the DM-RSs transmitted on each group of REs use a time domain orthogonal spread spectrum sequence which is defined by an LTE system version 10 and has the length of 2 and corresponds to a current DM-RS antenna port; or, the OFDM symbol added with the REs used for transmitting the DM-RS and the first OFDM symbol defined in LTE system release 10 that includes the REs used for transmitting the DM-RS are grouped into 2 REs corresponding to the same subcarrier number, and the DM-RS transmitted on each group of REs is spread by using a time domain orthogonal spreading sequence obtained by transforming a time domain orthogonal spreading sequence defined in LTE system release 10 and having a length of 2 corresponding to the current DM-RS antenna port, so as to transmit the DM-RS on the antenna port.

Preferably, the time domain orthogonal spreading sequence obtained after the transformation is as follows: and after two spreading factors in the time domain orthogonal spreading sequence with the length of 2 defined by the LTE system release 10 are exchanged, obtaining the time domain orthogonal spreading sequence with the length of 2.

Specifically, when the third method is adopted, in step 51, the base station maps the DM-RS to the current subframe for transmission according to the determined DM-RS mapping resource, and the specific implementation may be as follows:

for a conventional CP, on each antenna port where a DM-RS is transmitted in a current subframe, 4 REs corresponding to two adjacent subcarrier numbers on a plurality of OFDM symbols including REs used for transmitting the DM-RS are used as a group, and a time domain orthogonal spreading sequence with a length of 4 corresponding to the current DM-RS antenna port, defined by LTE system release 10, is used for spreading the DM-RS transmitted on each group of REs, so as to transmit the DM-RS on the antenna port.

for the extended CP, on each antenna port where the DM-RS is transmitted in the current subframe, 2 REs corresponding to two adjacent subcarrier numbers on each OFDM symbol including REs used for transmitting the DM-RS are used as a group, and the DM-RS transmitted on each group of REs is spread using a time domain orthogonal spreading sequence with a length of 2 corresponding to the current DM-RS antenna port, which is defined by LTE system release 10, to transmit the DM-RS on the antenna port.

In the method, the current subframe is a conventional downlink subframe or a special subframe configured corresponding to any TDD special subframe. When the current subframe is a conventional downlink subframe, N is a positive integer not more than 4; and/or when the current subframe is the special subframe, N is a positive integer not exceeding 2 or a positive integer not exceeding 3.

Preferably, for TDD special subframe configuration that does not support DM-RS transmission in Rel-10, for example, when the CP is downlink normal, TDD special subframe configuration 0 and 5, and when the CP is downlink extended, TDD special subframe configuration 0 and 4, the DM-RS resource mapping method corresponding to any TDD special subframe configuration obtained in the above manner may be used, and the DM-RS is transmitted or received only in the OFDM symbol where the DwPTS is located according to the DM-RS resource mapping method.

Preferably, when CRS transmission exists on the NCT, the DM-RS resource mapping manner in the present invention should avoid as much as possible the OFDM symbol where the DM-RS mapping resource is located from overlapping with the OFDM symbol containing the CRS mapping resource; when the NCT has the synchronization signal transmission, the DM-RS resource mapping method should avoid the OFDM symbol where the DM-RS mapping resource is located from overlapping with the OFDM symbol where the synchronization signal is mapped and transmitted as much as possible.

The high-level signaling in the invention can be Media Access Control (MAC) signaling, Radio Resource Control (RRC) signaling or the like; the PDCCH signaling may be legacy PDCCH signaling, E-PDCCH signaling, or the like. The antenna port for transmitting the DM-RS can be 7-14.

The invention is illustrated below with reference to specific examples:

the first embodiment is as follows: corresponding to the method one or the scheme one or the mode one;

for a conventional downlink subframe (i.e., a downlink subframe except for a TDD special subframe), performing time domain translation on DM-RS mapping resources in a DM-RS resource mapping mode of a corresponding antenna port in Rel-10 to obtain a DM-RS resource mapping mode as shown in fig. 6a to 6 j;

for example: mode 1: translating the DM-RS mapping resources of the first two columns in Rel-10 to the 2 nd and 3 rd OFDM symbols (or the 3 rd and 4 th OFDM symbols) to obtain figure 6a (under the normal CP) and figure 6b (under the extended CP);

mode 2: translating the last column of DM-RS mapping resources in Rel-10 to the 2 nd OFDM symbol (or the 3 rd OFDM symbol), and obtaining figure 6c (under the normal CP) and figure 6d (under the extended CP);

mode 3: translating the first two columns of DM-RS mapping resources in Rel-10 to the 1 st and 2 nd OFDM symbols (or the 2 nd and 3 rd OFDM symbols), and translating the last two columns of DM-RS mapping resources to the 2 nd and 3 rd last OFDM symbols to obtain a graph 6e (under a normal CP) and a graph 6f (under an extended CP);

mode 4: translating the first two columns of DM-RS mapping resources in Rel-10 to the 2 nd and 3 rd OFDM symbols (or the 1 st and 2 nd OFDM symbols, or the 3 rd and 4 th OFDM symbols), and translating the last two columns of DM-RS mapping resources to the 4 th and 5 th reciprocal OFDM symbols (or the 5 th and 6 th reciprocal OFDM symbols), resulting in fig. 6g (under normal CP) and fig. 6h (under extended CP);

mode 5: the first two columns of DM-RS mapping resources in Rel-10 are translated to the 2 nd and 3 rd OFDM symbols (or the 1 st and 2 nd OFDM symbols, or the 3 rd and 4 th OFDM symbols), and the last two columns of DM-RS mapping resources are translated to the 4 th and 2 nd OFDM symbols respectively, resulting in fig. 6i (under normal CP) and fig. 6j (under extended CP).

Mode 1 can avoid overlapping of the synchronization signal and the DM-RS resource in the FDD system.

Mode 2 can avoid the synchronization signal and the DM-RS resource from overlapping in the TDD system.

When assuming that CRS is not present on the NCT, mode 3 may avoid overlapping of synchronization signals and DM-RS resources in FDD and TDD systems, or, assuming that CRS is present on the NCT and CRS is different from a synchronization signal transmission subframe, it may be defined to use mode 3 in the synchronization signal transmission subframe, and other subframes may use other modes or methods.

The mode 4 and the mode 5 can simultaneously avoid overlapping of synchronization signals and DM-RS resources in FDD and TDD systems, but when CSI-RS transmission exists on the NCT, the mapping resources of the CSI-RS on the OFDM symbol where the DM-RS is located need to be limited.

Time domain orthogonal spread spectrum time:

for a conventional CP, in a DM-RS resource mapping mode, DM-RSs corresponding to the same subcarrier number in one downlink subframe are used as a group, and a time domain orthogonal spread spectrum sequence (namely, a sequence in a table 1) with the length of 4 corresponding to a corresponding DM-RS antenna port in Rel-10 is reused for each group of DM-RSs;

for the extended CP, in a DM-RS resource mapping manner, in one downlink subframe, DM-RSs corresponding to the same subcarrier number on the first two OFDM symbols including the DM-RS are used as a group, DM-RSs corresponding to the same subcarrier number on the last two OFDM symbols including the DM-RS are used as a group, and a time domain orthogonal spreading sequence (i.e., a sequence in table 2) with a length of 2 corresponding to a corresponding DM-RS antenna port in Rel-10 is reused for each group of DM-RSs; or, in the DM-RS resource mapping manner, in one downlink subframe, the DM-RSs corresponding to adjacent subcarrier numbers on the first two OFDM symbols including the DM-RS are used as a group, the DM-RSs corresponding to adjacent subcarrier numbers on the second two OFDM symbols including the DM-RS are used as a group, and the time domain orthogonal spreading sequences (i.e., the sequences in table 2) with the length of 2 corresponding to the DM-RS antenna ports in Rel-10 are reused for each group of DM-RSs, for example, for fig. 6d, the DM-RSs corresponding to subcarrier numbers i and i +1 (e.g., k1 and k 2) on the first two OFDM symbols including the DM-RS are used as a group, and the sequences in table 2 are used; or, in the DM-RS resource mapping manner, a DM-RS corresponding to the same subcarrier number in one downlink subframe is used as a group, and a time domain orthogonal spreading sequence (i.e., a sequence in table 2) with a length of 2 corresponding to a corresponding DM-RS antenna port in Rel-10 is reused for each group of DM-RS, for example, for fig. 6d, DM-RS corresponding to the same subcarrier number on the first and last OFDM symbols including DM-RS are used as a group, DM-RS corresponding to the same subcarrier number on the second and third OFDM symbols including DM-RS are used as a group, and a sequence in table 2 is used for each group; or, in the DM-RS resource mapping manner, two adjacent DM-RSs on the same OFDM in a downlink subframe in the frequency domain are taken as a group, a time domain orthogonal spreading sequence (i.e., a sequence in table 2) with a length of 2 corresponding to a corresponding DM-RS antenna port in Rel-10 is reused for each group of DM-RSs, and the method may be applied to all OFDM symbols including the DM-RSs, or only applied to non-continuous OFDM symbols including the DM-RSs, and for two adjacent OFDM symbols including the DM-RSs, grouping is performed in the time domain direction according to the above method, for example, for fig. 6d, grouping is performed only on the DM-RSs on the first and last OFDM symbols including the DM-RSs in the frequency domain, and grouping is performed on the 2 nd and 3 rd OFDM symbols including the DM-RSs in the time domain;

example two: corresponding to the method one or the scheme one or the mode one;

for the TDD special subframe, performing time domain translation on DM-RS mapping resources in a DM-RS resource mapping mode of a corresponding antenna port in Rel-10 to obtain DM-RS resource mapping modes shown in figures 7a to 7 i;

for example, in normal CP: mode 1: translating the DM-RS mapping resources of the first two columns in Rel-10 to the 1 st and 2 nd OFDM symbols to obtain a graph 7 a;

mode 2: translating the first two columns of DM-RS mapping resources in Rel-10 to the 1 st and 2 nd OFDM symbols, and for the special subframe configuration 1/2/6/7 translating the last two columns of DM-RS mapping resources backward by 2 OFDM symbols (or backward by 1 OFDM symbol), resulting in fig. 7 b;

mode 3: translating the DM-RS mapping resources of the first two columns in Rel-10 to the 2 nd and 3 rd OFDM symbols to obtain a graph 7 c;

when the CP is extended: mode 1: translating the first column of DM-RS mapping resources in Rel-10 to the 1 st OFDM symbol (or to the 2 nd or 3 rd OFDM symbol), resulting in fig. 7 d;

mode 2: translating the first row of DM-RS mapping resources in Rel-10 to the 1 st OFDM symbol, and translating the second row of DM-RS mapping resources backward by 2 OFDM symbols (or backward by 1 OFDM symbol), to obtain fig. 7 e;

mode 3: translating the first row of DM-RS mapping resources in Rel-10 to the 2 nd OFDM symbol, and translating the second row of DM-RS mapping resources backwards by 2 OFDM symbols to obtain a graph 7 f;

when it is assumed that no CRS exists in the special subframe on the NCT, the mode 1 and the mode 2 in the case of the normal CP, and the mode 1 in the case of the extended CP can avoid overlapping of a synchronization signal and a DM-RS resource in the FDD system;

time domain orthogonal spread spectrum time: in the conventional CP, the DM-RS on the RE corresponding to the same subcarrier number on two OFDM symbols including the DM-RS adjacent in the time domain in one subframe may be used as 1 group, and a time domain orthogonal spreading sequence with a length of 2, i.e., a sequence in table 2, corresponding to a corresponding DM-RS antenna port defined by Rel-10 is reused for each group, so as to ensure orthogonality between antenna ports using the same resource mapping manner; for example, in fig. 7a, at antenna port 7/8/11/13, DM-RS on two REs corresponding to k = k1 on two symbols with OFDM number l =0 and 1 is 1 group, DM-RS on two REs corresponding to k = k6 is 1 group, and DM-RS on two REs corresponding to k = k11 is 1 group; when expanding CP, taking DM-RS on RE corresponding to the same subcarrier number on two OFDM symbols containing DM-RS in a subframe as 1 group, and reusing a corresponding DM-RS antenna port defined by Rel-10 for each group to obtain a time domain orthogonal spread spectrum sequence with the length of 2, namely a sequence in a table 2; for example, in fig. 7d, the DM-RS on two REs corresponding to k = k1 on two symbols with OFDM numbers l =0 and 5 is 1 group, the DM-RS on two REs corresponding to k = k4 is 1 group, the DM-RS on two REs corresponding to k = k7 is 1 group, and the DM-RS on two REs corresponding to k = k10 is 1 group.

It should be noted that, in the first and second embodiments, if frequency domain translation is further introduced, for example, a number of subcarriers are translated to a high frequency or a low frequency part in the frequency domain, that is, each k in the figure represents a subcarrier number, and the method is also included, for example, on the basis of the above-mentioned fig. 6d, frequency domain translation is further performed, so as to obtain the resource mapping method shown in fig. 7g to fig. 7 i.

Example three: corresponding to the second method, the second scheme or the second mode;

for a conventional downlink subframe, when a conventional CP is downlink, according to the subcarrier position where the DM-RS mapping resource is located in the DM-RS resource mapping mode of the corresponding antenna port in Rel-10, adding the DM-RS mapping resource on the 2 nd and 3 rd OFDM symbols in a subframe to obtain the DM-RS resource mapping mode shown in fig. 8 a;

when the CP is extended in the downlink, according to the subcarrier positions where the DM-RS mapping resources on the first two or last two OFDM symbols of the DM-RS mapping resources are located in the DM-RS resource mapping mode of the corresponding antenna port in Rel-10, the DM-RS mapping resources are added on the 2 nd and 3 rd OFDM symbols in one subframe, so as to obtain the DM-RS resource mapping mode shown in fig. 8b or fig. 8 c; or the DM-RS mapping resources may also be increased on the 1 st and 2 nd OFDM symbols or the 3 rd and 4 th OFDM symbols in one subframe in the manner described above.

Time domain orthogonal spread spectrum time: for fig. 8a, the OFDM symbols with numbers l =1, 2, 5, and 6 in the first slot are grouped into DM-RSs corresponding to the same subcarrier number, 4 DM-RSs in each group are subjected to position transformation using orthogonal sequences shown in table 3, the OFDM symbols with numbers l =5 and 6 in the first slot and the DM-RSs corresponding to the same subcarrier number in the OFDM symbols with numbers l =5 and 6 in the second slot are grouped into another group, and 4 DM-RSs in each group are subjected to orthogonal spreading sequences in Rel-10; for fig. 8b and 8c, the DM-RSs corresponding to the same subcarrier number on two adjacent OFDM symbols (i.e., OFDM symbols with numbers l =1 and 2 in the first slot, OFDM symbols with numbers l =4 and 5 in the second slot, and OFDM symbols with numbers l =4 and 5 in the second slot) are respectively in one group, and the 2 DM-RS symbols in each group use the orthogonal spreading sequences in table 2.

Table 3: DM-RS orthogonal sequences of different antenna ports under normal CP

Example four: corresponding to the second method, the second scheme or the second mode;

for a conventional downlink subframe, when a conventional CP is downlink, according to the subcarrier position where the DM-RS mapping resource is located in the DM-RS resource mapping mode of the corresponding antenna port in Rel-10, adding the DM-RS mapping resource to the 2 nd OFDM symbol in one subframe to obtain the DM-RS resource mapping mode shown in fig. 9 a;

when the CP is extended in the downlink, according to the subcarrier positions where the DM-RS mapping resources on the first two or the last two OFDM symbols of the DM-RS mapping resources are located in the DM-RS resource mapping mode of the corresponding antenna port in Rel-10, the DM-RS mapping resources are added on the 2 nd OFDM symbol in one subframe, so as to obtain the DM-RS resource mapping mode shown in fig. 9b or fig. 9 c; or, the DM-RS mapping resource may also be increased on the 1 st, 3 rd, or 4 th OFDM symbol in one subframe according to the above manner.

Time domain orthogonal spreading: for fig. 9a, OFDM symbols numbered l =1, 5, 6 in the first slot and DM-RS corresponding to the same subcarrier number on OFDM symbols numbered l =5 in the second slot are taken as one group, OFDM symbols numbered l =5, 6 in the first slot and DM-RS corresponding to the same subcarrier number on OFDM symbols numbered l =5, 6 in the second slot are taken as another group, and 4 DM-RS symbols in each group use the sequence in table 4; for fig. 9b, fig. 9c, for the original Rel-10DM-RS mapping resource, reuse the corresponding orthogonal spreading sequences in Rel-10 in a grouped manner in Rel-10, that is, the DM-RSs corresponding to the same subcarrier numbers on the OFDM symbols with the numbers l =4 and 5 in the first slot are divided into one group, the DM-RSs corresponding to the same subcarrier numbers on the OFDM symbols with the numbers l =4 and 5 in the second slot are divided into one group, the sequences in table 2 are respectively used for 2 DM-RSs in each group, for DM-RSs on the OFDM symbol of l =1 in the first slot, two-by-two groups are divided into one group in the frequency domain, for example, the DM-RSs corresponding to k = k2 and k = k5 are 1 group in fig. 9c, DM-RSs for k = k8 and k = k11 were 1 group, with 2 DM-RSs in each group using the sequences in table 2; or, for fig. 9b, the DM-RSs corresponding to the same subcarrier number on the OFDM symbols with numbers l =1 and 4 in the first slot are divided into one group, the orthogonal sequence after position transformation shown in table 5 is used for the 2 DM-RSs in each group, the DM-RSs corresponding to the same subcarrier number on the OFDM symbols with numbers l =4 and 5 in the first slot are divided into one group, the DM-RSs corresponding to the same subcarrier number on the OFDM symbols with numbers l =4 and 5 in the second slot are divided into one group, and the sequence in Rel-10 is used for the 2 DM-RSs in each group.

Table 4: DM-RS orthogonal sequences of different antenna ports under normal CP

Table 5: DM-RS orthogonal sequences of different antenna ports under extended CP

Example five: corresponding to the second method, the second scheme or the second mode;

for TDD special sub-frames, when extending the CP in the downlink, according to the sub-carrier position where the DM-RS mapping resource is located in the DM-RS resource mapping manner of the corresponding antenna port in Rel-10, add the DM-RS mapping resource on the 1 st and 2 nd OFDM symbols in a sub-frame to obtain the DM-RS resource mapping manner shown in fig. 10a, or add the DM-RS mapping resource on the 2 nd and 3 rd OFDM symbols in a sub-frame to obtain the DM-RS resource mapping manner shown in fig. 10b, or add the DM-RS mapping resource on the 1 st OFDM symbol in a sub-frame to obtain the DM-RS resource mapping manner shown in fig. 10c, or add the DM-RS mapping resource on the 2 nd OFDM symbol in a sub-frame to obtain the DM-RS resource mapping manner shown in fig. 10d (or add the DM-RS mapping resource on the 3 rd OFDM symbol in the above manner), or, on the basis of the DM-RS pattern obtained after the DM-RS mapping resource is added, further performing DM-RS time domain/frequency domain translation, for example, adding the DM-RS mapping resource to the 1 st and 2 nd OFDM symbols in a subframe, and translating the DM-RS mapping resource of the corresponding antenna port in the original Rel-10 to the right by two OFDM symbols, so as to obtain the DM-RS resource mapping mode shown in fig. 10 e.

Time domain orthogonal spread spectrum time: for the original Rel-10DM-RS mapping resource, reusing a corresponding orthogonal spread spectrum sequence in Rel-10 according to a grouping mode in Rel-10, namely, dividing DM-RSs corresponding to the same subcarrier number on OFDM symbols with numbers of l =4 and 5 in a first time slot into a group, and using the orthogonal spread spectrum sequence with the length of 2 in Rel-10; for fig. 10a or fig. 10b, newly adding DM-RS mapping resources, that is, OFDM symbols with numbers l =0 and 1 or DM-RS corresponding to the same subcarrier number on OFDM symbols with l =1 and 2 as a group, and using orthogonal spreading sequences with length 2 in Rel-10 for 2 DM-RS symbols in each group; the DM-RS on the 1 st or 2 nd OFDM symbol added with DM-RS for fig. 10c and 10d are grouped into two by two in the frequency domain, for example the DM-RS corresponding to k = k1 and k = k4 is 1 group, the DM-RSs for k = k7 and k = k10 are 1 group, 2 DM-RSs in each group use the sequences in table 2, or, the DM-RSs corresponding to the same subcarrier number on the OFDM symbol with the number l =0 and 4 in the first slot (corresponding to fig. 10 c) or the OFDM symbol with the number l =1 and 4 (corresponding to fig. 10 d) are divided into one group, 2 DM-RSs in each group use the orthogonal sequence after position transformation shown in table 5, the DM-RSs corresponding to the same subcarrier number on the OFDM symbol with the number l =4 and 5 in the first slot are divided into one group, and 2 DM-RSs in each group use the orthogonal spreading sequence with the length of 2 in Rel-10.

Example six: corresponding to the third mode;

for the conventional downlink subframe, the DM-RS resource mapping manner shown in fig. 11a to 11d can be used; alternatively, the DM-RS mapping resources may also be placed on the 1 st or 3 rd OFDM symbol in the first slot (the normal CP may also be on the 4 th OFDM symbol of the first slot), the 2 nd last OFDM symbol in the second slot, or the 1 st or 2 nd or 3 rd OFDM symbol in the second slot (the normal CP may also be on the 4 th OFDM symbol of the second slot) according to the same frequency domain position in the illustration.

Time domain orthogonal spread spectrum time: for fig. 11a, regarding the DM-RS corresponding to two adjacent subcarrier numbers on two OFDM symbols including the DM-RS in one subframe as a group, for example, for antenna port 7/8/11/13, the DM-RS corresponding to subcarrier numbers k2 and k3 on the OFDM symbol with number l =1 in the first slot and on the OFDM symbol with number l =5 in the second slot is taken as a 1 group, and for antenna port 9/10/12/14, the DM-RS corresponding to subcarrier numbers k0 and k1 on the OFDM symbol with number l =1 in the first slot and on the OFDM symbol with number l =5 in the second slot is taken as a 1 group, and the orthogonal spreading sequences in table 1 are used for the 4 DM-RS symbols in each group; with respect to FIGS. 11 b-11 d, DM-RS corresponding to two adjacent subcarrier numbers on each OFDM symbol containing DM-RS in one subframe is taken as a group, for example, in fig. 11c, the DM-RS symbols corresponding to subcarrier numbers k1 and k2 on the OFDM symbol with number l =1 in the first slot are taken as 1 group, and the 2 DM-RS symbols in each group use the orthogonal spreading sequences in table 2, or, for fig. 11b and 11c, the DM-RSs corresponding to the same subcarrier number on two OFDM symbols containing DM-RSs in one subframe are taken as a group, for example, in fig. 11c, the DM-RS with the subcarrier number k1 is allocated to the OFDM symbol with the number l =1 in the first slot and the OFDM symbol with the number l =4 in the second slot as 1 group, and the orthogonal spreading sequences in table 2 are used for the 2 DM-RS symbols in each group.

The scheme can simultaneously avoid the overlapping of the synchronous signals and the DM-RS resources in FDD and TDD systems.

Example seven: corresponding to the third mode;

for the TDD special subframe, the DM-RS resource mapping method shown in fig. 12a to 12d can be used; alternatively, the DM-RS mapping resource may be placed in the 1 st OFDM symbol in the first slot (the normal CP may also be on the 4 th OFDM symbol of the first slot), the last or the second last OFDM symbol in the first slot according to the same frequency domain position in the illustration.

The time domain orthogonal spreading is similar to the regular downlink subframe in the sixth embodiment described above.

Specifically, the TDD special subframe under the special subframe configuration 9 uses the DM-RS resource mapping manner corresponding to the TDD special subframe configuration 8 defined in the above method, and only the OFDM symbol set corresponding to the DwPTS of the special subframe has DM-RS transmission.

The DM-RS resource mapping mode with the reduced overhead can be used in combination with a DM-RS overhead reduction scheme, namely, the DM-RS resource mapping mode with the reduced overhead or the DM-RS resource mapping mode can be selected to be used by appointing rules or high-level configuration information, wherein the DM-RS resource mapping mode with the reduced overhead can also be obtained by carrying out time domain and/or frequency domain truncation on the DM-RS resource mapping mode according to the preset rules or the high-level configuration information.

Referring to fig. 13, an embodiment of the present invention provides a terminal, where the terminal includes:

a resource mapping unit 70, configured to determine, according to a DM-RS resource mapping manner, mapping resources of a DM-RS in a current subframe, where the DM-RS mapping resources at least include a resource unit RE on at least one OFDM symbol in first N orthogonal frequency division multiplexing OFDM symbols of the current subframe, and N is an integer not less than 1;

and a signal obtaining unit 71, configured to obtain the DM-RS transmitted in the current subframe according to the determined DM-RS mapping resource.

Further, the resource mapping unit 70 is configured to: determining the mapping resource of the DM-RS in the current subframe according to the DM-RS resource mapping mode according to one of the following methods:

the method comprises the following steps: based on a pre-agreed rule and a DM-RS resource mapping mode defined in LTE system version 10, on an antenna port where DM-RS is transmitted in a current subframe, moving part of REs in an RE set corresponding to the DM-RS on the DM-RS antenna port defined in LTE system version 10 to at least one OFDM symbol in the first N OFDM symbols of the subframe through translation in a time domain and/or a frequency domain, and taking the moved REs and the rest of the non-moved REs as mapping resources of the DM-RS on the antenna port in the current subframe; or,

the second method comprises the following steps: based on a predetermined rule and a DM-RS resource mapping mode defined in LTE system version 10, increasing REs used for transmitting DM-RS on at least one OFDM symbol in the first N OFDM symbols on an antenna port where DM-RS is transmitted in the current subframe, and taking the increased REs and REs corresponding to the DM-RS on the DM-RS antenna port defined in LTE system version 10 as mapping resources of DM-RS on the antenna port in the current subframe; or,

the third method comprises the following steps: determining a DM-RS resource mapping mode according to configuration information carried in a high-level signaling or a Physical Downlink Control Channel (PDCCH), and determining a mapping resource of an antenna port where DM-RS is transmitted in a current subframe according to the determined DM-RS resource mapping mode, wherein the configuration information indicates a DM-RS resource mapping mode or indicates whether DM-RS mapping resources exist in the first N Orthogonal Frequency Division Multiplexing (OFDM) symbols of one subframe or not; or,

the method four comprises the following steps: and determining the mapping resources of the DM-RS on the antenna port where the DM-RS is transmitted in the current subframe according to a predefined DM-RS resource mapping mode, wherein the predefined DM-RS resource mapping mode at least meets the condition that the DM-RS mapping resources exist on at least 1 OFDM symbol in the first N OFDM symbols of one subframe.

Further, the resource mapping unit 70 is configured to: determining a DM-RS resource mapping mode according to configuration information carried in a high-level signaling or a PDCCH according to one of the following methods, and determining the mapping resource of the DM-RS in the current subframe according to the determined DM-RS resource mapping mode:

determining whether DM-RS mapping resources exist in the first N OFDM symbols of the current subframe according to the configuration information, when the DM-RS mapping resources exist, moving part of REs in an RE set corresponding to DM-RS on an antenna port of the DM-RS defined in LTE system version 10 on at least one OFDM symbol in the first N OFDM symbols of the subframe through translation on a time domain and/or a frequency domain on the antenna port where the DM-RS is transmitted in the current subframe based on a predetermined rule and a DM-RS resource mapping mode defined in LTE system version 10, and taking the moved REs and the rest of the non-moved REs as the mapping resources of the DM-RS on the antenna port in the current subframe; or,

determining whether DM-RS mapping resources exist in the first N OFDM symbols of the current subframe or not according to the configuration information, when the DM-RS mapping resources exist, increasing REs used for transmitting DM-RS on at least one OFDM symbol in the first N OFDM symbols on an antenna port where DM-RS is transmitted in the current subframe based on a pre-agreed rule and a DM-RS resource mapping mode defined in LTE system version 10, and taking the increased REs and REs corresponding to the DM-RS on the DM-RS antenna port defined in LTE system version 10 as the mapping resources of DM-RS on the antenna port in the current subframe; or,

selecting a predefined DM-RS resource mapping mode indicated by the configuration information from a plurality of predefined DM-RS resource mapping modes according to the configuration information, and determining the mapping resources on the antenna port where the DM-RS is transmitted in the current subframe according to the predefined DM-RS resource mapping mode; or,

and determining whether the DM-RS mapping resources exist in the first N OFDM symbols of the current subframe or not according to the configuration information, when the DM-RS mapping resources exist, selecting a predefined DM-RS resource mapping mode in which the DM-RS mapping resources exist in the first N OFDM symbols of one subframe from a plurality of predefined DM-RS resource mapping modes, and determining the mapping resources of the DM-RS on the antenna port where the DM-RS is transmitted in the current subframe according to the predefined DM-RS resource mapping mode.

Further, when the resource mapping unit 70 determines the mapping resource of the DM-RS in the current subframe according to the predefined DM-RS resource mapping manner, the predefined DM-RS resource mapping manner is defined according to one of the following methods:

the first method is as follows: moving part of REs in an RE set corresponding to DM-RS on each DM-RS antenna port defined in LTE system release 10 in a subframe to at least one OFDM symbol in the first N OFDM symbols on the antenna port in the subframe through translation in a time domain and/or a frequency domain to obtain a DM-RS resource mapping mode; or,

in the second mode, based on the DM-RS resource mapping mode corresponding to each DM-RS antenna port defined in the LTE system version 10, REs corresponding to the DM-RS are added to at least one OFDM symbol in the first N OFDM symbols on the antenna port in one subframe to obtain the DM-RS resource mapping mode; or,

and a third mode is that on each DM-RS antenna port in one subframe, OFDM symbols with DM-RS mapping resources are not adjacent, and at least 1 group of DM-RS mapping resources consisting of REs corresponding to at least 2 adjacent subcarrier numbers exist on the OFDM symbols.

Further, the signal obtaining unit 71 is configured to: when the method I is adopted, the DM-RS transmitted in the current subframe is obtained according to the determined DM-RS mapping resource according to the following method:

for the conventional cyclic prefix CP, on each antenna port where the DM-RS is transmitted in the current subframe, 4 REs corresponding to the same subcarrier number in the REs used for transmitting the DM-RS are taken as a group, and the DM-RS transmitted on each group of REs is despread by using a time domain orthogonal spreading sequence with a length of 4 corresponding to the DM-RS antenna port defined by the LTE system version 10, so as to obtain the DM-RS transmitted on the antenna port.

for the extended CP, on each antenna port where the DM-RS is transmitted in the current subframe, on the first two OFDM symbols containing REs used for transmitting the DM-RS, 2 REs used for transmitting the DM-RS corresponding to the same subcarrier number are used as a group, on the last two OFDM symbols containing REs used for transmitting the DM-RS, 2 REs used for transmitting the DM-RS corresponding to the same subcarrier number are used as a group, and the DM-RS transmitted on each group of REs is subjected to despreading by using a time domain orthogonal spreading sequence with the length of 2 corresponding to the DM-RS antenna port defined by the LTE system version 10 so as to obtain the DM-RS transmitted on the antenna port; or,

for the extended CP, on each antenna port where the DM-RS is transmitted in the current subframe, on the former two OFDM symbols containing REs used for transmitting the DM-RS, 2 REs used for transmitting the DM-RS corresponding to the serial number of the adjacent subcarriers are used as a group, on the latter two OFDM symbols containing REs used for transmitting the DM-RS, 2 REs used for transmitting the DM-RS corresponding to the serial number of the adjacent subcarriers are used as a group, and the DM-RS transmitted on each group of REs is subjected to despreading by using a time domain orthogonal spreading sequence with the length of 2 corresponding to the DM-RS antenna port defined by the LTE system version 10 so as to obtain the DM-RS transmitted on the antenna port; or,

for the extended CP, on each antenna port where the DM-RS is transmitted in the current subframe, taking 2 REs used for transmitting the DM-RS corresponding to the same subcarrier number as a group, and performing despreading on the DM-RS transmitted on each group of REs by using a time domain orthogonal spreading sequence with the length of 2 corresponding to the DM-RS antenna port defined by the LTE system version 10 so as to obtain the DM-RS transmitted on the antenna port; or,

for the extended CP, on each antenna port where the DM-RS is transmitted in the current subframe, two REs which are used for transmitting the DM-RS on each OFDM and are most adjacent to each other in a frequency domain and contain DM-RS mapping resources are used as a group, and the DM-RS transmitted on each group of REs is subjected to despreading by using a time domain orthogonal spreading sequence with the length of 2 corresponding to the DM-RS antenna port defined by the LTE system version 10 so as to obtain the DM-RS transmitted on the antenna port.

Further, the signal obtaining unit 71 is configured to: when the method two is adopted, the DM-RS transmitted in the current subframe is obtained according to the determined DM-RS mapping resource according to the following method:

and performing despreading on a time domain orthogonal spreading sequence with the length of 4 corresponding to the DM-RS antenna port defined by the LTE system version 10 for DM-RS transmitted on one group of REs, and performing despreading on a time domain orthogonal spreading sequence obtained by transforming a time domain orthogonal spreading sequence with the length of 4 corresponding to the DM-RS antenna port defined by the LTE system version 10 for DM-RS transmitted on the other group of REs to obtain the DM-RS transmitted on the antenna port.

Further, if REs used for transmitting DM-RS are added to two OFDM symbols in the first N OFDM symbols of the current subframe, the time domain orthogonal spreading sequence obtained after the transformation is: exchanging the first two spreading factors and the second two spreading factors of a time domain orthogonal spreading sequence with the length of 4, which is defined by the LTE system version 10, to obtain a time domain orthogonal spreading sequence; or,

for the extended CP, if REs used for transmitting the DM-RS are added to two OFDM symbols in the first N OFDM symbols of the current subframe, on each antenna port where the DM-RS is transmitted in the current subframe, 2 REs used for transmitting the DM-RS corresponding to the same subcarrier number on every two adjacent OFDM symbols in the multiple OFDM symbols including the REs used for transmitting the DM-RS are used as a group, and the DM-RS transmitted on each group of REs is despread using a time domain orthogonal spreading sequence with a length of 2 corresponding to the DM-RS antenna port defined by the LTE system version 10, so as to obtain the DM-RS transmitted on the antenna port; or,

for the extended CP, if an RE used for transmitting the DM-RS is added to one of the first N OFDM symbols of the current subframe, on each antenna port where the DM-RS is transmitted in the current subframe, performing despreading on the DM-RS transmitted on the RE used for transmitting the DM-RS on the DM-RS antenna port defined in the LTE system release 10 according to a manner defined in the LTE system release 10 to obtain the DM-RS transmitted on the antenna port; and the number of the first and second groups,

taking 2 REs used by two closest transmission DM-RSs on the frequency domain on an OFDM symbol added with REs used for transmitting the DM-RSs as a group, wherein the DM-RSs transmitted on each group of REs use a time domain orthogonal spread spectrum sequence with the length of 2 corresponding to the DM-RS antenna port defined by the LTE system version 10; or, the OFDM symbol added with the REs used for transmitting the DM-RS and the first OFDM symbol defined in the LTE system release 10 that includes the REs used for transmitting the DM-RS are used as a group, where 2 REs corresponding to the same subcarrier number are used as a group, and the DM-RS transmitted on each group of REs uses a time domain orthogonal spreading sequence obtained by transforming a time domain orthogonal spreading sequence with a length of 2 corresponding to the DM-RS antenna port defined in the LTE system release 10 to perform despreading, so as to obtain the DM-RS transmitted on the antenna port.

Further, the time domain orthogonal spreading sequence obtained after the transformation is as follows:

and (3) performing transposition on two spreading factors in the time domain orthogonal spreading sequence with the length of 2 defined by the LTE system release 10 to obtain the time domain orthogonal spreading sequence with the length of 2.

Further, the signal obtaining unit 71 is configured to: when the method III is adopted, the DM-RS transmitted in the current subframe is obtained according to the determined DM-RS mapping resource according to the following method:

for the extended CP, on each antenna port where the DM-RS is transmitted in the current subframe, 2 REs corresponding to two adjacent subcarrier numbers on each OFDM symbol containing the REs used for transmitting the DM-RS are taken as a group, and the DM-RS transmitted on each group of REs is subjected to despreading by using a time domain orthogonal spreading sequence with the length of 2 corresponding to the DM-RS antenna port defined by the LTE system version 10 so as to obtain the DM-RS transmitted on the antenna port.

Furthermore, the current subframe is a normal downlink subframe or a special subframe configured corresponding to any TDD special subframe.

Further, when the current subframe is a conventional downlink subframe, N is a positive integer not exceeding 4; and/or when the current subframe is the special subframe, N is a positive integer not exceeding 2 or a positive integer not exceeding 3.

Referring to fig. 14, an embodiment of the present invention provides a base station, where the base station includes:

a resource mapping unit 80, configured to determine, according to a DM-RS resource mapping manner, mapping resources of a DM-RS in a current subframe, where the DM-RS mapping resources at least include a resource unit RE on at least one OFDM symbol in first N orthogonal frequency division multiplexing OFDM symbols of the current subframe, and N is an integer not less than 1;

and a data transmission unit 81, configured to map the DM-RS to the current subframe for transmission according to the determined DM-RS mapping resource.

Further, the resource mapping unit 80 is configured to: determining the mapping resource of the DM-RS in the current subframe according to the DM-RS resource mapping mode according to one of the following methods:

the third method comprises the following steps: determining a DM-RS resource mapping mode according to actual needs, determining mapping resources on an antenna port where DM-RS is transmitted in a current subframe according to the DM-RS resource mapping mode, and sending configuration information to a terminal through a high-level signaling or a Physical Downlink Control Channel (PDCCH), wherein the configuration information indicates the DM-RS resource mapping mode or indicates whether DM-RS mapping resources exist in the first N Orthogonal Frequency Division Multiplexing (OFDM) symbols of one subframe; or,

Further, the resource mapping unit 80 is configured to: determining a DM-RS resource mapping mode according to actual needs according to one of the following methods, determining mapping resources on an antenna port where DM-RS is transmitted in a current subframe according to the DM-RS resource mapping mode, and sending configuration information to a terminal through a high-level signaling or a PDCCH:

determining whether DM-RS mapping resources exist in the first N OFDM symbols of the current sub-frame according to actual needs, when the existence is determined, based on the pre-agreed rule and the DM-RS resource mapping mode defined in the LTE system release 10, through the translation on the time domain and/or the frequency domain, on an antenna port where the DM-RS is transmitted in the current subframe, moving a part of REs in an RE set corresponding to the DM-RS on the DM-RS antenna port defined in LTE system release 10 to at least one OFDM symbol in the first N OFDM symbols of the subframe, taking the moved REs and the rest of the non-moved REs as mapping resources of the DM-RS on the antenna port in the current subframe, sending configuration information for indicating whether DM-RS mapping resources exist in the first N OFDM symbols of a subframe to a terminal through a high-level signaling or a PDCCH; or,

determining whether DM-RS mapping resources exist in the first N OFDM symbols of the current subframe according to actual needs, when the DM-RS mapping resources exist, increasing REs used for transmitting DM-RS on at least one OFDM symbol in the first N OFDM symbols on an antenna port where DM-RS is transmitted in the current subframe based on a pre-agreed rule and a DM-RS resource mapping mode defined in LTE system version 10, using the increased REs and REs corresponding to the DM-RS on the DM-RS antenna port defined in LTE system version 10 as the mapping resources of DM-RS on the antenna port in the current subframe, and sending configuration information for indicating whether the DM-RS mapping resources exist in the first N OFDM symbols of one subframe to a terminal through a high-level signaling or a PDCCH; or,

selecting a predefined DM-RS resource mapping mode from a plurality of predefined DM-RS resource mapping modes according to actual needs, determining mapping resources of an antenna port where DM-RS is transmitted in a current subframe according to the predefined DM-RS resource mapping mode, and sending configuration information for indicating the selected predefined DM-RS resource mapping mode to a terminal through a high-level signaling or a PDCCH, or sending configuration information for indicating whether DM-RS mapping resources exist in the first N OFDM symbols of a subframe to the terminal through the high-level signaling or the PDCCH.

Further, when the resource mapping unit 80 determines the mapping resource of the DM-RS in the current subframe according to the predefined DM-RS resource mapping manner, the predefined DM-RS resource mapping manner is defined according to one of the following methods:

the second method comprises the following steps: based on a DM-RS resource mapping mode corresponding to each DM-RS antenna port defined in LTE system version 10, increasing REs corresponding to DM-RS on at least one OFDM symbol in the first N OFDM symbols on the antenna port in a subframe to obtain the DM-RS resource mapping mode; or,

Further, the data transmission unit 81 is configured to: when the method I is adopted, according to the determined DM-RS mapping resource, the DM-RS is mapped to the current subframe for transmission according to the following method:

for a conventional cyclic prefix CP, on each antenna port where a DM-RS is transmitted in a current subframe, 4 REs corresponding to the same subcarrier number in REs used for transmitting the DM-RS are taken as a group, and for the DM-RS transmitted on each group of REs, a time domain orthogonal spreading sequence with a length of 4 corresponding to the DM-RS antenna port defined by the LTE system release 10 is used for spreading, so as to transmit the DM-RS on the antenna port.

for the extended CP, on each antenna port where the DM-RS is transmitted in the current subframe, on the first two OFDM symbols containing REs used for transmitting the DM-RS, 2 REs used for transmitting the DM-RS corresponding to the same subcarrier number are used as a group, on the last two OFDM symbols containing REs used for transmitting the DM-RS, 2 REs used for transmitting the DM-RS corresponding to the same subcarrier number are used as a group, and the DM-RS transmitted on each group of REs are spread by using a time domain orthogonal spreading sequence with the length of 2 corresponding to the DM-RS antenna port defined by LTE system version 10, so as to transmit the DM-RS on the antenna port; or,

for the extended CP, on each antenna port where the DM-RS is transmitted in the current subframe, on the former two OFDM symbols containing REs used for transmitting the DM-RS, 2 REs used for transmitting the DM-RS corresponding to the serial number of the adjacent subcarriers are used as a group, on the latter two OFDM symbols containing REs used for transmitting the DM-RS, 2 REs used for transmitting the DM-RS corresponding to the serial number of the adjacent subcarriers are used as a group, and for the DM-RS transmitted on each group of REs, the DM-RS is spread by using a time domain orthogonal spreading sequence with the length of 2 corresponding to the DM-RS antenna port defined by the LTE system version 10, so as to transmit the DM-RS on the antenna port; or,

for the extended CP, on each antenna port where the DM-RS is transmitted in the current subframe, taking 2 REs used for transmitting the DM-RS corresponding to the same subcarrier number as a group, and spreading the DM-RS transmitted on each group of REs by using a time domain orthogonal spreading sequence with the length of 2 corresponding to the DM-RS antenna port defined by the LTE system version 10 so as to transmit the DM-RS on the antenna port; or,

for the extended CP, on each antenna port where the DM-RS is transmitted in the current subframe, two REs that are used for transmitting the DM-RS on each OFDM and include DM-RS mapping resources and are most adjacent in the frequency domain are taken as a group, and the DM-RS transmitted on each group of REs is spread by using a time domain orthogonal spreading sequence with a length of 2 corresponding to the DM-RS antenna port defined by LTE system release 10, so as to transmit the DM-RS on the antenna port.

Further, the data transmission unit 81 is configured to: when the method two is adopted, according to the determined DM-RS mapping resource, the DM-RS is mapped to the current subframe for transmission according to the following method:

and spreading the time domain orthogonal spread spectrum sequence with the length of 4 corresponding to the DM-RS antenna port defined by the LTE system version 10 for the DM-RS transmitted on one group of REs, and spreading the time domain orthogonal spread spectrum sequence obtained by transforming the time domain orthogonal spread spectrum sequence with the length of 4 corresponding to the DM-RS antenna port defined by the LTE system version 10 for the DM-RS transmitted on the other group of REs so as to transmit the DM-RS on the antenna port.

for the extended CP, if REs used for transmitting the DM-RS are added to two OFDM symbols in the first N OFDM symbols of the current subframe, on each antenna port where the DM-RS is transmitted in the current subframe, 2 REs used for transmitting the DM-RS corresponding to the same subcarrier number on every two adjacent OFDM symbols in the multiple OFDM symbols including the REs used for transmitting the DM-RS are used as a group, and the DM-RS transmitted on each group of REs is spread by using a time domain orthogonal spreading sequence with a length of 2 corresponding to the DM-RS antenna port defined by LTE system release 10, so as to transmit the DM-RS on the antenna port; or,

for the extended CP, if an RE used for transmitting the DM-RS is added to one of the first N OFDM symbols of the current subframe, on each antenna port where the DM-RS is transmitted in the current subframe, spreading the DM-RS transmitted on the RE used for transmitting the DM-RS on the DM-RS antenna port defined in LTE system release 10 according to the manner defined in LTE system release 10, so as to transmit the DM-RS on the antenna port; and the number of the first and second groups,

taking 2 REs used by two closest transmission DM-RSs on the frequency domain on an OFDM symbol added with REs used for transmitting the DM-RSs as a group, wherein the DM-RSs transmitted on each group of REs use a time domain orthogonal spread spectrum sequence with the length of 2 corresponding to the DM-RS antenna port defined by the LTE system version 10; or, the OFDM symbol added with the REs used for transmitting the DM-RS and the first OFDM symbol defined in LTE system release 10 that includes the REs used for transmitting the DM-RS are grouped into 2 REs corresponding to the same subcarrier number, and the DM-RS transmitted on each group of REs is spread by using a time domain orthogonal spreading sequence obtained by transforming a time domain orthogonal spreading sequence with a length of 2 corresponding to the DM-RS antenna port defined in LTE system release 10, so as to transmit the DM-RS on the antenna port.

Further, the data transmission unit 81 is configured to: when the method III is adopted, according to the determined DM-RS mapping resource, the DM-RS is mapped to the current subframe for transmission according to the following method:

for a conventional CP, on each antenna port where a DM-RS is transmitted in a current subframe, 4 REs corresponding to two adjacent subcarrier numbers on a plurality of OFDM symbols including REs used for transmitting the DM-RS are used as a group, and a time domain orthogonal spreading sequence with a length of 4 corresponding to the DM-RS antenna port defined by LTE system release 10 is used for spreading the DM-RS transmitted on each group of REs, so as to transmit the DM-RS on the antenna port.

for the extended CP, on each antenna port where the DM-RS is transmitted in the current subframe, 2 REs corresponding to two adjacent subcarrier numbers on each OFDM symbol including REs used for transmitting the DM-RS are used as a group, and the DM-RS transmitted on each group of REs is spread using a time domain orthogonal spreading sequence with a length of 2 corresponding to the DM-RS antenna port defined by LTE system release 10, so as to transmit the DM-RS on the antenna port.

In conclusion, the beneficial effects of the invention include:

in the scheme provided by the embodiment of the invention, the mapping resources of the DM-RS exist in the control area of the subframe, namely the first N OFDM symbols, so that the channel estimation information on the first N OFDM symbols can be obtained by performing interpolation calculation on the DM-RS transmitted on the N OFDM symbols, and the channel estimation information is prevented from being obtained by performing an extrapolation algorithm on a limited array of DM-RSs which are far away from the N symbols in the time domain, thereby improving the data demodulation performance on the NCT carrier.

Further, the scheme provided by the embodiment of the invention can be applied to special subframes, and for TDD special subframe configuration which does not support DM-RS transmission in lte Rel-10, for example, when a normal CP is downlink, TDD special subframe configuration is 0 and 5, and when a CP is extended downlink, TDD special subframe configuration is 0 and 4, a DM-RS resource mapping mode corresponding to any TDD special subframe configuration can be obtained according to the method provided by the invention, so that DM-RS can also be transmitted on a special subframe which does not support DM-RS transmission in Rel-10, and then downlink data transmission based on DM-RS can be performed in a special subframe, thereby improving the resource utilization rate of an NCT carrier.

The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all such alterations and modifications as fall within the scope of the invention.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.

Claims

1. A method for transmitting a demodulation reference signal DM-RS special for a downlink user is characterized by comprising the following steps:

the terminal acquires the DM-RS transmitted in the current subframe according to the determined DM-RS mapping resource;

the terminal determines the mapping resource of the DM-RS in the current subframe according to the DM-RS resource mapping mode, and the method specifically comprises one of the following methods:

the method comprises the following steps: the terminal moves part of REs in an RE set corresponding to DM-RS on a DM-RS antenna port defined in LTE system version 10 to at least one OFDM symbol in the first N OFDM symbols of a subframe on the antenna port where the DM-RS is transmitted in the current subframe through translation in a time domain and/or a frequency domain based on a preset rule and a DM-RS resource mapping mode defined in LTE system version 10, and takes the moved REs and the rest of the non-moved REs as mapping resources of the DM-RS on the antenna port in the current subframe; or,

the second method comprises the following steps: the terminal increases REs used for transmitting the DM-RS on at least one OFDM symbol in the first N OFDM symbols on the antenna port where the DM-RS is transmitted in the current subframe based on a preset rule and a DM-RS resource mapping mode defined in LTE system version 10, and takes the increased REs and REs corresponding to the DM-RS on the DM-RS antenna port defined in LTE system version 10 as mapping resources of the DM-RS on the antenna port in the current subframe; or,

the third method comprises the following steps: the terminal determines a DM-RS resource mapping mode according to configuration information carried in a high-level signaling or a Physical Downlink Control Channel (PDCCH), and determines a mapping resource on an antenna port where DM-RS is transmitted in a current subframe according to the determined DM-RS resource mapping mode, wherein the configuration information indicates a DM-RS resource mapping mode or indicates whether DM-RS mapping resources exist in the first N OFDM symbols of one subframe or not; or,

the method four comprises the following steps: the terminal determines the mapping resources of the DM-RS on the antenna port where the DM-RS is transmitted in the current subframe according to a predefined DM-RS resource mapping mode, wherein the predefined DM-RS resource mapping mode at least meets the condition that the DM-RS mapping resources exist on at least 1 OFDM symbol in the first N OFDM symbols of one subframe.

2. The method of claim 1, wherein the terminal determines a DM-RS resource mapping manner according to configuration information carried in a higher layer signaling or a PDCCH, and determines a mapping resource of a DM-RS in a current subframe according to the determined DM-RS resource mapping manner, which specifically includes one of the following methods:

the method comprises the following steps: the terminal determines whether DM-RS mapping resources exist in the first N OFDM symbols of the current subframe according to the configuration information, when the DM-RS mapping resources exist, based on a predetermined rule and a DM-RS resource mapping mode defined in LTE system version 10, on an antenna port where DM-RS is transmitted in the current subframe through translation in a time domain and/or a frequency domain, part of REs in an RE set corresponding to DM-RS on the DM-RS antenna port defined in LTE system version 10 are moved to at least one OFDM symbol in the first N OFDM symbols of the subframe, and the moved REs and the rest of the non-moved REs are used as the mapping resources of the DM-RS on the antenna port in the current subframe; or,

the second method comprises the following steps: the terminal determines whether DM-RS mapping resources exist in the first N OFDM symbols of the current subframe according to the configuration information, when the DM-RS mapping resources exist, based on a predetermined rule and a DM-RS resource mapping mode defined in LTE system version 10, the RE used for transmitting DM-RS is added to at least one OFDM symbol in the first N OFDM symbols on the antenna port where DM-RS is transmitted in the current subframe, and the added RE and the RE corresponding to the DM-RS on the DM-RS antenna port defined in LTE system version 10 are used as the mapping resources of DM-RS on the antenna port in the current subframe; or,

the third method comprises the following steps: the terminal selects a predefined DM-RS resource mapping mode indicated by the configuration information from a plurality of predefined DM-RS resource mapping modes according to the configuration information, and determines the mapping resource of the antenna port where the DM-RS is transmitted in the current subframe according to the predefined DM-RS resource mapping mode; or,

the method four comprises the following steps: and the terminal determines whether the DM-RS mapping resources exist in the first N OFDM symbols of the current subframe according to the configuration information, selects a predefined DM-RS resource mapping mode in which the DM-RS mapping resources exist in the first N OFDM symbols of one subframe from a plurality of predefined DM-RS resource mapping modes when the DM-RS mapping resources exist, and determines the mapping resources of the DM-RS on the antenna port where the DM-RS is transmitted in the current subframe according to the predefined DM-RS resource mapping mode.

3. The method of claim 1, wherein when the terminal determines the mapping resource of the DM-RS in the current subframe according to the predefined DM-RS resource mapping manner, the predefined DM-RS resource mapping manner is defined according to one of the following methods:

the method comprises the following steps: moving part of REs in an RE set corresponding to DM-RS on each DM-RS antenna port defined in LTE system release 10 in a subframe to at least one OFDM symbol in the first N OFDM symbols on the antenna port in the subframe through translation in a time domain and/or a frequency domain to obtain a DM-RS resource mapping mode; or,

4. The method of claim 2, wherein when the terminal determines the mapping resource of the DM-RS in the current subframe according to the predefined DM-RS resource mapping scheme, the predefined DM-RS resource mapping scheme is defined according to one of the following methods:

5. The method according to any one of claims 1 to 4, wherein in the method of one, the terminal obtains the DM-RS transmitted in the current subframe according to the determined DM-RS mapping resource, specifically comprising:

6. The method according to any one of claims 1 to 4, wherein in the method of one, the terminal obtains the DM-RS transmitted in the current subframe according to the determined DM-RS mapping resource, specifically comprising:

7. The method according to any one of claims 1 to 4, wherein when the method two is adopted, the terminal obtains the DM-RS transmitted in the current subframe according to the determined DM-RS mapping resource, specifically including:

8. The method of claim 7, wherein if REs used for transmitting DM-RS are added to two OFDM symbols in the first N OFDM symbols of the current subframe, the time-domain orthogonal spreading sequence obtained after the transformation is: exchanging the first two spreading factors and the second two spreading factors of a time domain orthogonal spreading sequence with the length of 4, which is defined by the LTE system version 10, to obtain a time domain orthogonal spreading sequence; or,

9. The method according to any one of claims 1 to 4, wherein when the method two is adopted, the terminal obtains the DM-RS transmitted in the current subframe according to the determined DM-RS mapping resource, specifically including:

10. The method of claim 9, wherein the time domain orthogonal spreading sequence obtained after the transformation is:

11. The method according to claim 3 or 4, wherein, when the method three is adopted, the terminal obtains the DM-RS transmitted in the current subframe according to the determined DM-RS mapping resource, specifically comprising:

12. The method according to claim 3 or 4, wherein, when the method three is adopted, the terminal obtains the DM-RS transmitted in the current subframe according to the determined DM-RS mapping resource, specifically comprising:

13. The method of claim 1, wherein the current subframe is a normal downlink subframe or a special subframe corresponding to any one TDD special subframe configuration.

14. The method of claim 13, wherein when the current subframe is a normal downlink subframe, N is a positive integer not exceeding 4; and/or the presence of a gas in the gas,

when the current subframe is the special subframe, N is a positive integer not exceeding 2 or a positive integer not exceeding 3.

15. A method for transmitting a demodulation reference signal DM-RS special for a downlink user is characterized by comprising the following steps:

the base station maps the DM-RS to the current subframe for transmission according to the determined DM-RS mapping resource;

the base station determines the mapping resource of the DM-RS in the current subframe according to the DM-RS resource mapping mode, and the method specifically comprises one of the following methods:

the method comprises the following steps: a base station moves part of REs in an RE set corresponding to DM-RS on a DM-RS antenna port defined in LTE system version 10 to at least one OFDM symbol in the first N OFDM symbols of a subframe on the antenna port where the DM-RS is transmitted in the current subframe through translation in a time domain and/or a frequency domain based on a preset rule and a DM-RS resource mapping mode defined in LTE system version 10, and takes the moved REs and the rest of the non-moved REs as mapping resources of the DM-RS on the antenna port in the current subframe; or,

the second method comprises the following steps: based on a preset rule and a DM-RS resource mapping mode defined in LTE system version 10, a base station increases REs used for transmitting DM-RS on at least one OFDM symbol in the first N OFDM symbols on an antenna port where DM-RS is transmitted in the current subframe, and takes the increased REs and REs corresponding to the DM-RS on the DM-RS antenna port defined in LTE system version 10 as mapping resources of the DM-RS on the antenna port in the current subframe; or,

the third method comprises the following steps: a base station determines a DM-RS resource mapping mode according to actual needs, determines mapping resources on an antenna port where DM-RS is transmitted in a current subframe according to the DM-RS resource mapping mode, and sends configuration information to a terminal through a high-level signaling or a Physical Downlink Control Channel (PDCCH), wherein the configuration information indicates the DM-RS resource mapping mode or indicates whether DM-RS mapping resources exist in the first N Orthogonal Frequency Division Multiplexing (OFDM) symbols of one subframe; or,

the method four comprises the following steps: and the base station determines the mapping resources of the DM-RS on the antenna port where the DM-RS is transmitted in the current subframe according to a predefined DM-RS resource mapping mode, wherein the predefined DM-RS resource mapping mode at least meets the condition that the DM-RS mapping resources exist on at least 1 OFDM symbol in the first N OFDM symbols of one subframe.

16. The method of claim 15, wherein the base station determines a DM-RS resource mapping manner according to actual needs, determines mapping resources on an antenna port where the DM-RS is transmitted in a current subframe according to the DM-RS resource mapping manner, and sends configuration information to the terminal through a high layer signaling or a physical downlink control channel PDCCH, and specifically includes one of the following methods:

the method comprises the following steps: the base station determines whether DM-RS mapping resources exist in the first N OFDM symbols of the current subframe according to actual needs, when the existence is determined, based on the pre-agreed rule and the DM-RS resource mapping mode defined in the LTE system release 10, through the translation on the time domain and/or the frequency domain, on an antenna port where the DM-RS is transmitted in the current subframe, moving a part of REs in an RE set corresponding to the DM-RS on the DM-RS antenna port defined in LTE system release 10 to at least one OFDM symbol in the first N OFDM symbols of the subframe, taking the moved REs and the rest of the non-moved REs as mapping resources of the DM-RS on the antenna port in the current subframe, sending configuration information for indicating whether DM-RS mapping resources exist in the first N OFDM symbols of a subframe to a terminal through a high-level signaling or a PDCCH; or,

the second method comprises the following steps: a base station determines whether DM-RS mapping resources exist in the first N OFDM symbols of a current subframe according to actual needs, when the DM-RS mapping resources exist, based on a predetermined rule and a DM-RS resource mapping mode defined in LTE system version 10, the RE used for transmitting DM-RS is added to at least one OFDM symbol in the first N OFDM symbols on an antenna port where DM-RS is transmitted in the current subframe, the added RE and the RE corresponding to the DM-RS on the DM-RS antenna port defined in LTE system version 10 are used as the mapping resources of DM-RS on the antenna port in the current subframe, and configuration information used for indicating whether DM-RS mapping resources exist in the first N OFDM symbols of one subframe is sent to a terminal through a high-level signaling or a PDCCH; or,

the third method comprises the following steps: the base station selects a predefined DM-RS resource mapping mode from a plurality of predefined DM-RS resource mapping modes according to actual needs, determines mapping resources on an antenna port where DM-RS is transmitted in a current subframe according to the predefined DM-RS resource mapping mode, and sends configuration information for indicating the selected predefined DM-RS resource mapping mode to a terminal through a high-level signaling or a PDCCH, or sends configuration information for indicating whether DM-RS mapping resources exist in the first N OFDM symbols of one subframe to the terminal through the high-level signaling or the PDCCH.

17. The method of claim 15, wherein when the base station determines the mapping resources of the DM-RS in the current subframe according to the predefined DM-RS resource mapping scheme, the predefined DM-RS resource mapping scheme is defined according to one of the following methods:

18. The method of claim 16, wherein when the base station determines the mapping resources of the DM-RS in the current subframe according to the predefined DM-RS resource mapping scheme, the predefined DM-RS resource mapping scheme is defined according to one of the following methods:

19. The method according to any one of claims 15 to 18, wherein in the method one, the base station maps the DM-RS to the current subframe for transmission according to the determined DM-RS mapping resource, and specifically comprises:

20. The method according to any one of claims 15 to 18, wherein in the method one, the base station maps the DM-RS to the current subframe for transmission according to the determined DM-RS mapping resource, and specifically comprises:

21. The method according to any one of claims 15 to 18, wherein when the second method is adopted, the base station maps the DM-RS to the current subframe for transmission according to the determined DM-RS mapping resource, specifically comprising:

22. The method of claim 21, wherein if REs used for transmitting DM-RS are added to two OFDM symbols in the first N OFDM symbols of the current subframe, the time-domain orthogonal spreading sequence obtained after the transformation is: exchanging the first two spreading factors and the second two spreading factors of a time domain orthogonal spreading sequence with the length of 4, which is defined by the LTE system version 10, to obtain a time domain orthogonal spreading sequence; or,

23. The method according to any one of claims 15 to 18, wherein when the second method is adopted, the base station maps the DM-RS to the current subframe for transmission according to the determined DM-RS mapping resource, specifically comprising:

24. The method of claim 23, wherein the time domain orthogonal spreading sequence obtained after the transformation is:

25. The method according to claim 17 or 18, wherein when the third method is adopted, the base station maps the DM-RS to the current subframe for transmission according to the determined DM-RS mapping resource, and specifically includes:

26. The method according to claim 17 or 18, wherein when the third method is adopted, the base station maps the DM-RS to the current subframe for transmission according to the determined DM-RS mapping resource, and specifically includes:

27. The method of claim 15, wherein the current subframe is a normal downlink subframe or a special subframe corresponding to any one of TDD special subframe configurations.

28. The method of claim 27, wherein when the current subframe is a normal downlink subframe, N is a positive integer not exceeding 4; and/or the presence of a gas in the gas,

29. A terminal, characterized in that the terminal comprises:

the signal acquisition unit is used for acquiring the DM-RS transmitted in the current subframe according to the determined DM-RS mapping resource;

wherein the resource mapping unit is configured to: determining the mapping resource of the DM-RS in the current subframe according to the DM-RS resource mapping mode according to one of the following methods:

30. The terminal of claim 29, wherein the resource mapping unit is configured to: determining a DM-RS resource mapping mode according to configuration information carried in a high-level signaling or a PDCCH according to one of the following methods, and determining the mapping resource of the DM-RS in the current subframe according to the determined DM-RS resource mapping mode:

the method comprises the following steps: determining whether DM-RS mapping resources exist in the first N OFDM symbols of the current subframe according to the configuration information, when the DM-RS mapping resources exist, moving part of REs in an RE set corresponding to DM-RS on an antenna port of the DM-RS defined in LTE system version 10 on at least one OFDM symbol in the first N OFDM symbols of the subframe through translation on a time domain and/or a frequency domain on the antenna port where the DM-RS is transmitted in the current subframe based on a predetermined rule and a DM-RS resource mapping mode defined in LTE system version 10, and taking the moved REs and the rest of the non-moved REs as the mapping resources of the DM-RS on the antenna port in the current subframe; or,

the second method comprises the following steps: determining whether DM-RS mapping resources exist in the first N OFDM symbols of the current subframe or not according to the configuration information, when the DM-RS mapping resources exist, increasing REs used for transmitting DM-RS on at least one OFDM symbol in the first N OFDM symbols on an antenna port where DM-RS is transmitted in the current subframe based on a pre-agreed rule and a DM-RS resource mapping mode defined in LTE system version 10, and taking the increased REs and REs corresponding to the DM-RS on the DM-RS antenna port defined in LTE system version 10 as the mapping resources of DM-RS on the antenna port in the current subframe; or,

the third method comprises the following steps: selecting a predefined DM-RS resource mapping mode indicated by the configuration information from a plurality of predefined DM-RS resource mapping modes according to the configuration information, and determining the mapping resources on the antenna port where the DM-RS is transmitted in the current subframe according to the predefined DM-RS resource mapping mode; or,

the method four comprises the following steps: and determining whether the DM-RS mapping resources exist in the first N OFDM symbols of the current subframe or not according to the configuration information, when the DM-RS mapping resources exist, selecting a predefined DM-RS resource mapping mode in which the DM-RS mapping resources exist in the first N OFDM symbols of one subframe from a plurality of predefined DM-RS resource mapping modes, and determining the mapping resources of the DM-RS on the antenna port where the DM-RS is transmitted in the current subframe according to the predefined DM-RS resource mapping mode.

31. The terminal of claim 29, wherein when the resource mapping unit determines the mapping resource of the DM-RS in the current subframe according to the predefined DM-RS resource mapping scheme, the predefined DM-RS resource mapping scheme is defined according to one of the following methods:

32. The terminal of claim 30, wherein when the resource mapping unit determines the mapping resource of the DM-RS in the current subframe according to the predefined DM-RS resource mapping manner, the predefined DM-RS resource mapping manner is defined according to one of the following methods:

33. The terminal of any of claims 29-32, wherein the signal acquisition unit is configured to: when the method I is adopted, the DM-RS transmitted in the current subframe is obtained according to the determined DM-RS mapping resource according to the following method:

34. The terminal of any of claims 29-32, wherein the signal acquisition unit is configured to: when the method I is adopted, the DM-RS transmitted in the current subframe is obtained according to the determined DM-RS mapping resource according to the following method:

35. The terminal of any of claims 29-32, wherein the signal acquisition unit is configured to: when the method two is adopted, the DM-RS transmitted in the current subframe is obtained according to the determined DM-RS mapping resource according to the following method:

36. The terminal of claim 35, wherein if REs used for transmitting DM-RS are added to two OFDM symbols in the first N OFDM symbols of the current subframe, the time-domain orthogonal spreading sequence obtained after the transformation is: exchanging the first two spreading factors and the second two spreading factors of a time domain orthogonal spreading sequence with the length of 4, which is defined by the LTE system version 10, to obtain a time domain orthogonal spreading sequence; or,

37. The terminal of any of claims 29-32, wherein the signal acquisition unit is configured to: when the method two is adopted, the DM-RS transmitted in the current subframe is obtained according to the determined DM-RS mapping resource according to the following method:

38. The terminal of claim 37, wherein the time domain orthogonal spreading sequence obtained after the transformation is:

39. The terminal according to claim 31 or 32, wherein the signal acquisition unit is configured to: when the method III is adopted, the DM-RS transmitted in the current subframe is obtained according to the determined DM-RS mapping resource according to the following method:

40. The terminal according to claim 31 or 32, wherein the signal acquisition unit is configured to: when the method III is adopted, the DM-RS transmitted in the current subframe is obtained according to the determined DM-RS mapping resource according to the following method:

41. The terminal of claim 29, wherein the current subframe is a normal downlink subframe or a special subframe corresponding to any one of TDD special subframe configurations.

42. The terminal of claim 41, wherein N is a positive integer not exceeding 4 when the current subframe is a normal downlink subframe; and/or the presence of a gas in the gas,

43. A base station, comprising:

the data transmission unit is used for mapping the DM-RS to the current subframe for transmission according to the determined DM-RS mapping resource;

44. The base station of claim 43, wherein the resource mapping unit is configured to: determining a DM-RS resource mapping mode according to actual needs according to one of the following methods, determining mapping resources on an antenna port where DM-RS is transmitted in a current subframe according to the DM-RS resource mapping mode, and sending configuration information to a terminal through a high-level signaling or a PDCCH:

the method comprises the following steps: determining whether DM-RS mapping resources exist in the first N OFDM symbols of the current sub-frame according to actual needs, when the existence is determined, based on the pre-agreed rule and the DM-RS resource mapping mode defined in the LTE system release 10, through the translation on the time domain and/or the frequency domain, on an antenna port where the DM-RS is transmitted in the current subframe, moving a part of REs in an RE set corresponding to the DM-RS on the DM-RS antenna port defined in LTE system release 10 to at least one OFDM symbol in the first N OFDM symbols of the subframe, taking the moved REs and the rest of the non-moved REs as mapping resources of the DM-RS on the antenna port in the current subframe, sending configuration information for indicating whether DM-RS mapping resources exist in the first N OFDM symbols of a subframe to a terminal through a high-level signaling or a PDCCH; or,

the second method comprises the following steps: determining whether DM-RS mapping resources exist in the first N OFDM symbols of the current subframe according to actual needs, when the DM-RS mapping resources exist, increasing REs used for transmitting DM-RS on at least one OFDM symbol in the first N OFDM symbols on an antenna port where DM-RS is transmitted in the current subframe based on a pre-agreed rule and a DM-RS resource mapping mode defined in LTE system version 10, using the increased REs and REs corresponding to the DM-RS on the DM-RS antenna port defined in LTE system version 10 as the mapping resources of DM-RS on the antenna port in the current subframe, and sending configuration information for indicating whether the DM-RS mapping resources exist in the first N OFDM symbols of one subframe to a terminal through a high-level signaling or a PDCCH; or,

the third method comprises the following steps: selecting a predefined DM-RS resource mapping mode from a plurality of predefined DM-RS resource mapping modes according to actual needs, determining mapping resources of an antenna port where DM-RS is transmitted in a current subframe according to the predefined DM-RS resource mapping mode, and sending configuration information for indicating the selected predefined DM-RS resource mapping mode to a terminal through a high-level signaling or a PDCCH, or sending configuration information for indicating whether DM-RS mapping resources exist in the first N OFDM symbols of a subframe to the terminal through the high-level signaling or the PDCCH.

45. The base station of claim 43, wherein when the resource mapping unit determines the mapping resource of the DM-RS in the current subframe according to the predefined DM-RS resource mapping manner, the predefined DM-RS resource mapping manner is defined according to one of the following methods:

46. The base station of claim 44, wherein when the resource mapping unit determines the mapping resource of the DM-RS in the current subframe according to the predefined DM-RS resource mapping manner, the predefined DM-RS resource mapping manner is defined according to one of the following methods:

47. The base station according to any of claims 43-46, wherein the data transmission unit is configured to: when the method I is adopted, according to the determined DM-RS mapping resource, the DM-RS is mapped to the current subframe for transmission according to the following method:

48. The base station according to any of claims 43-46, wherein the data transmission unit is configured to: when the method I is adopted, according to the determined DM-RS mapping resource, the DM-RS is mapped to the current subframe for transmission according to the following method:

49. The base station according to any of claims 43-46, wherein the data transmission unit is configured to: when the method two is adopted, according to the determined DM-RS mapping resource, the DM-RS is mapped to the current subframe for transmission according to the following method:

50. The base station of claim 49, wherein if REs used for transmitting DM-RS are added to two OFDM symbols in the first N OFDM symbols of the current subframe, the time domain orthogonal spreading sequence obtained after the transformation is: exchanging the first two spreading factors and the second two spreading factors of a time domain orthogonal spreading sequence with the length of 4, which is defined by the LTE system version 10, to obtain a time domain orthogonal spreading sequence; or,

51. The base station according to any of claims 43-46, wherein the data transmission unit is configured to: when the method two is adopted, according to the determined DM-RS mapping resource, the DM-RS is mapped to the current subframe for transmission according to the following method:

52. The base station of claim 51, wherein the time domain orthogonal spreading sequence obtained after the transformation is:

53. The base station of claim 45 or 46, wherein the data transmission unit is configured to: when the method III is adopted, according to the determined DM-RS mapping resource, the DM-RS is mapped to the current subframe for transmission according to the following method:

54. The base station of claim 45 or 46, wherein the data transmission unit is configured to: when the method III is adopted, according to the determined DM-RS mapping resource, the DM-RS is mapped to the current subframe for transmission according to the following method:

55. The base station of claim 43, wherein the current subframe is a normal downlink subframe or a special subframe corresponding to any TDD special subframe configuration.

56. The base station of claim 55, wherein when the current subframe is a normal downlink subframe, N is a positive integer not exceeding 4; and/or the presence of a gas in the gas,