WO2008038352A1 - Wireless communication apparatus - Google Patents

Abstract

A synchronization channel is positioned in a part of a system band for each of constant sub-frames for transmission. In addition, a sub-band having the same frequency as the synchronization channel is allocated as an audio packet transmission part that is a radio resource for transmitting an audio packet. In this way, when capturing the synchronization channel during a hard handover, the terminal is allowed to use the same received band to receive the audio packet. Therefore, even if the telephone communication is interrupted due to a handover, it can be immediately resumed, resulting in alleviation of the problem of the telephone communication during the hard handover.

Description

 Specification

 Wireless communication device

 Technical field

 TECHNICAL FIELD [0001] The present invention relates to a wireless communication apparatus having a configuration for shortening an instantaneous interruption of a voice call and enabling effective transmission of broadcast data.

 Background art

 [0002] Currently, a basic study is being carried out as a next generation system of 3GPP system! / In EUTRAN (Evolved UTRAN), real-time voice data is transmitted as a voice packet even in a radio section. In addition to real-time (RT) data such as voice packets, user data includes non-real-time (NRT) data such as e-mail data, Web data, and download data from FTP servers. These NRT data other than voice packets have less severe delay requirement characteristics, and the data size also changes greatly. Download data, image data, etc. from the FTP server increase in size. Real-time voice data, on the other hand, is generally analog voice waveform data that is voice-coded and packetized every 20 to 30 ms, and the size of each voice packet is small. When transmitting voice packets, low transmission delay characteristics and low transmission fluctuation characteristics are required. In addition, when transmitting in the wireless section, the size of the accompanying control signal related to transmission control in the wireless section is relatively larger than the payload size of the voice packet compared to the case of NRT data. Therefore, in order to reduce the overhead caused by control signal transmission and improve the efficiency, voice packet transmission in the radio section is performed at a predetermined period in a pre-assigned time section. It is considered to be based on long-term radio resource advance reservation type transmission using a predetermined subband, and scheduling transmission for each packet is not basically applied.

 FIG. 1 and FIG. 2 are diagrams showing the concept of long-term radio resource advance reservation type transmission.

Figure 1 shows the concept of transmitting voice packets based on the long-term radio resource advance reservation type transmission method from a time domain perspective. As shown in Fig. 1, the time axis is divided into time intervals of a predetermined length, and multiple (6 in the example shown in Fig. 1) audio in each time interval. A packet is sent. Each voice packet is transmitted at regular regular intervals (eg every 20ms). A common modulation scheme and coding rate are optimized for each voice packet transmitted within a certain time interval. In FIG. 1, voice packets to which QPSK and coding rate R = 1Z3 are applied are transmitted in the first time interval. In the next time interval, voice packets to which QPSK and coding rate R = 2Z3 are applied are transmitted. Further, in the next time interval, a voice packet to which QPSK and coding rate R = 1, 3 are applied is transmitted.

[0004] FIG. 2 is a diagram showing a concept of a method of assigning radio resources to voice packets for each terminal from the viewpoint of both the time domain and the frequency domain.

 In Figure 2, the frame for transmitting data has a two-dimensional spread in the time and frequency directions. Voice packets for each terminal are placed in a subframe with a two-dimensional spread. The base station side scheduler determines which terminal the packet is placed in which part of the subframe. In long-term radio resource pre-scheduled transmission, the scheduler does not decide the allocation of radio resources each time for each voice packet, but a voice packet to a certain terminal is sent at certain intervals of time. Scheduled in units of multiple voice packets.

 [0005] Furthermore, the range of modulation schemes and error correction code rate that can be applied to voice packets transmitted in each time interval is limited, and the modulation scheme and code rate that are applied are limited for voice packet transmission. Minimize the amount of control signals transmitted in the radio section as much as possible by relating to the location of the radio resources used in the radio (locations in the radio resources having a two-dimensional spread in the time direction and frequency direction) Is considered. If the radio propagation environment of the terminal changes during voice packet transmission, the applied modulation method / code rate is changed.

[0006] In EUTRAN, hard handover is performed between cells covered by different base stations and in a power handover. Unlike make-before-break type handover such as soft handover in a WCDMA system, hard handover disconnects the line connection with the base station of the cell that was communicating and then moves to the base station of the destination cell. Connected with the line. Compared with the time required for the initial cell search when the terminal connects to the network for the first time, such as by obtaining system information of the base station of the handover destination cell immediately before the handover, the handover can be performed in a short time. Line Forces that can be met During a handover, a loss of user data transmission occurs.

[0007] In the downlink in EUTRAN, many users such as news, weather forecast, regional information, TV broadcasting, etc. can receive simultaneously in addition to normal ptp (Point To Point) type cast data. Multicast / broadcast data (hereinafter referred to as MBMS (Multimedia Broadcast Multicast Service) data) is also transmitted. MBMS data includes data that is transmitted only within a certain base station and data that is transmitted simultaneously by multiple adjacent base stations. Hereinafter, the former is referred to as cell-specific MBMS data, and the latter is referred to as cell common (or cell group common) MBMS data. Cell common MBMS data is transmitted in a wide range of areas (in the maximum case, all areas where one mobile carrier provides services) and narrow areas (for example, administrative divisions at the level of a town or village) There are things that are sent in. In addition, the multicast type of MBMS data may be transmitted only within the cell, in order to improve the utilization efficiency of radio resources, the user power to subscribe to receiving each target MBMS data ^. Yes.

 [0008] In the radio section in EUTRAN, the cell-common MBMS data transmits the same data at the same frequency (subband) at the same time, and multiple target base station powers at the same time. We are thinking of receiving the same data from the stations at the same time and combining them at the radio unit. Basically, MBMS data is transmitted on the assumption that the terminal can be received anywhere in the cell. By adopting a transmission method of simultaneous transmission from multiple base stations and combining on the terminal side, the base station Even if the MBMS data transmission output is not excessively large, terminals near the cell edge can receive sufficient data.

 FIG. 3 is a diagram illustrating a concept of a cell common MBMS data transmission method in the downlink.

Terminal 1 near the boundary between cell 1 of base station 1 and cell 2 of base station 2 receives cell common MBMS data # 1 from base station 1 and cell common MBMS data # 1 from base station 2. To do. In the vicinity of the boundary between cell 2 of base station 2 and cell 3 of base station 3, terminal 2 receives cell common MBMS data # 2 from base station 2 and cell common MBMS data # 2 from base station 3. Receive. Described below in Fig. 3 is an example of radio resource allocation for downlink data within each cell. In cell 1, cell common MBMS data # 1 contains long CP (size Click Prefix) A radio resource is allocated at the right end of the subframe. Here, since the cell common MBMS data # 1 is the data transmitted in common in the cell 1 and the cell 2, the radio resources allocated to the cell common MBMS data # 1 in the cell 2 are also in the cell 1. It is the right end of the long CP subframe. Similarly, in the cell common MBMS data # 2, in the cell 2 and the cell 3, similarly, the radio resource for the central portion of the long CP subframe is allocated.

 [0010] In the downlink of the EUTRAN radio section, the power of the OFDM signal is used. The length of the cyclic prefix (hereinafter referred to as CP, which is the same as Guard Interval) attached to each OFDM signal symbol is Two types of subframes consisting of OFDM symbols with different CP lengths are used. A subframe consisting only of OFDM symbols with long! And CP is a long CP subframe, and a subframe consisting only of OFDM symbols with a short CP is a short CP subframe. Both the long CP subframe and the short CP subframe have the same length. The number of OFDM symbols in the subframe is different. In the EUTRAN downlink, long CP subframes and short CP subframes are time multiplexed on the same RF (Radio Frequency) carrier.

 [0011] FIG. 4 is a diagram illustrating the concept of time multiplexing transmission of a short CP subframe and a long CP subframe in the downlink.

In the case of Fig. 4, cast data and cell-specific MBMS data are allocated to the short CP subframe, and low-latency request such as cell-common MBMS data and voice data is allocated to the long CP subframe. Data is allocated. However, low-delay request data such as audio data is transmitted in all subframes including short CP subframes (not shown in Fig. 4). Same for both short CP subframe and long CP subframe 0.5 ms in length The number of effective symbols in the time direction of the short CP subframe is 7 symbols, while that in the long CP subframe is effective in the time direction There are 6 symbols. This is because the CP length force of the long CP subframe is longer, and the number of effective symbols that can be stored in the subframe of the same length is longer. Changing the length of the CP is a major problem that is received by terminals far away in order to accurately transmit data to terminals near or slightly outside the cell boundary. This is because a CP that is long enough to absorb the propagation delay difference is required.

[0012] Cell common MBMS data transmitted simultaneously from multiple base stations and synthesized at the terminal side uses long CP subframes, and is used for normal multicast data or a cell transmitted only within a certain base station. Short CP subframes are used to transmit specific MBMS data. However, some multicast data and some cell-specific MBMS data may be transmitted even in long CP subframes (not shown in Fig. 4).

FIG. 5 is a diagram showing a concept of downlink transmission scheduling for multicast data including voice packets and cell-specific MBMS data.

 The base station packet scheduler 10 determines how data packets are allocated to each short CP subframe. The knot scheduler is provided with an RTZ voice packet scheduler 11 that schedules real-time (RT) and voice packets and an NRT-cast packet scheduler 12 that schedules non-real-time multicast data. When subframe radio resources are allocated to each data, radio resources are preferentially allocated to real-time voice packets with strict delay requirement characteristics, and the remaining radio resources are allocated to non-realtime data.

[0014] When short-cell CP subframes are being used continuously and cell-wide MBMS data is transmitted using long CP subframes, the use of short CP subframes is temporarily suspended, and long CP subframes are used. The power to use the frame Considering the signal processing at the receiver on the terminal side, the common control signal for notifying the use of the long CP subframe is transmitted on the downlink immediately before the long CP subframe is used. In addition, in long CP subframes that transmit cell-common MBMS data, delay characteristics such as voice data are strictly required, and RT data is also transmitted. Since voice packets are considered to be transmitted according to long-term radio resource advance reservation type transmission, long CP subframes are used when voice packets are transmitted with a predetermined transmission timing pattern. If this happens (when the timing for transmitting a voice packet for a terminal overlaps with the timing using a long CP subframe), it is necessary to transmit the voice packet even in the long CP subframe.

FIG. 6 and FIG. 7 are diagrams illustrating examples of radio resource allocation to the synchronization channel. In EUTRAN, the system bandwidth (the transmission bandwidth that the base station transmits / receives in the wireless zone) is 20 MHz at the maximum, and at the present time, the minimum transmission / reception bandwidth of the terminal is set to 10 MHz. The terminal is required to be capable of receiving a signal with a width of at least 10 MHz. However. Simultaneous decoding of all user data (excluding control signals) contained in a 1 OMHz signal is not required. As system bandwidth, 15 MHz, 10 MHz, 5 MHz, 2.5 MHz, (1.6 MHz, 1.67 MHz) and 1.25 MHz power S are considered to be supported in addition to 20 MHz. In actual cell deployment, base stations with different system bandwidths may be adjacent. Regardless of the system bandwidth or the receivable frequency bandwidth of the terminal, in order to make it easy for the terminal to perform the initial cell search, the synchronization channel and broadcast information signal channel (cell and base station A broadcast information channel that transmits information, etc. (hereinafter referred to as the broadcast channel) is located at the center of the system transmission band (Fig. 6). Also, if the system bandwidth is 20 MHz, the synchronization channel broadcast channel is considered to be divided into 20 MHz widths divided into two 10 MHz widths and placed at the center of each 10 MHz width. (Figure 7). When the synchronization channel and broadcast channel are located at the center of the system bandwidth, when the terminal performs an initial cell search or handover to an adjacent cell, the terminal sets its own reception center frequency to the center frequency of the system bandwidth. After setting, perform synchronization processing to the target cell, and after synchronization is established, change the reception center frequency according to the instructions of the base station as necessary in order to transmit and receive data.

 [0016] When a hard node is over during data transmission in a wireless section, data transmission interruption occurs. During NRT data transmission, there is almost no problem from the user's point of view even if data transmission is interrupted during handover. However, since the interruption of voice packet transmission means a short interruption of the voice call, ideally, it is not possible to interrupt voice packet transmission. Occurs. As a result, the voice conversation is temporarily disturbed. Therefore, it is necessary to perform hard handover in a short time during a voice call using voice packets.

 FIG. 8 and FIG. 9 are diagrams for explaining a problem due to handover during a voice call.

When performing node handover between base stations with different system bandwidths, or terminals When the received signal bandwidth is narrower than the system bandwidth of the base station of the hard handover destination cell, the terminal during voice communication supplements the synchronization channel transmitted on the downlink of the handover destination cell during the handover. After that, in order to synchronize with the handover destination base station and receive the subband used for downlink voice packet transmission in the handover destination cell, Depending on the position of the subband used, it is necessary to switch the reception center frequency. As a result, the voice call interruption time during handover may be longer than the time required for handover.

 FIG. 8 shows a case where the downlink bandwidth is 20 MHz and the reception bandwidth of the receiving terminal is 10 MHz. The synchronization channel is in the middle part of the downlink band, and the voice packet currently received by the receiving terminal is located at the right end of the downlink band in cell # 1, as shown at the top of FIG. And In the case of handover, in (1), reception of the voice packet from cell # 1 is stopped and handover to neighboring cell # 2 is started. In (2), in order to perform handover to cell # 2, the receiving terminal changes the reception center frequency so that the synchronization channel transmitted in cell # 2 can be received. In (3), after the handover to cell # 2 is completed, the voice packet to be transmitted is transmitted using the voice bucket transmission unit (radio resource to which the voice packet to be received is allocated) in adjacent cell # 2. The receiving terminal changes the reception center frequency so that reception is possible. In step (4), reception of the voice packet is resumed.

 FIG. 9 shows a case where the downlink bandwidth is 20 MHz, the reception band of the receiving terminal is 10 MHz, and the synchronization channel is provided at two locations on the frequency axis. In (1), the receiving terminal stops receiving voice packets from cell # 1 and starts handover to neighboring cell # 2. In (2), after the handover to cell # 2 is completed, the reception center frequency of the receiving terminal is changed so that the voice packet transmitted using the voice packet transmitter in adjacent cell # 2 can be received. In (3), voice packet reception is resumed.

 [0020] FIG. 10 is a diagram showing a concept of scheduling for cell-common MBMS data in the downlink.

In order to transmit MBMS data common to cells transmitted from multiple base stations 16 and 17 simultaneously In each of the participating base stations 16 and 17, a long CP subframe is inserted (time multiplexed) between short CP subframes transmitted continuously in the downlink. The cell-common MBMS data transmitted in this long CP subframe is transmitted simultaneously from other participating base stations 16 and 17, and is synthesized by the radio unit on the terminal side. Must be transmitted using the same subband in the long CP subframe transmitted from the same base station at the same timing. For this reason, it is the aGW (access gateway; equivalent to RNC in a WCDMA network) 15 that is positioned higher than the base station that determines which subband in the long CP subframe to transmit the cell-common MBMS data. Become. In addition, RT data such as voice packets is transmitted according to the long-term radio resource advance reservation type transmission, and is also transmitted within the long CP subframe. In transmitting cell common MBMS data, aGW15 instructs all base stations 16 and 17 involved in transmission at which timing and in which subband. The designated base stations 16 and 17 insert a long CP subframe at a designated timing, and transmit the designated cell common MBMS data using the designated subband in the long CP subframe. However, before instructing each base station to transmit cell-common MBMS data, the aGW 15 needs to know information on how much radio resources can be used for transmission in each base station 16 and 17. is there. In some cases, it is also checked whether the terminal that subscribes to the reception of the MBMS data exists in the cell that the base station serves. Therefore, when MBMS data to be transmitted arrives at aGW15 from the network side, each base station is requested to send radio resource information etc. to aGW15. When the radio resource information from each base station 16 and 17 gathers in aGWl 5, the aGW 15 sends the cell common MBMS data transmission timing / subband indication information and the MBMS data to be transmitted to each base station. .

 Figures 11 through 13 illustrate the problems associated with scheduling voice packets and MBMS data.

There may be multiple numbers (types) of MBMS data transmitted using one long CP subframe, and there are user terminals that subscribe to receive each MBMS data in each cell. To do. In such a case, there is no MBMS device with no user terminal to join. May not transmit in that cell. For each MBMS data, the aGW performs efficient scheduling / radio resource allocation based on the information sent from each base station so that it is not transmitted in a certain cell. Each base station performs voice packet transmission with long-term radio resource advance reservation type transmission, and the subbands used for voice packet transmission cannot be shared during MBMS data transmission. Therefore, if each base station uses different subbands for voice packet transmission, it tried to transmit the same cell-common MBMS data from multiple base stations in the same subband at the same timing. At this time, as the number of base stations involved (the base station transmitting this MBMS data) increases, it becomes difficult for the aGW to determine the subband used to transmit this MBMS data. Figure 11 shows an example in which the same cell common MBMS data is transmitted in three adjacent cells. In this example, to simplify the explanation, it is assumed that the downlink transmission band of each cell is divided into three subbands. In each base station shown in FIG. 11, as shown in FIG. 12, subbands for transmitting voice packets in the downlink are fixedly allocated, and sub-bands for transmitting voice packets in three base stations. Assume that the band positions are different from each other. In this assumed situation, when transmitting cell-common MBMS data, the power required to find the same MBMS data transmission location using the same subband position in three base stations is shown in the example shown in Figure 12. I can't find such a place. In this situation, if you want to send the cell common MBMS data, you have to send it from two of the three base stations! /. Do not transmit this MBMS data common to all cells! Even if there is a terminal that wants to receive the MBMS data in the cell of the remaining one base station, especially in a location where the cell edge force is sufficiently distant from that cell. The possibility of disappearing is increased. Another example is shown in Fig. 13. Here, in each of the three base stations, each base station independently assigns a separate voice packet transmission unit, and a specific subband is assigned for voice packet transmission. However, in this case as well, as in the example of Figure 12, it is necessary to find a place where the same MBMS data can be transmitted using the same subband position in the three base stations. Finding a place quickly is not easy. Non-Patent Document 1 describes EUTRAN regulations. Non-Patent Document 1: 3GPP TR25. 814

 Disclosure of the invention

 [0023] One aspect of the object of the present invention is to reduce the time required from the supplement of the synchronization channel at the handover destination to the reception of data with a short allowable delay time at the time of handover.

 [0024] Further, one aspect of the present invention is to facilitate transmission of data from a plurality of base stations at the same band position at the same frame position.

 It is another object of the present invention to provide a wireless communication apparatus having a configuration capable of shortening the instantaneous interruption time of a voice call and effectively transmitting notification data.

 [0025] In the present invention, the wireless communication device transmits the first data by using a predetermined band including a subband for transmitting the synchronization channel with priority over the predetermined band, and the second data Includes a transmission control unit that transmits by using the outside of the predetermined band with priority over the predetermined band, and the first data has a short delay time allowed for the second data. A wireless communication device characterized by this is used.

 [0026] Further, in the present invention, in the radio communication apparatus using the first subband and the second subband as transmission bands, the same subband at the same subframe position and the same for a plurality of subframes A wireless communication control system, comprising: a transmission control unit configured to control data transmitted to a terminal to have a higher rate of transmission in the first subband than in the second subband. Use the device.

 Brief Description of Drawings

[0027] FIG. 1 is a diagram (part 1) illustrating a concept of long-term radio resource advance reservation type transmission.

 FIG. 2 is a diagram (part 2) illustrating the concept of long-term radio resource advance reservation type transmission.

 FIG. 3 is a diagram showing a concept of a cell common MBMS data transmission method in downlink.

FIG. 4 is a diagram illustrating the concept of time-multiplexed transmission of a short CP subframe and a long CP subframe in the downlink.

FIG. 5 is a diagram showing the concept of downlink transmission scheduling for multicast data including voice packets and cell-specific MBMS data. FIG. 6 is a diagram (part 1) illustrating an example of radio resource allocation to a synchronization channel.

 FIG. 7 is a diagram (part 2) illustrating an example of radio resource allocation to a synchronization channel.

圆 8] This is a diagram (part 1) explaining the problem due to handover during a voice call.

[9] This is a diagram (part 2) illustrating the problem caused by handover during a voice call.

 [Fig. 10] A diagram showing a concept of scheduling for cell common MBMS data in the downlink.

 [Fig. 11] A diagram (part 1) illustrating a problem related to scheduling of voice packets and MBMS data.

 [Fig. 12] This is a diagram (part 2) illustrating the problem related to scheduling of voice packets and MBMS data.

 FIG. 13 is a diagram (part 3) illustrating a problem related to scheduling of voice packets and MBMS data.

[14] FIG. 14 illustrates the principle of the present invention (part 1).

[15] FIG. 15 is a diagram (part 2) for explaining the principle of the present invention.

[16] FIG. 16 is a diagram (part 3) for explaining the principle of the present invention.

[17] FIG. 17 is a diagram (part 4) for explaining the principle of the present invention.

[18] FIG. 18 is a diagram (part 1) for explaining the effect of the present invention.

[19] FIG. 19 is a diagram (part 2) for explaining the effect of the present invention.

FIG. 20] is a diagram (part 3) for explaining the effect of the present invention.

FIG. 21 is a diagram (part 1) illustrating an arrangement example of voice packets.

FIG. 22 is a diagram (part 2) illustrating an arrangement example of voice packets.

FIG. 23 is a diagram (part 3) illustrating an example of arrangement of voice packets.

FIG. 24 is a diagram (part 4) illustrating an arrangement example of voice packets.

FIG. 25 is a diagram (part 5) illustrating an example of arrangement of voice packets.

FIG. 26 is a diagram (part 6) illustrating an example of arrangement of voice packets.

FIG. 27 is a diagram (part 7) illustrating an arrangement example of voice packets.

FIG. 28 is a diagram (part 8) illustrating an example of arrangement of voice packets.

[Fig.29] Uplink and downlink are frequency division duplex (FDD: Frequency Division Duplex) FIG. 4 is a diagram illustrating an example of how voice packets are arranged when transmitted / received in ().

 FIG. 30 is a diagram showing a block configuration example of a base station according to the embodiment of the present invention.

 FIG. 31 is a diagram showing a block configuration example of an aGW according to the embodiment of the present invention.

 FIG. 32 is a diagram showing a block configuration example of a (mobile) terminal according to the embodiment of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION

 FIGS. 14 to 17 are diagrams for explaining the principle of the present invention.

 In the present invention, a voice packet (data whose allowable delay time is shorter than that of NRT, etc.) is the same subband as that used for synchronization channel transmission in each cell, or synchronization. Transmit on both adjacent subbands of the subband used for channel transmission. That is, in this example, a subband for transmitting a synchronization channel and an adjacent subband are set as predetermined bands.

 FIG. 14 is a diagram for explaining the first principle of the present invention.

 In FIG. 14, the synchronization channel is transmitted using a synchronization channel transmission subband near the center of the system band (transmission band). However, since the synchronization channel does not use all areas of the subframe in the subframe, radio resources are available in the subband of the subframe in which the synchronization channel is transmitted. Therefore, as a part for transmitting a voice packet (voice packet transmission part), a part of the subband in which the synchronization channel is transmitted and a radio resource in the subframe is empty is allocated.

 [0030] Alternatively, as in the second principle of FIG. 15, as shown in FIG. 14, the subbands that are the same as the subbands of the synchronization channel and the subbands adjacent thereto are not used. A voice packet is transmitted using a band. Here, as with the synchronization channel, the sub-channel may be assigned to another channel that is compatible with the synchronization channel and not used for audio packet transmission. In addition, here, a predetermined band is set up to adjacent subchannels. Preferably, however, the terminal simultaneously receives the width of this frequency band (reception frequency resetting (for example, local frequency change) is not required) ) Possible bandwidth or less.

Further, as shown in FIG. 16, the synchronization check is performed using two subbands in the system band. When a channel is transmitted, voice packets are sent using these two subbands where the synchronization channel is transmitted. Alternatively, as shown in FIG. 17, voice packets are transmitted using two subbands of the synchronization channel and adjacent subbands.

 [0032] As described above, if the synchronization channel and the transmission frequency of the voice packet are kept the same or close to each other, the terminal may change its reception band when the synchronization channel is captured at the time of a hard node over. Since voice calls can be started without any problems, the time required for handover can be shortened, and the time for disconnecting voice calls can be shortened.

 [0033] In this example, data (first data) having a short delay time allowed for NRT or the like such as RT such as voice is transmitted to a predetermined frequency band (a sub-channel including a band for transmitting a synchronization channel). It is also possible to allow force transmission that is transmitted outside the predetermined area. That is, the rate at which the first data (in this case, audio data) is transmitted within a predetermined frequency band is made larger than the rate at which it is transmitted outside the predetermined frequency band (for example, set to 2: 1). As a result, it is possible to increase the possibility that the time required until the first data can be received is shortened in the supplemental power of the synchronization channel.

 In the previous example, this ratio is set to 1: 0. Of course, this setting is preferable in terms of scheduling because the second data can be transmitted outside the predetermined frequency band independently of the transmission status of the first data.

 FIG. 18 to FIG. 20 are diagrams for explaining the operation when multicast data having the same content is transmitted from a plurality of cells (radio base stations).

 The system bandwidth in EUTRAN is the power to support multiple devices such as 20, 15, 10, 5, 2.5, 1.25 MHz, etc. One thing common to these system bandwidths is the synchronization channel and broadcast channel Is transmitted at the center of the system transmission band.

[0036] Even in the long CP subframe, when the voice packet to be transmitted and its transmission form are considered, the voice packet is transmitted in a common location (subband) rather than being transmitted in a different subband in each cell. If so (Figure 18), the aGW can easily determine the timing and subband position for transmitting cell-common MBMS data (Figure 19). In other words, since the transmission subband of the voice packet is known in advance, when trying to distribute the common subband between cells to the cell common MBMS data, as described in the prior art, The fact that radio resources are randomly allocated to voice packets means that a common subband cannot be found between cells. The effect increases as the number of base stations transmitting the same MBMS data increases and the number (type) of cell-common MBMS data transmitted using the long CP subgram transmitted at the same timing increases. To do. Since all cells share the position to transmit the synchronization channel / broadcast channel, it is effective to transmit voice packets in the subband transmitting the synchronization channel, or both adjacent subbands.

Note that the voice packet is shown as an example of data transmitted to the same terminal at the same subframe position, the same subband, and the same terminal for a plurality of subframes.

 In this example, the voice packet is transmitted in the first subband and not transmitted in the second subband. However, the rate of transmission in the first subband is the second subband. It is good also as raising with respect to the rate transmitted within a mode. Since the degree of freedom of channel assignment in the second subband is higher than the degree of freedom of channel assignment in the first subband, data can be received from multiple radio base stations at the same band position. It becomes easy to find the transmission area.

[0038] Preferably, such transmission control is commonly performed in each radio base station of a plurality of radio base station groups that may transmit data at the same band position and at the same frame position. Furthermore, in EUTRAN, base stations having different system bandwidths may be adjacent to each other, and the received signal bandwidth of the terminal may be narrower than the system bandwidth. In such a case, during handover between different base stations, it may be necessary to change the reception center frequency in the terminal in order to receive the synchronization channel transmitted in the downlink of the handover destination cell. Furthermore, depending on the position of the subband for voice packet transmission at the handover destination, the voice call at the handover destination is resumed after synchronization with the base station of the handover destination cell is completed depending on the position of the subband for voice packet transmission at the handover destination. Therefore, the terminal needs to change the reception center frequency again. However, if the subband power for transmitting voice packets is set to the subband that transmits the synchronization channel to all cells or both adjacent subbands, it can be used during a voice call. Since there is no need to change the reception center frequency, It is possible to minimize the talk time (Figure 20). As shown in FIG. 20, in (1), the mobile terminal stops receiving voice packets from cell # 1 and starts handing over to neighboring cell # 2. In (2), after the handover to cell # 2 is completed, the neighboring cell power also resumes receiving voice packets. At this time, if the present invention is used, it is not necessary to change the frequency of the reception band of the receiving terminal that has been received by the synchronization channel. 21 to 28 are diagrams showing examples of voice packet arrangement.

 FIG. 21 shows an example of a voice packet. The synchronization channel is transmitted at the center of the system transmission band. However, the synchronization channel is not necessarily transmitted in every subframe, and is inserted into a subframe and transmitted in a certain time period (eg, every 10 or 20 subframes). Is done. In each subframe, voice packets are transmitted on a subband that is in the same location as the subband on which the synchronization channel is transmitted. In one subband, voice packets for one or more terminals are transmitted. However, voice packets are transmitted within this subband, but non-voice data can also be transmitted within this subband. Non-voice data includes normal NRT user data, broadcast channels, paging signals, and so on. In Fig. 22, a long CP subframe is inserted to transmit cell common MBMS data, and a plurality of cell common MBMS data is inserted in this long CP subframe.

FIG. 23 shows an example in which a voice packet is transmitted using a subband adjacent to the subband of the synchronization channel. The synchronization channel is transmitted at the center of the system transmission band. It is not always transmitted in every subframe, but is inserted into a subframe at a certain time period (eg every 10 or 20 subframes). . In each subframe, a voice packet is transmitted on a subband that is in the same location as the subband to which the synchronization channel is transmitted and a subband that is in the same location as both adjacent subbands of the subband in which the synchronization channel is transmitted. An audio bucket for one or more terminals is transmitted in one subband. However, although voice packets are transmitted within this subband, non-voice data can also be transmitted within this subband. Non-voice data includes normal NRT user data, broadcast channels, paging signals, and so on. FIG. 24 shows a state in which a long CP subframe is inserted to transmit cell-common MBMS data, and a plurality of cell-common MBMS data is inserted in the long CP subframe. FIG. 25 shows an example of voice packet arrangement when two synchronization channels are arranged in the system band. In the subframe where the synchronization channel is transmitted, the synchronization channel is transmitted in two subbands within the system transmission band. The synchronization channel is not necessarily transmitted in every subframe, but is transmitted in a subframe at a fixed time period (eg, every 10 or 20 subframes). In each subframe, a voice packet is transmitted in a subband that is in the same location as the subband in which the synchronization channel is transmitted. In one subband, voice packets for one or more terminals are transmitted. However, although voice packets are transmitted within this subband, non-voice data can also be transmitted within this subband. Non-voice data includes normal NRT user data, broadcast channels, paging signals, and so on. FIG. 26 shows a state in which a long CP subframe is inserted to transmit cell common MBMS data, and a plurality of cell common MBMS data is inserted in the long CP subframe.

 FIG. 27 and FIG. 28 are diagrams showing an example of how voice packets are arranged when uplink and downlink are alternately transmitted / received by time division duplex (TDD).

 In FIG. 27, uplink subframes and downlink subframes are sent alternately. The synchronization channel is transmitted at regular intervals in the central part of the system band of the downlink short CP subframe. In the case of the time division duplex shown in FIG. 27, since the printer and downlink subframe share the same system band, voice packets are transmitted and received using the subband of the same frequency as the synchronization channel. In one subband, voice packets for one or more terminals are transmitted. Although not explicitly shown in FIG. 27, voice packets are transmitted within this subband, but non-voice data can also be transmitted within this subband. Non-voice data includes normal NRT user data, broadcast channels, paging signals, and so on. FIG. 28 shows a state in which a long CP subframe is inserted in order to transmit cell common MBMS data, and a plurality of cell common MBMS data is inserted in the long CP subframe.

[0044] FIG. 29 is a diagram illustrating an example of how voice packets are arranged when uplink and downlink are transmitted / received by frequency division duplex (FDD). In FIG. 29, the uplink subframe and the downlink subframe are transmitted using a system band at a frequency separated from each other by a duplex frequency. The synchronization channel is transmitted at regular intervals in the center of the system band of the downlink short CP subframe. In the case of frequency division duplex (FDD) in Fig. 29, the location where the uplink voice packet is transmitted is the subband where the synchronization channel is transmitted in the downlink and the subband separated by the duplex frequency. In the downlink, when the synchronization channel is transmitted at the center of the system band, the location where the voice packet is transmitted on the uplink is the center of the uplink transmission system band. A single or multiple terminal voice packets are transmitted in one subband. Transmission of voice packets is performed within this subband, but non-voice data can also be transmitted within this subband. Non-voice data includes normal NRT user data, broadcast channels, paging signals, and so on. Although not explicitly shown in FIG. 29, a long CP subframe is inserted in the downlink to transmit the cell common MBMS data, and a plurality of cell common MBMS data is inserted in the long CP subframe. Transmission is also possible.

 FIG. 30 is a diagram showing a block configuration example of the base station according to the embodiment of the present invention.

 In FIG. 30, the short CP subframe generation unit 12 and the long CP subframe generation unit 14 are configured so that data fits in the size of the channel coding unit (for example, turbo code unit), the interleaving unit, and the radio frame, respectively. The rate matching unit is included. Further, the modulation unit 16 includes an IFFT circuit for generating an OFDM signal. The data resending function unit such as HARQ (Hybrid Automatic Repeat reQuest) is included in the scheduler 11.

[0046] The radio resource management unit 10 is notified of the cell-wide MBMS data transmission advance notice for the aGW power, and the radio resource use unit 10 reports the radio resource usage status to the aGW. The radio resource management unit 10 notifies the scheduler 11 how to allocate radio resources to the MBMS. Cell common MBMS data radio resource allocation information, voice data, multicast data, and cell-specific MBMS data are input from the aGW to the scheduler 11 functioning as a transmission control unit. Scheduler 11 is a long CP subframe transmission notice Signal, audio data, multicast data, and cell-specific MBMS data are input to the short CP subframe generator 12. Further, the scheduler 11 inputs the audio data cast data to the long CP subframe generation unit 14. In addition, the scheduler 11 sends the radio resources allocated to the cell common MBMS data to the cell common MBMS data processing unit Z data buffer 13. Cell common MBMS data is input to the cell common MBMS data processing unit / data buffer 13 from the aGW. Cell common MBMS data is input from the cell common MBMS data processing unit Z data buffer 13 to the long CP subframe generation unit 14. In addition, the long CP subframe generation unit 14 receives a pilot signal, a control signal, and the like. The short CP subframe generation unit 12 receives a synchronization channel such as a pilot signal and a control signal.

 [0047] The short CP subframe and the long CP subframe are input from the short CP subframe generation unit 12 and the long CP subframe generation unit 14 to the time multiplexing unit 15, respectively. The time multiplexing unit 15 time-multiplexes the subframe according to the time multiplexing control signal from the scheduler 11 and sends the subframe to the transmission antenna via the modulation unit 16 and the radio unit 17.

 Note that the time division multiplexed data from 12 and 14 is input to the modulation unit 16. At this time, data corresponding to each subchannel is input in order. For example, as shown in FIG. 14, data corresponding to each subchannel corresponding to the left band of the synchronization channel transmission subband, data corresponding to the subchannel corresponding to the synchronization channel transmission subband (synchronization signal, audio) Packet) and the data power corresponding to each sub-channel corresponding to the right band of the synchronization channel transmission sub-band is input to the IFFT processing unit of the modulation unit 16 in the order of the data power, and the frequency domain signal is converted into a time domain signal, Given to part 17.

 FIG. 31 is a block configuration diagram of an aGW according to the embodiment of the present invention.

The cell common MBMS data is stored in the cell common MBMS data buffer 20, and is sent to the base stations # 1 to #N of the cell common MBMS data according to an instruction from the cell common MBMS data transmission control unit 21. Cell common MBMS data transmission control unit 21 sends cell common MBMS data radio resource allocation information and cell common MBMS data transmission notice to base stations # 1 to #N. Also, the radio resource usage report is notified from each of the base stations # 1 to #N to the cell MBMS data transmission control unit 21. FIG. 32 is a block diagram of a (mobile) terminal according to the embodiment of the present invention.

 Voice packets, multicast data, and control signals are coded by channel coding sections 25 to 27 and multiplexed by multiplexing section 28, respectively. The multiplexed signal and the pilot signal are mapped to a physical channel in the physical channel generation unit 29 and sent to the transmission antenna via the modulation unit 30 and the radio unit 31.

Claims

The scope of the claims  [1] In a wireless communication device that transmits first data and second data,  The first data is transmitted using a predetermined band including a subband for transmitting a synchronization channel with priority over the predetermined band, and the second data is transmitted outside the predetermined band. A transmission control unit that transmits by giving priority to a fixed bandwidth;  And the first data has a short allowable delay time with respect to the second data. [2] In a wireless communication apparatus using the first subband and the second subband as transmission bands,  For data transmitted to the same terminal at the same subframe position for a plurality of subframes, the rate of transmission in the first subband is higher than that in the second subband. A transmission control unit for controlling to  A wireless communication apparatus comprising: [3] A wireless communication device that performs communication by dividing a transmission frequency band into a plurality of subbands and arranging a synchronization channel in the subbands.  Voice packet transmitting means for transmitting voice packets using fixed subbands around the subband where the synchronization channel exists  A wireless communication apparatus comprising: 4. The radio communication apparatus according to claim 3, wherein the voice packet is transmitted using a subband having the same frequency as the synchronization channel. 5. The radio communication apparatus according to claim 3, wherein the voice packet is transmitted using a subband having the same frequency as that of the synchronization channel and subbands on both sides of the subband. [6] The signal band of the uplink signal is applied to a communication system that is different from the frequency of the signal band of the downlink signal by a predetermined frequency.  4. The radio packet according to claim 3, wherein the voice packet transmitted in the uplink is transmitted using a subband in an uplink signal band in which a subband of a downlink synchronization channel differs by the predetermined frequency. Communication device. [7] The wireless communication device transmits and receives uplink signals and downlink signals in a time division manner. The wireless communication apparatus according to claim 3, wherein the wireless communication apparatus is applied to a communication system. 8. The radio communication apparatus according to claim 3, wherein the processing of the voice packet transmitting means is performed in a cell of a base station. 9. The radio communication device according to claim 3, wherein the voice packet is arranged around a synchronization channel in a time direction. [10] Cell power of the first base station When the terminal is handed over to the cell of the second base station, a voice call is received by receiving a voice packet in a subband of a frequency around the received synchronization channel. 4. The wireless communication apparatus according to claim 3, wherein: [11] When broadcast data broadcast to multiple cells covered by multiple radio base stations is allocated to subbands, it is allocated to subbands excluding the subband in which the voice packet is transmitted. The wireless communication device according to claim 3. [12] A base station that realizes the function according to any one of claims 3 to 11. [13] A terminal that implements the uplink signal transmission function according to claim 6.  [14] In a control method of a wireless communication device that performs communication by dividing a transmission frequency band into a plurality of subbands and arranging a synchronization channel in the subbands,  Transmit voice packets using subbands around the subband where the synchronization channel exists  A method for controlling a wireless communication apparatus.