WO2017107177A1 - Signal transmission method and apparatus based on end-to-end communication - Google Patents

Abstract

Disclosed is a signal transmission method based on end-to-end (D2D) communication. The method comprises: a first terminal receiving first state information sent by each second terminal of at least one second terminal, wherein the first state information comprises a movement speed of the second terminal sending the first state information; the first terminal determining second state information, wherein the second state information comprises a movement speed of the first terminal; the first terminal determining relative speeds of the first terminal and the at least one second terminal according to the first state information about the at least one second terminal and the second state information; the first terminal determining an emission power of a D2D signal of the first terminal according to the relative speeds of the first terminal and the at least one second terminal; and the first terminal sending the D2D signal at the emission power. According to the embodiments of the present invention, the accuracy rate of transmitting a signal between terminals is improved.

Description

Signal transmission method and device based on end-to-end communication Technical field

Embodiments of the present invention relate to the field of communications, and in particular, to a signal transmission method and apparatus based on end-to-end communication.

Background technique

Device to Device (D2D) communication is a technology in which a terminal directly communicates with a terminal. FIG. 1 is a schematic diagram of a communication method based on D2D communication technology. It can be seen from FIG. 1 that D2D communication can directly perform communication and data transmission between a terminal and a terminal, and there is no need for relaying of a base station. The base station can assist the communication between the terminals through control signaling, for example, performing resource configuration, scheduling, coordination, and the like.

The D2D technology was discussed in the 3rd Generation Partnership Project (3GPP), and the Long Term Evolution (LTE) version 12 (Release 12, Rel. 12) specifies the D2D technology as follows. The terminal uses the form of broadcast for data transmission. The terminal that enters the D2D connection mode has two working modes: Discovery and Communication. The discovery is a periodic broadcast information of the terminal, so that other terminals can discover the terminal through information detection. Communication refers to the direct transfer of data between two terminals.

2 shows a transmission mechanism based on a D2D communication system. In the transmission mechanism shown in FIG. 2, the terminal can receive the authorization information (D2D-SA-grant) of the scheduling allocation information of the D2D system transmitted by the base station and the D2D system. The data transfer authorization information (D2D-Data-grant) enters the D2D connection mode. In the process of communicating with other terminals, the terminal adopts a mechanism for scheduling allocation information (SA) and data (Data) transmission, as shown in FIG. 2 . The SA is used to indicate information such as time-frequency resource information, modulation and coding scheme (MCS) information, frequency hopping indication, Timing Advance (TA), and receiving group ID of data transmitted by the terminal. The time-frequency resource information of the data is in the form of a Time Resource Pattern (T-RPT), indicating a subframe occupied by the transmission data. The data refers to the service data transmitted by the terminal, and the terminal can transmit the data at the time-frequency resource location indicated by the SA and in the format indicated by the SA.

In recent years, D2D technology applied to the Internet of Vehicles has received more and more attention. Terminals in the Internet of Vehicles can adopt the communication mode of communication in the D2D system, through vehicle communication or vehicle and roadside units. Inter-communication can improve the safety and reliability of road traffic and improve traffic efficiency. In the Internet of Vehicles, in order to ensure safe driving of vehicles, periodic interaction status information is required between vehicles and vehicles. The status information includes information such as the position, speed and moving direction of the vehicle, and the vehicle passes through a single hop (ie, does not pass through the base station). , broadcast its own status information to surrounding vehicles.

In the prior art, in a scenario of a long-term evolution LTE-V system, a terminal entering a D2D connection mode works on a dedicated carrier, and the terminal can determine a transmission power required to transmit a signal according to a moving speed of the vehicle, when the vehicle The higher the moving speed, the higher the transmission power determined by the terminal.

However, in the above solution, when the vehicle where the terminal is located moves at a different speed from other vehicles, there may be a safety hazard. For example, FIG. 3 shows a schematic diagram of a scenario of terminal communication based on D2D communication. In the scenario shown in FIG. 3, the car A travels toward the vehicle B at a speed of 30 km/h, and the vehicle B moves at a speed of 100 km/h. . Vehicle A can obtain the transmission power of the signal according to the current speed table, but because the current moving speed of the vehicle A is slow, the signal transmission power obtained by the look-up table is lower. At this time, if the distance between the vehicle B and the vehicle A is far. The transmission power of the signal determined by the vehicle A may not be sufficient for the vehicle B to correctly receive, until the distance between the vehicle B and the vehicle A is less than the driving safety distance of the vehicle B, the vehicle B may correctly receive the signal sent by the vehicle A. There may be a security risk.

Summary of the invention

It is an object of the present application to provide an improved scheme for determining the transmit power of a D2D signal to improve the accuracy of the transmission of signals between the terminal and the terminal.

In a first aspect, the present application provides a signal transmission method based on end-to-end communication, the method comprising: receiving, by a first terminal, first state information sent by each second terminal in at least one second terminal, the first state The information includes a moving speed of the second terminal that sends the first state information; the first terminal determines second state information, where the second state information includes a moving speed of the first terminal; and the first terminal is configured according to the at least one second Determining, by the first state information of the terminal and the second state information, a relative speed of the first terminal and the at least one second terminal; the first terminal determining from a relative speed of the first terminal and the at least one second terminal a maximum relative speed; the first terminal determines a transmit power of the D2D signal of the first terminal according to the maximum relative speed; and the first terminal transmits the D2D signal by using the transmit power.

The first terminal selects a maximum relative speed from the relative speeds between itself and other terminals, and determines a transmit power of the D2D signal according to the maximum relative speed, which is only through the terminal itself in the prior art. Compared with the method for determining the transmission power of the communication signal, the embodiment of the present invention avoids the terminal moving at a lower speed, and the determined transmission power of the D2D signal is lower, resulting in a shorter transmission distance of the D2D signal, and other terminals may The problem of the D2D signal cannot be correctly received, and the accuracy of transmitting signals between the terminal and the terminal is improved.

With reference to the first aspect, in a first possible implementation manner of the first aspect, the first terminal determines the transmit power of the D2D signal according to the maximum relative speed, including: the first terminal according to the maximum relative speed, The transmit power of the D2D signal is determined by a preset correspondence between the maximum relative speed and the transmit power.

With reference to the foregoing possible implementation manner of the first aspect, in a second possible implementation manner of the first aspect, the first state information of each second terminal of the at least one second terminal further includes the second The current location of the terminal, the second state information further includes a current location of the first terminal, and the first terminal determines the transmit power of the D2D signal according to the maximum relative speed, including: the first terminal according to the maximum relative speed Determining a transmission distance required by the D2D signal; the first terminal determines a current distance between the first terminal and the at least one second terminal according to a current location of the first terminal and a current location of the at least one second terminal; When the at least one second terminal has a target second terminal that is greater than or equal to the transmission distance of the first terminal, the first terminal selects a reference terminal from the target second terminal, where the reference terminal is the a second terminal in the target second terminal that is closest to the first terminal; the first terminal is based on a transmit power of the D2D signal of the reference terminal, the first terminal D2D received power of the reference signal terminal, the first terminal and a threshold D2D demodulated signal, determining the transmit power of the first terminal D2D signal.

With reference to the foregoing possible implementation manner of the first aspect, in a third possible implementation manner of the first aspect, the first terminal, according to the transmit power of the D2D signal of the reference terminal, the D2D of the first terminal to the reference terminal The received power of the signal and the demodulation threshold of the D2D signal by the first terminal, determining the transmit power of the D2D signal of the first terminal, including: the first terminal according to Pt _opt = Pt _k - (Pr _{k -} Pth), Determining a transmit power of the D2D signal of the first terminal, where Pt _opt represents a transmit power of the D2D signal of the first terminal, Pt _k represents a transmit power of the D2D signal of the reference terminal, and Pr _k represents the first terminal Referring to the received power of the D2D signal of the terminal, Pth represents the demodulation threshold of the D2D signal of the first terminal, and the demodulation threshold is set in the range of 0 dB-5 dB.

The first terminal determines the transmit power of the reference terminal and the received power of the reference terminal by adjusting the scheduling allocation information sent by the reference terminal, and adjusts the transmit power of the reference terminal, which can be more accurately estimated. It refers to the path loss when the terminal transmits signals to itself, so that the transmission power of the first terminal determines its own.

With reference to the foregoing possible implementation manner of the first aspect, in a fourth possible implementation manner of the foregoing aspect, the method further includes: when the target second terminal does not exist in the at least one second terminal, the first The terminal determines, according to the maximum relative speed, an initial transmit power of the D2D signal by a preset correspondence between the relative speed and the transmit power; the first terminal transmits the D2D signal by using the initial transmit power, and continuously increases the D2D signal. The transmit power until the transmit power reaches the maximum transmit power, or until the first terminal receives the D2D signal sent by the reference terminal, the current distance between the reference terminal and the first terminal is greater than or equal to the transmission distance; the first terminal The current transmit power is the transmit power of the D2D signal of the first terminal.

With reference to the foregoing possible implementation manner of the first aspect, in a fifth possible implementation manner of the first aspect, the method further includes: receiving, by the first terminal, path loss information sent by the base station, where the path loss information is used to indicate D2D Determining the true path loss of the signal at the location where the first terminal is located; determining, by the first terminal, the transmit power of the D2D signal according to the maximum relative speed, including: the first terminal adopting a preset according to the maximum relative speed a mapping relationship between the relative speed and the transmit power, determining an initial transmit power of the D2D signal; the first terminal determining a transmit power of the D2D signal according to the path loss information and the initial transmit power.

The first terminal adjusts its own transmit power by the difference between the path loss in the actual environment and the path loss under the preset condition. Based on the characteristics of different path loss in different propagation environments, the first transmit power can be determined more accurately.

With reference to the foregoing possible implementation manner of the first aspect, in a sixth possible implementation manner of the foregoing aspect, the mapping relationship table is determined based on a correspondence between a relative speed between the terminals and a preset path loss, The path loss information is a difference between the real path loss and the preset path loss, and the first terminal determines the transmit power of the D2D signal according to the path loss information and the initial transmit power, including: the first terminal Determining the transmit power of the signal according to Pt _opt =P _init +ΔPL, where Pt _opt represents the transmit power of the D2D signal, P _init represents the initial transmit power, and ΔPL represents the true path loss and the preset path loss. The difference between the two.

With reference to the foregoing possible implementation manner of the first aspect, in a seventh possible implementation manner of the first aspect, the first terminal determines the signal according to the maximum relative speed, and the corresponding relationship between the relative speed and the sending frequency. Sending a frequency; the first terminal transmitting the D2D signal by using the transmit power, comprising: the first terminal transmitting the D2D signal by using the transmit power and the transmit frequency.

With reference to the foregoing possible implementation manner of the first aspect, in the eighth possible implementation manner of the first aspect, the scheduling information of the D2D signal carries the transmit power information.

In a second aspect, the present application provides a signal transmission method based on end-to-end communication, the method comprising: receiving, by a first terminal, first state information sent by each second terminal in at least one second terminal, the first state The information includes a moving speed of the second terminal that sends the first state information; the first terminal determines second state information, where the second state information includes a moving speed of the first terminal; and the first terminal is configured according to the at least one Determining a relative speed of the first terminal and the at least one second terminal by using the first state information of the second terminal and the second state information; the relative speed of the first terminal from the first terminal and the at least one second terminal Determining a maximum relative speed; the first terminal determines a transmission frequency of the D2D signal of the first terminal according to the maximum relative speed.

In the embodiment of the present invention, the first terminal may determine the transmission frequency of the D2D signal by using the maximum relative speed. When the relative speed between the terminal and the terminal is larger, the transmission frequency of the D2D signal is higher, and the D2D signal is improved. The possibility that other terminals receive correctly.

In a third aspect, the present application provides a signal transmission apparatus based on end-to-end communication. The device includes: a receiving module, configured to receive first state information sent by each second terminal of the at least one second terminal, where the first state information includes a second terminal that sends the first state information And a determining module, configured to determine second state information, where the second state information includes a moving speed of the first terminal, and is further configured to use the first state information of the at least one second terminal received by the first receiving module Determining, by the second state information, a relative speed of the first terminal and the at least one second terminal; and determining to determine a maximum relative speed from a relative speed of the first terminal and the at least one second terminal; And determining, according to the maximum relative speed, a transmit power of the D2D signal of the first terminal; and sending, by the sending module, the D2D signal by using the transmit power determined by the determining module.

The first terminal selects a maximum relative speed from the relative speeds between itself and other terminals, and determines a transmit power of the D2D signal according to the maximum relative speed, and a method for determining a transmit power of the communication signal only by the moving speed of the terminal itself in the prior art. In contrast, the embodiment of the present invention avoids the terminal moving at a lower speed, and the determined transmit power of the D2D signal is lower, which causes the transmission distance of the D2D signal to be closer, and other terminals may not correctly receive the D2D signal, thereby improving The accuracy of the signal transmitted between the terminal and the terminal.

With reference to the third aspect, in a first possible implementation manner of the third aspect, the determining module is further configured to: use the preset maximum relative speed and the transmit power according to the maximum relative speed It should be determined that the transmit power of the D2D signal is determined.

With reference to the foregoing possible implementation manner of the third aspect, in a second possible implementation manner of the third aspect, the first state information of each second terminal of the at least one second terminal further includes the second The current location of the terminal, the second state information further includes a current location of the first terminal, and the determining module is further configured to: determine, according to the maximum relative speed, a transmission distance required by the D2D signal; according to the first terminal a current location and a current location of the at least one second terminal, determining a current distance between the first terminal and the at least one second terminal; and a current distance from the first terminal in the at least one second terminal is greater than or equal to the current distance When the target second terminal transmits the distance, the reference terminal is selected from the target second terminal, where the reference terminal is the second terminal in the target second terminal that is closest to the first terminal; according to the D2D signal of the reference terminal Transmitting power, the received power of the D2D signal of the reference terminal by the first terminal, and the demodulation threshold of the D2D signal of the first terminal, determining the first terminal D2D transmit power signal.

With reference to the foregoing possible implementation manner of the third aspect, in a third possible implementation manner of the third aspect, the determining module is further configured to: determine, according to Pt _opt =Pt _k -(Pr _k -Pth) The transmit power of the D2D signal of a terminal, where Pt _opt represents the transmit power of the D2D signal of the first terminal, Pt _k represents the transmit power of the D2D signal of the reference terminal, and Pr _k represents the first terminal to the reference terminal The received power of the D2D signal, Pth represents the demodulation threshold of the first terminal to the D2D signal, and the demodulation threshold is set in the range of 0 dB-5 dB.

With the above-mentioned possible implementation manner of the third aspect, in a fourth possible implementation manner of the third aspect, the determining module is further configured to: when the target second terminal does not exist in the at least one second terminal, Determining an initial transmit power of the D2D signal by a preset maximum relative speed and a transmit power; the sending module is further configured to: send the D2D signal by using the initial transmit power, and continuously increase the The transmit power of the D2D signal until the transmit power reaches the maximum transmit power, or until the first terminal receives the D2D signal sent by the reference terminal, and the current distance between the reference terminal and the first terminal is greater than or equal to the transmission distance; The determining module is further configured to determine a transmit power of the D2D signal of the first terminal that is currently transmitting power.

With reference to the foregoing possible implementation manner of the third aspect, in a fifth possible implementation manner of the third aspect, the receiving module is further configured to receive path loss information sent by the base station, where the path loss information is used to indicate that the D2D signal is The real path loss propagated by the location of the first terminal; the determining module is further configured to: determine, according to the maximum relative speed, a preliminary transmit power of the D2D signal by using a preset mapping relationship between the maximum relative speed and the transmit power According to the path loss information and the initial transmission power, The transmit power of the D2D signal is determined.

With reference to the foregoing possible implementation manner of the third aspect, in a sixth possible implementation manner of the third aspect, the mapping relationship table is determined based on a correspondence between a relative speed between the terminals and a preset path loss, The path loss information is a difference between the real path loss and the preset path loss, and the determining module is further configured to: determine the transmit power of the signal according to Pt _opt =P _init +ΔPL, where Pt _opt Indicates the transmit power of the D2D signal, P _init represents the initial transmit power, and ΔPL represents the difference between the true path loss and the preset path loss.

With reference to the foregoing possible implementation manner of the third aspect, in a seventh possible implementation manner of the third aspect, the device further includes: determining, according to the maximum relative speed, and the correspondence between the maximum relative speed and the sending frequency, The sending frequency of the signal; the sending module is further configured to: send the D2D signal by using the transmitting power and the sending frequency.

With reference to the foregoing possible implementation manner of the third aspect, in an eighth possible implementation manner of the third aspect, the transmit power information is carried in the scheduling allocation information of the D2D signal.

In a fourth aspect, the present application provides a processor located on a first terminal, the processor for executing an instruction, and when the instruction is executed, the processor performs the method in the first aspect.

In a fifth aspect, the present application provides a computer readable storage medium for storing program code for determining transmit power, the program code comprising instructions for performing the method of the first aspect.

In some implementations, the first terminal receives the first state information sent by each of the at least one second terminal, where the first terminal receives each second of the at least one second terminal. Data information sent by the terminal, the data information carrying the first status information.

In some implementations, the transmit power information of the first terminal is carried in the scheduling allocation information of the D2D signal.

In some implementations, the first terminal and the second terminal may be in-vehicle terminals, and the moving speed may be the traveling speed of the vehicle where the terminal is located.

DRAWINGS

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings to be used in the embodiments of the present invention will be briefly described below. It is obvious that the drawings described below are only some embodiments of the present invention, Those skilled in the art can also obtain other drawings based on these drawings without paying any creative work.

FIG. 1 is a schematic diagram of a communication method based on D2D communication technology.

2 is a transmission mechanism based on a D2D communication system.

3 is a schematic diagram of a scenario of terminal communication based on D2D communication.

4 is a schematic diagram of an application scenario of a transmission signal based on D2D communication.

FIG. 5 is a schematic flowchart of a signal transmission method based on D2D communication according to an embodiment of the present invention.

FIG. 6 is a schematic flowchart of a signal transmission method based on D2D communication according to another embodiment of the present invention.

FIG. 7 is a schematic block diagram of a signal transmission apparatus based on D2D communication according to an embodiment of the present invention.

FIG. 8 is a schematic block diagram of a signal transmission apparatus based on D2D communication according to another embodiment of the present invention.

detailed description

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are a part of the embodiments of the present invention, but not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

It should be understood that the technical solution of the present invention can be applied to various communication systems, for example, Global System of Mobile communication (GSM), Code Division Multiple Access (CDMA) system, and wideband code division. Wideband Code Division Multiple Access Wireless (WCDMA), General Packet Radio Service (GPRS), Long Term Evolution (LTE), and the like.

It should also be understood that a mobile terminal (Mobile Terminal), which may also be called a user equipment (UE), a mobile user equipment, etc., may be connected to one or more via a radio access network (eg, Radio Access Network, RAN). The core network communicates, such as a mobile phone (or "cellular" phone) and a computer with a mobile terminal, for example, a portable, pocket, handheld, computer built-in or in-vehicle mobile device with wireless access Network exchange language and / or data.

The base station may be a base station (BTS, Base Transceiver Station) in GSM or CDMA, or may be a base station (Node B) in WCDMA, or may be an evolved base station (eNB or e-NodeB, evolutional Node B) in LTE. The present invention is not limited, but for convenience of description, the following The example is described by taking Node B as an example.

FIG. 4 is a schematic diagram of an application scenario of a transmission signal of a D2D communication. In the application scenario shown in FIG. 4, the terminal uses a mobile phone as an example for description, and the present invention does not specifically limit this. In the scenario shown in FIG. 4, UE1 and UE2 are terminals that access the D2D system and are in communication working mode, and UE3 is a terminal that participates in cellular communication. As can be seen from FIG. 4, the distance ratio between UE1 and the base station The distance between UE3 and the base station is closer. When UE1 and UE3 transmit data on the same subframe (that is, UE1 and UE3 simultaneously perform data transmission) and occupy adjacent frequency domain resources, if UE1 does not control transmit power, the signal is transmitted at the maximum transmit power, so that the base station can The received signal energy of the UE1 is relatively large, and the UE3 receives a signal energy that is weakly transmitted by the UE3 because the distance from the base station is far. Considering that UE1 and UE3 occupy adjacent frequency domain resources, the out-of-band leakage may cause the user's signal to leak into the adjacent frequency domain resources. Thus, the signal of UE1 may flood the signal of UE3, and the base station may send to UE3. The data reception failed, resulting in system performance degradation. Therefore, it is necessary to control the transmission power of the terminal accessing the D2D system.

For the above-mentioned problem that may cause interference, a method of controlling the transmission power of a terminal accessing the D2D system is described in detail below.

FIG. 5 is a schematic flowchart of a signal transmission method based on D2D communication according to an embodiment of the present invention. The method shown in Figure 5 includes:

S510. The first terminal receives first state information that is sent by each second terminal of the at least one second terminal, where the first state information includes a moving speed of the second terminal that sends the first state information.

Specifically, in S510, the foregoing first state information includes a moving speed of each second terminal, and may refer to the first state information including a moving speed of each second terminal and a moving direction of each second terminal, in other words. In other words, the moving speed of each of the second terminals can be expressed in the form of a vector.

S520. The first terminal determines second state information, where the second state information includes a moving speed of the first terminal.

Specifically, in S520, the foregoing second state information includes a moving speed of the first terminal, and may refer to the second state information including a moving speed of the first terminal and a moving direction of the first terminal, in other words, the first terminal. The speed of movement can be expressed in the form of a vector.

S530. The first terminal determines, according to the first state information of the at least one second terminal and the second state information, a relative speed of the first terminal and the at least one second terminal.

S540. The first terminal determines a maximum relative speed from a relative speed of the first terminal and the at least one second terminal.

S550. The first terminal determines, according to the maximum relative speed, a transmit power of the D2D signal of the first terminal.

It should be understood that, in S550, the transmit power may be the lowest transmit power corresponding to the relative speed, or may be any power between the lowest transmit power and the maximum transmit power corresponding to the terminal, which is not specifically limited in the present invention.

S560. The first terminal sends the D2D signal with the transmit power.

Specifically, in S560, the D2D signal may be a D2D signal sent by the first terminal to the second terminal in a communication working mode in the D2D system, and the D2D signal may carry scheduling allocation information, and/or data information.

The terminal selects the maximum relative speed from the relative speed between itself and other terminals, and determines the transmit power of the D2D signal according to the maximum relative speed, which is compared with the method for determining the transmit power of the D2D signal only by the moving speed of the terminal itself in the prior art. For example, the embodiment of the present invention avoids the terminal moving at a lower speed, and the determined transmission power of the D2D signal is lower, which causes the transmission distance of the D2D signal to be closer, and other terminals may not correctly receive the D2D signal, thereby improving the problem. The accuracy of the signal transmitted between the terminal and the terminal.

Optionally, as an embodiment, the determining, by the first terminal, the transmit power of the D2D signal according to the maximum relative speed, including: the first terminal, according to the maximum relative speed, by using a preset maximum relative speed and the transmitting The corresponding relationship of the power determines the transmit power of the D2D signal.

It should be understood that the corresponding relationship between the preset relative speed and the transmission power may be a relative speed-transmit power table, see Table 1. The relative speed-transmitting power table may be one speed range corresponding to one transmitting power, or one speed corresponding to one transmitting power, which is not specifically limited in the present invention.

Table 1 Corresponding relationship between relative speed and transmission power

It should also be understood that the relative speed-transmit power table described above can be formulated by a base station. The base station determines the relative speed-transmitted power table by calculating a path loss in the preset scenario and a relative speed between the terminals in a preset transmission signal scenario (eg, a highway or a city environment, etc.).

It should also be understood that the above relative speed-transmit power table may be transmitted by the base station to the first terminal through any of a broadcast channel, an RRC configuration channel, and a control channel. The relative speed-transmitting power table may also be recorded by the first terminal device in a pre-stored manner.

Optionally, as an embodiment, the first state information of each second terminal of the at least one second terminal further includes a current location of each second terminal, where the second state information further includes the first terminal Determining the transmit power of the D2D signal according to the maximum relative speed, the first terminal determining, according to the maximum relative speed, a transmission distance required by the D2D signal; the first terminal is configured according to the current terminal Determining a current distance between the first terminal and the at least one second terminal, and determining, by the current location of the first terminal, a current distance of the first terminal and the at least one second terminal; When the distance is greater than or equal to the target second terminal, the first terminal selects a reference terminal from the target second terminal, where the reference terminal is the second terminal in the target second terminal that is closest to the first terminal. The first terminal according to the transmit power of the D2D signal of the reference terminal, the received power of the D2D signal of the first terminal to the reference terminal, and the first terminal D2D demodulation threshold signal, determining a transmit power of the first signal D2D terminal.

Specifically, in the transmission distance required by the first terminal to determine the D2D signal according to the maximum relative speed, the transmission distance required for the D2D signal may be determined based on a formula D=TTC×V, where D represents a required value of the D2D signal. Transmission distance, V represents relative speed, TTC (Time to Collision) represents user response time, that is, the maximum relative speed is substituted into the above formula, and the obtained transmission distance of the D2D signal can refer to the first terminal and the second The safety distance at which the first terminal and the second terminal do not collide when the relative speed between the terminals is the maximum relative speed.

It should be understood that the demodulation threshold of the D2D signal by the first terminal may be determined according to the error rate of the first terminal.

The first terminal determines that the transmit power of the D2D signal of the reference terminal is obtained by receiving the scheduling allocation information sent by the reference terminal, where the scheduling allocation information carries the reference terminal The transmit power information of the D2D signal, the transmit power information may be the real transmit power of the reference terminal, or may be the speed grade or power level information of the reference terminal, and the first terminal may determine the transmit of the reference terminal according to the speed grade or the power level information. The power is not specifically limited in the present invention.

It should be understood that the transmit power information of the D2D signal carried in the scheduling allocation information sent by the reference terminal may be the transmit power information of the scheduling allocation information, or may be the transmit power information of the data information corresponding to the scheduling information, and the present invention is This is not specifically limited.

The first terminal determines the received power of the D2D signal of the reference terminal, and performs energy detection on the D2D signal sent by the reference terminal to obtain the received power of the D2D signal of the reference terminal.

It should be understood that, in determining the transmission distance required for the D2D signal, the first terminal may be determined according to the maximum relative speed described above, or may be determined according to any speed value in the speed interval to which the maximum relative speed belongs. For example, the first terminal may determine the transmission distance required for the D2D signal according to the average speed of the speed interval to which the maximum relative speed belongs.

Optionally, as an embodiment, the first terminal according to the transmit power of the D2D signal of the reference terminal, the received power of the D2D signal of the reference terminal by the first terminal, and the demodulation of the D2D signal by the first terminal Determining, determining the transmit power of the D2D signal of the first terminal, comprising: determining, by the first terminal, the transmit power of the D2D signal of the first terminal according to Pt _opt = Pt _k - (Pr _{k -} Pth), where Pt _opt Denoting the transmit power of the D2D of the first terminal, Pt _k represents the transmit power of the D2D signal of the reference terminal, Pr _k represents the received power of the D2D signal of the first terminal to the reference terminal, and Pth represents the first terminal to the D2D The demodulation threshold of the signal, the demodulation threshold is set in the range of 0dB-5dB.

Optionally, as an embodiment, the method further includes: when the target second terminal does not exist in the at least one second terminal, the first terminal passes the preset relative speed and the transmit power according to the maximum relative speed. Corresponding relationship, determining an initial transmit power of the D2D signal; the first terminal transmitting the D2D signal with the initial transmit power, and continuously increasing a transmit power of the D2D signal until the transmit power reaches a maximum transmit power, or until the The first terminal receives the D2D signal sent by the reference terminal, and the current distance between the reference terminal and the first terminal is greater than or equal to the transmission distance; the first terminal uses the current transmit power as the transmit power of the D2D signal of the first terminal.

Specifically, the first terminal may increase the transmit power of the D2D signal according to Pt _opt =P _init +ΔP, where Pt _opt represents the transmit power of the D2D signal, P _init represents the initial transmit power, and ΔP represents a fixed Power step size. The first terminal may perform the iteration according to the above formula, obtain the transmit power, and send the D2D signal according to the transmit power obtained after the iteration, until the transmit power reaches the maximum transmit power, and the first terminal may use the maximum transmit power. Transmitting the D2D signal; or until the first terminal receives the D2D signal sent by the reference terminal, the first terminal may send the D2D signal at the transmit power obtained by the current iteration.

It should be understood that the maximum transmit power may be the maximum transmit power corresponding to the maximum relative speed, or may be the maximum transmit power allowed by the first terminal, which is not specifically limited in the present invention.

Optionally, as an embodiment, the method further includes: receiving, by the first terminal, path loss information sent by the base station, where the path loss information is used to indicate a real path loss of the D2D signal propagating at the location of the first terminal; Determining, by the first terminal, the transmit power of the D2D signal according to the maximum relative speed, the first terminal determining, according to the maximum relative speed, a mapping relationship between the preset relative speed and the transmit power to determine an initial of the D2D signal. Transmit power; the first terminal determines the transmit power of the D2D signal according to the path loss information and the initial transmit power.

Optionally, as an embodiment, the mapping relationship table is determined according to a correspondence between a relative speed between the terminals and a preset path loss, where the path loss information is the real path loss and the preset path loss. Between the difference, the first terminal determines the transmit power of the D2D signal according to the path loss information and the initial transmit power, including: the first terminal determines the transmit power of the signal according to Pt _opt =P _init +ΔPL Where Pt _opt represents the transmit power of the D2D signal, P _init represents the initial transmit power, and ΔPL represents the difference between the true path loss and the preset path loss.

It should be understood that the difference between the actual path loss and the preset path loss may be a positive value, may be a negative value, or may be 0, which is not specifically limited in the present invention.

Optionally, as an embodiment, the method further includes: determining, by the first terminal, a sending frequency of the D2D signal according to the maximum relative speed and a correspondence between the relative speed and the sending frequency; The power transmitting the D2D signal comprises: the first terminal transmitting the D2D signal with the transmit power and the transmit frequency.

It should be understood that the correspondence between the above relative speed and the transmission frequency may be a relative speed-transmission frequency table, see Table 2. The relative speed-transmitting frequency table may include a speed level, that is, a relative speed corresponds to a speed range, each speed range corresponds to one speed level, and each speed level corresponds to one transmission frequency, and the present invention applies the above speed and transmission. The form of the correspondence relationship of frequencies is not specifically limited.

Table 2 Relative speed-transmission frequency correspondence

Speed grade 1 2 3 4 Relative speed km/h >288 144-288 72-144 <72 Transmission frequency Hz 10 5 2 1

The first terminal determines the transmission frequency of the signal according to the maximum relative speed based on the maximum relative speed determination signal. When the relative speed between the terminal and the terminal is larger, the transmission frequency of the signal is higher. Increased the likelihood that the signal will be received correctly by other terminals.

Optionally, as an embodiment, the transmit power information of the first terminal is carried in the scheduling allocation information of the D2D signal.

It should be understood that the foregoing transmit power information may be a transmit power value of the first terminal, or a transmit power level, and the transmit power information may also be a minimum power corresponding to the transmit power level, or a maximum power, etc., which is not limited by the present invention. .

FIG. 6 shows a schematic flow chart of a signal transmission method based on D2D communication according to another embodiment of the present invention. The method shown in Figure 6 includes:

S610. The first terminal receives first state information that is sent by each second terminal of the at least one second terminal, where the first state information includes a moving speed of the second terminal that sends the first state information.

S620. The first terminal determines second state information, where the second state information includes a moving speed of the first terminal.

S630. The first terminal determines, according to the first state information of the at least one second terminal and the second state information, a relative speed of the first terminal and the at least one second terminal.

S640, the first terminal determines a maximum relative speed from a relative speed of the first terminal and the at least one second terminal;

S650. The first terminal determines, according to the maximum relative speed, a transmission frequency of the D2D signal of the first terminal.

In the embodiment of the present invention, the first terminal may determine the transmission frequency of the D2D signal by using the maximum relative speed. When the relative speed between the terminal and the terminal is larger, the transmission frequency of the D2D signal is higher, and the D2D signal is improved. The possibility that other terminals receive correctly.

The signal transmission method based on the end-to-end system will be described in detail above with reference to FIGS. 1 through 6, and the signal transmission apparatus based on the end-to-end system will be described below with reference to FIGS. 7 and 8. It should be understood that the apparatus shown in FIG. 7 and FIG. 8 can implement the various steps in the method shown in FIG. 5 and FIG. 6 , and for brevity, no further details are provided herein.

FIG. 7 shows a schematic block diagram of a D2D communication based signal transmission apparatus according to an embodiment of the present invention. The apparatus shown in FIG. 7 includes a receiving module 710, a determining module 720, and a transmitting module 730.

a receiving module 710, configured to receive first state information sent by each second terminal of the at least one second terminal, where the first state information includes a mobile terminal that sends the first state information speed;

a determining module 720, configured to determine second state information, where the second state information includes a moving speed of the first terminal;

And determining, according to the first state information of the at least one second terminal that is received by the first receiving module, and the second state information, determining a relative speed of the first terminal and the at least one second terminal;

And determining, according to a relative speed of the first terminal and the at least one second terminal, determining a transmit power of the D2D signal of the first terminal;

The sending module 730 sends the D2D signal with the transmit power determined by the determining module.

The terminal of the embodiment of the present invention determines the maximum transmit power from the relative speed between itself and other terminals, and determines the transmit power of the D2D signal according to the maximum relative speed, and determines the D2D signal only by the moving speed of the terminal itself in the prior art. Compared with the method for transmitting power, the embodiment of the present invention avoids the terminal moving at a lower speed, and the determined transmission power of the D2D signal is lower, so that the transmission distance of the D2D signal is relatively close, and other terminals may not correctly receive the D2D signal. The problem is to improve the accuracy of the signal transmitted between the terminal and the terminal.

FIG. 8 shows a schematic block diagram of a signal transmission apparatus based on D2D communication according to another embodiment of the present invention. It should be understood that the function of the transmitting module in the embodiment of the modular device may be implemented by the transmitter in the embodiment, and the function of the determining module in the embodiment of the modular device may be implemented by the processor of the embodiment. It should be understood that the technical solutions provided by the embodiments of the present invention have been described in detail in the foregoing embodiments, and details are not described herein again. The device shown in Figure 8 includes:

a memory 810, configured to store a program;

The processor 820 is configured to execute a program, when the program is executed, the processor 720 is specifically configured to receive first state information sent by each second terminal of the at least one second terminal, where the first state information includes sending a moving speed of the second terminal of the first state information; determining second state information, where the second state information includes a moving speed of the first terminal; according to the first state information of the at least one second terminal, and the second State information, determining a relative speed of the first terminal and the at least one second terminal; determining a maximum relative speed from a relative speed of the first terminal and the at least one second terminal; determining the first according to the maximum relative speed The transmit power of the D2D signal of the terminal;

The transmitter 830 is configured to transmit the D2D signal by using the transmit power determined by the processor 820.

The terminal of the embodiment of the present invention selects the maximum relative speed from the relative speed between itself and other terminals, and determines the transmit power of the D2D signal according to the maximum relative speed, and determines the D2D signal only by the moving speed of the terminal itself in the prior art. Compared with the method for transmitting power, the embodiment of the present invention avoids the terminal moving at a lower speed, and the determined transmission power of the D2D signal is lower, so that the transmission distance of the D2D signal is relatively close, and other terminals may not correctly receive the D2D signal. The problem is to improve the accuracy of the signal transmitted between the terminal and the terminal.

It should be understood that in the embodiment of the present invention, "B corresponding to A" means that B is associated with A, and B can be determined according to A. However, it should also be understood that determining B from A does not mean that B is only determined based on A, and that B can also be determined based on A and/or other information.

It should be understood that the term "and/or" herein is merely an association relationship describing an associated object, indicating that there may be three relationships, for example, A and/or B, which may indicate that A exists separately, and A and B exist simultaneously. There are three cases of B alone. In addition, the character "/" in this article generally indicates that the contextual object is an "or" relationship.

It should be understood that, in various embodiments of the present invention, the size of the sequence numbers of the above processes does not mean the order of execution, and the order of execution of each process should be determined by its function and internal logic, and should not be directed to the embodiments of the present invention. The implementation process constitutes any limitation.

Those of ordinary skill in the art will appreciate that the elements and algorithm steps of the various examples described in connection with the embodiments disclosed herein can be implemented in electronic hardware or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the solution. A person skilled in the art can use different methods for implementing the described functions for each particular application, but such implementation should not be considered to be beyond the scope of the present invention.

A person skilled in the art can clearly understand that for the convenience and brevity of the description, the specific working process of the system, the device and the unit described above can refer to the corresponding process in the foregoing method embodiment, and details are not described herein again.

In the several embodiments provided by the present application, it should be understood that the disclosed systems, devices, and methods may be implemented in other manners. For example, the device embodiments described above are merely illustrative. For example, the division of the unit is only a logical function division. In actual implementation, there may be another division manner, for example, multiple units or components may be combined or Can be integrated into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed may be indirect coupling through some interface, device or unit. Or a communication connection, which may be in electrical, mechanical or other form.

The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

The functions may be stored in a computer readable storage medium if implemented in the form of a software functional unit and sold or used as a standalone product. Based on such understanding, the technical solution of the present invention, which is essential or contributes to the prior art, or a part of the technical solution, may be embodied in the form of a software product, which is stored in a storage medium, including The instructions are used to cause a computer device (which may be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods described in various embodiments of the present invention. The foregoing storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, and the like, which can store program codes. .

The above is only a specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily think of changes or substitutions within the technical scope of the present invention. It should be covered by the scope of the present invention. Therefore, the scope of the invention should be determined by the scope of the appended claims.

Claims (18)

A signal transmission method based on end-to-end D2D communication, comprising: The first terminal receives first state information that is sent by each of the at least one second terminal, where the first state information includes a moving speed of the second terminal that sends the first state information; Determining, by the first terminal, second state information, where the second state information includes a moving speed of the first terminal; Determining, by the first terminal, a relative speed of the first terminal and the at least one second terminal according to the first state information of the at least one second terminal and the second state information; Determining, by the first terminal, a maximum relative speed from a relative speed of the first terminal and the at least one second terminal; Determining, by the first terminal, a transmit power of the D2D signal of the first terminal according to the maximum relative speed; The first terminal transmits the D2D signal at the transmit power. The method of claim 1, wherein the determining, by the first terminal, the transmit power of the D2D signal according to the maximum relative speed comprises: Determining, by the first terminal, the transmit power of the D2D signal by using a preset correspondence between a maximum relative speed and a transmit power according to the maximum relative speed. The method of claim 1, wherein the first state information of each of the at least one second terminal further comprises a current location of each of the second terminals, the second state The information also includes a current location of the first terminal, Determining, by the first terminal, the transmit power of the D2D signal according to the maximum relative speed, including: Determining, by the first terminal, a transmission distance required by the D2D signal according to the maximum relative speed; Determining, by the first terminal, a current distance between the first terminal and the at least one second terminal according to a current location of the first terminal and a current location of the at least one second terminal; When the at least one second terminal has a target second terminal that is greater than or equal to the transmission distance of the first terminal, the first terminal selects a reference terminal from the target second terminal, The reference terminal is a second terminal in the target second terminal that is closest to the first terminal; The first terminal according to the transmit power of the D2D signal of the reference terminal, the first terminal And determining, by the terminal, the received power of the D2D signal of the reference terminal, and the demodulation threshold of the D2D signal by the first terminal, determining a transmit power of the D2D signal of the first terminal. The method according to claim 3, wherein the first terminal receives the power of the D2D signal of the reference terminal according to the transmit power of the D2D signal of the reference terminal, and the Demodulating a threshold of the D2D signal by the first terminal, determining a transmit power of the D2D signal of the first terminal, including: Determining, by the first terminal, a transmit power of the D2D signal of the first terminal according to Pt _opt = Pt _k - (Pr _{k -} Pth), where Pt _opt represents a transmit power of the D2D signal of the first terminal, Pt _k represents the transmission power of the D2D signal of the reference terminal, Pr _k represents the received power of the D2D signal of the reference terminal by the first terminal, and Pth represents the demodulation threshold of the D2D signal of the first terminal, The demodulation threshold is set in the range of 0dB-5dB. The method of claim 3 or 4, wherein the method further comprises: When the target second terminal does not exist in the at least one second terminal, the first terminal determines, according to the maximum relative speed, a correspondence between the preset relative speed and the transmit power to determine the D2D signal. Initial transmission power Transmitting, by the first terminal, the D2D signal by using the initial transmit power, and continuously increasing a transmit power of the D2D signal until the transmit power reaches a maximum transmit power, or until the first terminal receives the reference terminal The transmitted D2D signal, the current distance between the reference terminal and the first terminal is greater than or equal to the transmission distance; The first terminal determines that the current transmit power is the transmit power of the D2D signal of the first terminal. The method of claim 1 wherein the method further comprises: The first terminal receives the path loss information sent by the base station, where the path loss information is used to indicate the real path loss of the D2D signal that is transmitted at the location of the first terminal; Determining, by the first terminal, the transmit power of the D2D signal according to the maximum relative speed, including: Determining, by the first terminal, an initial transmit power of the D2D signal by using a preset mapping relationship between a maximum relative speed and a transmit power according to the maximum relative speed; The first terminal determines a transmit power of the D2D signal according to the path loss information and the initial transmit power. The method of claim 6 wherein said mapping relationship table is based on a final Determining a correspondence between a relative speed between the ends and a preset path loss, where the path loss information is a difference between the real path loss and the preset path loss, Determining, by the first terminal, the transmit power of the D2D signal according to the path loss information and the initial transmit power, including: Determining, by the first terminal, the transmit power of the signal according to Pt _opt =P _init +ΔPL, wherein Pt _opt represents a transmit power of the D2D signal, P _init represents the initial transmit power, and ΔPL represents the The difference between the true path loss and the preset path loss. The method of any of claims 1-7, wherein the method further comprises: Determining, by the first terminal, a transmission frequency of the signal according to the maximum relative speed and a correspondence between the relative speed and the transmission frequency; Transmitting, by the first terminal, the D2D signal by using the transmit power, including: The first terminal transmits the D2D signal with the transmit power and the transmit frequency. The method according to any one of claims 1 to 8, wherein the transmission allocation information is carried in the scheduling allocation information of the D2D signal. A signal transmission device based on end-to-end D2D communication, comprising: a receiving module, the first receiving module is configured to receive first state information sent by each second terminal of the at least one second terminal, where the first state information includes a second terminal that sends the first state information Moving speed; a determining module, configured to determine second state information, where the second state information includes a moving speed of the first terminal; And determining, according to the first state information of the at least one second terminal received by the first receiving module, and the second state information, determining a relative speed of the first terminal and the at least one second terminal. ; Also for determining a maximum relative speed from a relative speed of the first terminal and the at least one second terminal; And a method for determining, according to the maximum relative speed, a transmit power of a D2D signal of the first terminal; And a sending module, where the D2D signal is sent by using the transmit power determined by the determining module. The device according to claim 10, wherein the determining module is further configured to: And determining, according to the maximum relative speed, the transmit power of the D2D signal by a preset correspondence between a maximum relative speed and a transmit power. The apparatus according to claim 11, wherein the first state information of each of the at least one second terminal further comprises a current location of each of the second terminals, the second state The information also includes a current location of the first terminal, The determining module is further specifically configured to: Determining a transmission distance required for the D2D signal according to the maximum relative speed; Determining a current distance between the first terminal and the at least one second terminal according to a current location of the first terminal and a current location of the at least one second terminal; When the at least one second terminal has a target second terminal that is greater than or equal to the transmission distance of the first terminal, selecting a reference terminal from the target second terminal, where the reference terminal is a second terminal in the target second terminal that is closest to the first terminal; Determining the received power of the D2D signal of the reference terminal, the received power of the D2D signal of the reference terminal by the first terminal, and the demodulation threshold of the D2D signal by the first terminal, determining the first terminal The transmit power of the D2D signal. The device according to claim 12, wherein the determining module is further configured to: Determining, according to Pt _opt = Pt _k - (Pr _{k -} Pth), a transmit power of the D2D signal of the first terminal, where Pt _opt represents a transmit power of the D2D signal of the first terminal, and Pt _k represents the reference The transmit power of the D2D signal of the terminal, Pr _k represents the received power of the D2D signal of the first terminal to the reference terminal, and Pth represents the demodulation threshold of the D2D signal of the first terminal, and the demodulation threshold is set at In the range of 0dB-5dB. The device according to claim 12 or 13, wherein the determining module is further configured to: when the target second terminal does not exist in the at least one second terminal, pass the maximum relative speed Determining a relationship between a maximum relative speed and a transmit power, and determining an initial transmit power of the D2D signal; The sending module is further configured to: send the D2D signal by using the initial transmit power, and continuously increase a transmit power of the D2D signal until the transmit power reaches a maximum transmit power, or until the first terminal receives a D2D signal sent by the reference terminal, where a current distance between the reference terminal and the first terminal is greater than or equal to the transmission distance; The determining module is further configured to determine that the current transmit power is a D2D signal of the first terminal Transmit power. The device according to claim 10, wherein the receiving module is further configured to receive path loss information sent by the base station, where the path loss information is used to indicate that the D2D signal is transmitted at a location where the first terminal is located. True road loss; The determining module is further specifically configured to: Determining, according to the maximum relative speed, an initial transmit power of the D2D signal by a preset mapping relationship between a maximum relative speed and a transmit power; And determining a transmit power of the D2D signal according to the path loss information and the initial transmit power. The device according to claim 15, wherein the mapping relationship table is determined based on a correspondence between a relative speed between the terminals and a preset path loss, and the path loss information is the real path loss. And the difference between the preset path loss, The determining module is further specifically configured to: Determining the transmit power of the signal according to Pt _opt =P _init +ΔPL, where Pt _opt represents the transmit power of the D2D signal, P _init represents the initial transmit power, and ΔPL represents the true path loss and The difference between the preset path losses. The device of any of claims 10-16, wherein the device further comprises: Determining a transmission frequency of the signal according to the maximum relative speed and a correspondence between a maximum relative speed and the transmission frequency; The sending module is further specifically configured to: Transmitting the D2D signal at the transmit power and the transmit frequency. The apparatus according to any one of claims 10-17, wherein the transmission allocation information is carried in the scheduling allocation information of the D2D signal.

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