Transmitter, receiver, and method of vehicle-mounted communication system

Abstract

The present invention belongs to the field of vehicle-mounted communication technology and relates to a transmitting end, a receiving end, a vehicle-mounted communication system and a method thereof; a multi-antenna base station uses generalized spatial modulation technology to construct a mapping relationship between index bits and reflection array element groups and transmission array element groups, modulates the index bits and information bits to obtain a target signal to be transmitted, and transmits the target signal to be transmitted and a carrier signal; an omnidirectional intelligent metasurface transmits the target signal to be transmitted to a demodulator, modulates and encodes the carrier signal based on a reflection phase offset control signal and a transmission phase offset control signal generated by a controller, generates and transmits a reflection signal matrix and a transmission signal matrix; the demodulator demodulates the target signal to be transmitted to obtain index bits and information bits; the controller divides multiple array element groups of the omnidirectional intelligent metasurface into a reflection array element group set and a transmission array element group set based on the index bits, and generates a reflection phase offset control signal and a transmission phase offset control signal based on the information bits.

Description

Technical Field

[0001] The present invention relates to the field of vehicle-mounted communication technology, and in particular to a transmitting end, a receiving end, a vehicle-mounted communication system, and a method thereof. Background Art

[0002] In-vehicle communications within the sixth-generation mobile network (6G) technology aims to achieve more efficient and stable wireless communication between vehicles and the outside world. In recent years, specialized in-vehicle communications technologies have been developed, including vehicle-to-everything (V2X), dedicated short-range communication (DSRC), and cellular vehicle-to-everything (C-V2X). However, with increasing urbanization, the complex and dense urban environment poses severe challenges to the stability and coverage of in-vehicle communications. Improving signal coverage and communication efficiency in in-vehicle communications is a pressing issue.

[0003] The document with DOI number 10.1109 / JCOM.2020.9876543 proposes an in-vehicle communication system and method, which applies a reconfigurable intelligence surface (RIS) to in-vehicle communications. The intelligent metasurface is used to reflect the signal emitted by the transmitting vehicle, thereby transmitting the signal to the receiving vehicle, and improving the signal coverage by regulating the signal transmission path. However, since the intelligent metasurface can only reflect signals, it still cannot effectively cover areas that are not within the range of the reflection beam, resulting in limitations in its coverage range. Moreover, since the intelligent metasurface can only reflect signals in a fixed pattern, it cannot select the appropriate signal modulation method and coding rate according to the channel quality, resulting in poor adaptability of the reflected signal to channel changes, thereby reducing communication efficiency. The document with DOI number 10.1109 / TVT.2020.2984484 proposes deploying multiple antennas on the transmitting vehicle and the receiving vehicle to form multiple signal transmission channels, and using spatial modulation technology to dynamically select and activate the target antenna for signal transmission according to the communication environment and transmission requirements, thereby optimizing the signal transmission path and quality and improving the performance and reliability of the system. However, in spatial modulation technology, signal transmission depends on the spatial position information of the antenna. If multiple antennas transmit signals at the same time, factors such as the mutual coupling effect between antennas will cause the receiving vehicle to be unable to distinguish the signals transmitted by different antennas. Therefore, in this communication method, only one antenna can be activated at a time to avoid signal interference. Not only can it not form a high-gain directional beam through the collaborative work of multiple antennas to increase the signal coverage range, but it also cannot fully utilize the spatial reuse of spectrum resources, resulting in low frequency utilization and communication efficiency.

[0004] In summary, the existing vehicle communication system has the problem of being unable to effectively improve signal coverage and communication efficiency. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the problem that the vehicle-mounted communication system in the prior art cannot effectively improve the signal coverage and communication efficiency.

[0006] To solve the above technical problems, the present invention provides a transmitting end of a vehicle-mounted communication system, comprising:

[0007] A multi-antenna base station is configured to construct a mapping relationship between index bits and the reflective array elements and the transmissive array elements of the omnidirectional smart metasurface using generalized spatial modulation technology based on a preset number of reflective array elements and a preset number of transmissive array elements of the omnidirectional smart metasurface; modulate the index bits and information bits to obtain a target signal to be transmitted, and transmit the target signal to be transmitted and a carrier signal;

[0008] An omnidirectional intelligent metasurface, comprising a plurality of array element groups, configured to receive the target signal to be transmitted and the carrier signal, and transmit the target signal to be transmitted to a demodulator; based on a reflection phase offset control signal and a transmission phase offset control signal generated by a controller, modulate and encode the carrier signal using a reflection array element group set and a transmission array element group set to generate a reflection signal matrix and a transmission signal matrix, and transmit the reflection signal matrix and the transmission signal matrix:

[0009] A demodulator, connected to the omnidirectional intelligent metasurface, for demodulating the target signal to be transmitted transmitted by the omnidirectional intelligent metasurface to obtain an index bit and an information bit in the target signal to be transmitted;

[0010] a controller connected to the demodulator and the omnidirectional smart metasurface, configured to divide a plurality of array element groups in the omnidirectional smart metasurface into a reflection array element group set and a transmission array element group set based on the index bits, and generate a reflection phase offset control signal and a transmission phase offset control signal based on the phase angle information in the information bits.

[0011] Preferably, the number of bits of the target signal to be transmitted is:

[0012] ,

[0013] in, Indicates the number of bits of the target signal to be transmitted; Indicates the number of index bits in the target signal to be transmitted; Indicates the number of information bits in the target signal to be transmitted;

[0014] The calculation formula for the number of index bits is:

[0015] ,

[0016] ,

[0017] in, Represents the sum of the preset number of reflection array element groups and the preset number of transmission array element groups; Indicates the preset number of reflection array elements; Indicates the preset number of transmission array elements; Indicates rounding down;

[0018] The calculation formula for the number of information bits is:

[0019] ,

[0020] in, Indicates the modulation order.

[0021] Preferably, the omnidirectional smart metasurface includes 4 array element groups, each of which includes N / 4 array elements; wherein N represents the number of array elements of the omnidirectional smart metasurface;

[0022] The reflection array element group set and the transmission array element group set each include two array element groups.

[0023] Preferably, based on the reflection phase offset control signal and the transmission phase offset control signal generated by the controller, modulating and encoding the carrier signal using the reflection array element group set and the transmission array element group set to generate the reflection signal matrix and the transmission signal matrix includes:

[0024] The reflection array element set generates a reflected M-ary phase shift keying signal based on the reflected phase offset control signal; generates a reflected M-ary phase shift keying signal encoding matrix based on the reflected M-ary phase shift keying signal using an Alamouti encoding technique, and generates a reflected signal matrix based on the reflected M-ary phase shift keying signal encoding matrix;

[0025] The transmission array element set generates a transmission M-ary phase shift keying signal based on the transmission phase offset control signal; uses Alamouti coding technology to generate a transmission M-ary phase shift keying signal encoding matrix based on the transmission M-ary phase shift keying signal, and generates a transmission signal matrix based on the transmission M-ary phase shift keying signal encoding matrix.

[0026] Preferably, the reflected M-ary phase shift keying signal encoding matrix is ​​expressed as:

[0027] ,

[0028] in, represents the reflected M-ary phase shift keying signal encoding matrix; Represents the M-ary phase-shift keying signal generated by the first array element group in the reflection array element group set; represents an M-ary phase-shift keying signal generated by the second array element group in the reflection array element group set; indicates conjugation;

[0029] The reflected signal matrix is ​​expressed as:

[0030] ,

[0031] ,

[0032] ,

[0033] in, represents the reflected signal matrix; The channel matrix representing the set of reflection array elements; Represents the channel fading coefficient of the first array element group in the reflection array element group set; Indicates the first array element in the reflection array element set. The channel fading coefficient of each array element; Indicates the number of array elements in the first array element group in the reflection array element group set; Represents the channel fading coefficient of the second array element group in the reflection array element group set; Indicates the first element in the second array element set of the reflection array element set The channel fading coefficient of each array element; Indicates the number of array elements in the second array element group of the reflection array element set; The noise matrix representing the set of reflection array elements; Represents the noise of the first array element in the reflection array element set; represents the noise of the second array element in the reflection array element set;

[0034] The transmission M-ary phase shift keying signal encoding matrix is ​​expressed as:

[0035] ,

[0036] in, represents the transmission M-ary phase shift keying signal encoding matrix; represents an M-ary phase-shift keying signal generated by the first array element group in the transmission array element group set; represents an M-ary phase-shift keying signal generated by the second array element group in the transmission array element group set;

[0037] The transmission signal matrix is ​​expressed as:

[0038] ,

[0039] ,

[0040] ,

[0041] in, represents the transmission signal matrix; The channel matrix representing the set of transmitted array elements; represents the channel fading coefficient of the first array element group in the transmission array element group set; Indicates the first array element in the transmission array element set. The channel fading coefficient of each array element; Indicates the number of array elements in the first array element group in the transmission array element group set; represents the channel fading coefficient of the second array element group in the transmission array element group set; Indicates the first The channel fading coefficient of each array element; Indicates the number of array elements in the second array element group of the transmission array element group set; The noise matrix representing the set of transmission array elements; represents the noise of the first array element group in the transmission array element group set; represents the noise of the second array element in the transmission array element set.

[0042] The present invention also provides a receiving end of a vehicle-mounted communication system, comprising:

[0043] A reflection receiving end is configured to receive the reflection signal matrix sent by the transmitting end of the above-mentioned vehicle communication system using maximum ratio combining diversity reception technology to obtain a reflection receiving signal, and normalize the power of the reflection receiving signal; detect the normalized reflection receiving signal using a maximum likelihood detection algorithm to obtain an index bit in the reflection signal matrix; and decode the normalized reflection receiving signal using a soft demodulation algorithm to obtain information bits in the reflection signal matrix;

[0044] The transmission receiving end is used to receive the transmission signal matrix sent by the transmitting end of the above-mentioned vehicle communication system using maximum ratio combining diversity reception technology to obtain a transmission receiving signal and normalize the power of the transmission receiving signal; detect the normalized transmission receiving signal using a maximum likelihood detection algorithm to obtain index bits in the transmission signal matrix; and decode the normalized transmission receiving signal using a soft demodulation algorithm to obtain information bits in the transmission signal matrix.

[0045] Preferably, the normalized reflected received signal is expressed as:

[0046] ,

[0047] ,

[0048] in, represents the first reflected received signal after normalization; represents the second reflected received signal after normalization; Represents the channel fading coefficient of the first array element group in the reflection array element group set; Represents the channel fading coefficient of the second array element group in the reflection array element group set; Represents the received signal of the first array element group in the reflection array element group set; Represents the received signal of the second array element group in the reflection array element group set; Represents the noise of the first array element in the reflection array element set; represents the noise of the second array element in the reflection array element set; indicates conjugation;

[0049] The normalized transmission reception signal is expressed as:

[0050] ,

[0051] ,

[0052] in, represents the first transmission receiving signal after normalization; represents the second transmission receiving signal after normalization; represents the channel fading coefficient of the first array element group in the transmission array element group set; represents the channel fading coefficient of the second array element group in the transmission array element group set; represents the received signal of the first array element group in the transmission array element group set; represents the received signal of the second array element group in the transmission array element group set; represents the noise of the first array element group in the transmission array element group set; represents the noise of the second array element in the transmission array element set.

[0053] Preferably, the index bits in the reflection signal matrix are expressed as:

[0054] ,

[0055] in, Represents the estimated value of the reflection array tuple set index; Indicates the phase of the first array element in the reflection array element set; Represents the phase estimate of the first array element in the reflection array element set; Represents the phase of the second array element group in the reflection array element group set; Represents the phase estimate of the second array element group in the reflection array element group set; Represents the reflection array tuple set index; Indicates the variable value when the objective function reaches the minimum value; represents the reflected signal matrix; represents the reflected M-ary phase shift keying signal encoding matrix; The channel matrix representing the set of reflection array elements; represents the vector norm;

[0056] The index bits in the transmission signal matrix are expressed as:

[0057] ,

[0058] in, represents the estimated value of the transmission array tuple set index; Represents the phase of the first array element group in the transmission array element group set; represents the phase estimate of the first array element group in the transmission array element group set; represents the phase of the second array element group in the transmission array element group set; represents the phase estimate of the second array element group in the transmission array element group set; Represents the transmission array tuple set index; represents the transmission signal matrix; represents the transmission M-ary phase shift keying signal encoding matrix; The channel matrix representing the set of transmitted array elements.

[0059] The present invention also provides a vehicle-mounted communication system, comprising:

[0060] The transmitting end of the above-mentioned vehicle communication system;

[0061] The receiving end of the above-mentioned vehicle communication system.

[0062] The present invention also provides a vehicle-mounted communication method, which is applied to the above-mentioned vehicle-mounted communication system, comprising:

[0063] The multi-antenna base station uses generalized spatial modulation technology to construct a mapping relationship between index bits and the reflective array elements and the transmissive array elements of the omnidirectional smart metasurface based on the preset number of reflective array elements and the preset number of transmissive array elements of the omnidirectional smart metasurface; and modulates the index bits and information bits to obtain the target signal to be transmitted, and transmits the target signal to be transmitted and the carrier signal;

[0064] The omnidirectional intelligent metasurface receives the target signal to be transmitted and the carrier signal, and transmits the target signal to be transmitted to a demodulator;

[0065] The demodulator demodulates the target signal to be transmitted transmitted by the omnidirectional intelligent metasurface to obtain an index bit and an information bit in the target signal to be transmitted;

[0066] The controller divides the plurality of array element groups in the omnidirectional smart metasurface into a reflection array element group set and a transmission array element group set based on the index bit, and generates a reflection phase offset control signal and a transmission phase offset control signal based on the phase angle information in the information bit;

[0067] The omnidirectional intelligent metasurface modulates and encodes the carrier signal using a reflection array element set and a transmission array element set based on the reflection phase offset control signal and the transmission phase offset control signal generated by the controller, generates a reflection signal matrix and a transmission signal matrix, and transmits the reflection signal matrix and the transmission signal matrix:

[0068] The reflection receiving end receives the reflection signal matrix using a maximum ratio combining diversity receiving technology to obtain a reflection receiving signal, and normalizes the power of the reflection receiving signal; detects the normalized reflection receiving signal using a maximum likelihood detection algorithm to obtain an index bit in the reflection signal matrix; and decodes the normalized reflection receiving signal using a soft demodulation algorithm to obtain information bits in the reflection signal matrix;

[0069] The transmission receiving end uses the maximum ratio combining diversity receiving technology to receive the transmission signal matrix, obtain the transmission receiving signal, and normalize the power of the transmission receiving signal; use the maximum likelihood detection algorithm to detect the normalized transmission receiving signal to obtain the index bit in the transmission signal matrix; use the soft demodulation algorithm to decode the normalized transmission receiving signal to obtain the information bit in the transmission signal matrix.

[0070] The transmitting end of the vehicle communication system provided by the present application deploys an omnidirectional intelligent metasurface that integrates the characteristics of transmission and transmission. Based on the preset number of reflection array elements for reflecting signals and the number of transmission array elements for transmitting signals, the generalized spatial modulation technology is used to construct a mapping relationship between the index bit and the reflection array element and the transmission array element of the omnidirectional intelligent metasurface; the index bit and the information bit are modulated to obtain the target signal to be transmitted, and then the target transmission signal is decoded by a demodulator connected to the omnidirectional intelligent metasurface to obtain the index bit and the information bit. Since the index bit of the target signal to be transmitted contains the preset number of reflection array element groups and the preset number of transmission array element groups, and the information bit contains phase angle information, the controller divides the multiple array element groups of the omnidirectional intelligent metasurface into a reflection array element group set for reflecting signals and a transmission array element group set for transmitting signals based on the index bit, and generates a reflection phase based on the phase angle information in the information bit. The offset control signal and the transmission phase offset control signal are used to regulate the phase offset of the transmitting array element group set and the transmitting array element group set, so that the reflecting array element group set and the transmitting array element group set modulate and encode the carrier signal transmitted by the multi-antenna base station, and generate and transmit the reflected signal matrix and the transmitted signal matrix; the present application fully utilizes the reflection and transmission characteristics of the omnidirectional intelligent metasurface by combining the generalized spatial modulation technology, and regulates the array elements of the omnidirectional intelligent metasurface so that the transmitting end can simultaneously transmit the reflected signal and the transmitted signal, so that the signal can be transmitted within the reflection beam range and the transmission beam range, thereby improving the signal coverage range. At the same time, the signal transmission area is divided into the reflection area and the transmission area in the spatial dimension, which increases the signal propagation path. In addition, by using the space-time block coding technology to encode and transmit the signal in the time dimension and the spatial dimension, the frequency utilization and communication efficiency of the vehicle communication system are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0071] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments of the present invention in conjunction with the accompanying drawings, wherein:

[0072] Figure 1 A schematic diagram of the transmitting end structure of the vehicle-mounted communication system provided in this application;

[0073] Figure 2 Flowchart of signal reception and demodulation at the receiving end of the vehicle communication system provided by this application;

[0074] Figure 3 A schematic diagram of the vehicle communication system provided in this application;

[0075] Figure 4 A schematic diagram comparing the bit error rate performance curves of the system when the modulation order of the multi-antenna base station and the number of array elements of the omnidirectional intelligent metasurface provided by this application are different;

[0076] Figure 5 This is a schematic diagram comparing the bit error rate curves of the vehicle-mounted communication system provided in this application and the vehicle-mounted communication system in the prior art. DETAILED DESCRIPTION

[0077] The present invention will be further described below with reference to the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it. However, the embodiments are not intended to limit the present invention.

[0078] See also Figure 1 , Figure 1 The figure shows the receiving end of the vehicle-mounted communication system provided by this application, which specifically includes a multi-antenna base station, an omnidirectional intelligent metasurface, a demodulator and a controller.

[0079] Based on the preset number of reflection array elements and the preset number of transmission array elements of the omnidirectional intelligent metasurface, the multi-antenna base station uses generalized spatial modulation technology to construct a mapping relationship between index bits and the reflection array elements and transmission array elements of the omnidirectional intelligent metasurface; and modulates the index bits and information bits to obtain the target signal to be transmitted, and transmits the target signal to be transmitted and the carrier signal.

[0080] The omnidirectional intelligent metasurface includes multiple array element groups, which are used to receive the target signal to be transmitted and the carrier signal, and transmit the target signal to be transmitted to the demodulator; based on the reflection phase offset control signal and the transmission phase offset control signal generated by the controller, the carrier signal is modulated and encoded using the reflection array element group set and the transmission array element group set to generate the reflection signal matrix and the transmission signal matrix, and the reflection signal matrix and the transmission signal matrix are transmitted.

[0081] Specifically, the omnidirectional intelligent metasurface is a programmable electromagnetic metasurface unit, which includes N array elements. Each array element can change its electromagnetic properties through external control to achieve reflection and transmission of the incident signal. The reflection coefficient of the i-th array element is , the transmission coefficient is , , , the signal has no intensity loss after being reflected or transmitted by the omnidirectional intelligent metasurface; and all channels between each array element of the omnidirectional intelligent metasurface and the receiving end obey the independent Rayleigh Fading Channel (RFC) model, that is, The reflection channel fading coefficient of the array element , transmission channel fading coefficient , It means that it obeys the complex Gaussian distribution with a mean of 0 and a variance of 1. All noises are additive white Gaussian noise (AWGN). Reflection noise of each element , transmission noise .

[0082] By equally dividing N array elements to obtain multiple array element groups, and further dividing the multiple array element groups, a reflection array element group set for reflecting signals and a transmission array element group set for transmitting signals can be obtained, thereby dividing the signal transmission space into a reflection area and a transmission area, and signal transmission between the two areas is independent of each other, thereby achieving signal reflection and transmission. By equally dividing N array elements to obtain multiple array element groups, and further dividing the multiple array element groups, a reflection array element group set for reflecting signals and a transmission array element group set for transmitting signals can be obtained, thereby dividing the signal transmission space into a reflection area and a transmission area, and signal transmission between the two areas is independent of each other, thereby achieving signal reflection and transmission.

[0083] The demodulator is connected to the omnidirectional intelligent metasurface and is used to demodulate the target signal to be transmitted by the omnidirectional intelligent metasurface to obtain the index bit and information bit in the target signal to be transmitted.

[0084] The controller is connected to the demodulator and the omnidirectional smart metasurface, and is used to divide multiple array element groups in the omnidirectional smart metasurface into a reflection array element group set and a transmission array element group set based on the index bit, and generate a reflection phase offset control signal and a transmission phase offset control signal based on the phase angle information in the information bit.

[0085] Specifically, the number of bits of the target signal to be transmitted is:

[0086] ,

[0087] in, Indicates the number of bits of the target signal to be transmitted; Indicates the number of index bits in the target signal to be transmitted; Indicates the number of information bits in the target signal to be transmitted;

[0088] The calculation formula for the number of index bits is:

[0089] ,

[0090] ,

[0091] in, Represents the sum of the preset number of reflection array element groups and the preset number of transmission array element groups; Indicates the preset number of reflection array elements; Indicates the preset number of transmission array elements; Indicates rounding down;

[0092] The calculation formula for the number of information bits is:

[0093] ,

[0094] in, Indicates the modulation order.

[0095] In a specific example of the present application, since most vehicles in the vehicle-mounted communication scenario move on the ground and most communication requirements are horizontal coverage, the N array elements of the omnidirectional smart metasurface are divided into four groups in the horizontal direction to obtain four array element groups. In order to balance the quality of the reflected signal and the transmitted signal, the array element groups are evenly divided into a reflection array element group set containing two array element groups and a transmission array element group set containing two array element groups, that is, , , , then the number of index bits , the modulation order in the information bits , the number of information bits , further, including the index bit and the information bit The bit data is modulated and transmitted to the omnidirectional smart metasurface, so that the omnidirectional smart metasurface transmits an M-ary phase-shift keying reflection signal and a transmission signal based on the target signal to be transmitted.

[0096] Optionally, the multi-antenna base station can select different signal modulation schemes according to different transmission bit data streams to adapt to different channel conditions. Table 1 shows the M-ary phase shift keying signal when the omnidirectional intelligent metasurface transmits the target signal using different signal modulation schemes under different index bits and information bits:

[0097] Table 1

[0098]

[0099] Furthermore, the indexes of the four array element groups of the omnidirectional smart metasurface are 1, 2, 3, and 4, respectively. Any two groups are considered as a reflection array element set / transmission array element set, and all of the groupings include: [1,2], [1,3], [1,4], [2,3], [2,4], and [3,4]. Generalized spatial modulation technology can be used to construct a mapping relationship between index bits and reflection array element sets and transmission array element sets according to different application scenarios, so that the controller can divide the multiple array element groups of the omnidirectional smart metasurface into reflection array element sets and transmission array element sets based on the index bits. In a specific embodiment of the present application, in order to avoid a strong coupling effect between two array element groups in the array element set when activated and to reduce interference between the array element groups, the controller can select two array element groups that are farther apart from each other according to the index bits to form a reflection array element set / transmission array element set. For example, Table 2 shows the mapping relationship between index bits and reflection array element sets and transmission array element sets provided in a specific example of the present application:

[0100] Table 2

[0101]

[0102] As can be seen from Table 2, when the index bit is 01, the controller uses the first and fourth array element groups as the reflection array element group set, and the second and third array element groups as the transmission array element group set. In other embodiments of the present application, the mapping relationship between the index bit and the array element group set may be other. For example, when the index bit is 01, the first and third array element groups are used as the reflection array element group set, and the second and fourth array element groups are used as the transmission array element group set.

[0103] Furthermore, by using the omnidirectional intelligent metasurface as an access point, the controller can set the corresponding phase offset for the reflection array element set and the transmission array element set according to the received information bits, thereby dynamically controlling the phase and amplitude information of the array element set to match the modulated signal. The reflection array element set and the transmission array element set actively modulate the carrier signal transmitted by the multi-antenna base station, encode the modulated signal using the Alamouti coding technology, and transmit the encoded signal.

[0104] Specifically, in some embodiments of the present application, the omnidirectional intelligent metasurface modulates and encodes a carrier signal using a reflection array element group set and a transmission array element group set based on a reflection phase offset control signal and a transmission phase offset control signal generated by a controller, and generates a reflection signal matrix and a transmission signal matrix, including:

[0105] The reflection array element set generates a reflected M-ary phase shift keying signal based on a reflected phase offset control signal; generates a reflected M-ary phase shift keying signal encoding matrix based on the reflected M-ary phase shift keying signal using an Alamouti encoding technique; and generates a reflected signal matrix based on the reflected M-ary phase shift keying signal encoding matrix;

[0106] The transmission array element set generates a transmission M-ary phase shift keying signal based on a transmission phase offset control signal; utilizes Alamouti coding technology to generate a transmission M-ary phase shift keying signal encoding matrix based on the transmission M-ary phase shift keying signal, and generates a transmission signal matrix based on the transmission M-ary phase shift keying signal encoding matrix.

[0107] Optionally, in some embodiments of the present application, the receiving end may further include a memory connected to the omnidirectional intelligent metasurface, for storing the M-ary phase shift keying signals generated by the reflection array element set and the transmission array element set until all the M-ary phase shift keying signals are generated, and then using the Alamouti coding technology to generate a reflection M-ary phase shift keying signal encoding matrix and a transmission M-ary phase shift keying signal encoding matrix based on the reflection M-ary phase shift keying signal and the transmission M-ary phase shift keying signal, modulate and encode the carrier signal, and generate a reflection signal matrix and a transmission signal matrix.

[0108] The space-time block code Alamouti coding technology is suitable for the communication scenario of 2 transmission and 1 reception, which is consistent with the vehicle communication system provided by this application. Specifically, according to the Alamouti coding rule, the omnidirectional intelligent metasurface is in the first time slot. Transmit and reflect the M-ary phase shift keying signal generated by the first and second array elements in the array element set and , and the M-ary phase shift keying signal generated by the first array element group and the second array element group in the transmission array element group and ; In the second time slot emission 、 、 and , therefore, the reflected M-ary phase shift keying signal encoding matrix is ​​expressed as:

[0109] ,

[0110] in, represents the reflected M-ary phase shift keying signal encoding matrix; Represents the M-ary phase-shift keying signal generated by the first array element group in the reflection array element group set; represents an M-ary phase-shift keying signal generated by the second array element group in the reflection array element group set; Indicates conjugation.

[0111] The encoding matrix of the transmitted M-ary phase shift keying signal is expressed as:

[0112] ,

[0113] in, represents the transmission M-ary phase shift keying signal encoding matrix; represents an M-ary phase-shift keying signal generated by the first array element group in the transmission array element group set; It represents the M-ary phase-shift keying signal generated by the second array element group in the transmission array element group set.

[0114] Furthermore, according to the Alamouti coding rule, for the reflection array tuple set, in the first time slot and the second time slot The received signals are:

[0115] ,

[0116] ,

[0117] For the transmission array tuple set, in the first time slot and the second time slot The received signals are:

[0118] ,

[0119] ,

[0120] make , , then for the reflection array tuple set, in the first time slot and the second time slot The received signals are:

[0121] ,

[0122] ,

[0123] Furthermore, the reflected signal matrix is ​​expressed as;

[0124] ,

[0125] in, represents the reflected signal matrix; The channel matrix representing the set of reflection array elements; Represents the channel fading coefficient of the first array element group in the reflection array element group set; Indicates the first array element in the reflection array element set. The channel fading coefficient of each array element; Indicates the number of array elements in the first array element group in the reflection array element group set; Represents the channel fading coefficient of the second array element group in the reflection array element group set; Indicates the first element in the second array element set of the reflection array element set The channel fading coefficient of each array element; Indicates the number of array elements in the second array element group of the reflection array element set; The noise matrix representing the set of reflection array elements; Represents the noise of the first array element in the reflection array element set; Represents the noise of the second array element in the reflection array element set.

[0126] make , , then for the transmission array tuple set, in the first time slot and the second time slot The received signals are:

[0127] ,

[0128] ,

[0129] Furthermore, the transmission signal matrix is ​​expressed as;

[0130] ,

[0131] in, represents the transmission signal matrix; The channel matrix representing the set of transmitted array elements; represents the channel fading coefficient of the first array element group in the transmission array element group set; Indicates the first array element in the transmission array element set. The channel fading coefficient of each array element; Indicates the number of array elements in the first array element group in the transmission array element group set; represents the channel fading coefficient of the second array element group in the transmission array element group set; Indicates the first The channel fading coefficient of each array element; Indicates the number of array elements in the second array element group of the transmission array element group set; The noise matrix representing the set of transmission array elements; represents the noise of the first array element group in the transmission array element group set; represents the noise of the second array element in the transmission array element set.

[0132] Specifically, in this application, since the amplitude of the M-ary phase-shift keying signal is 1, it is only necessary to adjust the phase information of the array element group. That is, the M-ary phase-shift keying signals generated by the array element groups in each array element group set in the omnidirectional intelligent metasurface are respectively:

[0133] ,

[0134] ,

[0135] ,

[0136] .

[0137] Table 3 shows a mapping relationship between information bits and phases when the modulation order M is 2, 4, or 8, as provided in a specific example of this application:

[0138] Table 3

[0139]

[0140] Based on the transmitting end of the vehicle-mounted communication system provided in the above embodiment, the embodiment of the present application further provides a receiving end of the vehicle-mounted communication system, which specifically includes a reflection receiving end and a transmission receiving end.

[0141] like Figure 2 The figure shows a flow chart of receiving and demodulating signals at the receiving end. Specifically, the reflection receiving end uses the maximum ratio combining diversity reception technology to receive the reflection signal matrix sent by the transmitting end of the vehicle communication system provided by the above embodiment, obtains the reflection receiving signal, and normalizes the power of the reflection receiving signal; uses the maximum likelihood detection algorithm to detect the normalized reflection receiving signal to obtain the index bit in the reflection signal matrix; and uses the soft demodulation algorithm to decode the normalized reflection receiving signal to obtain the information bit in the reflection signal matrix.

[0142] The transmission receiving end uses the maximum ratio combining diversity receiving technology to receive the transmission signal matrix sent by the transmitting end of the vehicle communication system provided by the above embodiment, obtain the transmission receiving signal, and normalize the power of the transmission receiving signal; use the maximum likelihood detection algorithm to detect the normalized transmission receiving signal to obtain the index bit in the transmission signal matrix; use the soft demodulation algorithm to decode the normalized transmission receiving signal to obtain the information bit in the transmission signal matrix.

[0143] Specifically, the receiver uses maximum ratio combining (MRC) diversity reception technology to weight the received signal according to the channel gain, which can maximize the signal-to-noise ratio (SNR) of the signal and fully utilize the diversity gain. The two received signals from the two array elements in the reflection array element set / transmission array element set are input into the maximum ratio combiner for processing. The channel estimator can obtain complete channel state information. Specifically, the reflected received signal is expressed as:

[0144] ,

[0145] ,

[0146] The transmitted received signal is expressed as:

[0147] ,

[0148] ,

[0149] In order to standardize the energy of the received signal, the power of the received signal is normalized to ensure that the signal can be correctly decoded. Specifically, the reflected received signal after normalization is expressed as:

[0150] ,

[0151] ,

[0152] in, represents the first reflected received signal after normalization; represents the second reflected received signal after normalization; Represents the channel fading coefficient of the first array element group in the reflection array element group set; Represents the channel fading coefficient of the second array element group in the reflection array element group set; Represents the received signal of the first array element group in the reflection array element group set; Represents the received signal of the second array element group in the reflection array element group set; Represents the noise of the first array element in the reflection array element set; represents the noise of the second array element in the reflection array element set; indicates conjugation;

[0153] The normalized transmission reception signal is expressed as:

[0154] ,

[0155] ,

[0156] in, represents the first transmission receiving signal after normalization; represents the second transmission receiving signal after normalization; represents the channel fading coefficient of the first array element group in the transmission array element group set; represents the channel fading coefficient of the second array element group in the transmission array element group set; represents the received signal of the first array element group in the transmission array element group set; represents the received signal of the second array element group in the transmission array element group set; represents the noise of the first array element group in the transmission array element group set; represents the noise of the second array element in the transmission array element set.

[0157] Furthermore, after obtaining the received signal, the receiving end first performs array element group index decoding and then modulation symbol decoding. In generalized spatial modulation technology, the index bits in the signal are not directly sent to the receiving end as a separate bit stream, but are implicitly transmitted through the activated array element groups. Therefore, the embodiment of the present application performs maximum likelihood detection on the received signal at the receiving end to detect the index bits in the signal matrix. The specific detection method includes: first modulating the input bits into symbols to generate a received signal in an array element group activation mode; then generating candidate signals based on the channel characteristics and modulation symbols of different array element group combinations; finally, by comparing the Euclidean distance between the received signal and the candidate signals, the array element group index corresponding to the candidate signal with the smallest distance is found, and decoding is used to obtain the index bits.

[0158] Specifically, the index bit in the reflection signal matrix is ​​expressed as:

[0159] ,

[0160] in, Represents the estimated value of the reflection array tuple set index; Indicates the phase of the first array element in the reflection array element set; Represents the phase estimate of the first array element in the reflection array element set; Represents the phase of the second array element group in the reflection array element group set; Represents the phase estimate of the second array element group in the reflection array element group set; Represents the reflection array tuple set index; Indicates the variable value when the objective function reaches the minimum value; represents the reflected signal matrix; represents the reflected M-ary phase shift keying signal encoding matrix; The channel matrix representing the set of reflection array elements; represents the vector norm;

[0161] The index bits in the transmission signal matrix are expressed as:

[0162] ,

[0163] in, represents the estimated value of the transmission array tuple set index; Represents the phase of the first array element group in the transmission array element group set; represents the phase estimate of the first array element group in the transmission array element group set; represents the phase of the second array element group in the transmission array element group set; represents the phase estimate of the second array element group in the transmission array element group set; Represents the transmission array tuple index set; represents the transmission signal matrix; represents the transmission M-ary phase shift keying signal encoding matrix; The channel matrix representing the set of transmitted array elements.

[0164] Furthermore, after obtaining the index bits in the signal matrix, the received signal needs to be decoded to obtain the information bits in the signal matrix. The embodiment of the present application uses soft demodulation to demodulate the received signal, thereby providing more accurate information than traditional hard decisions, thereby improving the bit error rate of the communication system.

[0165] Specifically, assuming the received signal is a, for the binary phase-shift keying signal, the soft demodulation algorithm is: negate the received complex signal to obtain -a as the soft output result, and finally make a judgment. If the soft output result is greater than 0, the demodulated information bit is 1; if the soft output result is less than or equal to 0, the demodulated information bit is 0.

[0166] Assuming that the received complex signal is a+jb, for the quaternary phase-shift keying signal, the soft demodulation demodulation algorithm is: negate the imaginary part of the received signal to obtain -b as the first soft output result, then negate the real part of the received signal to obtain -a as the second soft output result, and finally make a judgment. If the first soft output result is greater than 0, the first information bit obtained by demodulation is 1; if the first soft output result is less than or equal to 0, the first information bit obtained by demodulation is 0; if the second soft output result is greater than 0, the second information bit obtained by demodulation is 1; if the second soft output result is less than or equal to 0, the second information bit obtained by demodulation is 0.

[0167] Assuming that the received signal is a+jb, for the octal phase shift keying signal, the demodulation algorithm of soft demodulation is: negate the imaginary part of the received signal to get -b as the first soft output result, then negate the real part of the received signal to get -a as the second soft output result, and then process the real and imaginary parts to get As the third soft output result, a final judgment is made. If the first soft output result is greater than 0, the first information bit obtained by demodulation is 1; if the first soft output result is less than or equal to 0, the first information bit obtained by demodulation is 0; if the second soft output result is greater than 0, the second information bit obtained by demodulation is 1; if the second soft output result is less than or equal to 0, the second information bit obtained by demodulation is 0; if the third soft output result is greater than 0, the third information bit obtained by demodulation is 1; if the third soft output result is less than or equal to 0, the third information bit obtained by demodulation is 0.

[0168] The embodiment of the present application also provides a vehicle-mounted communication system, which includes a transmitting end of the vehicle-mounted communication system and a receiving end of the vehicle-mounted communication system provided in the above embodiment, such as Figure 3 Shown is a model schematic diagram of the vehicle communication system.

[0169] Based on the vehicle-mounted communication system provided in the above embodiment, an embodiment of the present application further provides a vehicle-mounted communication method, which specifically includes:

[0170] S10: The multi-antenna base station uses generalized spatial modulation technology to establish a mapping relationship between index bits and the reflective array elements and the transmissive array elements of the omnidirectional smart metasurface based on the preset number of reflective array elements and the preset number of transmissive array elements of the omnidirectional smart metasurface; modulates the index bits and information bits to obtain the target signal to be transmitted, and transmits the target signal to be transmitted and the carrier signal;

[0171] S20: The omnidirectional intelligent metasurface receives the target signal to be transmitted and the carrier signal, and transmits the target signal to be transmitted to the demodulator;

[0172] S30: The demodulator demodulates the target signal to be transmitted transmitted by the omnidirectional intelligent metasurface to obtain an index bit and an information bit in the target signal to be transmitted;

[0173] S40: The controller divides the multiple array element groups in the omnidirectional smart metasurface into a reflection array element group set and a transmission array element group set based on the index bit, and generates a reflection phase offset control signal and a transmission phase offset control signal based on the phase angle information in the information bit;

[0174] S50: The omnidirectional intelligent metasurface modulates and encodes the carrier signal using the reflection array element set and the transmission array element set based on the reflection phase offset control signal and the transmission phase offset control signal generated by the controller, generates the reflection signal matrix and the transmission signal matrix, and transmits the reflection signal matrix and the transmission signal matrix:

[0175] S60: The reflection receiving end receives the reflection signal matrix using a maximum ratio combining diversity reception technique to obtain a reflection reception signal, and normalizes the power of the reflection reception signal; detects the normalized reflection reception signal using a maximum likelihood detection algorithm to obtain an index bit in the reflection signal matrix; and decodes the normalized reflection reception signal using a soft demodulation algorithm to obtain information bits in the reflection signal matrix.

[0176] S70: The transmission receiving end uses the maximum ratio combining diversity receiving technology to receive the transmission signal matrix, obtain the transmission receiving signal, and normalize the power of the transmission receiving signal; use the maximum likelihood detection algorithm to detect the normalized transmission receiving signal to obtain the index bit in the transmission signal matrix; use the soft demodulation algorithm to decode the normalized transmission receiving signal to obtain the information bit in the transmission signal matrix.

[0177] Furthermore, in order to verify the superiority of the vehicle communication system provided by this application, the embodiment of this application verified the bit error rate of the vehicle communication system in the Visual Studio 2022 environment:

[0178] like Figure 4 The figure shows the system's bit error rate performance curve for different modulation orders and the number of array elements of the omnidirectional smart metasurface provided by this application. As can be seen from the figure, generally, the lower the modulation order, the better the system's bit error rate performance. Furthermore, it is worth noting that the bit error rate curves for BPSK and QPSK modulation almost overlap, indicating that when the modulation order M is low, the impact on the system's bit error rate performance is not significant due to its compatibility with BPSK and QPSK modulation in terms of channel characteristics.

[0179] like Figure 5The figure shows a schematic diagram comparing the bit error rate curves of the vehicle-mounted communication system provided by the present application and the vehicle-mounted communication system in the prior art. Through horizontal comparison, it can be found that with the increase in the number of array elements of the omnidirectional intelligent metasurface, the bit error rate of the system gradually decreases, indicating that the performance of the communication system can be improved by increasing the number of array elements of the omnidirectional intelligent metasurface; through vertical comparison, it can be found that compared with the communication system in the prior art, the present application utilizes the reflection and transmission characteristics of the omnidirectional intelligent metasurface, combined with generalized spatial modulation technology and space-time block coding technology to encode signals in spatial and temporal dimensions, which not only improves the signal coverage and simplifies the channel conditions, but also greatly improves the system bit error rate performance and significantly enhances the reliability of signal transmission.

[0180] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present application may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0181] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0182] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0183] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0184] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A transmitting end of a vehicle-mounted communication system, characterized in that: include: A multi-antenna base station is configured to construct a mapping relationship between index bits and the reflective array elements and the transmissive array elements of the omnidirectional smart metasurface using generalized spatial modulation technology based on a preset number of reflective array elements and a preset number of transmissive array elements of the omnidirectional smart metasurface; modulate the index bits and information bits to obtain a target signal to be transmitted, and transmit the target signal to be transmitted and a carrier signal; An omnidirectional intelligent metasurface, comprising a plurality of array element groups, configured to receive the target signal to be transmitted and the carrier signal, and transmit the target signal to be transmitted to a demodulator; Based on the reflection phase offset control signal and the transmission phase offset control signal generated by the controller, the carrier signal is modulated and encoded using the reflection array element group set and the transmission array element group set to generate a reflection signal matrix and a transmission signal matrix, and the reflection signal matrix and the transmission signal matrix are transmitted: A demodulator, connected to the omnidirectional intelligent metasurface, for demodulating the target signal to be transmitted transmitted by the omnidirectional intelligent metasurface to obtain an index bit and an information bit in the target signal to be transmitted; a controller connected to the demodulator and the omnidirectional smart metasurface, configured to divide a plurality of array element groups in the omnidirectional smart metasurface into a reflection array element group set and a transmission array element group set based on the index bits, and generate a reflection phase offset control signal and a transmission phase offset control signal based on the phase angle information in the information bits.

2. The transmitting end of the vehicle-mounted communication system according to claim 1, characterized in that: The number of bits of the target signal to be transmitted is: ， in, Indicates the number of bits of the target signal to be transmitted; Indicates the number of index bits in the target signal to be transmitted; Indicates the number of information bits in the target signal to be transmitted; The calculation formula for the number of index bits is: ， ， in, Represents the sum of the preset number of reflection array element groups and the preset number of transmission array element groups; Indicates the preset number of reflection array elements; Indicates the preset number of transmission array elements; Indicates rounding down; The calculation formula for the number of information bits is: ， in, Indicates the modulation order.

3. The transmitting end of the vehicle-mounted communication system according to claim 1, characterized in that: The omnidirectional intelligent metasurface includes 4 array element groups, each of which includes N / 4 array elements; wherein N represents the number of array elements of the omnidirectional intelligent metasurface; The reflection array element group set and the transmission array element group set each include two array element groups.

4. The transmitting end of the vehicle-mounted communication system according to claim 3, characterized in that: Based on the reflection phase offset control signal and the transmission phase offset control signal generated by the controller, modulating and encoding the carrier signal using the reflection array element group set and the transmission array element group set to generate the reflection signal matrix and the transmission signal matrix includes: The reflection array element set generates a reflected M-ary phase shift keying signal based on the reflected phase offset control signal; generates a reflected M-ary phase shift keying signal encoding matrix based on the reflected M-ary phase shift keying signal using an Alamouti encoding technique, and generates a reflected signal matrix based on the reflected M-ary phase shift keying signal encoding matrix; The transmission array element set generates a transmission M-ary phase shift keying signal based on the transmission phase offset control signal; uses Alamouti coding technology to generate a transmission M-ary phase shift keying signal encoding matrix based on the transmission M-ary phase shift keying signal, and generates a transmission signal matrix based on the transmission M-ary phase shift keying signal encoding matrix.

5. The transmitting end of the vehicle-mounted communication system according to claim 4, characterized in that: The reflected M-ary phase shift keying signal encoding matrix is ​​expressed as: ， in, represents the reflected M-ary phase shift keying signal encoding matrix; Represents the M-ary phase-shift keying signal generated by the first array element group in the reflection array element group set; represents an M-ary phase-shift keying signal generated by the second array element group in the reflection array element group set; indicates conjugation; The reflected signal matrix is ​​expressed as: ， ， ， in, represents the reflected signal matrix; The channel matrix representing the set of reflection array elements; Represents the channel fading coefficient of the first array element group in the reflection array element group set; Indicates the first array element in the reflection array element set. The channel fading coefficient of each array element; Indicates the number of array elements in the first array element group in the reflection array element group set; Represents the channel fading coefficient of the second array element group in the reflection array element group set; Indicates the first element in the second array element set of the reflection array element set The channel fading coefficient of each array element; Indicates the number of array elements in the second array element group of the reflection array element set; The noise matrix representing the set of reflection array elements; Represents the noise of the first array element in the reflection array element set; represents the noise of the second array element in the reflection array element set; The transmission M-ary phase shift keying signal encoding matrix is ​​expressed as: ， in, represents the transmission M-ary phase shift keying signal encoding matrix; represents an M-ary phase-shift keying signal generated by the first array element group in the transmission array element group set; represents an M-ary phase-shift keying signal generated by the second array element group in the transmission array element group set; The transmission signal matrix is ​​expressed as: ， ， ， in, represents the transmission signal matrix; The channel matrix representing the set of transmitted array elements; represents the channel fading coefficient of the first array element group in the transmission array element group set; Indicates the first array element in the transmission array element set. The channel fading coefficient of each array element; Indicates the number of array elements in the first array element group in the transmission array element group set; represents the channel fading coefficient of the second array element group in the transmission array element group set; Indicates the first The channel fading coefficient of each array element; Indicates the number of array elements in the second array element group of the transmission array element group set; The noise matrix representing the set of transmission array elements; represents the noise of the first array element group in the transmission array element group set; represents the noise of the second array element in the transmission array element set.

6. A receiving end of a vehicle-mounted communication system, characterized in that: include: a reflection receiving end, configured to receive the reflection signal matrix sent by the transmitting end of the in-vehicle communication system according to any one of claims 1 to 5 using a maximum ratio combining diversity receiving technology, obtain a reflection receiving signal, and normalize the power of the reflection receiving signal; Detecting the normalized reflected received signal using a maximum likelihood detection algorithm to obtain an index bit in the reflected signal matrix; Decoding the normalized reflected received signal using a soft demodulation algorithm to obtain information bits in the reflected signal matrix; A transmission receiving end is configured to receive a transmission signal matrix transmitted by a transmitting end of the vehicle-mounted communication system according to any one of claims 1 to 5 using a maximum ratio combining diversity reception technique, obtain a transmission receiving signal, and normalize the power of the transmission receiving signal; detect the normalized transmission receiving signal using a maximum likelihood detection algorithm to obtain index bits in the transmission signal matrix; and decode the normalized transmission receiving signal using a soft demodulation algorithm to obtain information bits in the transmission signal matrix.

7. The receiving end of the vehicle-mounted communication system according to claim 6, characterized in that: The normalized reflected received signal is expressed as: ， ， in, represents the first reflected received signal after normalization; represents the second reflected received signal after normalization; Represents the channel fading coefficient of the first array element group in the reflection array element group set; Represents the channel fading coefficient of the second array element group in the reflection array element group set; Represents the received signal of the first array element group in the reflection array element group set; Represents the received signal of the second array element group in the reflection array element group set; Represents the noise of the first array element in the reflection array element set; represents the noise of the second array element in the reflection array element set; indicates conjugation; The normalized transmission reception signal is expressed as: ， ， in, represents the first transmission receiving signal after normalization; represents the second transmission receiving signal after normalization; represents the channel fading coefficient of the first array element group in the transmission array element group set; represents the channel fading coefficient of the second array element group in the transmission array element group set; represents the received signal of the first array element group in the transmission array element group set; represents the received signal of the second array element group in the transmission array element group set; represents the noise of the first array element group in the transmission array element group set; represents the noise of the second array element in the transmission array element set.

8. The receiving end of the vehicle communication system according to claim 6, characterized in that: The index bits in the reflection signal matrix are expressed as: ， in, Represents the estimated value of the reflection array tuple set index; Indicates the phase of the first array element in the reflection array element set; Represents the phase estimate of the first array element in the reflection array element set; Represents the phase of the second array element group in the reflection array element group set; Represents the phase estimate of the second array element group in the reflection array element group set; Represents the reflection array tuple set index; Indicates the variable value when the objective function reaches the minimum value; represents the reflected signal matrix; represents the reflected M-ary phase shift keying signal encoding matrix; The channel matrix representing the set of reflection array elements; represents the vector norm; The index bits in the transmission signal matrix are expressed as: ， in, represents the estimated value of the transmission array tuple set index; Represents the phase of the first array element group in the transmission array element group set; represents the phase estimate of the first array element group in the transmission array element group set; represents the phase of the second array element group in the transmission array element group set; represents the phase estimate of the second array element group in the transmission array element group set; Represents the transmission array tuple set index; represents the transmission signal matrix; represents the transmission M-ary phase shift keying signal encoding matrix; The channel matrix representing the set of transmitted array elements.

9. A vehicle-mounted communication system, characterized in that: include: The transmitting end of the vehicle-mounted communication system according to any one of claims 1 to 5; A receiving end of the in-vehicle communication system according to any one of claims 6 to 8.

10. A vehicle-mounted communication method, characterized in that: The vehicle-mounted communication system according to claim 9 comprises: The multi-antenna base station uses generalized spatial modulation technology to construct a mapping relationship between index bits and the reflective array elements and the transmissive array elements of the omnidirectional smart metasurface based on the preset number of reflective array elements and the preset number of transmissive array elements of the omnidirectional smart metasurface; and modulates the index bits and information bits to obtain the target signal to be transmitted, and transmits the target signal to be transmitted and the carrier signal; The omnidirectional intelligent metasurface receives the target signal to be transmitted and the carrier signal, and transmits the target signal to be transmitted to a demodulator; The demodulator demodulates the target signal to be transmitted transmitted by the omnidirectional intelligent metasurface to obtain an index bit and an information bit in the target signal to be transmitted; The controller divides the plurality of array element groups in the omnidirectional smart metasurface into a reflection array element group set and a transmission array element group set based on the index bit, and generates a reflection phase offset control signal and a transmission phase offset control signal based on the phase angle information in the information bit; The omnidirectional intelligent metasurface modulates and encodes the carrier signal using a reflection array element set and a transmission array element set based on the reflection phase offset control signal and the transmission phase offset control signal generated by the controller, generates a reflection signal matrix and a transmission signal matrix, and transmits the reflection signal matrix and the transmission signal matrix: The reflection receiving end receives the reflection signal matrix using a maximum ratio combining diversity receiving technology to obtain a reflection receiving signal, and normalizes the power of the reflection receiving signal; detects the normalized reflection receiving signal using a maximum likelihood detection algorithm to obtain an index bit in the reflection signal matrix; and decodes the normalized reflection receiving signal using a soft demodulation algorithm to obtain information bits in the reflection signal matrix; The transmission receiving end uses the maximum ratio combining diversity receiving technology to receive the transmission signal matrix, obtain the transmission receiving signal, and normalize the power of the transmission receiving signal; use the maximum likelihood detection algorithm to detect the normalized transmission receiving signal to obtain the index bit in the transmission signal matrix; use the soft demodulation algorithm to decode the normalized transmission receiving signal to obtain the information bit in the transmission signal matrix.

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