A signal modulation and transmission method based on transform domain and communication system

Abstract

A transform domain-based signal transmission method, the method is used at the transmitting end of a wireless communication system, the method comprising: A1, mapping constellation-mapped data symbols to the Doppler-frequency domain to obtain a first symbol matrix; A2, transforming the first symbol matrix from the Doppler-frequency domain to the time-delay domain through a two-dimensional signal transformation to generate a second symbol matrix; A3, performing parallel / serial conversion on the second symbol matrix, and inserting a cyclic prefix to generate a third symbol matrix; A4, generating a transmission signal based on the third symbol matrix.

Description

Technical Field

[0001] The present invention relates to the field of wireless communications, in particular to a signal modulation technology in the field of wireless communications, and more particularly to a transform domain-based signal modulation, transmission method and communication system. Background Art

[0002] The current mainstream communication system is based on time-frequency domain signal processing, using Orthogonal Frequency Division Multiplexing (OFDM) technology for signal modulation, which realizes fast modulation and demodulation of signals by carrying data symbols in the time-frequency domain and using fast Fourier transform (FFT) and its inverse transform technology. However, due to the complexity of the wireless environment, the transmission performance of OFDM technology is severely restricted in a fast-moving wireless environment because the orthogonality between subcarriers is destroyed.

[0003] At present, the Orthogonal Time-Frequency Space Modulation (OTFS) technology based on the delay-Doppler domain proposed by the industry has attracted much attention due to its superior performance over OFDM technology. OTFS technology first maps data symbols to the Delay Doppler domain (DD domain for short), uses the Inverse Symplectic Finite Fourier Transform (ISFFT) to map data symbols from the DD domain to the Time-Frequency domain (TF domain for short), and transmits signals through the pulse shaping technology of the TF domain. Compared with OFDM technology, OTFS technology realizes two-dimensional modulation of signals and better realizes the coupling of wireless signals and wireless environment.

[0004] However, the current main signal modulation technologies can only obtain one-dimensional signal gain. Figure 1 As shown in FIG, OFDM modulation transforms data symbols from the time-frequency space to the time-delay domain space for signal transmission. Independent data symbols distributed on different subcarriers within the same OFDM symbol period are extended to the entire delay dimension. Therefore, OFDM modulation can obtain diversity gain in the delay dimension. However, data symbols between different symbols are independent of each other, that is, they only occupy the symbol period in time, and do not obtain the complete time gain. Refer to the attached Figure 2As shown in the figure, OTFS modulation also transforms the data symbols from the time-Doppler domain space to the time-delay domain for signal transmission, and extends the independent data symbols of the same delay dimension distributed in different Doppler domains to the entire time dimension. Therefore, OTFS modulation can obtain diversity gain in the time dimension. However, the data symbols in different delay dimensions are still independent of each other, that is, they only occupy independent delays in the delay, and no complete delay gain is obtained.

[0005] In summary, the current mainstream signal modulation methods have only achieved one-dimensional transmission gain, that is, gain only in the time or delay dimension, and the transmission performance needs to be further improved. Summary of the invention

[0006] Therefore, the object of the present invention is to overcome the defects of the prior art and provide a signal modulation and transmission method and a communication system based on transform domain in wireless communication.

[0007] According to a first aspect of the present invention, a transform domain-based signal transmission method is provided, the method comprising: A1, mapping constellation-mapped data symbols to the Doppler-frequency domain to obtain a first symbol matrix; A2, transforming the first symbol matrix from the Doppler-frequency domain to the time-delay domain through a two-dimensional signal transformation to generate a second symbol matrix; A3, performing parallel / serial conversion on the second symbol matrix, and inserting a cyclic prefix to generate a third symbol matrix; A4, generating a transmission signal based on the third symbol matrix.

[0008] In some embodiments of the present invention, the mapping in step A1 is to fill a symbol sequence consisting of multiple data symbols into a matrix of N rows × M columns in sequence to form a first symbol matrix, where M is equal to the total number of subcarriers and the value of M × N is the total number of data symbols.

[0009] In some embodiments of the present invention, in step A2, multiple data symbols are transformed from the Doppler-frequency domain to the time-delay domain through a two-dimensional discrete Fourier inverse transform to achieve a full diversity gain of the signal, wherein the full diversity gain refers to the entire resource plane of each data symbol in the first symbol matrix transformed from the Doppler-frequency domain to the time-delay domain and then superimposed to generate a second symbol matrix.

[0010] Preferably, the two-dimensional inverse discrete Fourier transform is calculated as follows:

[0011]

[0012] Wherein, X[·] represents the data symbol in the time-delay domain of the transmitter, M represents the total number of subcarriers, the value of M×N is the total number of data symbols, x[·] represents the data symbol in the Doppler-frequency domain of the transmitter, k represents the kth delay interval, l represents the lth Doppler interval, n represents the nth row of the matrix, m represents the mth subcarrier, and j represents an imaginary number.

[0013] According to the second aspect of the present invention, there is provided a signal receiving method for the first aspect of the present invention, the method comprising: B1, receiving a transmission signal transmitted by a transmitting end at a receiving end to obtain a received signal, and obtaining a third symbol matrix based on the received signal; B2, removing the cyclic prefix from the third symbol matrix, and performing a serial / parallel conversion to generate a second symbol matrix; B3, transforming the second symbol matrix from the time-delay domain to the Doppler-frequency domain through a two-dimensional signal inverse transform to generate a first symbol matrix; B4, inverse mapping the first symbol matrix to obtain data symbols and performing constellation demapping.

[0014] In some embodiments of the present invention, in step B3, multiple data symbols are transformed from the time-delay domain to the Doppler-frequency domain by two-dimensional discrete Fourier transform to restore the signal of the full diversity gain.

[0015] Preferably, the two-dimensional discrete Fourier transform is calculated as follows:

[0016]

[0017] Wherein, y[·] represents the data symbol in the Doppler-frequency domain of the receiving end, k represents the kth delay interval, l represents the lth Doppler interval, Y[·] represents the data symbol in the time-delay domain of the receiving end, M represents the total number of subcarriers, the value of M×N is the total number of data symbols, n represents the nth row of the matrix, m represents the mth subcarrier, and j represents an imaginary number.

[0018] In some embodiments of the present invention, the inverse mapping in step B4 is to arrange each data symbol in the first symbol matrix of N rows × M columns arranged in the Doppler-frequency domain into a sequence one by one according to the arrangement order, where M is equal to the total number of subcarriers and the value of M×N is the total number of data symbols.

[0019] According to a third aspect of the present invention, a transform domain-based wireless communication method is provided, the method comprising: transmitting a wireless signal according to the method as described in the first aspect of the present invention; and receiving the wireless signal according to the method as described in the second aspect of the present invention.

[0020] According to a fourth aspect of the present invention, there is provided a wireless communication system comprising a transmitting end and a receiving end, wherein the transmitting end transmits information bits to be sent according to the method of the first aspect of the present invention; and the receiving end receives the signal transmitted by the transmitting end according to the method of the second aspect of the present invention to obtain the information bits.

[0021] Compared with the prior art, the advantages of the present invention are:

[0022] 1. Compared with the current mainstream OFDM technology and OTFS technology, the present invention can achieve higher broadband transmission performance and transmission efficiency.

[0023] 2. The present invention realizes the acquisition of signal diversity gain in the full resource plane through two-dimensional signal transformation, which can effectively improve the transmission efficiency and the receiving end performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The embodiments of the present invention are further described below with reference to the accompanying drawings, in which:

[0025] Figure 1 It is a schematic diagram of the transformation of OFDM modulation technology in the prior art;

[0026] Figure 2 It is a transformation schematic diagram of the OTFS modulation technology in the prior art;

[0027] Figure 3 A schematic diagram of a flow chart of a signal transmission method based on a transform domain according to an embodiment of the present invention;

[0028] Figure 4 A schematic diagram of a two-dimensional signal transformation according to an embodiment of the present invention;

[0029] Figure 5 A schematic diagram of a flow chart of a signal receiving method based on a transform domain according to an embodiment of the present invention;

[0030] Figure 6 A schematic diagram of a two-dimensional signal inverse transformation according to an embodiment of the present invention;

[0031] Figure 7 A schematic diagram of transformation between a Doppler-frequency domain and a time-delay domain according to an embodiment of the present invention;

[0032] Figure 8 A schematic diagram of the structure of a wireless communication system according to an embodiment of the present invention;

[0033] Fig. 9 The figure is a schematic diagram of comparing block error rate performances using various testing methods according to an embodiment of the present invention. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail by specific embodiments below. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0035] As mentioned in the background technology, the modulation of the baseband part in the mainstream signal modulation methods in the existing wireless communication field (such as using OFDM technology and using OTFS technology) can only obtain one-dimensional transmission gain, that is, only gain in the time or delay dimension, and the transmission performance needs to be further improved. Among them, the scheme using OFDM technology in the prior art carries data symbols in the time-frequency domain, uses fast Fourier transform and its inverse transform, and transmits signals in the time-delay domain to achieve fast modulation and demodulation of signals; while the scheme using OTFS technology carries data in the Doppler-delay domain, uses finite sigmoid Fourier transform and its inverse transform, and transmits signals in the time-delay domain. In response to this, the inventor proposes a signal gain transmission scheme based on the transform domain, which achieves signal expansion by transforming the signal domain to obtain more signal gain. Compared with OFDM technology, which can only achieve gain in the delay dimension and OTFS technology, which can only achieve gain in the time dimension, the scheme provided by the present invention aims to achieve diversity gain of the signal on the transformed full resource plane (that is, the signal obtains gain in both dimensions), so as to achieve the purpose of improving the performance of the receiving end while improving the transmission efficiency. Taking the time-frequency space signal as an example, the wireless signal is mapped to the Doppler-frequency domain at the transmitting end of the wireless communication system, and is transformed to the time-delay domain through a two-dimensional signal transformation for signal transmission; correspondingly, due to the change of the modulation mode (modulation of the baseband part), the received signal is transformed from the time-delay domain to the Doppler-frequency domain through the corresponding two-dimensional signal inverse transformation at the receiving end, and then the signal in the Doppler-frequency domain is restored through inverse mapping. Such a transmission mode enables the wireless signal to obtain not only the transmission gain in the time and delay dimensions, but also higher broadband transmission performance and transmission efficiency. It should be understood that the present invention is mainly aimed at improving the modulation of the baseband part in the existing wireless communication field (i.e., replacing OFDM modulation or OTFS modulation with the solution provided by the present invention), and the contents of other parts (such as encoding and decoding, constellation mapping, parallel / serial conversion, digital / analog conversion, up-conversion and down-conversion, etc.) belong to the existing technology in the field of wireless communication, so they will not be described in detail.

[0036] In order to better understand the present invention, the present invention is described from the perspectives of the transmitter, the receiver and the application scenario in combination with the embodiments and the accompanying drawings. It should be noted that the embodiments of the present invention are described by taking time-frequency-space signals as examples, but the types of wireless signals are not limited.

[0037] 1. Transmitter

[0038] According to one embodiment of the present invention, the present invention provides a signal transmission method based on a transform domain (or also referred to as a signal gain transmission method based on a transform domain), see Attachment 1. Figure 3 The method is used for the transmitting end of a wireless communication system. The method includes four steps A1, A2, A3 and A4. Each step is described below.

[0039] In step A1, constellation-mapped data symbols are mapped to the Doppler-frequency domain to obtain a first symbol matrix.

[0040] According to one embodiment of the present invention, the information bits to be sent are encoded at the transmitting end to generate an information sequence, and the information sequence is constellation mapped to obtain a symbol sequence consisting of multiple data symbols, and then the symbol sequence is mapped to the Doppler-frequency domain to obtain a first symbol matrix. For example, at the transmitting end, the information bits to be sent are obtained (usually generated by a source on the transmitting end), the information bits are encoded to generate an information sequence, and the information sequence is constellation mapped to generate a symbol sequence consisting of multiple data symbols, and then the symbol sequence is mapped to the Doppler-frequency to generate a first symbol matrix. The information bit refers to the data to be sent consisting of 0 and 1 bits. The coding rules used to encode the information bits may be the coding rules corresponding to Polar codes, LDPC codes and / or Turbo codes, or other existing available coding rules, as well as new coding rules that appear after this application, as long as they do not conflict with the principles of the present invention, they can still be used, and the present invention does not impose any restrictions on this. After the information bits to be sent are encoded to generate an information sequence, the information sequence is mapped to a symbol sequence consisting of multiple data symbols in the form of a constellation diagram through constellation mapping. Here, the constellation mapping method that can be used can be an existing constellation mapping method such as QAM, PSK, APSK, and a constellation mapping method that appears after this application, as long as it does not conflict with the principle of the present invention, it can still be used, and the present invention does not impose any restrictions on this. The mapping refers to filling a symbol sequence consisting of multiple (M×N) data symbols into a matrix of N rows×M columns in order to form a first symbol matrix, where M is equal to the total number of subcarriers, and the value of M×N is the total number of data symbols.

[0041] For example, suppose there is a segment of information bits to be sent, and it is encoded to generate an information sequence with a bit number of 16 [0 0 0 0 0 1 1 1 1 0 0 0 1 0 0 1], and then the information sequence is constellation mapped using the QPSK mapping in the constellation mapping method to obtain a symbol sequence consisting of 8 data symbols [-1+1i,-1+1i,1+1i,1-1i,-1-1i,-1+1i,-1-1i,1+1i]. Set M=4,M=2, and map the symbol sequence to the Doppler-frequency domain to obtain a first symbol matrix of size 2×4:

[0042]

[0043] In step A2, the first symbol matrix is ​​transformed from the Doppler-frequency domain to the time-delay domain by two-dimensional signal transformation to generate a second symbol matrix.

[0044] According to one embodiment of the present invention, the first symbol matrix is ​​transformed from the Doppler-frequency domain to the time-delay domain by two-dimensional signal transformation to generate a second symbol matrix. For example, the present invention first maps the symbol sequence to the Doppler-frequency domain (DF domain) to obtain a first symbol matrix, and then transforms the first symbol matrix from the Doppler-frequency domain to the time-delay domain by two-dimensional signal transformation to generate a second symbol matrix (the process diagram can be found in the attached figure). Figure 4 As shown). The symbol sequence is mapped into the Doppler-frequency domain (DF domain) through the above process. The two-dimensional signal is transformed into a two-dimensional inverse discrete Fourier transform (Two-Dimensional In-verse Discrete Fourier Transform, 2D-IDFT), and multiple data symbols are transformed from the Doppler-frequency domain to the time-delay domain (TD domain) through the two-dimensional inverse discrete Fourier transform to achieve the full diversity gain of the signal. The full diversity gain refers to the superposition of each data symbol in the first symbol matrix from the Doppler-frequency domain to the entire resource plane of the time-delay domain to generate a second symbol matrix (finally generating a second symbol matrix formed by superposition of M×N data symbols). In this process, the transformation and superposition are realized by the two-dimensional inverse discrete Fourier transform to achieve full utilization of resources. In general, the present invention maps data symbols into the Doppler-frequency domain, and then transforms the data symbols in the Doppler-frequency domain into the corresponding transformation domain of the time-delay domain through a two-dimensional signal transformation.

[0045] In the wireless communication system of the present invention, the bandwidth is set to B=MΔf, with a unit of Hz. The information bits to be sent are encoded and constellation mapped to obtain M×N data symbols, which are mapped to a symbol matrix of N rows×M columns on the Doppler-frequency domain resource plane, wherein M represents the total number of subcarriers, m represents the mth subcarrier, the value of M×N is the total number of data symbols, n represents the nth row of the matrix, and Δf represents the subcarrier frequency interval, with a unit of Hz.

[0046] At the transmitting end, it is assumed that the Doppler-frequency domain (DF domain) resource plane is represented as: Γ = {(kv, lΔf), k∈[0,N-1], l∈[0,M-1]}, and the Doppler interval T represents the time interval in seconds, and the frequency interval The bandwidth is B = MΔf.

[0047] Doppler-frequency domain data symbols: The transmitted signal is represented by x[k,l], k∈[0,N-1], l∈[0,M-1]; the received signal is represented by y[k,l], k∈[0,N-1], l∈[0,M-1].

[0048] According to one embodiment of the present invention, the transmitting end generates a full diversity gain signal by transforming the data symbol x[k, l] in the Doppler-frequency domain into the time-delay domain using a two-dimensional discrete Fourier inverse transform, wherein the two-dimensional discrete Fourier inverse transform is calculated as follows:

[0049]

[0050] Wherein, X[·] represents the data symbol in the time-delay domain of the transmitter, M represents the total number of subcarriers, the value of M×N is the total number of data symbols, x[·] represents the data symbol in the Doppler-frequency domain of the transmitter, k represents the kth delay interval, l represents the lth Doppler interval, n represents the nth row of the matrix, m represents the mth subcarrier, and j represents an imaginary number.

[0051] For example, a two-dimensional discrete Fourier inverse transform is performed on the first symbol matrix in the Doppler-frequency domain, and it is transformed into the time-delay domain to obtain the second symbol matrix:

[0052]

[0053] In step A3, the second symbol matrix is ​​parallel / serial converted and a cyclic prefix is ​​inserted to generate a third symbol matrix.

[0054] According to one embodiment of the present invention, the second symbol matrix obtained in step A2 is converted into a parallel / serial matrix in the time-delay domain, and a cyclic prefix is ​​inserted to generate a third symbol matrix. For example, the second symbol matrix in the form of a matrix on the two-dimensional plane in the time-delay domain is read out column by column and converted into a serial data stream by parallel / serial conversion, and a part of the data at the end of the serial data stream is copied to the front end of the data stream by inserting a cyclic prefix (also referred to as inserting a CP) so that the data length is equal to the maximum delay of the channel, and the third symbol matrix is ​​generated. Since the process of parallel / serial conversion and insertion of a cyclic prefix belongs to the well-known technology in the field of wireless communication, the specific process involved is not repeated here.

[0055] In step A4, a transmission signal is generated based on the third symbol matrix.

[0056] According to one embodiment of the present invention, the third symbol matrix obtained in step A3 is subjected to digital / analog conversion and up-conversion to generate a transmission signal and transmit the signal. For example, the third symbol matrix in the form of a digital signal is converted into an analog signal by digital / analog conversion (DAC), and then the analog signal is added to a carrier by up-conversion to form a signal to be transmitted so as to transmit the signal (send a wireless signal through an antenna). Since the specific process of digital / analog conversion and up-conversion belongs to the well-known technology in the field of wireless communication, it will not be specifically described here.

[0057] 2. Receiver

[0058] According to one embodiment of the present invention, the present invention provides a signal receiving method based on a transform domain (or also referred to as a signal gain receiving method based on a transform domain), see Attachment 1. Figure 5 The method is used at the receiving end of a wireless communication system. The method includes four steps: B1, B2, B3 and B4. Each step is described below.

[0059] In step B1, a transmission signal transmitted by a transmitting end is received at a receiving end to obtain a received signal, and a third symbol matrix is ​​obtained based on the received signal.

[0060] According to one embodiment of the present invention, a signal transmitted by a transmitting end is received at a receiving end to obtain a received signal, and the received signal is subjected to down-conversion and analog / digital conversion to obtain a third symbol matrix. For example, a signal transmitted by a transmitting end is received at a receiving end to obtain a received signal, an analog signal is extracted from a carrier of the received signal by down-conversion, and the analog signal is subjected to analog / digital conversion to obtain a third symbol matrix in the form of a digital signal.

[0061] In step B2, the cyclic prefix is ​​removed from the third symbol matrix, and a serial / parallel conversion is performed to generate a second symbol matrix.

[0062] According to one embodiment of the present invention, the cyclic prefix is ​​removed from the third symbol matrix obtained in step B1 in the time-delay domain, and a serial / parallel conversion is performed to generate a second symbol matrix. For example, the present invention removes the cyclic prefix (removes the CP) from the third symbol matrix in the time-delay domain, and restores the serial data to a second symbol matrix in a matrix form on a two-dimensional plane through a serial / parallel conversion.

[0063] For example, the second symbol matrix at this time is (it should be understood that this is an ideal state):

[0064]

[0065] In step B3, the second symbol matrix is ​​transformed from the time-delay domain to the Doppler-frequency domain by two-dimensional signal inverse transformation to generate a first symbol matrix.

[0066] According to one embodiment of the present invention, the present invention performs a two-dimensional signal inverse transformation on the second symbol matrix in the time-delay domain to transform it into the Doppler frequency domain to generate a first symbol matrix (the process diagram can be found in the attached Figure 6 The two-dimensional signal inverse transform is a two-dimensional discrete Fourier transform (2D-DFT), through which the data symbols of the full diversity gain state are transformed from the time-delay domain to the Doppler-frequency domain to restore to the state before the full diversity gain.

[0067] Correspondingly, at the receiving end, assuming that the time-delay domain (TD domain) resource plane is represented by Λ={(nT,mτ),n∈[0,N-1],m∈[0,M-1]},N,M>0; the delay interval The unit is seconds, the time domain duration is T f =NT, in seconds.

[0068] Time-delay domain data symbol: the transmitted signal is X[n,m], n∈[0,N-1], m∈[0,M-1]; the received signal is Y[n,m], n∈[0,N-1], m∈[0,M-1].

[0069] According to an embodiment of the present invention, after receiving the signal, the receiving end maps the signal to the time-delay domain to obtain Y[n,m], and uses a two-dimensional discrete Fourier transform to transform the signal of the full diversity gain into a data symbol in the Doppler-frequency domain:

[0070]

[0071] Wherein, y[·] represents the data symbol in the Doppler-frequency domain of the receiving end, k represents the kth delay interval, l represents the lth Doppler interval, Y[·] represents the data symbol in the time-delay domain of the receiving end, M represents the total number of subcarriers, the value of M×N is the total number of data symbols, n represents the nth row of the matrix, m represents the mth subcarrier, and j represents an imaginary number.

[0072] For example, a two-dimensional discrete Fourier transform is performed on the second symbol matrix in the time-delay domain, and it is transformed into the Doppler-frequency domain to obtain the first symbol matrix (it should be understood that this is an ideal state):

[0073]

[0074] In step B4, the first symbol matrix is ​​inversely mapped to obtain data symbols and constellation demapping is performed.

[0075] According to one embodiment of the present invention, at the receiving end, the first symbol matrix is ​​inversely mapped in the Doppler-frequency domain to generate a symbol sequence, the symbol sequence is constellation demapped to generate an information sequence, the information sequence is decoded, the information bit corresponding to the received signal is obtained, and it is transmitted to the destination. The inverse mapping is to arrange each data symbol in the first symbol matrix of N rows × M columns arranged in the Doppler-frequency domain into a sequence one by one according to the arrangement order and restore it to a symbol sequence, wherein M is equal to the total number of subcarriers and N is equal to the total number of data symbols. In general, corresponding to the process of transforming the domain at the transmitting end, the receiving end restores the data symbols in the time-delay domain to the Doppler-frequency domain through a two-dimensional signal inverse transform through the inverse process of the corresponding transform domain. The decoding rules used to decode the information bits are the decoding rules corresponding to the encoding rules of Polar codes, LDPC codes and / or Turbo codes, or other decoding rules available, as well as new decoding rules that appear after this application, as long as they do not conflict with the principles of the present invention, they can still be used, and the present invention does not impose any restrictions on this. Constellation demapping is the inverse process of constellation mapping, which is used to restore a symbol sequence composed of multiple data symbols in the form of a constellation diagram to an information sequence. Here, the constellation demapping method that can be used can be the constellation demapping method corresponding to the existing constellation mapping methods such as QAM, PSK, APSK, etc., as well as the constellation demapping method that appears after this application, which can still be used as long as it does not conflict with the principles of the present invention, and the present invention does not impose any restrictions on this.

[0076] For example, after inverse mapping, the first symbol matrix is ​​restored to a symbol sequence consisting of 8 data symbols [-1+1i,-1+1i,1+1i,1-1i,-1-1i,-1+1i,-1-1i,1+1i], and the symbol sequence is constellation demapping performed using the demapping corresponding to the QPSK mapping in the constellation mapping method to restore it to an information sequence with a bit number of 16 [0 0 0 0 0 1 1 11 0 0 0 1 0 0 1], which is then decoded and finally restored to the information bits transmitted by the transmitter.

[0077] For the transformation relationship between the Doppler-frequency domain and the time-delay domain corresponding to the entire transmitting end and the receiving end, please refer to the attached Figure 7 shown.

[0078] 3. Application Scenarios

[0079] According to one embodiment of the present invention, the present invention also provides a wireless communication method based on a transform domain, which is used in a wireless communication system including a transmitting end and a receiving end. The method includes using the above-mentioned signal transmission method based on the transform domain at the transmitting end of the wireless communication system to transmit a wireless signal, and using the above-mentioned signal receiving method based on the transform domain at the receiving end of the wireless communication system to receive the wireless signal.

[0080] According to one embodiment of the present invention, the present invention further provides a wireless communication system, as shown in the attached Figure 8 As shown, it includes a transmitting end and a receiving end. The transmitting end uses a signal transmitting method based on a transform domain to transmit a signal to be transmitted, and the receiving end uses a signal receiving method based on a transform domain to receive the signal transmitted by the transmitting end.

[0081] Specifically, the transmitting end encodes the information bits to be sent (the information bits to be sent are usually generated by a signal source) to generate an information sequence, and performs constellation mapping on the information sequence to obtain a symbol sequence composed of multiple data symbols; the transmitting end maps the obtained symbol sequence to the Doppler-frequency domain to obtain a first symbol matrix, and transforms the first symbol matrix from the Doppler-frequency domain to the time-delay domain through a two-dimensional discrete Fourier inverse transform to generate a second symbol matrix; the transmitting end performs parallel / serial conversion on the second symbol matrix in the time-delay domain, and inserts a cyclic prefix to generate a third symbol matrix; the transmitting end generates a signal by subjecting the third symbol matrix to digital / analog conversion and up-conversion, and transmits the signal. The receiving end receives the signal transmitted by the transmitting end, and obtains a third symbol matrix after down-conversion and analog / digital conversion; the receiving end removes the cyclic prefix of the obtained third symbol matrix in the time-delay domain, and performs serial / parallel conversion to generate a second symbol matrix; the receiving end transforms the obtained second symbol matrix from the time-delay domain to the Doppler-frequency domain through a two-dimensional discrete Fourier transform to generate a first symbol matrix, and inversely maps the first symbol matrix in the Doppler-frequency domain to obtain a symbol sequence; the receiving end constellation demaps the obtained symbol sequence to generate an information sequence, and decodes based on the information sequence to generate information bits and transmits them to a destination.

[0082] In order to verify the technical effect of the present invention, the inventors conducted a simulation performance test based on the 5G physical downlink shared channel (PDSCH). The specific test case parameters are shown in Table 1. The system block error rate of the scheme of the present invention is compared with that of the existing OFDM scheme and OTFS scheme. Fig. 9 From the block error rate performance comparison shown in the figure, it can be seen that under the same system block error rate (BLER), the solution of the present invention requires lower power, that is, the signal-noise ratio (SNR) is lower. Therefore, the performance of the solution of the present invention is significantly better than the current mainstream transmission solutions OFDM and OTFS, and can significantly improve broadband transmission capabilities.

[0083] Table 1

[0084]

[0085]

[0086] Compared with the prior art, the advantages of the present invention are:

[0087] 1. Compared with the current mainstream OFDM technology and OTFS technology, the present invention can achieve higher broadband transmission performance and transmission efficiency.

[0088] 2. The present invention realizes the acquisition of signal diversity gain in the full resource plane through two-dimensional signal transformation, which can effectively improve the transmission efficiency and the receiving end performance.

[0089] It should be noted that although the above describes the various steps in a specific order, it does not mean that the various steps must be executed in the above specific order. In fact, some of these steps can be executed concurrently or even in a different order as long as the required functions can be achieved.

[0090] The present invention may be a system, a method and / or a computer program product. The computer program product may include a computer-readable storage medium carrying computer-readable program instructions for causing a processor to implement various aspects of the present invention.

[0091] Computer readable storage medium can be a tangible device that holds and stores instructions used by an instruction execution device. Computer readable storage medium can include, for example, but is not limited to, an electrical storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination thereof. More specific examples (non-exhaustive list) of computer readable storage medium include: a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a static random access memory (SRAM), a portable compact disk read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanical encoding device, for example, a punch card or a protruding structure in a groove on which instructions are stored, and any suitable combination thereof.

[0092] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or technical improvements in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A signal transmission method based on transform domain, characterized in that: The method comprises: A1. Mapping the constellation-mapped data symbols to the Doppler-frequency domain to obtain a first symbol matrix, wherein the mapping in step A1 is to fill a symbol sequence consisting of a plurality of data symbols into a matrix of N rows×M columns in sequence to form the first symbol matrix, wherein M is equal to the total number of subcarriers, and the value of N×M is the total number of data symbols; A2. Transforming the first symbol matrix from the Doppler-frequency domain to the time-delay domain by two-dimensional signal transformation to generate a second symbol matrix, wherein in the step A2, a plurality of data symbols are transformed from the Doppler-frequency domain to the time-delay domain by two-dimensional inverse discrete Fourier transform to achieve full diversity gain of the signal, wherein the full diversity gain refers to superimposing the entire resource plane of each data symbol in the first symbol matrix from the Doppler-frequency domain to the time-delay domain to generate the second symbol matrix; A3, performing parallel / serial conversion on the second symbol matrix, and inserting a cyclic prefix to generate a third symbol matrix; A4. Generate a transmit signal based on the third symbol matrix.

2. The method according to claim 1, characterized in that The two-dimensional inverse discrete Fourier transform is calculated as follows: Wherein, X[·] represents the data symbol in the time-delay domain of the transmitter, M represents the total number of subcarriers, the value of M×N is the total number of data symbols, x[·] represents the data symbol in the Doppler-frequency domain of the transmitter, k represents the kth delay interval, l represents the lth Doppler interval, n represents the nth row of the matrix, m represents the mth subcarrier, and j represents an imaginary number.

3. A signal receiving method for the transform domain based signal transmission method according to claim 1 or 2, characterized in that: The method comprises: B1. Receiving, at a receiving end, a transmission signal transmitted by a transmitting end to obtain a received signal, and obtaining a third symbol matrix based on the received signal; B2. removing a cyclic prefix from the third symbol matrix and performing a serial / parallel conversion to generate a second symbol matrix; B3, transforming the second symbol matrix from the time-delay domain to the Doppler-frequency domain by two-dimensional signal inverse transformation to generate a first symbol matrix; B4. Inversely map the first symbol matrix to obtain data symbols and perform constellation demapping.

4. The method according to claim 3, characterized in that In step B3, multiple data symbols are transformed from the time-delay domain to the Doppler-frequency domain by two-dimensional discrete Fourier transform to restore the signal of the full diversity gain.

5. The method according to claim 4, characterized in that The two-dimensional discrete Fourier transform is calculated as follows: Wherein, y[·] represents the data symbol in the Doppler-frequency domain of the receiving end, k represents the kth delay interval, l represents the lth Doppler interval, Y[·] represents the data symbol in the time-delay domain of the receiving end, M represents the total number of subcarriers, the value of M×N is the total number of data symbols, n represents the nth row of the matrix, m represents the mth subcarrier, and j represents an imaginary number.

6. The method according to claim 3, characterized in that The inverse mapping in step B4 is to arrange each data symbol in the first symbol matrix of N rows×M columns arranged in the Doppler-frequency domain into a sequence one by one according to the arrangement order, where M is equal to the total number of subcarriers and the value of M×N is the total number of data symbols.

7. A wireless communication method based on transform domain, characterized in that: The method comprises: Transmitting a wireless signal according to the method of claim 1 or 2; The wireless signal is received according to the method according to any one of claims 3-6.

8. A wireless communication system, comprising a transmitting end and a receiving end, characterized in that ， The transmitting end transmits the information bits to be sent according to the method of claim 1 or 2; The receiving end receives the signal transmitted by the transmitting end according to one of the methods of claims 3-6 to obtain the information bits.

9. A computer-readable storage medium, characterized in that: A computer program is stored thereon, and the computer program can be executed by a processor to implement the steps of any method described in claims 1-7.

10. An electronic device, characterized in that: include: one or more processors; A storage device for storing one or more programs, which, when executed by the one or more processors, enables the electronic device to implement the steps of the method as claimed in any one of claims 1 to 7.

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