A WFRFT parameter and modulation mode combined two-dimensional index transmission method

Abstract

The application discloses a kind of WFRFT parameter and modulation mode joint two-dimensional index modulation multi-subband transmission method, it belongs to wireless communication field.The present application solves the problem of low spectrum utilization rate of existing method.The application sets each subcarrier possible constellation map mapping mode to two, and then changes subcarrier constellation mapping mode as first dimension index information transmission, and weighted fractional fourier transform coefficient is used as second dimension index information transmission, the index mode has higher spectrum utilization rate compared with traditional one-dimensional index, and increases the security of system while improving spectrum utilization rate, so it can also be applied to high-speed transmission and secure communication.The method of the application can be applied to wireless communication field.

Description

Technical Field

[0001] This invention belongs to the field of wireless communication, specifically relating to a multi-subband transmission method that uses WFRFT (Weighted-Type Fractional Fourier Transform) parameters and modulation modes in conjunction with two-dimensional index modulation. Background Technology

[0002] With the development of modern communication systems, people have increasingly higher demands for these systems, requiring higher speeds, lower latency, and more diverse applications, such as ultra-high-definition video, telemedicine, smart cities, and smart homes. This has led to further congestion of spectrum resources. Therefore, to solve the problem of spectrum congestion, it is necessary to expand to higher frequencies and improve spectrum utilization.

[0003] The concept of indexed modulation has attracted widespread attention since its inception. Indexed modulation refers to the method of controlling the transmission of information at the transmitting end through index information. For example, it controls the number and arrangement of the transmit antenna, subcarriers, spreading code, and time slots to transmit additional index information. After correct demodulation at the receiving end, the index information can be obtained by looking up the index. Because the index information is embedded in the transmitted or received signal, it consumes little or no power. Using this method to transmit information can improve energy efficiency and spectral efficiency. Currently, most research combines indexed modulation with OFDM, using index information to control the activated subcarriers at the transmitting end. Information is transmitted in two ways: one is using classical amplitude modulation and phase modulation, and the other is using the index method implicit in the subcarrier activation. This improves the power efficiency and spectral efficiency of the OFDM system. However, existing methods are all one-dimensional indexed modulation techniques, and the spectral efficiency of one-dimensional indexed modulation techniques is still relatively low. Summary of the Invention

[0004] The purpose of this invention is to solve the problem of low spectrum utilization in existing methods, and to propose a multi-subband transmission method that combines WFRFT parameters and modulation modes with two-dimensional index modulation.

[0005] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows:

[0006] A multi-subband transmission method using WFRFT parameters and modulation modes combined with two-dimensional index modulation, the method specifically includes the following steps:

[0007] At the sending end

[0008] Step 1: For data with a length of Bit binary source information sequence Perform bit segmentation, that is Average score Group, among which , , , It is the number of information bits contained in each group of data;

[0009] Each group of data corresponds to a sub-band after grouping, and each sub-band includes... Subcarriers, , yes The total number of subcarriers contained in each subband;

[0010] No. The grouped data corresponding to each sub-band includes: constellation pattern index information. Subband precoding index information and modulation information , , , and All are binary sequences. , and They are binary sequences , and Length;

[0011] Step 2, for the first Each sub-band, based on sub-band precoding index information Map a WFRFT parameter Based on constellation pattern index information Map to a length of Constellation pattern index sequence Constellation pattern index sequence The subcarrier corresponding to "1" is modulated using modulation mode A, and the subcarrier corresponding to "0" is modulated using modulation mode B.

[0012] Step 3, according to Modulation information Modulation is performed to obtain the modulated symbol sequence. ,in, They are the first The first, second, ..., second of the sub-bands Modulated data of each subcarrier;

[0013] right Perform the following parameters The weighted fractional Fourier transform is used to obtain the weighted fractional Fourier transform result. ,in, The first The first, second, ..., second of the sub-bands The weighted fractional Fourier transform results of the modulated data of each subcarrier;

[0014] Step 4: Repeat steps 2 to 3 to obtain the weighted fractional Fourier transform results for each sub-band.

[0015] The weighted fractional Fourier transform results corresponding to each sub-band are concatenated in order to obtain the concatenated result. Then, the spliced ​​results are subjected to IFFT and parallel-to-serial conversion processes in sequence to obtain the final result. ; give again Add length is cyclic prefix Get the data after adding the loop prefix. The data with the added loop prefix will be sent out.

[0016] At the receiving end

[0017] Step 5: Represent the serial data points received by the receiving end as follows: The superscript T represents transpose. After removing the cyclic prefix, the serial data points are obtained. And then Perform serial-to-parallel conversion to obtain the converted data. ;

[0018] right Perform FFT transform to obtain the frequency domain signal And then Perform frequency domain equalization to obtain the equalized signal. ;

[0019] Step Six: According to the distribution principle of the transmitting end, distribute the equalized signal... Divided into Each sub-band contains The symbol, the first The symbol for each sub-band is , ;

[0020] Step 7, for the first Each sub-band, for the first The WFRFT parameters of each subband and the constellation pattern index sequence are identified, and then the precoded index information is estimated based on the WFRFT parameters. Estimate constellation pattern index information based on constellation pattern index sequence ;

[0021] Based on the identified WFRFT parameters, the first The symbols of each sub-band are pre-decoded using WFRFT to obtain the decoding result. The decoding result of each subband is represented as ;

[0022] Step 8: Based on the constellation pattern index sequence recognition results, identify the first... The decoding results of each sub-band are demodulated to obtain the first... Modulation information of each subband The corresponding demodulation information, based on , and modulation information The corresponding demodulation information is obtained as follows: Each sub-band corresponds to the received information;

[0023] Step 9: Perform steps 7 and 8 on each sub-band to obtain the received information corresponding to each sub-band; then perform bit combining on the received information of each sub-band to obtain the complete received information.

[0024] Furthermore, the aforementioned .

[0025] Furthermore, the constellation pattern index information length for:

[0026]

[0027] in, For the first The number of subcarriers with modulation mode A in each subband For the first The number of subcarriers with modulation mode B in each subband This represents rounding down to the nearest integer.

[0028] Furthermore, the modulation information length for:

[0029]

[0030] in, The number of constellation points corresponding to modulation mode A. This indicates the number of constellation points corresponding to modulation mode B.

[0031] Furthermore, the transformation process of the weighted fractional Fourier transform is as follows:

[0032]

[0033] in, Representative to Perform a weighted fractional Fourier transform. for The Fourier transform result, for The inverse form, for The inverse form, , , and These are weighting coefficients. For WFRFT parameters;

[0034]

[0035] in, , It is the imaginary unit.

[0036] Furthermore, the method for identifying the WFRFT parameters is as follows:

[0037] Step 1, for the first Each sub-band, respectively for Do WFRFT transform of order 1 Data points obtained after WFRFT transformation , ;

[0038] for Find the corresponding points from all constellation points of modulation mode A and modulation mode B. Recent constellation points, then calculate. Euclidean distance to the nearest constellation point ;

[0039] Similarly, for data points Each piece of data in the dataset is processed sequentially to obtain... ; then By summing, we get The corresponding accumulated results are then used as the negative of the order corresponding to the smallest accumulated result as the first... WFRFT parameter estimation results for each sub-band;

[0040] Step 2: Perform the process of Step 1 on each subband to obtain the WFRFT parameter estimation results for each subband.

[0041] Furthermore, the method for identifying the constellation pattern index sequence is as follows:

[0042] for If with If the nearest constellation point is in the constellation point set of modulation mode A, then the estimated value of the position of the first subcarrier in the constellation mode index sequence is 1; otherwise, the estimated value of the position of the first subcarrier is 0.

[0043] Similarly, for After processing sequentially, the estimated position of each subcarrier in the constellation mode index sequence is obtained, that is, the position of the first subcarrier is obtained. Initial estimation results of the constellation pattern index sequence of each sub-band;

[0044] Let the set of constellation pattern index sequences be ,but , Represents a set The total number of constellation pattern index sequences included; calculate the initial estimated constellation pattern index sequences and sets respectively. The Hamming distance of each constellation pattern index sequence in the set is used to find the minimum Hamming distance in the set. The corresponding constellation pattern index sequence is used as the final estimated constellation pattern index sequence;

[0045] Similarly, the final estimation results of the constellation pattern index sequence corresponding to each sub-band are obtained.

[0046] The beneficial effects of this invention are:

[0047] This invention sets two possible constellation mapping modes for each subcarrier, transmits the changes in the subcarrier constellation mapping modes as the first-dimensional index information, and transmits the weighted fractional Fourier transform coefficients as the second-dimensional index information. Compared with the traditional one-dimensional index, this indexing method has a higher spectrum utilization rate, and while improving the spectrum utilization rate, it also increases the system's confidentiality. Therefore, it can be applied to high-speed transmission and secure communication. Attached Figure Description

[0048] Figure 1 This is a flowchart of the sending end of the method of the present invention;

[0049] Figure 2 This is a schematic diagram of two QPSK constellation modulation methods;

[0050] Figure 3 This is a flowchart of the receiving end processing of the method of the present invention;

[0051] Figure 4 A flowchart for estimating WFRFT parameters using the maximum constellation likelihood method;

[0052] Figure 5 This is a graph showing the bit error rate of dual-mode modulation.

[0053] In the figure, BER represents the bit error rate;

[0054] Figure 6 The bit error rate curve for a two-dimensional indexed modulation system demodulated using the maximum constellation likelihood method. Detailed Implementation

[0055] Specific Implementation Method 1: Combination Figure 1 and Figure 3 This embodiment describes a multi-subband transmission method using WFRFT parameters and modulation modes combined with two-dimensional index modulation. The method specifically includes the following steps:

[0056] At the sending end

[0057] Step 1: For data with a length of A sequence of binary source information bits Perform bit segmentation, that is Average score Group (will) As the first set of data, As the second set of data, ..., will As the first (set data), among which , , , It is the number of information bits contained in each data set;

[0058] Each group of data corresponds to a sub-band (total of 1000 data points). Each sub-band contains data in a one-to-one correspondence with each sub-band, and each sub-band includes... Subcarriers, , yes The total number of subcarriers contained in each subband;

[0059] No. The grouped data corresponding to each sub-band includes: constellation pattern index information. Subband precoding index information and modulation information , , , and All are binary sequences. , and They are binary sequences , and Length;

[0060] Step 2, for the first Each sub-band, based on sub-band precoding index information Map a WFRFT parameter , , , Is The size obtained by discrete sampling within the range of values ​​is A collection; indexed by constellation pattern. Map to a length of Constellation pattern index sequence Constellation pattern index sequence The subcarrier corresponding to "1" is modulated using modulation mode A, and the subcarrier corresponding to "0" is modulated using modulation mode B. The constellation mode index sequences output by the modulation mode selection module are different for each constellation mode. There are a total of... The set of all possible cases constitutes the subband modulation mode characterization set. , , for the Sub-bands, their index information The output after the modulation mode selection module is , ;

[0061] Step 3, according to Modulation information Modulation is performed to obtain the modulated symbol sequence. ,in, They are the first The first, second, ..., second of the sub-bands Modulated data of each subcarrier;

[0062] right Perform the following parameters The weighted fractional Fourier transform is used to obtain the weighted fractional Fourier transform result. ,in, The first The first, second, ..., second of the sub-bands The weighted fractional Fourier transform results of the modulated data of each subcarrier;

[0063] Step 4: Repeat steps 2 to 3 to obtain the weighted fractional Fourier transform results for each sub-band.

[0064] The weighted fractional Fourier transform results corresponding to each sub-band are concatenated in order (according to their order in the binary source information sequence) to obtain the concatenated result. The concatenated result is then subjected to IFFT (Inverse Fast Fourier Transform) and parallel-to-serial conversion processes to obtain the final result. ; give again Add length is cyclic prefix Get the data after adding the loop prefix. The data with the added loop prefix will be sent out.

[0065] At the receiving end

[0066] Step 5: Represent the serial data points received by the receiving end as follows: The superscript T represents transpose. After removing the cyclic prefix, the serial data points are obtained. And then Perform serial-to-parallel conversion to obtain the converted data. ;

[0067] right The frequency domain signal is obtained by performing an FFT (Fast Fourier Transform). And then Perform frequency domain equalization to obtain the equalized signal. ;

[0068] Step Six: According to the distribution principle of the transmitting end, distribute the equalized signal... Divided into Each sub-band contains The symbol, the first The symbol for each sub-band is , ;

[0069] Step 7, for the first Each sub-band, for the first The WFRFT parameters of each subband and the constellation pattern index sequence are identified, and then the precoded index information is estimated based on the WFRFT parameters. Estimate constellation pattern index information based on constellation pattern index sequence ;

[0070] Based on the identified WFRFT parameters, the first The symbols of the nth subband are pre-decoded using WFRFT (i.e., WFRFT is performed on the symbols of the corresponding subband according to the identified WFRFT parameters, where the order of the WFRFT is the negative of the identified WFRFT parameters) to obtain the decoding result. The decoding result of each subband is represented as ;

[0071] Step 8: Based on the constellation pattern index sequence recognition results, identify the first... The decoding results of each sub-band are demodulated to obtain the first... Modulation information of each subband The corresponding demodulation information, based on , and modulation information The corresponding demodulation information is obtained as follows: Each sub-band corresponds to the received information;

[0072] Step 9: Perform steps 7 and 8 on each sub-band to obtain the received information corresponding to each sub-band; then perform bit combining on the received information of each sub-band to obtain the complete received information.

[0073] The implementation of the two-dimensional index in this invention involves dividing the transmitted information into several sub-bands. Each sub-band transmits information consisting of index information and modulation information. The index information is further divided into constellation mode index information and sub-band precoding index information, resulting in a total of three parts of information transmission. The first part is the constellation mode index information controlling the transmission constellation mapping mode, and the second part controls the weighted fractional Fourier transform parameters. The sub-band precoding index information, the third part is the modulation information mapped by different constellation diagram modes, and the receiver uses parameters... The estimation is used to decode the subband precoding index information, and the correct identification of the constellation mapping pattern is used to decode the constellation pattern index information. Then, the third part of the modulation information is digitally demodulated to obtain the demodulated information. Furthermore, this invention employs a maximum constellation likelihood method to simultaneously analyze the WFRFT parameters. Identify modulation patterns and, After the parameters are correctly estimated, the receiver processes the signal. The modulation information is then decoded using a WFRFT operation of order 1, followed by digital demodulation to recover the modulation information. The constellation pattern index information is obtained by identifying the modulation pattern. Simulation results demonstrate that this identification method has excellent recognition performance.

[0074] In this invention, mapping WFRFT parameters based on subband precoding index information and mapping constellation pattern index sequences based on constellation pattern index information are performed according to pre-defined mapping relationships. Assume the first... Each subcarrier has 4 subcarriers, of which 2 subcarriers are modulated in mode A, and the other 2 subcarriers are modulated in mode B, i.e. , , The index information is 2 bits, that is As shown in Table 1, the constellation pattern index information There are four indexing methods, namely: , , , , corresponding to the modulation mode representation set The four elements, , , , ,gather In the element sequence, the position corresponding to "1" indicates that the subcarrier position uses modulation mode A, and the position corresponding to "0" indicates that the subcarrier position uses modulation mode B. For example, This indicates that the modulation mode of the first and second subcarriers out of the four subcarriers is A, and the modulation mode of the third and fourth subcarriers is B. This indicates that the modulation mode of the 2nd and 3rd subcarriers out of the four subcarriers is A, and the modulation mode of the 1st and 4th subcarriers is B. This indicates that the modulation mode of the 3rd and 4th subcarriers is A, and the modulation mode of the 1st and 2nd subcarriers is B. This indicates that the modulation mode of the 1st and 4th subcarriers is A, and the modulation mode of the 2nd and 3rd subcarriers is B. Establish the indexing method and set. After establishing the one-to-one correspondence between the sequences, the constellation pattern index sequence can be mapped according to the indexing method.

[0075] Table 1. Correspondence between constellation mode index information and subcarrier modulation mode

[0076]

[0077] Similarly, after establishing a one-to-one correspondence between subband precoding index information and WFRFT parameters, the WFRFT parameters can be mapped from the subband precoding index information. Taking g2=2 as an example to illustrate this correspondence, in this case... The sequence length is 2, and the mapping rules between the subband precoding index information and the WFRFT parameters are shown in Table 2.

[0078] Table 2 Subband Precoding Index Information and Parameter correspondence table

[0079]

[0080] Subband precoding indexing essentially utilizes the information shared by all subcarriers within the entire subband. The larger the subband size and the more subcarriers, the greater the energy representing each bit of subband precoding index information, making it easier to determine the appropriate subband precoding index. Conversely, a larger set of precoding parameters offers more selectable parameters, resulting in smaller differences between different subbands and making it more difficult to determine the appropriate precoding parameters. Therefore, a trade-off between information transmission efficiency and transmission performance (effectiveness and reliability) must be considered in application.

[0081] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that... .

[0082] The other steps and parameters are the same as in Specific Implementation Method 1.

[0083] Specific Implementation Method Three: This implementation method differs from Specific Implementation Method One or Two in that the constellation pattern index information... length for:

[0084]

[0085] in, For the first The number of subcarriers with modulation mode A in each subband For the first The number of subcarriers with modulation mode B in each subband This represents rounding down to the nearest integer.

[0086] Other steps and parameters are the same as in specific implementation method one or two.

[0087] Specific Implementation Method Four: This implementation method differs from Specific Implementation Methods One to Three in that the modulation information... length for:

[0088]

[0089] in, The number of constellation points corresponding to modulation mode A. This indicates the number of constellation points corresponding to modulation mode B.

[0090] The other steps and parameters are the same as those in one of the specific implementation methods one to three.

[0091] set up This represents the set of constellation points corresponding to modulation mode A. , The number of constellation points corresponding to modulation mode A. This represents the set of constellation points corresponding to modulation mode B. , This indicates the number of constellation points corresponding to modulation mode B. To distinguish between the two modulation modes at the receiver, it is required that... and The intersection of constellation points is an empty set. Figure 2 This is an example of a feasible constellation diagram scheme for constellation pattern indexing. In the diagram, dots represent modulation mode A, squares represent modulation mode B, and both modulation modes A and B have a modulation order of 4. The set... for ,gather for .

[0092] The number of bits carried by each symbol in constellation-indexed modulation mode can be calculated using the following formula:

[0093]

[0094] From the above formula, we can obtain that if If it is determined, then the information bits transmitted by the constellation pattern index information are: According to the properties of permutations and combinations, for a fixed... In order to make maximum, It should be set to ,if and equal, This method of modulation is compared to the traditional The number of bits that each symbol can carry in the modulated base is:

[0095]

[0096] Specific Implementation Method Five: This implementation method differs from Specific Implementation Methods One to Four in that the transformation process of the weighted fractional Fourier transform is as follows:

[0097]

[0098] in, Representative to Perform a weighted fractional Fourier transform. for The Fourier transform result, for The inverse form, for The inverse form, , , and These are weighting coefficients. For WFRFT parameters;

[0099]

[0100] in, , It is the imaginary unit.

[0101] The other steps and parameters are the same as those in one of the specific implementation methods one to four.

[0102] Because WFRFT signals have the property of rotation and addition, the receiver can perform... Demodulate using a WFRFT transform of order 1.

[0103] Specific Implementation Method Six: Combination Figure 4 This embodiment is described below. The difference between this embodiment and one of the specific embodiments one to five is that the method for identifying the WFRFT parameters is as follows:

[0104] Step 1, for the first Each sub-band, respectively for Do WFRFT transform of order 1 Data points obtained after WFRFT transformation , ;

[0105] for Find the corresponding points from all constellation points of modulation mode A and modulation mode B. Recent constellation points, then calculate. Euclidean distance to the nearest constellation point ;

[0106] Similarly, for data points Each piece of data in the dataset is processed sequentially to obtain... ; then By summing, we get The corresponding accumulated results are then used as the negative of the order corresponding to the smallest accumulated result as the first... WFRFT parameter estimation results for each sub-band;

[0107] Step 2: Perform the process of Step 1 on each subband to obtain the WFRFT parameter estimation results for each subband.

[0108] The other steps and parameters are the same as those in one of the specific implementation methods one to five.

[0109] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Methods One through Six in that the method for identifying the constellation pattern index sequence is as follows:

[0110] for If with If the nearest constellation point is in the constellation point set of modulation mode A, then the estimated value of the position of the first subcarrier in the constellation mode index sequence is 1; otherwise, the estimated value of the position of the first subcarrier is 0.

[0111] Similarly, for After processing sequentially, the estimated position of each subcarrier in the constellation mode index sequence is obtained, that is, the position of the first subcarrier is obtained. Initial estimation results of the constellation pattern index sequence of each sub-band;

[0112] Let the set of constellation pattern index sequences be ,but , Represents a set The total number of constellation pattern index sequences included; calculate the initial estimated constellation pattern index sequences and sets respectively. The Hamming distance of each constellation pattern index sequence in the set is used to find the minimum Hamming distance in the set. The corresponding constellation pattern index sequence is used as the final estimated constellation pattern index sequence;

[0113] Similarly, the final estimation results of the constellation pattern index sequence corresponding to each sub-band are obtained.

[0114] The other steps and parameters are the same as those in one of the specific implementation methods one to six.

[0115] This invention proposes a method that uses maximum constellation likelihood to simultaneously identify sub-band precoding parameters and the modulation mode of each subcarrier, which reduces computational complexity compared to the traditional maximum likelihood method.

[0116] Simulation of the bit error rate for this type of dual-mode modulation is as follows: Figure 5 As shown, the constellation points for this simulation are set as follows: Figure 2 As shown, it is divided into mode A and mode B, with the number of subcarriers... It is 4. The number of simulations is 2. , Figure 5 Displays the bit error rate curves for one-dimensional constellation index modulation, two-dimensional index modulation, QPSK, and 8PSK modulation.

[0117] Figure 6 The figure shows the bit error rate (BER) curves estimated for a two-dimensional indexed modulation system using the maximum constellation likelihood method. The curves include the BER curves for constellation mode index information, sub-band precoding index information, modulation information, and the BER curve for the sum of these three information components. The number of simulations was As can be seen from the figure, the bit error rate of constellation mode index information is the highest, the bit error rate of modulation information is the lowest, and the bit error rate curve of the sum of the three types of information is between that of modulation information and subband precoding index information.

[0118] The above examples of the present invention are merely illustrative of the computational model and process of the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is impossible to exhaustively list all possible implementations here. Any obvious variations or modifications derived from the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A two-dimensional index transmission method for WFRFT parameters and modulation modes, characterized in that, The method specifically includes the following steps: At the sending end Step 1: For data with a length of Bit binary source information sequence Perform bit segmentation, that is Average score Group, among which , , , It is the number of information bits contained in each data set; Each group of data corresponds to a sub-band after grouping, and each sub-band includes... Subcarriers, , yes The total number of subcarriers contained in each subband; No. The grouped data corresponding to each sub-band includes: constellation pattern index information. Subband precoding index information and modulation information , , , and All are binary sequences. , and They are binary sequences , and Length; Step 2, for the first Each sub-band, based on sub-band precoding index information Map a WFRFT parameter Based on constellation pattern index information Map to a length of Constellation pattern index sequence Constellation pattern index sequence The subcarrier corresponding to "1" is modulated using modulation mode A, and the subcarrier corresponding to "0" is modulated using modulation mode B. Step 3, according to Modulation information Modulation is performed to obtain the modulated symbol sequence. ,in, They are the first The first, second, ..., second of the sub-bands Modulated data of each subcarrier; right Perform the following parameters The weighted fractional Fourier transform is used to obtain the weighted fractional Fourier transform result. ,in, The first The first, second, ..., second of the sub-bands The weighted fractional Fourier transform results of the modulated data of each subcarrier; Step 4: Repeat steps 2 to 3 to obtain the weighted fractional Fourier transform results for each sub-band. The weighted fractional Fourier transform results corresponding to each sub-band are concatenated in order to obtain the concatenated result. Then, the spliced ​​results are subjected to IFFT and parallel-to-serial conversion processes in sequence to obtain the final result. ; give again Add length is cyclic prefix Get the data after adding the loop prefix. The data with the added loop prefix will be sent out. At the receiving end Step 5: Represent the serial data points received by the receiving end as follows: The superscript T represents transpose. After removing the cyclic prefix, the serial data points are obtained. And then Perform serial-to-parallel conversion to obtain the converted data. ; right Perform FFT transform to obtain the frequency domain signal And then Perform frequency domain equalization to obtain the equalized signal. ; Step Six: According to the distribution principle of the transmitting end, distribute the equalized signal... Divided into Each sub-band contains The symbol, the first The symbol for each sub-band is , ; Step 7, for the first Each sub-band, for the first The WFRFT parameters of each subband and the constellation pattern index sequence are identified, and then the precoded index information is estimated based on the WFRFT parameters. Estimate constellation pattern index information based on constellation pattern index sequence ; The method for identifying the WFRFT parameters is as follows: Step 1, for the first Each sub-band, respectively for Do WFRFT transform of order 1 Data points obtained after WFRFT transformation , ; for Find the corresponding points from all constellation points of modulation mode A and modulation mode B. The nearest constellation point, then calculate. Euclidean distance to the nearest constellation point ; Similarly, for data points Each piece of data in the dataset is processed sequentially to obtain... ; then By summing, we get The corresponding accumulated results are then used as the negative of the order corresponding to the smallest accumulated result as the first... WFRFT parameter estimation results for each sub-band; Step 2: Perform the process of Step 1 on each subband to obtain the WFRFT parameter estimation results for each subband; The method for identifying the constellation pattern index sequence is as follows: for If with If the nearest constellation point is in the constellation point set of modulation mode A, then the estimated value of the position of the first subcarrier in the constellation mode index sequence is 1; otherwise, the estimated value of the position of the first subcarrier is 0. Similarly, for After processing sequentially, the estimated position of each subcarrier in the constellation mode index sequence is obtained, that is, the position of the first subcarrier is obtained. Initial estimation results of the constellation pattern index sequence of each sub-band; Let the set of constellation pattern index sequences be ,but , Represents a set The total number of constellation pattern index sequences included; calculate the initial estimated constellation pattern index sequences and sets respectively. The Hamming distance of each constellation pattern index sequence in the set is used to find the minimum Hamming distance in the set. The corresponding constellation pattern index sequence is used as the final estimated constellation pattern index sequence; Similarly, the final estimation results of the constellation pattern index sequence corresponding to each sub-band are obtained respectively; Based on the identified WFRFT parameters, the first The symbols of each sub-band are pre-decoded using WFRFT to obtain the decoding result. The decoding result of each subband is represented as ; Step 8: Based on the constellation pattern index sequence recognition results, identify the first... The decoding results of each sub-band are demodulated to obtain the first... The demodulation information corresponding to the modulation information of each sub-band ,according to , and the The demodulation information corresponding to the modulation information of each sub-band Get the first Each sub-band corresponds to the received information; Step 9: Perform steps 7 and 8 on each sub-band to obtain the received information corresponding to each sub-band; then perform bit combining on the received information of each sub-band to obtain the complete received information.

2. The WFRFT parameter and modulation mode joint two-dimensional index transmission method according to claim 1, characterized in that, The .

3. The WFRFT parameter and modulation mode joint two-dimensional index transmission method according to claim 2, characterized in that, The constellation pattern index information length for: in, For the first The number of subcarriers with modulation mode A in each subband. For the first The number of subcarriers with modulation mode B in each subband This represents rounding down to the nearest integer.

4. The WFRFT parameter and modulation mode joint two-dimensional index transmission method according to claim 3, characterized in that, The modulation information length for: in, The number of constellation points corresponding to modulation mode A. This indicates the number of constellation points corresponding to modulation mode B.

5. The WFRFT parameter and modulation mode joint two-dimensional index transmission method according to claim 1, characterized in that, The transformation process of the weighted fractional Fourier transform is as follows: in, Representative to Perform a weighted fractional Fourier transform. for The Fourier transform result, for The inverse form, for The inverse form, , , and These are weighting coefficients. For WFRFT parameters; in, , It is the imaginary unit.

Images