A fast search method of partial transmission sequence algorithm optimal time domain candidate signal

Abstract

The present application is suitable for wideband digital communication technology field, and relates to a fast search method of optimal time domain candidate signal of partial transmission sequence algorithm, which is characterized by the following steps: through equivalent exchange of calculation and selection process of time domain candidate signal of PTS scheme, the calculation and selection process of scrambling signal of time domain signal corresponding to original frequency domain signal is converted; and through setting of peak value threshold, fast screening of scrambling signal is realized; through calculation and comparison of a small proportion of local values, time domain candidate signal with minimum or smaller peak average ratio value is quickly found, calculation proportion of element value of candidate signal is greatly reduced, thereby calculation complexity of algorithm is effectively reduced, and peak average ratio value efficiency is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of broadband digital communications, and in particular relates to a method for quickly searching for optimal time-domain candidate signals of a partial transmission sequence algorithm. Background Art

[0002] Orthogonal Frequency Division Multiplexing (OFDM) technology enables high-speed data transmission with high spectrum utilization, effectively combats multipath fading, and requires low computational complexity for channel equalization. Therefore, it is widely used in digital broadband communications, including LTE, 5G, digital audio broadcasting (DAB), digital video broadcasting (DVB), and broadband power line carrier (HPLC). However, the high Peak-to-Average Power Ratio (PAPR) of the transmitted signal caused by its multi-carrier system reduces the efficiency of the power amplifier at the transmitter, places higher demands on the linear range of the amplifier, and increases the hardware cost of the system. Therefore, peak-to-average power ratio reduction technology has always been a key technology in OFDM systems.

[0003] Researchers have conducted extensive research on the PAPR reduction problem of OFDM signals and proposed a series of solutions. These solutions can be divided into signal distortion methods and signal distortion-free methods. Signal distortion methods include limiting methods, compression and expansion methods, etc.; signal distortion-free methods can be divided into block coding methods, selective mapping, partial transmit sequences (PTS), etc. Among them, the PTS method is a commonly used peak-to-average ratio reduction algorithm. Its basic idea is to divide an input frame of OFDM symbols into V non-overlapping subsequences in the frequency domain, and multiply each subsequence by a different weighting coefficient. By selecting appropriate weighting coefficients, the PAPR value of the combined sequence is reduced. The core of this method is to generate a certain number of time domain candidate signals, and then select the signal with the smallest PAPR value for transmission. However, when there are W possible weighting coefficients, the process of selecting the optimal signal requires W steps. VThe high computational complexity of multiple iterations places a heavy burden on the system, so both computational complexity and peak-to-average ratio performance must be considered. Currently proposed methods all sacrifice significant PAPR reduction performance to reduce system computational complexity, making them suboptimal. Patent publication number CN102075483B provides a method for reducing the peak-to-average ratio (PAPR) of OFDM signals. The method first employs an SLM or PTS with a smaller number of packets to preliminarily reduce the signal's PAPR. The PAPR is then reduced to the target value by limiting the time-domain data output by the PTS or SLM by setting a limiting rate. This method still suffers from high computational complexity in reducing the peak-to-average ratio of OFDM signals, making it impossible to quickly find the optimal time-domain candidate signal. The drawbacks of the prior art persist.

[0004] Therefore, how to quickly search for time-domain candidate signals with the smallest or smaller peak-to-average ratio, thereby reducing computational complexity and improving peak-to-average ratio reduction efficiency, is an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0005] In view of the steps of the prior art, the purpose of the present invention is to provide a method for quickly searching for the optimal time domain candidate signal of a partial transmission sequence algorithm, so as to solve the problems of high computational complexity and poor peak-to-average power reduction efficiency in the selection process of the optimal signal in the partial transmission sequence algorithm of the prior art.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] The present invention provides a method for quickly searching for optimal time-domain candidate signals of a partial transmission sequence algorithm, comprising the following steps:

[0008] S10, through V times of IDFT operation with length N, calculate x v =IDFT(X v ),v=0,1,...,V-1;

[0009] S20, calculate the time domain signal x=[x(0), x(1), ..., x(N-1)] corresponding to the original frequency domain signal X, that is,

[0010] S30, for x v ,v=0,1,...,V-1 are multiplied by a complex phase rotation factor with an amplitude of 1 Calculated where each phase rotation factor is selected from a discrete set of W elements, θ v ∈S v ={0,s v,1 ,...,s v,W-1}, and obtain the equivalent expression of the time domain candidate signal set

[0011] S40, let W V A signal of length N It is represented by the following matrix:

[0012] S50, sorting the signal x=[x(0), x(1), ..., x(N-1)] in step S20 according to the amplitude values ​​of its elements from large to small, assuming that the sorted signal is recorded as y=[y(0), y(1), ..., y(N-1)], and the position of each element of the sorted signal in the original signal is recorded as δ=[δ(0), δ(1), ..., δ(N-1)];

[0013] S60, set a threshold C (C>0), calculate the back W of the vector of the δ(0)th row of the matrix in step S40 V -1 element value, judge whether the amplitude of each element is greater than min(C,|y(0)|), if the mth, 1≤m≤W V -1 element has a magnitude greater than min(C,|y(0)|), then it is removed from the matrix of step S40;

[0014] S70, assuming that k(0) column vectors are eliminated in step S60, then the matrix in step S40 is updated to contain V W -k(0) column vector matrix △0, starting from the δ(1)th row of matrix △0, calculate the vector's back V W -k(0)-1 elements, reducing the number in the matrix until it is less than or equal to 4, or completing the calculation process of the δ(N-1)th row;

[0015] S80, after completing the calculation process in step S70, the remaining matrix is ​​recorded as Ω=[Ω0,Ω1,...,H K-1 ], K≥4, calculate Ω respectively k +x,k=0,...,K-1, and then search for the signal with the smallest peak-to-average ratio from the K column vector signals and send it.

[0016] Furthermore, the value of the threshold C in step S60 is the value of the CCDF curve in the PTS technology using the exhaustive search scheme at δ=10 -2 The PAPR value corresponding to the location.

[0017] Furthermore, in step S40, a threshold C (C>0) is set, and for a column vector H in the matrix m ,1≤m≤WV -1, if there is at least one element n that satisfies |x(n)+h n,m |≥C,0≤n≤N-1, then max(|x+H m |)≥C.

[0018] Furthermore, in step S40, for any column vector H in the matrix m ,1≤m≤W V -1, if its numerical calculation process is calculated one by one in time sequence, an element value h is obtained in the step-by-step calculation process of N elements. n,m ,0≤n≤N-1, and satisfy|x(m)+h m,n |>C, then it can be judged without calculating the value of the remaining elements So the vector H m Remove from search.

[0019] Furthermore, the value in step S60 is recorded as calculate

[0020] Compared with the prior art, the method for quickly searching for the optimal time-domain candidate signal of the partial transmission sequence algorithm provided by the present invention has at least the following beneficial effects:

[0021] In the prior art, the selection process of the optimal signal of some transmission sequence algorithms requires many iterations, resulting in high computational complexity and poor peak-to-average ratio reduction performance, which places a heavy burden on the system. The proposed solutions all reduce the amount of system calculation by sacrificing a lot of peak-to-average ratio performance, and cannot take both into account. The present invention converts the calculation and selection process of the time domain candidate signal of the PTS scheme into the calculation and selection process of the scrambled signal of the time domain signal corresponding to the original frequency domain signal, and realizes rapid screening of the scrambled signal by setting a peak threshold. The time domain candidate signal with the smallest or smaller peak-to-average ratio can be quickly found by calculating and comparing a small proportion of local values. While obtaining peak-to-average ratio performance that is similar to that of an exhaustive search, the calculation ratio of the element values ​​of the candidate signal can be greatly reduced, thereby effectively reducing the computational complexity of the algorithm and improving the efficiency of peak-to-average ratio reduction. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the scheme of the present invention, a brief introduction is given below to the figures required for use in the description of the embodiments. Obviously, the figures described below are some embodiments of the present invention. For ordinary technicians in this field, other figures can be obtained based on these figures without paying any creative work.

[0023] Figure 1A schematic diagram of the overall flow of a method for rapidly searching for optimal time-domain candidate signals using a partial transmission sequence algorithm provided by an embodiment of the present invention;

[0024] Figure 2 Schematic diagram of the signal processing flow of the traditional PTS solution;

[0025] Figure 3 A CCDF curve diagram of an OFDM system without adopting the PTS technology and after adopting the PTS technology, in which a method for quickly searching for an optimal time domain candidate signal of a partial transmission sequence algorithm provided by an embodiment of the present invention is provided;

[0026] Figure 4 A numerical calculation ratio diagram of 256 time domain candidate signals in a method for quickly searching for optimal time domain candidate signals using a partial transmission sequence algorithm provided by an embodiment of the present invention;

[0027] Figure 5 A comparison chart of peak-to-average power ratio performance between a search scheme and an exhaustive search scheme for a fast search method for an optimal time-domain candidate signal of a partial transmission sequence algorithm provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0028] To facilitate understanding of the present invention, the present invention will be described more fully below with reference to the accompanying drawings. Preferred embodiments of the present invention are shown in the accompanying drawings. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the present disclosure.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in this specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0030] The present invention provides a method for rapidly searching for an optimal time-domain candidate signal for a partial transmission sequence algorithm, which is applied to a PTS peak-to-average ratio reduction technology for OFDM signals. The method comprises:

[0031] S10, through V times of IDFT operation with length N, calculate x v =IDFT(X v ),v=0,1,...,V-1;

[0032] S20, calculate the time domain signal x=[x(0), x(1), ..., x(N-1)] corresponding to the original frequency domain signal X, that is,

[0033] S30, for x v ,v=0,1,...,V-1 are multiplied by a complex phase rotation factor with an amplitude of 1 Calculated where each phase rotation factor is selected from a discrete set of W elements, θ v ∈S v ={0,s v,1 ,...,s v,W-1}, and obtain the equivalent expression of the time domain candidate signal set

[0034] S40, let W V A signal of length N It is represented by the following matrix:

[0035] S50, sorting the signal x=[x(0), x(1), ..., x(N-1)] in step S20 according to the amplitude values ​​of its elements from large to small, and denoting the sorted signal as y=[y(0), y(1), ..., y(N-1)], and denoting the position of each element of the sorted signal in the original signal as δ=[δ(0), δ(1), ..., δ(N-1)];

[0036] S60, set a threshold C (C>0), calculate the back W of the vector of the δ(0)th row of the matrix in step S40 V -1 element value, judge whether the amplitude of each element is greater than min(C,|y(0)|), if the mth, 1≤m≤W V If the magnitude of -1 element is greater than min(C,|y(0)|), it is removed from the matrix in step S40;

[0037] S70, assuming that k(0) column vectors are eliminated in step S60, then the matrix in step S40 is updated to contain V W -k(0) column vector matrix △0, starting from the δ(1)th row of matrix △0, calculate the vector's back V W -k(0)-1 elements, reducing the number in the matrix until it is less than or equal to 4, or completing the calculation process of the δ(N-1)th row;

[0038] S80, after completing the calculation process in step S70, the remaining matrix is ​​recorded as Ω=[Ω0,Ω1,...,H K-1 ], K≥4, calculate Ω respectively k +x,k=0,...,K-1, and then search for the signal with the smallest peak-to-average ratio from the K column vector signals and send it.

[0039] The present invention converts the calculation and selection process of the time domain candidate signal of the PTS scheme into the calculation and selection process of the scrambled signal of the time domain signal corresponding to the original frequency domain signal, and realizes the rapid screening of the scrambled signal by setting the peak threshold. The time domain candidate signal with the smallest or smaller peak-to-average ratio value can be quickly found by calculating and comparing a small proportion of local numerical values. While obtaining peak-to-average ratio reduction performance that converges with exhaustive search, the calculation ratio of the element values ​​of the candidate signal can be greatly reduced, thereby effectively reducing the computational complexity of the algorithm and improving the efficiency of peak-to-average ratio reduction.

[0040] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0041] In an OFDM system with N subcarriers, X = [X(0), X(1), ..., X(N-1)] represents the frequency domain signal, and x = [x(0), x(1), ..., x(N-1)] represents the corresponding time domain signal. The relationship between the two is as follows:

[0042]

[0043] Among the many technologies for reducing peak-to-average ratio (PAR), the PTS algorithm does not cause signal distortion and has excellent PAR reduction performance. The core idea of ​​this algorithm is to group N subcarriers, multiply each group of subcarriers by the same phase rotation factor, and then combine them. By selecting the rotation phase for each group, the PAR of the transmitted signal is reduced.

[0044] like Figure 2 As shown, the original frequency domain signal X = [X(0), X(1), ..., X(N-1)] is divided into V non-overlapping group signals, denoted as {X0, X1, ..., X V-1} and these group signals satisfy

[0045]

[0046] Then, a phase rotation factor with an amplitude of 1 is added to each packet signal. where each phase rotation factor is selected from a discrete set of W elements, θ v ∈S v ={0,s v,1 ,...,s v,W-1}.

[0047] Note: Each phase rotation factor set of W elements must contain a 0-valued element, which is used to generate the time domain signal corresponding to the original frequency domain signal.

[0048] Then calculate the generated time domain candidate signal set

[0049]

[0050] The above produces a total of W V time domain candidate signals, and then select the signal with the smallest peak-to-average ratio through a certain selection algorithm To send, find the corresponding rotation phase factor, as follows:

[0051]

[0052] Based on the above process, it can be seen that if exhaustive search is used, the sender needs to calculate all W V The value of the time domain candidate signal, the calculation process includes:

[0053] V times of IDFT operation with length N, that is, x is calculated v =IDFT(X v ),v=0,1,...,V-1;

[0054] Then for x v ,v=0,1,...,V-1 are multiplied by a complex rotation phase factor with an amplitude of 1, that is, e is calculated jθ x v ,v=0,1,...,V-1 (Note: the first phase factor is 1 and does not need to be calculated);

[0055] Finally, these V complex signals of length N are added together to obtain a time domain candidate signal.

[0056] The IDFT operation process can use the Fast Fourier Transform (IFFT) algorithm, and completing an N-point IFFT operation requires Complex multiplication and Complex number addition. In summary, calculate all W V The number of complex multiplications required for the time-domain candidate signal is , and the number of complex additions is It can be seen that as the values ​​of V and W increase, the amount of algorithm calculation will increase rapidly, especially the number of complex additions will increase exponentially, so it is necessary to carry out research on fast calculation algorithms.

[0057] Based on the above analysis of the prior art, the present invention provides a fast search method for the optimal time domain candidate signal of the partial transmission sequence algorithm, which is applied to the PTS peak-to-average ratio reduction technology of OFDM signals. Figures 1 to 5In this embodiment, the method for quickly searching for the optimal time-domain candidate signal of the partial transmission sequence algorithm includes the following steps:

[0058] S10, through V times of IDFT operation with length N, calculate x v =IDFT(X v ),v=0,1,...,V-1;

[0059] S20, calculate the time domain signal x=[x(0), x(1), ..., x(N-1)] corresponding to the original frequency domain signal X, that is,

[0060] S30, for x v ,v=0,1,...,V-1 are multiplied by a complex phase rotation factor with an amplitude of 1 Calculated

[0061] Based on the above analysis, Equivalent to

[0062] According to the above equivalent expression, we can know that the goal of the PTS algorithm has changed from the original W V Time domain candidate signals Selecting the signal with the smallest peak-to-average ratio is equivalent to converting it from this W V signal Select a signal from the time domain signal x, so that the peak-to-average ratio of the signal obtained after adding it to the time domain signal x is the smallest.

[0063] S40. Without loss of generality, let W V A signal of length N It is represented by the following matrix:

[0064] The values ​​of the first column vector H0 in the matrix are all 0, so the following conclusions exist:

[0065] Assume a threshold C (C>0), for a column vector H in the matrix of step S40 m ,1≤m≤W V -1, if there is at least one element that satisfies |x(n)+h n,m |≥C,0≤n≤N-1, then max(|x+H m |)≥C.

[0066] Assume that the goal of the search algorithm is to select the W in the matrix of step S40 V Find a column vector in a matrix Make Then for any column vector H in the matrix of step S40m ,1≤m≤W V -1, if the calculation process of its value is calculated one by one in time sequence, then based on the content of the conclusion, if an element value h is obtained in the step-by-step calculation process of N elements n,m ,0≤n≤N-1, and satisfy|x(m)+h m,n |>C, then it is obvious that without calculating the value of the remaining elements, we can determine So we can transform the vector H m Remove from search.

[0067] S50, sorting the signal x=[x(0), x(1), ..., x(N-1)] in step S20 according to the amplitude values ​​of its elements from large to small, and denoting the sorted signal as y=[y(0), y(1), ..., y(N-1)], and denoting the position of each element of the sorted signal in the original signal as δ=[δ(0), δ(1), ..., δ(N-1)];

[0068] S60, set a suitable threshold C (C>0), first calculate the back W of the vector of the δ(0)th row in the matrix of step S40 V -1 element value, recorded as (Note: The first element is 0, no calculation is required), then calculate Then determine whether the amplitude of each element is greater than min(C,|y(0)|) one by one. If the mth element, 1≤m≤W V -1 element has a magnitude greater than min(C,|y(0)|), which means max(|x+H m |)>min(C,|y(0)|), so there is no need to calculate the column vector H m The remaining values ​​are directly removed from the matrix of step S40. Assuming that k(0) column vectors are removed in this step, the matrix of step S40 is updated to contain V W -Matrix △0 of k(0) column vectors;

[0069] S70, calculate the back V of the vector of the δ(1)th row in the matrix △0 W -k(0)-1 elements, similar to step S60, first calculate x(δ(1)) and this V W -k(0)-1 elements are added, and then the amplitude of the added element is determined to be greater than min(C,|y(0)|). If it is, the column vector corresponding to the column position of the element does not need to calculate the remaining value and is directly removed from the matrix △0. If k(0) column vectors are removed in step S60, the matrix in step S40 is updated to contain V W-k(0) column vector matrix △0, starting from the δ(1)th row of matrix △0, calculate the vector's back V W -k(0)-1 elements, continuously reducing the number in the matrix until it is less than or equal to 4, or the calculation process of the δ(N-1)th row is completed;

[0070] S80, after completing the calculation process in step S70, the remaining matrix is ​​recorded as Ω=[Ω0,Ω1,...,H K-1 ], K≥4, if there are still elements in the matrix whose values ​​have not been calculated, then continue to calculate the values ​​of these elements and calculate Ω respectively. k +x,k=0,...,K-1, and then search for the signal with the smallest peak-to-average ratio from the K column vector signals and send it.

[0071] Furthermore, in this embodiment, regarding the specific value setting method of the threshold C, it can be seen from the above calculation steps that when the value of the threshold C is small, a higher proportion of column vectors can be eliminated, thereby effectively reducing the amount of calculation. However, in the time domain candidate signal with the smallest peak-to-average ratio, satisfy If the threshold C is too large, the proportion of column vectors that can be eliminated is reduced, the amount of calculation is increased, but the problem of not including the signal with the smallest peak-to-average ratio among all candidate signals in the K signals searched in step S80 may occur, resulting in a certain loss of peak-to-average ratio performance. On the contrary, if the threshold C is too large, the proportion of column vectors that can be eliminated is reduced, the amount of calculation is increased, but the problem of The probability of peak-to-average performance reduction is reduced, thus reducing the performance loss of peak-to-average performance.

[0072] In applications, CCDF curves are often used to represent the peak-to-average ratio performance of OFDM time domain signals. The specific definition is as follows

[0073] CCDF(PAPR(x))=prob(PAPR(x)>δ),

[0074] Where δ represents the threshold.

[0075] Assume an OFDM system uses 16QAM modulation, N = 1024, V = 4, and the rotation phase set satisfies S0 = S1 = ... = S V-1 ={0,π / 2,π,3π / 2}, then Figure 3 The CCDF curves of the system before and after adopting PTS technology (using exhaustive search scheme) are given.

[0076] Based on the above analysis, the value of the threshold C is set to the CCDF curve of the PTS technology using the exhaustive search scheme at δ = 10 -2At this time, the fast search method of the embodiment of the present invention has a 99% probability of searching for the signal with the smallest peak-to-average ratio among all candidate signals, and can effectively reduce the amount of calculation, while the performance loss of reducing the peak-to-average ratio is negligible.

[0077] Furthermore, in this embodiment, Figure 3 Under the same parameters, based on Figure 3 CCDF curve, let C=8.05dB, Figure 4 Given 4 4 = The ratio of element values ​​that need to be calculated for each of the 256 candidate time-domain signals. The results in the figure show that candidate signals with a larger ratio are eliminated after a smaller ratio of element values ​​is calculated, and the values ​​of the remaining elements for a large proportion of them no longer need to be calculated. Ultimately, only 16 candidate time-domain signals require full element value calculation. The final number of elements requiring calculation is 44,308, accounting for approximately 16.8% of the total number of elements (1024 × 256 = 262,144). Therefore, it can be seen that the fast search method of the present invention can effectively reduce the computational complexity of the search algorithm.

[0078] Furthermore, in this embodiment, Figure 3 Under the same parameters, Figure 5 A comparison of the peak-to-average power ratio (APWR) performance of the fast search method and the exhaustive search method provided by an embodiment of the present invention is given. As can be seen from the results in the figure, the APWR performance of the two schemes is basically the same, which means that the optimal time-domain candidate signal of the partial transmission sequence algorithm provided by an embodiment of the present invention can still achieve equivalent APWR performance to the existing exhaustive search method while greatly reducing the computational complexity.

[0079] The rapid search method for the optimal time-domain candidate signal of the partial transmission sequence algorithm described in the above embodiment is compared with the prior art. The selection process of the optimal signal of the partial transmission sequence algorithm in the prior art requires many iterations, has high computational complexity, and poor peak-to-average ratio reduction performance, which brings a heavy burden to the system. The proposed solutions also reduce the amount of system calculation by sacrificing a lot of peak-to-average ratio reduction performance, and cannot take both into account. The present invention converts the calculation and selection process of the time-domain candidate signal of the PTS scheme into the calculation and selection process of the scrambled signal of the time-domain signal corresponding to the original frequency-domain signal, and realizes rapid screening of the scrambled signal by setting a peak threshold. The time-domain candidate signal with the smallest or smaller peak-to-average ratio can be quickly found by calculating and comparing a small proportion of local values. While obtaining peak-to-average ratio reduction performance that is similar to that of the exhaustive search, the calculation ratio of the element values ​​of the candidate signal can be greatly reduced, thereby effectively reducing the computational complexity of the algorithm and improving the efficiency of peak-to-average ratio reduction.

[0080] Obviously, the embodiments described above are only preferred embodiments of the present invention, rather than all embodiments. The preferred embodiments of the present invention are given in the accompanying drawings, but they do not limit the patent scope of the present invention. The present invention can be implemented in many different forms. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive. Although the present invention has been described in detail with reference to the aforementioned embodiments, for those skilled in the art, it is still possible to modify the technical solutions described in the aforementioned specific embodiments, or to make equivalent replacements for some of the technical features therein. Any equivalent structure made using the contents of the present invention specification and drawings, directly or indirectly used in other related technical fields, is also within the scope of patent protection of the present invention.

Claims

1. A fast search method for optimal time domain candidate signals of a partial transmission sequence algorithm, characterized in that: The following steps are involved: S10, through V times of IDFT operation with length N, calculate x v =IDFT(X v ),v=0,1,...,V-1; S20, calculate the time domain signal x=[x(0), x(1), ..., x(N-1)] corresponding to the original frequency domain signal X, that is, S30, for x v ,v=0,1,...,V-1 are multiplied by a complex phase rotation factor with an amplitude of 1 Calculated v=0,1,...,V-1, where each phase rotation factor is selected from a discrete set of W elements, namely θ v ∈S v ={0,s v,1 ,...,s v,W-1 }, and obtain the equivalent expression of the time domain candidate signal set S40, let W V A signal of length N It is represented by the following matrix: S50, sorting the signal x=[x(0), x(1), ..., x(N-1)] in step S20 according to the amplitude values ​​of its elements from large to small, assuming that the sorted signal is recorded as y=[y(0), y(1), ..., y(N-1)], and the position of each element of the sorted signal in the original signal is recorded as δ=[δ(0), δ(1), ..., δ(N-1)]; S60, set a threshold C, calculate the back W of the vector of the δ(0)th row of the matrix in step S40 V -1 element value, judge whether the amplitude of each element is greater than min(C,|y(0)|), if the mth, 1≤m≤W V -1 element has a magnitude greater than min(C,|y(0)|), then it is removed from the matrix of step S40; S70, assuming that k(0) column vectors are eliminated in step S60, then the matrix in step S40 is updated to contain W v -k(0) column vectors in the matrix △0, starting from the δ(1)th row of the matrix △0, calculate the back W of the vector v -k(0)-1 elements, reducing the number in the matrix until it is less than or equal to 4, or completing the calculation process of the δ(N-1)th row; S80, after completing the calculation process in step S70, the remaining matrix is ​​recorded as Ω = [Ω0, Ω1, ..., Ω K-1 ], K≥4, calculate Ω respectively k +x,k=0,...,K-1, and then search for the signal with the smallest peak-to-average ratio from the K column vector signals and send it.

2. The method for rapidly searching for optimal time-domain candidate signals of a partial transmission sequence algorithm according to claim 1, characterized in that: The value of the threshold C in step S60 is the value of the CCDF curve in the PTS technology using the exhaustive search scheme at δ=10 -2 The PAPR value corresponding to the location.

3. The method for rapidly searching for optimal time-domain candidate signals of a partial transmission sequence algorithm according to claim 1, characterized in that: In the step S40, a threshold C is set, and for a column vector H in the matrix m ,1≤m≤W V -1, if there is at least one element n that satisfies |x(n)+h n,m |≥C,0≤n≤N-1, then max(|x+H m |)≥C.

4. The method for rapidly searching for optimal time-domain candidate signals of a partial transmission sequence algorithm according to claim 3, characterized in that: In the step S40, for any column vector H in the matrix m ,1≤m≤W V -1, if its numerical calculation process is calculated one by one in time sequence, an element value h is obtained in the step-by-step calculation process of N elements. n,m ,0≤n≤N-1, and satisfy|x(m)+h m,n |>C, then it can be judged without calculating the value of the remaining elements So the vector H m Remove from search scope, To satisfy Column vector of .

5. The method for rapidly searching for the optimal time-domain candidate signal of a partial transmission sequence algorithm according to claim 4, characterized in that: The value in step S60 is recorded as calculate

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