CN110381003A - The multiuser signal detection method inhibited for peak-to-average force ratio in SCMA-OFDM system - Google Patents
The multiuser signal detection method inhibited for peak-to-average force ratio in SCMA-OFDM system Download PDFInfo
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Abstract
The multiuser signal detection method inhibited for peak-to-average force ratio the invention belongs to wireless communication technology field, in specifically a kind of SCMA-OFDM system.Choose for user method is applied to the transmitting terminal of SCMA-OFDM system by the present invention, successfully reduces the PAPR of signal.In view of the sparsity of SCMA-OFDM signal, the present invention is decoded using Message Passing Algorithm in receiving end, and after the characteristic of integrated phase alternative sequence and the characteristic of used SCMA code book the sending probability of each code word can be adjusted in each iterative process of Message Passing Algorithm and finally accurately recover transmission signal in the case where not transmitting side information.Therefore the present invention realizes the blind Detecting for Choose for user algorithm and does not bring the promotion of apparent computation complexity.
Description
Technical Field
The invention belongs to the technical field of wireless communication, and relates to a multi-user signal detection method aiming at peak-to-average power ratio suppression in a SCMA-OFDM system.
Background
Driven by the rapid development of mobile internet and internet of things services, a large number of terminal device accesses and extreme user experiences in the future provide new requirements and huge challenges for mobile communication. Therefore, in order to meet the demand of future communication, a Fifth Generation mobile communication technology (5G) has come, wherein a wireless air interface technology is an important field of current 5G research, and a multiple access technology is a hot issue of research. In the face of these challenges and development vision in 5G, the conventional orthogonal Multiple Access technology has not been able to meet the requirements of future mobile communication development, so some Non-orthogonal Multiple Access (NOMA) technologies have been proposed. The SCMA technology is used as a non-orthogonal air interface technology for 5G wireless mobile communication, a non-orthogonal sparse coding superposition technology is adopted, and the SCMA technology can support more user connections under the same time-frequency resource condition. The invention adopts OFDM technology, and carries the SCMA signal block on the orthogonal sub-carrier of OFDM to transmit data. The OFDM technique has a problem of high PAPR of a signal, which causes nonlinear distortion of the signal when the signal is amplified at the transmitting end, and finally deteriorates BER performance of the system. Therefore, it is important how to reduce PAPR of SCMA-OFDM signal and improve performance of the system.
Disclosure of Invention
The invention aims to solve the problem of high PAPR of SCMA-OFDM signals, and adopts a method of distortion-free PAPR suppression, such as: the mapping algorithm and the partial sequence transmission algorithm are selected to reduce the PAPR of the SCMA-OFDM signal, so that the signal is not further distorted or is distorted as little as possible when passing through a signal amplifier, and a blind detection algorithm based on a message transfer algorithm is provided aiming at the PAPR restraining method, so that the calculation complexity of a receiving end is not obviously increased while sideband information is prevented from being transmitted, and the information transmission efficiency of the system is improved.
The technical scheme of the invention is as follows:
a multi-user signal detection method in an SCMA-OFDM system is based on a message transfer algorithm and used for multi-user signal detection in an uplink SCMA-OFDM system, a system model is assumed that J users share K resources in an SCMA signal block, one SCMA-OFDM signal occupies N orthogonal subcarriers, namely the SCMA-OFDM signal comprises N/K SCMA signal blocks, the number of constellation points adopted by each user is M, and the number of alternative sequences of a selective mapping algorithm adopted by the system is S.
The blind detection method comprises the following steps:
s1 setting parameters of SCMA-OFDM systemThe number of the alternative sequences comprises the number J of users, the time-frequency resource K, the size M of a codebook, the number S of the alternative sequences of the selective mapping algorithm adopted by the system, and the maximum iteration number is set to be tmax;
S2, generating alternative phase sequence according to alternative sequence number S of selective mapping algorithm adopted by systemAnd finally determines the signal x with the smallest PAPR for transmissionj。
S3, initializing the message delivery probability value as:
wherein,refers to the user node u in the factor graphjTo the resource node rkWherein t is the number of iterations, xj=(x1,j,x2,j…,xK,j)T∈CKRepresenting the codeword transmitted by the jth user;
s4, setting an initial value t of iteration times to be 1;
s5, updating the message of the resource node, and r for all resource nodeskAnd (3) calculating:
wherein, ykIs a received signalThe signal received by the k-th time-frequency resource,refers to the user node u in the factor graphpTo the resource node rkMessage update procedure of xikRepresenting users connected to resource node k in a factor graphSet, xik\ j represents the set after user j is removed;
s6, updating the message of user node, and updating all user nodes ujAnd (3) calculating:
s7, calculating the transmission probability of each code word according to the information obtained in the step S5
S7.1, calculating the code word sending probability when using the forward codebook:
s7.2, calculating the code word sending probability when the reverse codebook is used:
s8, estimating the phase candidate sequence according to the codeword transmission probability obtained in step S7, specifically:
s8.1, calculating a transmission probability value of each phase candidate sequence on each SCMA block, where i represents the ith SCMA block (the candidate phase sequence may also be estimated using euclidean distance):
wherein p iss,lIs an alternative sequenceOf the first element and ps,l∈(-1,1)。
S8.2, estimating alternative sequences used for processing signals at a transmitting end by using the probability value obtained in the step S8.1:
s9, using the alternative sequence information obtained in the step S8 for the next iteration of the message passing algorithm:
s9.1, correcting information in the user node:
s9.2, correcting the codebook:
s10, message iteration updating: judging whether t exceeds the maximum iteration number set in the step S1, if t is less than or equal to tmaxThen the flow proceeds to step S5, if t>tmaxIf yes, the iterative update of the message is terminated and the step S11 is entered;
s11, completing multi-user detection by using the updated probability distribution, and outputting the soft decision of the user as follows:
wherein ζjIs a set ζ representing a resource node connected to a user j in a factor graphj\ k then represents the removal of the set of resource nodes k.
The invention is based on that at the transmitting end of SCMA-OFDM system, the PAPR of the signal processed by the selective mapping method is effectively suppressed, but in order to accurately recover the transmitted signal at the receiving end, the selected alternative sequence must be transmitted together as sideband information, which results in the reduction of transmission efficiency. Therefore, there are many studies on blind detection algorithms for the selective mapping method, which estimate the selected candidate sequence at the receiving end, and although the transmission of side information is avoided, the blind detection algorithms also cause an increase in decoding complexity. The message passing algorithm is a low-complexity decoding algorithm provided based on the sparsity of an SCMA codebook, the algorithm can continuously calculate and update the sending probability of each code word in the iteration process, the invention estimates the selected phase alternative sequence at a receiving end by utilizing the sending probability of each code word calculated by the algorithm, and synchronously and effectively recovers the sending signal when the message passing algorithm reaches the maximum iteration times.
The invention has the beneficial effects that: the selective mapping method is applied to the transmitting end of the SCMA-OFDM system, and the PAPR of the signal is successfully reduced. In consideration of sparsity of an SCMA-OFDM signal, the invention utilizes a message transfer algorithm to decode at a receiving end, and can adjust the transmission probability of each code word in each iteration process of the message transfer algorithm to finally and accurately recover the transmission signal under the condition of not transmitting sideband information after the characteristics of a phase alternative sequence and the characteristics of an SCMA codebook used are synthesized. Therefore, the invention realizes blind detection aiming at the selection mapping algorithm and does not bring obvious improvement of the computational complexity.
Drawings
FIG. 1 is a block diagram of an uplink SCMA-OFDM system (taking the selective mapping algorithm as an example);
FIG. 2 is a schematic diagram of a SCMA-OFDM system receiving end blind detection algorithm;
FIG. 3 is a SCMA encoding schematic;
figure 4 is a SCMA factor graph.
Detailed Description
The technical solution of the present invention is described in detail below with reference to the accompanying drawings and examples.
Considering an uplink SCMA-OFDM communication system model, where K frequency domain resource blocks are occupied by J users, a schematic block diagram is shown in fig. 1. Firstly, mapping bit data into a codeword to be transmitted according to a SCMA codebook one-to-one mapping principle of a bit data stream generated by a user, wherein the SCMA coding principle is shown in fig. 2; secondly, a plurality of groups of serial code words are converted into parallel data through serial-parallel conversion, the parallel data are in one-to-one correspondence to a plurality of orthogonal subcarriers of the SCMA-OFDM system, frequency domain signals are converted into time domain signals through N-point IFFT conversion, then the parallel time domain signals are converted into serial data through parallel-serial conversion, and finally the serial data are modulated onto carriers to be sent out. At a signal transmitting end, an SCMA (single chip multiple access) directly maps bit stream data into a multidimensional code word in a codebook, and the process combines two processes of modulation and spread spectrum in the traditional orthogonal multiple access scheme, so that a more efficient coding mode is obtained. At the receiving end, the signals received by the base station are the superposition of codewords sent by J different users, and because of the sparsity of the codewords, the base station end adopts an MPA algorithm to realize low-complexity detection and decoding.
Assuming that all users are synchronized, the signal received at the base station can be expressed as:
wherein y ═ y1,y2,…,yK)TRepresenting signals received at the base station, xj=(x1,j,x2,j…,xK,j)TIndicating the code word sent by the jth user, hj=(h1,j,h2,j…,hK,j)TIndicating channel state information between the base station and the jth user, n ═ n (n)1,n2,…,nK)TRepresents Additive White Gaussian Noise (AWGN) and obeys a distribution n-CN (0, sigma)2I)。
Since the SCMA-OFDM system uses OFDM multi-carrier to carry SCMA data for transmission, the SCMA-OFDM signal still has the problem of too high PAPR of the signal, so in the transmitting end of fig. 1, we can use a selective mapping algorithm to suppress the PAPR of the signal below a desired value.
The specific implementation steps of the selection mapping algorithm are as follows:
1. firstly, S mutually independent phase candidate sequences p are generateds=(ps,1,ps,2,...,ps,N)T。
2. Will send a signal xjAnd alternative sequencesAfter multiplication, a new set of combined signals is obtained:
Xj,s=(xj,1ps,1,xj,2ps,2,...,xj,Nps,N)T(s=1,2...S)
3. the frequency domain signal is converted into a time domain signal by IFFT and then the PAPR of each joint signal is calculated:
5. according to the PAPR data calculated in step 4, selecting a joint signal with the smallest PAPR for transmission, where the signal may be represented as:
the PAPR of the SCMA-OFDM signal processed by the selective mapping algorithm may be described by using a Complementary Cumulative Distribution Function (CCDF), which is expressed as follows:
Pr(PAPR>PAPR0)=p,0≤p≤1
when the number N of carriers is large enough, according to the central limit theorem, the real part and the imaginary part of the sampling point of the transmitted signal approximately satisfy gaussian distribution, the amplitude of the sampling point satisfies rayleigh distribution, and the probability density can be expressed as:
and the power distribution of the sampling signal obeys χ2Distribution, and mean 0 χ of unit variance2The power spectral density of the distribution can be expressed as p ═ e-yWe defineTo represent the sparseness of the SCMA system, the CCDF of the SCMA-OFDM signal after processing by the selective mapping algorithm is as follows:
Pr(PAPR>PAPR0)=[1-(1-e-PAPR 0)BN]S
as can be seen from the above equation, the PAPR of the signal at the transmitting end is effectively suppressed after the selective mapping algorithm is processed, but the following problems occur: selected phase candidate sequences for decoding at the receiving end using a message passing algorithmMust be transmitted to the transmitting end together as sideband information, which certainly results in a reduction in transmission efficiency. Therefore, a plurality of blind detection algorithms aiming at the selective mapping algorithm are provided, wherein one of the blind detection algorithms is realized at a receiving end by using an ML algorithm, and the process is as follows:
although the above scheme can achieve blind detection, the attendant high computational complexity increase is unacceptable for any communication system. Considering that an SCMA receiving end adopts a message transfer algorithm which needs to continuously calculate and update information of user nodes in an iteration process, and an SCMA codebook has sparsity and certain symmetry, the invention provides a blind detection algorithm based on the message transfer algorithm to avoid transmitting sideband information and accurately recover a transmitted signal on the premise of not greatly increasing complexity.
Examples
In this embodiment, a Matlab simulation platform is used for the experiment.
The object of the present example is achieved by the steps of:
and S1, setting SCMA system parameters. The system parameters in this example are as follows: the number of users J is 6, the number of time-frequency resources K is 4, and the system is multi-carrierThe number of subcarriers is 256, the simulation channel is AWGN, and the simulation times is 106Maximum number of iterations tmax6, the selected candidate sequence number S is 4, the candidate sequence elements are {1, -1}, and the adopted codebook is shown in the following table:
s2, randomly generating S mutually independent alternative phase sequences p with the length of NsWherein the elements are {1, -1 }.
S3, multiplying the generated transmission signals by the S phase bit sequences respectively, that is:
Xj,s=(xj,1ps,1,xj,2ps,2,...,xj,Nps,N)T(s=1,2...S)
s4, performing IFFT operation on the joint signal obtained in step S3, and converting the frequency domain signal into a time domain signal:
and S5, calculating the PAPRs of the S combined signals, and selecting the signal with the minimum PAPR to pass through a Gaussian channel simulation model.
S6, initializing the message delivery probability value as:
wherein,refers to the user node u in the factor graphjTo the resource node rkWherein t is the number of iterations, xj=(x1,j,x2,j…,xK,j)T∈CKRepresenting the codeword transmitted by the jth user;
s7, setting an initial value t of iteration times to be 1;
s8, message iteration updating: judging whether t exceeds the maximum iteration number set in the step S1, if t is less than or equal to tmaxThen the flow proceeds to step S9, if t>tmaxIf yes, the iterative update of the message is terminated and the step S15 is entered;
s9, updating the message of the resource node according to the factor graph F (t) (figure 3), and r all the resource nodeskAnd (3) calculating:
wherein, ykIs the signal received by the kth time-frequency resource of the received signal Y,refers to the user node u in the factor graphpTo the resource node rkMessage update procedure of xikRepresenting the set of users, ξ, connected to a resource node k in a factor graphk\ j represents the set after user j is removed;
s10, updating the message of the user node according to the factor graph F (t) (figure 3), and updating all the user nodes ujAnd (3) calculating:
s11, calculating the transmission probability of each code word according to the information obtained in the step S10
S11.1, calculating the code word sending probability when using the forward codebook:
s11.2, calculating the code word sending probability when the reverse codebook is used:
s12, estimating the phase candidate sequence according to the codeword transmission probability obtained in step S10, specifically:
s12.1, calculating a transmission probability value of each phase alternative sequence on each SCMA block, wherein i represents the ith SCMA block:
s12.2, estimating alternative sequences used for processing signals at a transmitting end by using the probability value obtained in the step S12.1:
s13, using the alternative sequence information obtained in the step S8 for the next iteration of the message passing algorithm:
s13.1, correcting information in the user node:
s13.2, correcting the codebook:
s14, updating iteration times: t +1 and returns to step S8;
s15, completing multi-user detection by using the updated probability distribution, and outputting the soft decision of the user as follows:
wherein ζjIs a set ζ representing a resource node connected to a user j in a factor graphj\ k then represents the removal of the set of resource nodes k.
The method of the invention is adopted to carry out simulation test. We compare the BER performance of the proposed decoding algorithm with the conventional decoding algorithm for transmission side information. It can be seen that the BER performance of the proposed algorithm is only slightly lost in the case of low signal-to-noise ratio compared to the decoding algorithm for transmitting side information, and there is no difference between the BER performance of the proposed algorithm and the BER performance of the decoding algorithm for transmitting side information in the case of high signal-to-noise ratio. Since the algorithm estimates the candidate sequence more and more accurately as the signal-to-noise ratio increases, the performance of the algorithm should be theoretically equivalent to a decoding algorithm that transmits sideband information when the candidate sequence is estimated without errors. Compared with the algorithm which uses the ML mode to carry out blind detection, the algorithm provided by the invention has the advantage that the estimation process of the alternative sequence is synchronously carried out in the algorithm decoding process of the message passing process, so the calculation complexity of the algorithm is not obviously increased compared with the traditional message passing algorithm.
Claims (1)
- A multi-user signal detection method aiming at peak-to-average ratio suppression in a SCMA-OFDM system is characterized in that a system model is that J users share K resources in one SCMA signal block, one SCMA-OFDM signal occupies N orthogonal subcarriers, namely one SCMA-OFDM signal comprises N/K SCMA signal blocks, the number of constellation points adopted by each user is M, and the number of alternative sequences of a selective mapping algorithm adopted by the system is S; the detection algorithm comprises the following steps:s1, setting parameters of the SCMA-OFDM system including user number J, time frequency resource K, codebook size M, alternative sequence number of selective mapping algorithm adopted by the system as S, and setting maximum iteration number as tmax;S2, generating an alternative phase sequence p according to the alternative sequence number S of the selective mapping algorithm adopted by the systems=(ps,1,ps,2,...,ps,N)TAnd finally determines the signal x with the smallest PAPR for transmissionj;S3, initializing the message delivery probability value as:wherein,refers to the user node u in the factor graphjTo the resource node rkWherein t is the number of iterations, xj=(x1,j,x2,j…,xK,j)T∈CKRepresenting the codeword transmitted by the jth user;s4, setting an initial value t of iteration times to be 1;s5, updating the message of the resource node, and r for all resource nodeskAnd (3) calculating:wherein, ykIs a received signalThe signal received by the k-th time-frequency resource,refers to the user node u in the factor graphpTo the resource node rkMessage update procedure of xikRepresenting the set of users, ξ, connected to a resource node k in a factor graphk\ j represents the set after user j is removed;s6, updating the message of user node, and updating all user nodes ujAnd (3) calculating:s7, calculating the transmission probability of each code word according to the information obtained in the step S5S7.1, calculating the code word sending probability when using the forward codebook:s7.2, calculating the code word sending probability when the reverse codebook is used:s8, estimating the phase candidate sequence according to the codeword transmission probability obtained in step S7, specifically:s8.1, calculating a transmission probability value of each phase alternative sequence on each SCMA block, wherein i represents the ith SCMA block:s8.2, estimating alternative sequences used for processing signals at a transmitting end by using the probability value obtained in the step S8.1:s9, using the alternative sequence information obtained in the step S8 for the next iteration of the message passing algorithm:s9.1, correcting information in the user node:s9.2, correcting the codebook:s10, message iteration updating: judging whether t exceeds the maximum iteration number set in the step S1, if t is less than or equal to tmaxThen the flow proceeds to step S5, if t>tmaxIf yes, the iterative update of the message is terminated and the step S11 is entered;s11, completing multi-user detection by using the updated probability distribution, and outputting the soft decision of the user as follows:wherein ζjIs a set ζ representing a resource node connected to a user j in a factor graphj\ k then represents the removal of the set of resource nodes k.
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Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN112383328A (en) * | 2020-10-13 | 2021-02-19 | 哈尔滨工业大学(深圳) | Improved matched filtering message transmission detection method based on probability cutting in communication system |
CN113114309A (en) * | 2021-03-22 | 2021-07-13 | 南京航空航天大学 | Enhanced message propagation method based on channel hardening phenomenon |
Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20080292013A1 (en) * | 2007-05-23 | 2008-11-27 | Texas Instruments Incorporated | Nested precoding codebook structures for mimo systems |
CN103929390A (en) * | 2013-01-14 | 2014-07-16 | 中兴通讯股份有限公司 | Baseband load shifting method and device of LTE system |
CN104468455A (en) * | 2014-12-29 | 2015-03-25 | 西安电子科技大学 | LTE system OFDM signal peak-to-average ratio suppression method combining constellation expansion with tone reservation |
CN105141566A (en) * | 2015-08-19 | 2015-12-09 | 电子科技大学 | PTS method for reducing PAPR of SCMA system |
US20160119073A1 (en) * | 2014-10-22 | 2016-04-28 | Huawei Technologies Co., Ltd. | System and Method for Low Peak to Average Power Ratio Multiple Access Communications |
CN107743056A (en) * | 2017-10-25 | 2018-02-27 | 电子科技大学 | A kind of SCMA multi-user test methods based on compressed sensing auxiliary |
CN107864029A (en) * | 2017-11-10 | 2018-03-30 | 电子科技大学 | A kind of method for reducing Multiuser Detection complexity |
-
2019
- 2019-07-25 CN CN201910676615.9A patent/CN110381003B/en active Active
Patent Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20080292013A1 (en) * | 2007-05-23 | 2008-11-27 | Texas Instruments Incorporated | Nested precoding codebook structures for mimo systems |
CN103929390A (en) * | 2013-01-14 | 2014-07-16 | 中兴通讯股份有限公司 | Baseband load shifting method and device of LTE system |
US20160119073A1 (en) * | 2014-10-22 | 2016-04-28 | Huawei Technologies Co., Ltd. | System and Method for Low Peak to Average Power Ratio Multiple Access Communications |
CN104468455A (en) * | 2014-12-29 | 2015-03-25 | 西安电子科技大学 | LTE system OFDM signal peak-to-average ratio suppression method combining constellation expansion with tone reservation |
CN105141566A (en) * | 2015-08-19 | 2015-12-09 | 电子科技大学 | PTS method for reducing PAPR of SCMA system |
CN107743056A (en) * | 2017-10-25 | 2018-02-27 | 电子科技大学 | A kind of SCMA multi-user test methods based on compressed sensing auxiliary |
CN107864029A (en) * | 2017-11-10 | 2018-03-30 | 电子科技大学 | A kind of method for reducing Multiuser Detection complexity |
Non-Patent Citations (1)
Title |
---|
LIN YANG: "Low Complexity MPA Detector Based on Sphere Decoding for SCMA", 《IEEE COMMUNICATIONS LETTERS》 * |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN112383328A (en) * | 2020-10-13 | 2021-02-19 | 哈尔滨工业大学(深圳) | Improved matched filtering message transmission detection method based on probability cutting in communication system |
CN112383328B (en) * | 2020-10-13 | 2022-01-18 | 哈尔滨工业大学(深圳) | Improved matched filtering message transmission detection method based on probability cutting in communication system |
CN113114309A (en) * | 2021-03-22 | 2021-07-13 | 南京航空航天大学 | Enhanced message propagation method based on channel hardening phenomenon |
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