Research On Messaging Algorithm For 5G Wireless System Receiver

With the development requirements of mobile communication,such as enhanced mobile broadband mobile broadband,vehicle to vehicle and vehicle to infrastructure communication and large-scale machine communication,5G must have the characteristics of ultra wideband,low delay and high reliability network connection.At present,the IMT2020 propulsion unit has proposed that the 5G wireless system will introduce a new signal processing theory,method and technical system in the aspects of coded modulation,multiple access,millimeter wave and large-scale MIMO.The new coding modulation and new multiple access technology bring great challenges to the detection and decoding of the receiver.Therefore,the key to solve this problem is to study the efficient and low complex decoding and detection technology for the receiver.The message transfer algorithm is updated from the probability graph model angle,through the message iteration.In the 5G wireless system,LDPC decoding and SCMA multiuser detection achieve good detection and decoding performance.It also provides a convenient and effective way for the detection of the 5G receiver,and assists 5G from the theory to the practical.This paper first introduces the technical characteristics and route of 5G communication system,and the research status of message passing algorithm in 5G wireless system receiver.The factor graph and related theory of edge function and message passing algorithm are introduced emphatically.Then,for LDPC decoding,the algorithms of belief propagation?BP?decoding algorithm,logarithmic domain belief propagation decoding algorithm?LLR-BP?,min-sum?MS?decoding are introduced.A new DW-LLR-BP decoding algorithm is proposed from the message transfer mechanism.The algorithm simulation results show that when the bit error rate?BER?is 10;⁴,the DW-LLR-BP decoding algorithm proposed in this paper improved by 0.15 dB compared with the original LLR-BP decoding algorithm.When the signal-to-noise ratio is 3.5dB,the average number of iterations required by the original LLR-BP decoding algorithm is 18.The DW-LLR-BP decoding algorithm proposed in this paper has an iterative number of 16.In summary,the DW-LLR-BP algorithm can improve the performance of LDPC decoding and accelerate the convergence speed of decoding.Finally,based on the SCMA multi user detection,the original MPA and the serial strategy message passing detection algorithm?S-Based MPA?are introduced.From the shortcomings of the algorithm detection,two improved algorithms are proposed,which are serial weighted SW-MPA and multi-weighted MW-MPA,and the system modeling and simulation are carried out.The simulation results show that the iteration is iterative.When the number of times is the same,the BER performance of the SW-MPA and MW-MPA algorithm system is better than the BER performance of the original MPA and the serial MPA algorithm.When the BER value is 10;^3.8,the performance of the SW-MPA algorithm increases 0.23dB;MW-MPA algorithm improves the 0.46dB.When the signal to noise ratio is constant,when the number of iterations is less than 3,the bit error rate performance of SW-MPA and MW-MPA multiuser detection algorithm is better than the BER performance of serial MPA and original MPA algorithm,and the convergence speed of detection is also improved.