Research On The Simple Hybrid Projection Algorithm And Hardware Implementation Of The ADMM Decoding Of LDPC

The Low Density Parity Check(LDPC)has the performance close to the Shannon limit proposed by Shannon in 1948,and the decoding algorithm complexity of LDPC code is low,which makes it is the one of the best channel coding schemes.For decades,communication researchers deeply study the decoding of LDPC code,and a large number of excellent research results show.What is a kind of mainstream decoding algorithm of LDPC codes is that which is based on the Alternating Direction Multiplier(ADMM)Linear Programming(LP)decoding algorithm.Under the high Signal-to-Noise Ratio,ADMM-LP decoding algorithm is not only eliminates the error floor of traditional Belief Propagation(BP)decoding algorithm,but also it has Maximum Likelihood(ML)authentication and easily analysis,what shows that it is a decoding algorithm with broad application prospects.In the process of the ADMM decoding algorithm in LDPC code,Euclidean projection is the most complex and time-consuming operation on the check polys.Therefore,how to construct a simple and efficient projection algorithm can effectively improve the decoding efficiency of ADMM decoding algorithm.Based on the Even-vertex Projection Algorithm(EVA)proposed by our laboratory.This algorithm directly avoids Euclidean projection calculation,but it has a great loss of decoding performance.In this paper,we propose the ADMM decoding algorithm with Simple Hybrid Projection Algorithm(SHPA).Which improves the LDPC code of decoding performance and decoding efficiency.On the other hand,Field Programmable logic Gate Array(FPGA)platform contains abundant logic unit,the RAM/ROM storage resources,Lookup table,FIFO memory and so on hardware resources.And the FPGA has the parallel processing and pipelining is implemented and reconstruct the advantage of strong sex,which provides the best platform for the hardware implementation of projection algorithm with simple computation and high parallelism.We built the hardware implementation platform of HPA(LSA+EVA)projection algorithm in this paper.The main work of this paper is as following:1.Summary some basic concepts and related background of LDPC code,introduce the traditional Belief Propagation(BP)and Linear Programming(LP)decoding algorithm,and gave the ADMM decoding algorithm of LDPC code.2.The SHPA projection algorithm based on EVA is proposed,and the ADMM-SHPA decoding algorithm is presented.The simulation results show that compared with ADMM-CSA decoding algorithm,the decoding performance of ADMM-SHPA improves about 0.5dB-1.0dB.And without any additional parameters,and the decoding performance of ADMM-SHPA is better than ADMM-PD-CSA.On the other hand,the decoding time of ADMM-SHPA is about 25%that of ADMM-CSA and about 50%that of ADMM-PD-CSA.3.Analyze the SHPA projection algorithm based on LSA projection algorithm and EVA projection algorithm.LSA projection algorithm includes EVA projection algorithm,and the projection algorithm has the characteristics of simple calculation and easy to parallelize the implementation.Based on the advantage of FPGA hardware platform,this paper built the FPGA hardware platform of SHPA projection algorithm,after simulation testing and board-level debugging.We verify the correctness of the hardware implementation by the testing compared with the PC results,and give the corresponding hardware resource consumption.