Design And Implementation Of Low Density Parity Check Code Based On USRP RIO Platform

The research goal of the 5G mobile communication system is to realize high-quality data transmission anywhere and provide better performance,such as a significant increase in access speed and broadband.In the future,mobile communications are faced with increasingly complex communication environments,application scenarios and requirements are increasingly diversified.The Low Density Parity Check Code(LDPC)has good performance to approach the Shannon limit,besides,it has lower decoding complexity.Therefore,it is widely used in various fields.However,in terms of engineering implementation,both the coding and the decoding have the problems of high time complexity and computational resource complexity.Thus,this paper studies the digital implementation of LDPC encoding and decoding.The paper introduces the research status and common algorithms of LDPC encoding and decoding technology.In terms of coding algorithms,The RU algorithm has a linear code characteristic that has been applied to various types of encoders,but it requires high demand on check matrix.For decoding algorithms,Belief Propagation(BP)has the advantage that its computational complexity is linearly related to the code length,and it uses iterative convergence to reduce the decoding complexity.However,a large number of matrix operations require more multipliers and memories.As a result,the hardware implementation of LDPC encoders and decoders becomes more difficult and further affects the development of LDPC encoding and decoding.In order to solve the problem of RU encoding algorithm and BP decoding algorithm,this paper proposes the core problem solving method of LDPC encoding and decoding digital algorithm design.In terms of coding,in order to solve matrix storage resource consumption and matrix multiplication complexity problems,this paper proposes methods such as check matrix selection,matrix storage,multiplication and addition improvement,and backward iterators,which are optimized from resource storage and operation respectively.On the other hand,in order to solve the problem of the delay of decoding matrix shift operation and the problem that the iteration times are set too high to affect the decoding efficiency,the design of the shifter,the number of iterations,and the number are proposed.Divider and other methods.These methods solve the problems of LDPC encoding and decoding,which make the implementation of LDPC encoding and decoding more smooth.It can be said that it is the core of the whole LDPC encoding and decoding design and implementation.Then the check matrix of the LDPC code used in this paper is determined according to the IEEE 802.16 e standard,and the code rate,code length and code weight of LDPC encoding and decoding are simulated to determine the final parameter design: including code length and code.Rate,code weight.Finally,a Filter Bank Multicarrier with Offset Quadrature Amplitude Modulation(OQAM/FBMC)system is implemented in the Universal Software Radio Periphera Reconfigurable I/O(USRP RIO)platform.The LDPC encoding and decoding module,this article detailed design details of this block and simulation and debugging contrast.