Research Of Encode And Decode Algorithm Optimization For Non-binary LDPC Codes

In order to adapt to the standard for next generation mobile communication technology and provide users with the best communication experience,looking for communication capacity,high-quality communication technology has become an important task.Adopting channel coding technology is an important measure to solve the problem of communication quality.While non-binary LDPC codes have a significant advantage in the channel coding technology,but its high encoding and decoding complexity has hindered its application in wireless communication systems.Therefore,channel coding technology is facing new challenges,which is reducing the complexity of coding algorithms while to ensure that non-binary LDPC error correction code excellent performance to achieve hardware realizable.And it can effectively solve the problem of communication capacity,that the design of integrated non-binary LDPC coded modulation scheme is used in wireless communication systems,and has important significance and practical value.Firstly,encoding algorithms of non-binary LDPC codes are described,encoding process is analyzed,and the advantages and disadvantages of each algorithm are compared with.The decoding algorithms are emphatically introduced.At last,encoding and decoding complexity are analyzed.Then,with reducing encoding complexity of non-binary LDPC codes,this paper presents an improved structure scheme of construction algorithms for check matrix of non-binary PEG-QC-LDPC codes.The scheme constructs based matrix of check matrix by the improved PEG algorithm,which is applied in the construction of the QC-LDPC codes,and ultimately obtain non-binary PEG-QC-LDPC codes of high performance and low complexity.Meanwhile,combining with the scheme and combing rows obtains an improved structure scheme of non-binary multi-rate LDPC codes with fixed bit length.Finally,in order to meet the high data capacity of communication system,advanced modulation techniques—multiple quadrature amplitude modulation(MQAM)is presented,which is consist of coded modulation system combining with non-binary LDPC codes.The design can improve communication capacity,and effectively enhance the anti-burst error capability in the wireless communication channel.To further enhance the performance of the system,a communication system based on joint LDPC-MQAM iterative detection was proposed.Joint LDPC-MQAM iteration is essentially a joint demodulation and decoding iterative detection based on Turbo principle.The system improves the BER performance while ensuring the bandwidth efficiency.