Research On APSK Modulation And LDPC Coding In Power Line Communication

Power line communication has become an excellent solution for smart home and home broadband due to its convenient and economical network,strong scalability and wide coverage.However,the initial design of power lines,wiring and electrical devices did not take into account the possibility of power lines as communication media.Power line in a real environment is not an ideal information transmission medium and the channel environment is bad.With the development of communication technology,many coding technologies and modulation technologies with superior performance have emerged.These technologies provide reliable guarantee for communication systems in complex environments.Power line communication,which takes power line as communication medium,has gradually entered people's vision,and a large number of products based on power line communication have been derived.This paper studies the APSK modulation and LDPC coding technology based on the power line communication system model,and demonstrates the applicability and superiority of the BICM system based on APSK and LDPC in power line communication.On this basis,the constellation and demapping algorithm of APSK are optimized for the channel characteristics of power line communication.As a result,the APSK constellation with the best error performance is obtained and the complexity of APSK demapping is effectively reduced.Since APSK has a large difference in the degree of error protection for different bits mapped to a symbol on the constellation,these bits with a low degree of protection limit the overall error performance of coded modulation system.This paper proposes a nonuniform coded scheme,which is to group data with different protection levels and match low density parity check code with different error correction capabilities through bit interleaving.Compared with the traditional MLC scheme,the hardware complexity of this scheme is lower and the delay is smaller.Simulation results show that the scheme has better performance gain without increasing the coding redundancy.This paper provides a new entry point for the research of coded modulation system in power line communication.The nonuniform coded scheme provides a theoretical reference for practical hardware implementation,and has great values on the fields of power line communication,error correction coding and modulation technology.