Research On Timing Synchronization Algorithms Of Cable Communication System Based On OFDM

In underground cable transmission system,OFDM system as the core technology solves the problems of inter-symbol interference and low utilization of spectrum resources.But at the same time,OFDM technology brings more sensitive problems to the effect of symbol timing synchronization.If timing errors occur,the system performance will be degraded.Therefore,good symbol timing synchronization is the key link of OFDM system.This paper focuses on improving the timing accuracy of the system,and studies and simulates the timing synchronization technology.Firstly,the characteristics,basic principles and key technologies of OFDM system and the model of underground cable transmission system are introduced,and the influence of synchronization error on the system is analyzed.Then,the data-aided timing synchronization algorithm and non-data-aided timing synchronization algorithm are simulated and analyzed respectively,and the improved algorithm is proposed based on the original algorithm.In data-aided class algorithm,a new training sequence is constructed by using the good autocorrelation of CAZAC sequence instead of PN sequence;in non-data-aided class algorithm,three improvements are made respectively from signal denoising,timing synchronization point calculation and result optimization,among which timing synchronization point calculation is weighted by ZC sequence,and result optimization is realized by improved iteration algorithm.