Sample Frequency Offset Estimation For Power Line Communication Based On OFDM

Power line communication (PLC) is a broadband communication method using thepower line as the information transmission media for the transmission and exchange of voiceand video. However, the inherent characteristics of power line channel, such as noise,multipath propagation and frequency selective attenuation greatly affect the performance ofPLC. Orthogonal Frequency Division Multiplexing (OFDM) has the abality of againstingnoise, multipath interference and frequency selective fading, it also has the advantages of highbandwidth utilization, simple structure and low cost, providing an effective solution toachieve high-speed, reliable power line communication.As a modulation technique, OFDM itself has some problems to be solved, such assampling synchronization, symbol synchronization, Peak-to-Average Power Ratio and so on.When OFDM applied to the PLC system, there exist serious sampling frequencysynchronization issues, which will greatly reduce the performance of the PLC system. How toestimate the sampling frequency offset exists in the PLC system is the focus of this study.Taking the transmission characteristics of the power line channel into account, this paperproposes a weighted SFO estimation algorithm based on SNR. The main work andinnovations are as follows:1.A detailed analysis and description of the transmission characteristics of the power linechannel are given, refers to a new, practical and flexible power line channel modelingmethods, and simulate the amplitude-frequency response of power line channel.2.Analysis of the advantages and disadvantages of OFDM used in power linecommunication. Analysis and simulate the impacts of SFO on the time domain and thefrequency domain of the OFDM system. Introduces the traditional directed SFO estimationalgorithm, and put forward a SNR based weighted SFO estimation algorithm.Use MATLABto simulate the statistical estimation performance of the weighted SFO estimation algorithm.3.A brief introduction of G.hn9960powerline communication protocol, simulate theperformance of sampling frequency synchronization using the value of the weighted SFOestimation algorithm. Compared with directed SFO estimation, the simulation results showthat the weighted SFO estimation algorithm can effectively improve the reliability of theperformance of the PLC communication.