A Residual Frequency Offset Compensation Scheme for OFDM System Base on MLE

摘要

The outage performance of an OFDM system will be seriously degraded by the residual frequency offset (RFO) systems, although the RFO is small in account. In this paper, an non-data aided (NDA) estimate algorithm based on MLE is proposed, which extracts pha.se offset information from sub-carriers of adjacent OFDM symbols to estimate and compensate the residual frequency offset. Based on the algorithm proposed, an approximate iterative algorithm is further presented which greatly reduces the computational complexity without losing much accuracy, thus it's suitable in engineering. Simulation shows that the proposed algorithm has a better performance both in AWGN channel and multipath channel. Compared with traditional feedback decision algorithm, especially on the conditions of high frequency offset and low signal-noise ratio, the system performance can be improved up to 5 dB.