Reduction of the effect of carrier frequency offset at orthogonal frequency division multiplexing systems

Performance of the orthogonal frequency division multiplexing systems is significantly influenced by the carrier frequency offset. This imposes the use of differential modulation schemes instead of the coherent detection based schemes. The paper presents two classes of receivers with the improved performance in the presence of the frequency offset. The first class are the improved existing receivers, and the second class are new reconfigurable receivers, based on adaptive filters. The detection performance of the reconfigurable receivers is close to the coherent detection performance of the differentially encoded signal. Also these receivers are able to operate within significantly wider frequency offsets range than the other receivers with similar complexity.