Improved Phase Tracking Algorithm in Cooperative OFDM Systems
Jibo Wei · Modern Electronics Technique · 2010
Compared to conventional MIMO-OFDM systems,the cooperative OFDM(CO-OFDM) systems have the advantage that is suitable for all kinds of user terminals with small size receivers.However,multiple carrier frequency offsets(MCFO) caused by the mismatch of the nodes' crystal oscillators or Doppler frequency shifts result in an inter-carrier interference(ICI) and decrease the performance of CO-OFDM systems significantly.In order to mitigate the ICI in CO-OFDM systems,a so-called phase-tracking algorithm applied to 1-2-1 models is directly extended to 1-3-1 models in this paper.By resetting the pilot frequency sequence and changing the computing method,an improved phase-tracking algorithm is also gave out.It cuts down the computing complexity,so can be adopted in practical systems.The simulation results show that the improved algorithm can further improve the system performance at high SNR.