将基于循环前缀的时域相位跟踪与基于频域导频的CPE校正技术相互结合,提出了一种旨在提高无线OFDM接收机抵抗相位噪声能力、低复杂度的相位噪声自适应补偿方案,时域跟踪可以对信道相位偏移低频成分起到初步的抑制作用,而在频域则通过引入导频子载波可信度判决机制,将CPE估计放在信道判决前进行,更为精确地消除由频率选择性相位偏移对CPE估计所带来的影响.仿真结果表明,本方案能够显著改善OFDM接收机在相位噪声条件下的系统误码率性能.
In OFDM receivers, phase noise caused by local oscillator instabilities is a potentially serious problem. To cope with the phase noise in actual OFDM receiver, a common phase error correcting algorithm in frequency domain based on pilots and phase noise tracking method in time domain based on the correlation of cyclic prefix of OFDM symbol with low computational complexity were proposed. A feed-forward correction scheme with channel state information based on frequency pilot was proposed to eliminate common phase error more precisely. Numerical simulation results show that the effectiveness in actual wireless OFDM communication systems can be improved by using the proposed scheme.