OFDM基带接收机中残余同步误差的消除

Elimination of Residual Synchronization Errors for OFDM Baseband Receivers

OFDM基带接收机在跟踪阶段仍然残存着同步误差.这些误差尽管数量微小,但会使系统性能严重恶化.本文提出了一种消除OFDM接收机中残余同步误差的方案.与现有方案相比,该方案应用了三种新的算法和技术:载波频率与采样定时误差联合估计的导频辅助递推算法,基于延迟的定时误差校正技术以及基于递推最小二乘(RLS)的判决引导信道增益更新算法.仿真结果表明该误差消除方案能显著地改善OFDM接收机在多径传输环境中的误比特率(BER)性能.

For an OFDM baseband receiver, residual synchronization errors still exist in its tracking stage. These errors, even though very small, will severely degrade the overall bit error rate （BER） performance. In this paper, we propose a residual synchronization error elimination scheme for OFDM baseband receivers. Compared with existing schemes, it employs three new algorithms： a pilot-aided recursive algorithm for joint estimation of the carrier frequency sampling time offsets, a delay-based timing error correction technique and a new decision-directed channel gain update algorithm based on recursive least-squares （RLS） criterion. Simulation results show that this error elimination scheme can effectively improve the OFDM receiver＇s BER performance even in the multipath transmission conditions.