研究了信道估计的均方误差,利用无限长、非因果的维纳滤波器推导出了它的下界.通过对不同衰落信道多普勒谱的积分,求出了相应的信道估计均方误差下界的闭合表达式,并在此基础上得到了分集系统在独立同分布的衰落信道中采用最大比合并时的误码率下界.数值分析结果表明,非理想信道估计下最大比合并的误码率性能是以理想信道估计的结果为下界,并随着最大多普勒频移的增加或信道估计信噪比的减小而逐渐劣化. The mean square error of channel estimation is studied, and its lower bound is deduced by the Wiener filter of infinite length and non-causality.Based on the integral of Doppler spectrum of different fading channels, the corresponding lower bound of mean square error of channel estimation And the lower bound of the bit error rate (BER) when the maximum ratio is adopted by the diversity system in independent and identically distributed fading channels is obtained.The numerical results show that the maximum ratio error rate under the non-ideal channel estimation Performance is the result of the ideal channel estimation as the lower bound, and gradually degrades as the maximum Doppler shift increases or the SNR of the channel estimates decreases.