【摘要】 讨论了多发射天线OFDM系统中有限比率反馈对通信系统误码率的影响。通过发射端的波束成形将多天线OFDM无线信道等价为独立的并行子信道,并结合有限比率反馈下的波束成形矢量集的最优设计,推导了多发射天线下OFDM系统中反馈比特数对误码率影响的表达式,同时给出了反馈比特数对误码率的相对误差的影响。数值仿真表明,当发射天线数为2且10dB≤Es/N0≤20dB时,为使误码率的相对误差小于20%,每一子信道需3～5的反馈比特数,当发射天线数为3时则需7～8的反馈比特数,可为带反馈信道的多天线OFDM系统设计提供参考。更多还原

【Abstract】 The effect of finite rate feedback in multiple-antenna OFDM systems on communication performance is discussed in this paper. Through transmit wave beamforming, the wireless channel in multiple-antenna OFDM systems is transformed into several equivalent parallel sub-channels, with the combination of the optimal design of beamformer set, the expression of number of feedback bits related to BER is derived and the effect of finite number of bits on relative error of BER is presented The numerical simulation results indicate that when 10dB≤E_s/N₀≤20dB and the relative error 20% of BER, each sub-channel needs 3⁵ feedback bits for two transmit antennas, and 7⁸ bits for three transmit antennas. The resuluta may be considered as a reference design in multiple-antenna OFDM systems with finite rate feedback.更多还原