随着传输速率越来越高,信号所占用的带宽越来越宽,实际信道呈现出频率选择性衰落特

性。根据频率选择性衰落信道特性,建立了频率选择性衰落M IMO信道模型,采用频域和时域的方

法研究了在频率选择性衰落下,发射端已知和未知信道状态信息的M IMO信道容量,并给出了相关

的仿真结果。研究结果表明:在相同发射功率和传输带宽下,M IMO系统可以不牺牲信号带宽而显

著提高信道的容量,并且天线数量和输入信噪比的大小对信道容量具有不同的影响。研究结果为如

何提高频率选择性衰落环境下M IMO信道容量提供了依据。-With the higher and higher of transmitting rate, the signal bandwidth iswider and wider, and the

p ractical channel p resents the frequency selective fading character. In this paper, a multi- input multi-

output (M IMO) channelmodel under frequency selective fading is constructed according to the character of

frequency selective fading channel. The frequency and time domain methods are used to discussM IMO

channel capacity due to the known and unknown channel state information under the frequency selective fa2

ding. The simulation results show thatM IMO system can imp rove the channel capacity remarkably but no

exchanging signal bandwidth under the circumstances of the same launching power and transmitting band2

width, and the numbers of antennas and the quantity of SNR have the different effect on the channel capaci2

ty. The conclusion offers the basis of how to imp rove M IMO channel capacity under the circumstances of

frequency selective fading.