多天线Rayleigh衰落相关信道的平均信道容量

Ergodic Capacity of Multiple Antenna Rayleigh-Fading Correlated Channel

研究了空间衰落相关的R ay le igh信道的平均信道容量,其发射端和接收端均采用多天线系统。在实际情况中,接收端有理想的信道状态信息,而发射端没有任何信道信息,因此在各发射天线上采用等功率分配进行发射。本文推导了具有2根发射天线和多根接收天线(T IM O)衰落相关信道的平均信道容量,将其和M on te-C arlo仿真结果比较,并进一步研究空间相关性对信道容量的影响。数值结果表明:信道的空间相关性降低了平均信道容量,而且不同于多入单出(M ISO)信道,当信噪比一直增大,由相关性带来的容量损失也增大且不收敛。

The ergodic capacity of the spatially correlated Rayleigh-fading channel is studied with multiple antennas at both the transmitter and the receiver. In the practical communication scenario, the receiver usually has a perfect channel state information, while the transmitter has not any channel state information, therefore a uniform power allocation strategy is employed at the transmitter. An exact capacity formula of a two-input multi-output （TIMO） correlated fading channel is derived, then the capacity result is compared with that of the Monte-Carlo simulation and the impact of the spatial correlation on the channel capacity is studied. Numerical results show that the spatial correlation degrades the ergodic capacity. And the capacity loss due to the correlation increases without the bound when the signal-to-noise ratio increases. The capacity loss is upper bounded by some constants in the multi-input single-output （MISO） channel.