Adaptive spatial multiplexing order based on cumulative channel capacity

We investigate an adaptive spatial multiplexing order based on an increase in channel capacity. The channel capacity of a MIMO (Multiple Input Multiple Output) system increases linearly as the number of transmit antennas. However, the throughput cannot increase in a poor channel environment as the number of antennas. The spatial multiplexing order is then required to be controlled according to channel state. Although the spatial multiplexing order depends on rank of a MIMO channel, it which gives the maximum throughput is less than the rank of a MIMO channel. This is because of a gap between an ideal channel capacity and actual channel capacity due to additive white Gaussian noise (AWGN) and the performance of a transmitter and a receiver. In order to solve the problem, the proposed adaptive spatial multiplexing order system takes advantages of cumulative channel capacity.