The analysis and study on MIMO channels capacity is benifit to wireless sensor networks construction and optimization in the future.Under the condition of invariable coefficient of channels

different power allocation schemes’ influence on channel capacity is given and compared with them at the transmitter.Among them waterfilling algorithm is optimal from simulation experiments.The result is consistent with the theory

but it is too complex.Approximate expression of channel capacity in low SNR is deduced and compared with theoretical value by simulation when equal transmit energy scheme is adopted.It is known that its complexity significantly decreases and its value is closed to theoretical one.Antenna correlation affecting on MIMO random channel capacity is analyzed and simulated.The tendency of change on ergodic capacity and outage capacity is compared in various antenna configurations.The result is helpful to adopt acceptable number of antennas when network is constructed.