On the Capacity of Linear Precoder and Decoder in Semi-Correlated MIMO System

MIMO system has been proven to provide more capacity than conventional SISO system, which is linear increase with the number of minimum transmit and receive antennas. But it is true only in independent conditions, when the spatial fading correlation exists, the capacity may be different. Linear precoder and decoder enable optimal allocation of power and bits over the spatial and temporal domain, depend on the channel conditions. Based on the two criterions, Maximum information rate and Minimum Mean Square Error, the optimal MIMO capacity is deduced and shown that the optimum linear precoder and decoder diagonalize the MIMO channel into eigen subchannels. Effect of the correlation on the capacity of both MIMO and linear precoder is also analyzed. Simulation shows that the linear precoder is more robust than that of MIMO system with no preceding.