Analysis of the LS estimation error for a MIMO system on a Rician fading channel

Coherent detection techniques require the channel information for the symbol detection and such techniques are reported to have better performance than the non coherent ones. Method of Least Squares (LS) is a popular technique for performing channel estimation. The LS Estimation method requires the channel to be constant through out the estimation period. In reality, the wireless channel is time varying and we will always get an estimation error when we estimate the channel with block techniques like the LS Estimation. Moreover, the channel is affected by noise and this will also add some error in estimation. MIMO system, which offers gain in capacity, is an area of recent interest. Analysis of LS estimation error for SISO Rayleigh channel is available in literature. Approximate analytical expressions for the variance of the error for a Rician fading channel for a MIMO system is presented here. The validity of the expression has been checked through computer simulation.