Capacity of Wireless Systems with Channel Estimation Errors

Analysis of mutual information for wireless systems is usually performed by assuming perfect channel state information (CSI). In many practical applications, however, channel uncertainty occurs due to channel variation and additive noise. Such uncertainty introduces a product term between signal and channel estimation error in the received signal whose probability density function is thus difficult to determine. This situation makes the direct evaluation of mutual information difficult and forces the adoption of a bounding technique in current literature by treating the product term either as a signal component or as a noise component. In this paper, we solve the problem by accurately fitting the received signal with the multivariate Pearson´s type-7 (MPT-7) distribution. The new results are simple in expression, very accurate as evidenced by simulation.