On Optimal Signal Detection using Covariance shaping method

Abstract: In this paper, a new class of linear multiuser detector, referred to as the Covariance Shaping Multiuser (CSMUD) detector has been designed for the suppression of Multi Access Interference (MAI) in multiuser wireless communication systems. We develop an algorithm using quantum constraints and some of its axioms to minimize the total variance of the weighted error between the receiver output and observed signal, subject to the limit that the covariance of the noise component in the receiver output proportional to a given covariance matrix, with the intention that we control the dynamic range and spectral shape of the output noise. We consider the problem of multiuser detection in which we seek to detect probability of bit error for some set of users with different noise levels. The exact and approximate expressions for the probability of bit error for some set of users with different noise level are illustrated. The performance of the CSMU receiver is characterized and finally through examples that the CSMU receiver can significantly increase the performance over the conventional multiuser receivers.