Performance analysis of multiuser diversity for MIMO systems with linear zero-forcing receiver

In multiantenna systems exploiting linear zero-forcing receivers, the Signal-to-Noise Ratio (SNR) on each of the simultaneous sub-streams is not independent with each other. This makes the performance analysis of the multiuser diversity much more difficult. By means of hypothesis testing and the maximum likelihood parameter estimation, this paper uses the Gamma distribution to approximate the probability distribution of the maximum, the minimum and the mean value of the SNRs on all the streams. Based on this, the performance of multiuser diversity for multiantenna systems is analyzed. Simulation shows that the aforementioned approximation closely matches the real distribution and the analysis provides a good estimation on the multiuser diversity gain.