Performance Analysis of Multiple Antenna Multi-User Detection

TL;DR

This paper derives the diversity order of multi-user detection schemes using multiple antennas and space-time codes, showing how diversity gains depend on system parameters and highlighting the optimality of maximum-likelihood decoding.

Contribution

It provides a theoretical analysis of diversity order for multi-user detection schemes with space-time coding, revealing conditions for maximum diversity gain.

Findings

Array-processing schemes achieve diversity order of N(M-J+1).

Maximum-likelihood decoding attains full diversity NM.

Diversity order depends on number of users, antennas, and decoding method.

Abstract

We derive the diversity order of some multiple antenna multi-user cancellation and detection schemes. The common property of these detection methods is the usage of Alamouti and quasi-orthogonal space-time block codes. For detecting $J$ users each having $N$ transmit antennas, these schemes require only $J$ antennas at the receiver. Our analysis shows that when having $M$ receive antennas, the array-processing schemes provide the diversity order of $N(M-J+1)$. In addition, our results prove that regardless of the number of users or receive antennas, when using maximum-likelihood decoding we get the full transmit and receive diversities, i.e. $NM$, similar to the no-interference scenario.