Amplify-and-forward Multiple-input Multiple-output Research Articles

Optimum Antenna Selection with Doubly ZF Processing for AF MIMO Relay Systems

In this letter, we propose a novel antenna selection algorithm for amplify-and-forward (AF) multiple-input multiple-output (MIMO) relay systems with Zero-Forcing (ZF) processing applied both at the source node and at the destination node. We obtain the optimum antenna selection criterion by deriving an iterative closed-form expression for capacity maximization.

Outage probability of MIMO AF relay networks over Nakagami-m fading channels

The outage probability (OP) of multiple-input multiple-output (MIMO) amplify-and-forward (AF) relay networks using orthogonal space-time block code is investigated. In particular, a closed-form tight lower bound expression for the OP over independently but not necessarily identically distributed Nakagami-m fading channels is derived. Moreover, an asymptotic approximation for OP which reveals the coding and diversity gains is presented. The analytical expressions are validated by Monte-Carlo simulations.

Performance analysis of beamforming in two hop amplify and forward relay networks with antenna correlation

The performance of beamforming with antenna correlation in a two hop amplify and forward (AF) multiple input multiple-output (MIMO) relay network is analyzed. This network consists of a single relay which is used to amplify and forward the signal from the source to the destination. The source and destination are both equipped with multiple antennas, which are correlated in space, while the relay has a single antenna. In this paper, we derive new closed form expressions for the outage probability and probability density function of the received signal-to-noise ratio (SNR) at the destination. We also present exact symbol error rate expressions for the two hop AF MIMO relay network, and show that the full spatial diversity order can be achieved. Our results also indicate that spatial correlation is detrimental to the outage probability and symbol error rate at high SNR, and beneficial at low SNR.

Symbol error probability of hop-by-hop beamforming in Nakagami-m fading

The symbol error probability (SEP) of amplify-and-forward (AF) multiple-input multiple-output (MIMO) cooperative networks where beamforming is adopted at both the source and destination is investigated. In particular, the tight lower bound for SEP of AF MIMO relay systems is presented with hop-by-hop beamforming over independent, but not necessarily identically distributed, Nakagami-m fading channels. Furthermore, assessing the high SNR, an asymptotic SEP expression is derived which reveals the array and diversity gain. Numerical results are shown to verify the analysis in some representative scenarios.