Design and analysis of linear distributed MIMO relaying algorithms

Abstract

The use of multiple antennas at both ends of a wireless link, also known as multiple-input multiple-output (MIMO) wireless, has been shown to offer significant improvements in the quality of communication in terms of both higher data rates and better reliability at no additional cost of spectrum or power. In this paper, MIMO communication in a wireless network is considered where multiple MIMO source-destination pair terminals simultaneously communicate through a large common set of MIMO relay terminals. With ever increasing demands for tetherless, ubiquitous and high data rate applications, there has been great interest in developing novel decentralised communication methods through distributed relaying techniques to enhance performance and enable more efficient usage of system resources. Distributed MIMO linear relaying techiques are designed that take advantage of local channel state information (CSI) at the relay terminals to simultaneously beamform multiple users' signals to their intended destinations. The merits of distributed MIMO relaying over direct transmissions through the analytical characterisation of the signal-to-interference ratio (SIR) statistics in the high and low signal-to-noise ratio (SNR) regimes are demonstrated and theoretical predictions are verified by numerical simulations. Finally, relay beamforming based on the quantised finite-rate feedback of the channel states is considered and the SIR degradation through Monte-Carlo simulations is quantified.