End-to-End Joint Antenna Selection Strategy and Distributed Compress and Forward Strategy for Relay Channels

TL;DR

This paper introduces an end-to-end antenna selection strategy and a distributed compress-and-forward method for multi-hop relay channels, improving diversity-multiplexing tradeoff performance over existing codes.

Contribution

It proposes a novel antenna selection strategy that achieves all points of the optimal diversity-multiplexing tradeoff, surpassing prior distributed space-time coding methods.

Findings

Achieves corner points of the optimal diversity-multiplexing tradeoff.

Outperforms existing distributed space-time codes at intermediate multiplexing gains.

Proposes a compress-and-forward strategy for two-hop relay channels.

Abstract

Multi-hop relay channels use multiple relay stages, each with multiple relay nodes, to facilitate communication between a source and destination. Previously, distributed space-time codes were proposed to maximize the achievable diversity-multiplexing tradeoff, however, they fail to achieve all the points of the optimal diversity-multiplexing tradeoff. In the presence of a low-rate feedback link from the destination to each relay stage and the source, this paper proposes an end-to-end antenna selection (EEAS) strategy as an alternative to distributed space-time codes. The EEAS strategy uses a subset of antennas of each relay stage for transmission of the source signal to the destination with amplify and forwarding at each relay stage. The subsets are chosen such that they maximize the end-to-end mutual information at the destination. The EEAS strategy achieves the corner points of the optimal diversity-multiplexing tradeoff (corresponding to maximum diversity gain and maximum multiplexing gain) and achieves better diversity gain at intermediate values of multiplexing gain, versus the best known distributed space-time coding strategies. A distributed compress and forward (CF) strategy is also proposed to achieve all points of the optimal diversity-multiplexing tradeoff for a two-hop relay channel with multiple relay nodes.