Alternate Distributed Beamforming for Decode-and-Forward Multi-Relay Systems Using Buffers

TL;DR

This paper introduces a novel fixed scheduling scheme called alternate distributed beamforming (ADB) for buffer-aided relay systems, which improves throughput without requiring instantaneous channel state information.

Contribution

The paper proposes a new fixed scheduling policy for relay systems that enhances throughput and operates without needing real-time channel information.

Findings

ADB achieves higher throughput than existing policies.

Theoretical throughput analysis is validated by numerical results.

Closed-form expressions for throughput are derived.

Abstract

In this paper, link selection for half-duplex buffer-aided relay systems is revisited. A new fixed scheduling policy referred as alternate distributed beamforming (ADB) is proposed, in which the relays are divided into two groups, with one group receiving the same information broadcast from the source and the other group transmitting the common messages to the destination via distributed beamforming in each time slot. It is worth noting that the relays used for reception and transmission are determined without the need of instantaneous channel state information (CSI). Theoretical analysis of the achievable throughput of the proposed scheme in Rayleigh fading is provided and the approximate closed-form expressions are derived. Through numerical results, it is shown that compared with existing link selection policies, the proposed fixed scheduling ADB achieves a significant improvement in achievable throughput.