Study of Buffer-Aided Space-Time Coding for Multiple-Antenna Cooperative Wireless Networks

TL;DR

This paper introduces an adaptive buffer-aided space-time coding scheme for cooperative wireless networks with multiple antennas, improving performance through relay selection, adjustable coding, and stochastic gradient optimization.

Contribution

It proposes a novel buffer-aided space-time coding scheme with adaptive relay selection and adjustable code vectors, enhancing cooperative wireless network performance.

Findings

Performance gains over existing schemes

Effective relay selection based on SNR

Reduced complexity with stochastic gradient algorithm

Abstract

In this work we propose an adaptive buffer-aided space-time coding scheme for cooperative wireless networks. A maximum likelihood receiver and adjustable code vectors are considered subject to a power constraint with an amplify-and-forward cooperation strategy. Each multiple-antenna relay is equipped with a buffer and is capable of storing the received symbols before forwarding them to the destination. We also present an adaptive relay selection and optimization algorithm, in which the instantaneous signal to noise ratio in each link is calculated and compared at the destination. An adjustable code vector obtained by a feedback channel at each relay is employed to form a space-time coded vector which achieves a higher coding gain than standard schemes. A stochastic gradient algorithm is developed to compute the parameters of the adjustable code vector with reduced computational complexity. Simulation results show that the proposed buffer-aided scheme and algorithm obtain performance gains over existing schemes.