Improving Two-Way Selective Decode-and-forward Wireless Relaying with Energy-Efficient One-bit Soft Forwarding

TL;DR

This paper introduces an energy-efficient two-way relaying protocol using one-bit soft forwarding to improve block-error-rate performance in battery-powered wireless sensor networks, with theoretical analysis and asymptotic gains.

Contribution

The paper proposes the TW-1bSF protocol that enhances two-way relaying with minimal complexity and derives tight BLER bounds, demonstrating its superiority over traditional methods.

Findings

TW-1bSF outperforms TW-SDF in BLER performance.

Derived tight upper bounds on block-error-rate for both protocols.

Asymptotic analysis shows significant gains with long block codes.

Abstract

Motivated by applications such as battery-operated wireless sensor networks (WSN), we propose an easy-to-implement energy-efficient two-way relaying scheme. In particular, we address the challenge of improving the standard two-way selective decode-and-forward protocol (TW-SDF) in terms of block-error-rate (BLER) with minor additional complexity and energy consumption. By following the principle of soft relaying, our solution is the two-way one-bit soft forwarding (TW-1bSF) protocol in which the relay forwards the one-bit quantization of a posterior information metric about the transmitted bits, associated with an appropriately designed reliability parameter. In WSN-related standards (such as IEEE802.15.6 and Bluetooth), block codes are adopted instead of convolutional and other sophisticated codes, due to their efficient decoder hardware implementation. As the second main contribution, we derive tight upper bounds on the BLER performance for both TW-SDF and TW-1bSF, when the two-way relaying network employs block codes and hard decoding. The error probability analysis confirms the superiority of TW-1bSF. Moreover, we derive the asymptotic performance gain of TW-1bSF over TW-SDF, which further suggests that the proposed protocol is a good choice, especially when long block codes are used.