Broadcast Approach and Oblivious Cooperative Strategies for the Wireless Relay Channel - Part II: Block-Markov Decode-and-Forward (BMDF)

TL;DR

This paper explores the use of broadcast and oblivious cooperative strategies, specifically Block-Markov decode-and-forward, to improve relay channel communication rates, demonstrating enhanced performance over previous schemes and establishing new conjectures.

Contribution

It introduces and analyzes the BMDF scheme with multi-layer transmissions, showing improved rates and a conjecture on optimal source-relay correlation, advancing relay channel strategies.

Findings

Enhanced single-layer transmission results.

Achieved perfect cooperation rates with low collocation gains.

Improved multi-layer transmission performance over SDF.

Abstract

This is the second in a two part series of papers on incorporation of the broadcast approach into oblivious protocols for the relay channel where the source and the relay are collocated. Part I described the broadcast approach and its benefits in terms of achievable rates when used with the sequential decode- and-forward (SDF) scheme. Part II investigates yet another oblivious scheme, the Block-Markov decode- and-forward (BMDF) under the single and two-layered transmissions. For the single layer, previously reported results are enhanced and a conjecture regarding the optimal correlation coefficient between the source and the relay's transmission is established. For the discrete multi-layer transmission of two or more layers, it is shown that perfect cooperation (2x1 MISO) rates are attained even with low collocation gains at the expense of a longer delay, improving upon those achievable by the SDF.