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

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 decodeand-forward (SDF) scheme. Part II investigates yet another oblivious scheme, the Block-Markov decodeand-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.