Optimal Relay Location and Power Allocation for Low SNR Broadcast Relay Channels
The authors consider the Broadcast Relay Channel (BRC), where a single source transmits to multiple destinations with the help of a relay, in the limit of a large bandwidth. They address the problem of optimal relay positioning and power allocations at source and relay, to maximize the multicast rate from source to all destinations. To solve such a network planning problem, they develop a three-faceted approach based on an underlying information theoretic model, computational geometric aspects, and network optimization tools. Firstly, assuming superposition coding and frequency division between the source and the relay, the information theoretic framework yields a hypergraph model of the wide-band BRC, which captures the dependency of achievable rate-tuples on the network topology.