Large-Scale Cooperative Relaying Network with Optimal Coherent Combining under Aggregate Relay Power Constraints
Peter Larsson, Rong Lin Hu · KTH Publication Database DiVA (KTH Royal Institute of Technology) · 2003
Communication schemes exploiting cooperating relay nodes can enable significant SNR and diversity order enhancements. In this paper, a communicating pair of nodes with support from an arbitrary number of relay nodes cooperating in parallel is considered, and the optimal weighting parameters for coherent combining based non-regenerative relaying are derived under aggregate relay power constraint. The analysis demonstrates that each relay merely requires multiplying the received signal with an individual phase and amplitude factor and a common amplitude normalization factor. It is illustrated that the resulting SNR is substantially enhanced compared to direct communication and that SNR improves with increasing relay station density.