Joint power allocation and relay selection for two-way relaying with digital network coding
The resource allocation problem for two sources communicating via an amplify-forward relay is studied from an outage perspective. Analog network coding is considered for half-duplex nodes with perfect receiver-side channel knowledge. Under a sum power constraint, an optimal power allocation that minimizes an approximate outage probability is derived and shown to improve the performance upto 4.77 dB. A cutset bound is also optimized to serve as a comparison reference. When such a power allocation is not feasible, two novel resourceoptimized schemes, which exploit conventional one-way relaying, are proposed to reduce the outage at low multiplexing gains.