Anywhere decoding: Low-overhead basestation cooperation for interference- and fading-limited wireless environments

In the context of interference channels with multiple transmitters and receivers, we propose a novel decoding scheme called anywhere decoding that does not pre-assign the receiver at which each message should be decoded, but rather requires that each message must be decoded at some receiver. This paper illustrates how system performance can improve if we allow for this flexibility. After developing a system model based upon the classical two-user, discrete-memoryless interference channel, we present two decoding schemes based upon the anywhere decoding concept, each requiring extremely low overhead to enable cooperation among the receivers. Both of these schemes offer the same achievable rate region, for which we outline the proof in the discrete-memoryless case and state the result for the Gaussian case with independent and identically distributed Gaussian inputs. When cast into a cellular setting with two cooperating basestations experiencing path-loss and multipath fading, we assess performance in terms of two system metrics: the common outage probability and the symmetric throughput. Asymptotic analysis of the outage probability of the anywhere decoding schemes demonstrates that they achieve full spatial diversity through multiple decoding opportunities, and they are no more than 1.5 decibels (dB) from full basestation cooperation at high signal-to-noise ratio (SNR).