On the Achievable Rate of Three-Node Wireless Networks
Lifeng Lai, Ke Liu, Hesham El-Gamal · 2005
Wc propose an information theoretic wireless network model consisting of three half-duplex nodes under the total power constraint. The three-node network formulation specializes to many generalized scenarios including relay and multi-cast, with realistic feedback and cooperation. In this framework, cooperation and feedback are naturally incorporated via different patterns of node transmission or reception. We focus on several important sub-problems to gain fundamental insights on the role of cooperation and feedback. In particular, we characterize the achievable rate for the relay case under various cooperation strategies. Our analytical results help identify scenarios where one strategy may outperform the others. We propose a novel (noisy, half-duplex) feedback scheme that can improve upon known non-feedback methods. However, the gain of feedback diminishes in either high power or low power regime. We then extend our results on the relay case into the multicast scenario, and show that receiver cooperation enlarges achievable rate region even under the stringent half-duplex and total power constraint. Numerical results are provided to demonstrate our theoretical findings.