Analysis on Decode-and-Forward Two-Path Relay Networks: When and How to Cooperate

Two-path relay networks can be deployed to achieve full-rate transmissions. In this paper, we introduce stable throughput analysis into decode-and-forward (DF) two-path relay networks. We establish the queueing model and take outage probabilities into consideration to characterize the packet-level cooperation and derive the closed-form stable throughput region. Based on the stable throughput region, we also propose a power-allocation scheme between the source node and relays to maximize the achievable packet rate. The maximal achievable packet rate determines the admission control of certain cooperation (i.e., when to cooperate) under a specific interrelay interference (IRI) cancellation technique. The power allocation is utilized to illustrate how to cooperate between the source node and relays. Three IRI responses are considered, and the system behaviors under various circumstances are presented through simulations.