ARQ Protocols in Cognitive Decode-and-Forward Relay Networks: Opportunities Gain
Zongsheng Zhang, Qihui Wu, Jinlong Wang · Radioengineering · 2015
In this paper, two novel automatic-repeat-request (ARQ) based protocols are proposed, which exploit cooperation opportunity inherent in secondary retransmission to create access opportunities.If the signal was not decoded correctly by destination, another user can be acted as a relay to reduce retransmission rounds by relaying the signal.For comparison, we also propose a Direct ARQ Protocol.Specifically, we derive the exact closed-form outage probability of three protocols, which provides an effective means to evaluate the effects of several parameters.Moreover, we propose a new metric to evaluate the performance improvement for cognitive networks.Finally, Monte Carlo simulations were presented to validate the theory analysis, and a comparison is made among the three protocols.