A delay-constrained rateless coded incremental relaying protocol for two-hop transmission

We develop an efficient relay selection protocol for two-hop transmission in cognitive radio networks where secondary users interfere with a primary user. Our protocol provides joint benefits of two well-known relaying strategies, namely relay sub-set selection and incremental relaying. It aims at minimizing the outage probability for delay-constrained applications by utilizing rateless codes. The advantages of the proposed scheme compared to conventional relay selection protocols can be summarized as follows: (1) feedback overhead is significantly reduced, (2) resources are exploited efficiently, (3) outage probability is minimized. In order to evaluate the proposed strategy, analytical and numerical results are presented.