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.
Ashish JamesA. S. MadhukumarErnest KurniawanFumiyuki Adachi