LAUSR

Multihop relaying is used for increasing the communication range of cognitive radio networks. To circumvent the implied loss in throughput due to multihop relaying, in this paper, we propose incremental relaying (IR) for cooperative multihop cognitive radio networks (CMHCRNs). Two IR protocols that select a relay from the qualified relays (the relays whose received signal-to-noise-ratio (SNR) values are greater than a predefined threshold) in each hop are proposed to study the performance of the considered CMHCRN. The first protocol is named IR-based highest SNR (IR-HSNR) protocol that selects a relay with best SNR to the destination. Another one, termed IR-based highest transmit power (IR-HTP) protocol, selects a relay with the highest available transmit power. Expressions for the exact outage probability and throughput are derived for both routing protocols by considering both peak–power and peak–interference constraints. Moreover, closed-form expressions for floor values of outage probability and throughput are derived for both the protocols. It is shown through numerical results that throughput of the considered system shows a concave behavior with respect to number of relaying hops for both the proposed protocols. It is further observed that the performance of the IR-HSNR is superior to that of the IR-HTP, whereas the latter has lower implementation complexity.