Throughput and Sensing Bandwidth Tradeoff in Cognitive Radio Networks

Within the sequential sensing and transmission paradigm (SSTP), spectrum sensing over the whole primary user (PU) band always suspends secondary user (SU) data transmission in the sensing interval. Delay incurred by this kind of suspension may be intolerable to delay sensitive SU services. To alleviate this problem, we adopt a parallel sensing and transmission paradigm (PSTP), within which the SU transmits and senses simultaneously. In this paper, we investigate the relationship between the achievable SU throughput and bandwidth allocated for spectrum sensing within the PSTP, under the constraint that the PU is sufficiently protected. We also study the delay improvements of the PSTP over that of the SSTP. Both theoretical analyses and simulation results that there exists an optimal sensing bandwidth that maximizes the achievable SU throughput within the PSTP. Furthermore, compared to the SSTP, the SU delay is reduced by using the PSTP.