Time-constrained detection probability and sensing parameter optimization in cognitive radio networks
- PDF / 910,901 Bytes
- 12 Pages / 595.28 x 793.7 pts Page_size
- 19 Downloads / 175 Views
RESEARCH
Open Access
Time-constrained detection probability and sensing parameter optimization in cognitive radio networks Jae-Kark Choi and Sang-Jo Yoo*
Abstract Sensing-throughput tradeoff has widely been investigated in cognitive radio networks. Detection probability and interference ratio are usually considered the main constraints to the protection of primary signals. However, the detection probability defined during a sensing duration does not fully capture the goal of primary protection because two important factors are not taken into consideration. Neither the detection latency during the detection of the primary signal nor the unavoidable misdetection of the primary signal due to its ability to only occupy the channel between two consecutive sensing durations are considered. Motivated by these problems, we propose a new detection probability called the time-constrained detection probability (TDP) and investigate the effect of the sensing interval on the TDP. This sensing interval consists of a sensing duration and a transmission duration. Moreover, both an optimal sensing duration and an optimal sensing interval are proposed, which not only satisfy both the TDP and the interference ratio constraints for primary protection, but also maximize the achievable throughput for secondary users. Numerical analyses show the relationship between the sensing interval and the TDP and the optimal sensing parameters consisting of the optimal sensing duration and the optimal sensing interval. Keywords: Cognitive radio, Detection probability, Sensing parameter optimization, Sensing-throughput tradeoff
1. Introduction The rapid growth of wireless communications requires more spectrum bands, but most of the public radio spectrum bands are currently allocated to licensed users and severely underutilized in both time and spatial domains [1]. As a result, efficient use of spectrum bands is one of the challenging issues in wireless communications. Cognitive radio (CR), a paradigm originated by Mitola [2], has been considered a promising technology to cope with the lack of radio resources. In CR networks, one of the challenging issues is how to maximize the throughput for secondary users while protecting primary users from interference, and accordingly the sensing-throughput tradeoff issue has widely been studied in the literature. In this field, secondary users sense the spectrum bands of interest during a sensing duration in every sensing interval. While considering the * Correspondence: [email protected] Graduate School of Information Technology & Telecommunication, Inha University, 253 Yonghyun-dong, Incheon, Nam-gu 402751, Korea
energy detection as the sensing method, the detection probability and the interference ratio (or collision probability) are used as the metrics to measure how primary users are protected. In general, with a longer sensing duration, sensing accuracy can be improved (i.e., there will be fewer misdetections and false alarms) at the cost of reduced transmission duration. In [3], the effect of sensing
Data Loading...
