Adaptive Sensing Threshold Control Based on Transmission Power in Cognitive Radio Systems

Abstract

Spectrum sensing is a key enabling technology for cognitive radio. Since there is a tradeoff between the probability of missed detection and the probability of false alarm according to a value of sensing threshold, it is very important to determine the sensing threshold suitable for cognitive radio environments. In this paper, we propose a novel method to determine the sensing threshold in the cognitive radio system, in which the secondary user (SU) first decides its transmission power for the communication and then decides the sensing threshold for the coexistence with the primary user (PU). For the coexistence, the SU controls its sensing threshold adaptively according to its transmission power in order to guarantee the minimum decodable SINR for the primary receiver. The analysis results show that the adaptively controlled sensing threshold decreases both the missed detection and the false alarm simultaneously and so enables both SU and PU to coexist in the same channel without interfering each other.

A Novel Method for Weighted Cooperative Spectrum Sensing in Cognitive Radio Network

“…Under the hypothesis 1 H , the received signal ) (t y is the sum of the transmitted signal and the noise, i.e., the PU is using the present frequency band within the observation duration from 0 to T seconds. Under the hypothesis 0 H , the signal ) (t y consists only of the noise, that is, the frequency band is not being used.…”

“…Considering that the distance between the SU and PU is tightly related to a path loss. Particularly, the relation between the average power loss value P and the signal propagation distance (km) can be described by (Choi et al 2008) (dB) ) ( log 10 10 d n P …”

Joint optimization of detection threshold and resource allocation in infrastructure-based multi-band cognitive radio networks

“…For instance, they aim at minimizing the MDP and the FAP, but the performance of SUs is barely considered. In [15], the trade-off between transmission power and detection threshold is studied. However, the focus of their work is on how to reduce interference caused to PUs rather than on the optimization of SUs' capacity.…”

“…Once the values of FAP or MDP are determined, the initial detection threshold is determined. This method for selecting the initial detection threshold has been widely used in [13,15,28]. For the online algorithm, since we iteratively find the best values of λ and (P, ρ), the sub-carrier assignment ρ and power allocation P are determined by random sub-carrier assignment and equal power allocation.…”

Joint optimal power allocation and sensing threshold selection for SU's capacity maximisation in SS CRNs

“…sensing threshold, h, and sensing time, t, for a given sensed SNR, g, need to be also carefully selected [1]. Previous studies on SU's capacity maximisation include SS CRNs models with SpSe [2,3] or without SpSe [4,5]. For the former and more general case, the optimisation presented in [2] is considered over P t and t assuming h to be constant.…”