| Cognitive radio is an exciting emerging technology that has the potential of dealing with the stringent requirement and scarcity of the radio spectrum. Such revolutionary and transforming technology represents a paradigm shift in the design of wireless systems, as it will allow the agile and efficient utilization of the radio spectrum by offering distributed terminals or radio cells the abili...

—Disaster relief networks are designed to be adaptable and resilient so to encompass the demands of the emergency service. Cognitive Radio enhanced ad-hoc architecture has been put forward as a candidate to enable such networks. Spectrum sensing, the cornerstone of the Cognitive Radio paradigm, has been the focus of intensive research, from which the main conclusion was that its performance can...

The performance of cooperative spectrum sensing in cognitive radio (CR) networks depends on the sensing mode, the sensing time and the number of cooperative users. In order to improve the sensing performance and reduce the interference to the primary user (PU), a periodic cooperative spectrum sensing model based on weight fusion is proposed in this paper. Moreover, the sensing period, the sensi...

While it is well accepted that cooperative spectrum sensing will significantly improve the sensing performance, the necessity of cooperation is not sufficiently appreciated. In this paper, by analyzing the spectrum sensing problem from the system perspective, we show that without cooperation, the performance will suffer from a fundamental tradeoff between reliability and efficiency. However, if...

By taking into account the reporting channel fading and the differences in the reliability of the decisions made by different secondary users (SUs), a general performance analysis of cooperative spectrum sensing are given. The analysis results show that the performance of cooperative spectrum sensing is limited by the probability of reporting error and decision fusion rule. To deal with the lim...

Energy detection is one of the popular spectrum sensing technique for cognitive radio. Better performance can be obtained by cooperative detection, but only when cognitive radios did not have different geographic locations and channel environment. To avoid this drawback, the paper presents an improved energy-based weighted cooperative spectrum sensing method which allows to achieve higher detec...

Cooperative spectrum sensing was proposed to combat fading, noise uncertainty, shadowing, and even hidden node problem due to primary users (PUs) activity that is not spatially localized. It improves the probability of detection by collaborating to detect PUs signal in cognitive radio (CR) system as well. This paper studies cooperative spectrum sensing and signal detection in CR system by imple...

The growing number of wireless devices for in-house use is causing a more intense use of the spectrum to satisfy the required quality-of-service such as throughput. This has contributed to spectrum scarcity and interference problems particularly in home area networks (HAN). Cognitive radio (CR) has been recognized as one of the most important technologies which could solve these problems and su...

Spectrum sensing is a key technology in the study of cognitive radios, but its attributes are easily influenced by the channel fading. Compared with singleuser spectrum sensing, multiple-user spectrum sensing can overcome the impacts caused by the fading environment of cognitive radio. Since diversity technology has been proved to provide the system high transmission rate and high link reliabil...