Performance evaluation of transport layer protocols in cognitive radio sensor networks (CRSNs) is useful to provide quality-of-service for real-time reliable applications. This paper develops an analytical framework to model the steady-state sending rate of collecting cognitive radio (CR) sensors in rate-based generic additive-increase multiplicative-decrease (AIMD) and additive-increase additi...

In industry and academia, researchers have given more and more attention to Cognitive Radio (CR). The key idea of CR is to make it possible for a wireless system to find the vacant spectrum and transfer data without interfering with licensed users (LUs). Then, OFDM is proposed as a candidate signaling technology for such applications. However, the sidelobe interference of subcarriers has become...

Vertical handover, which often occurs in wireless mobile communication, is very important for heterogeneous wireless networks based on the cognitive radio (CR). However, a major issue is how to control vertical handover for secondary user without interfering primary user while achieving the desired quality of service (QoS) and eliminating the influence caused by hidden channel and exposed chann...

Cognitive Radio (CR) or soft ware defined radio is a new concept for maximizing the utilization of the radio spectrum. The CR can sense the unused frequency spectrum at any time from the wide range of wireless radio spectrum. This gives the efficient use of radio resources. In cognitive radio environment, a primary licensed user (PU) can share spectrum availability information with a secondary ...

Cognitive Radio (CR) systems are smart systems capable of sensing the surrounding radio environment and adapting their operating parameters in order to efficiently utilize the available radio spectrum. To reach this goal, different transmission parameters across the Open Systems Interconnection (OSI) layers, such as transmit power, modulation scheme, and packet length, should be optimized. This...

The Power allocation in Orthogonal Frequency Division Multiplexing (OFDM)-based cognitive radio networks is designed by gradient based method. The gradient based method in which the power allocated between subcarriers by considering the interference constraint, capacity of CR users and channel gain. Utilize the gradient based descent approach to allocate power to subcarriers in Cognitive Radio ...

Since cognitive radio (CR) in conjunction with nonorthogonal multiple access is a candidate techniques for future mobile radio networks, realizing underlay spectrum sharing with high capacity gain is an important issue. In this paper, we propose an adaptive linear precoder design for a CR based multiuser MIMO broadcasting system. The proposed adaptive precoder employs regularized channel invers...

Dynamic spectrum access is an attractive area of research these days. Cognitive Radio (CR) enabled networks are being deployed to effectively utilize the RF spectrum. Wireless mesh networks have been experiencing the bandwidth scarcity but such networks can easily enhance their throughput by using the CR transceivers as these networks have the capability of multipath routing. Existing routing p...

The cognitive radio (CR) systems usually arrange for the quiet period to detect the primary user (PU) effectively. Since all CR users do not transmit any data during quiet period, the interference caused by other CR users can be prevented in the channel sensing for PU detection. Even though the quiet period improves the PU detection performance, it degrades the channel utilization of CR system....

The radio frequency spectrum is a scarce natural resource and its efficient use is of the utmost importance. The spectrum bands are usually licensed to certain services, such as mobile fixed broadcast, and satellite, to avoid harmful interference between different networks. Most spectrum bands are allocated to certain services but worldwide spectrum occupancy measurements show that only portion...