Abstract
The inefficient use of spectrum is the key subject to overcome the upcoming spectrum crunch issue. This paper presents a study of performance of cooperative cognitive network via hard combining of decision fusion schemes. Simulation results presented different cooperative hard decision fusion schemes for cognitive network. The hard-decision fusion schemes provided different discriminations for detection levels. They also produced small values of Miss-Detection Probability at different values of Probability of False Alarm and adaptive threshold levels. The sensing performance was investigated under the influence of channel condition for proper operating conditions. An increase in the detection performance was achieved for cognitive users (secondary users) of the authorized unused dynamic spectrum holes (primary users) while operating in a very low signal-to-noise ratio with the proper condition of minimum total error rate.
Highlights
Today’s wireless networks are characterized by fixed spectrum assignment policy
We presented a study of cognitive radio networks with various effective techniques of cooperative hard combining spectrum detection
Cooperative schemes (AND, OR, and HV) were employed and their performance was evaluated through signal-to-noise ratio (SNR), Qd,Qfa, and Qmd
Summary
Today’s wireless networks are characterized by fixed spectrum assignment policy. There is a continuously increasing demand for frequency spectrum associated with limited resource availability. The underutilized spectrum holes, shown in Figure-1, develop to white spectrum holes These frequency bands are assigned to Specific system users called primary users (PU) or licensed users and the assigned frequency bands are called licensed bands. The spectrum detection is sustained by uncertainty due to channel fading, i.e. the secondary user needs to differentiate between a white space, where the licensed signal is absent, and a deep fading, where the licensed signal is present. Similar difficulties arise in the case of shadowing To treat these issues, many different secondary users can cooperate to detect the presence of licensed signal. Secondary users detect the spectrum to check the absence or presence of the primary signal depending on sensing parameters, such as signal-to-noise ratio (SNR), bandwidth, bit error probability, spectral efficiency, and throughput. Where x(t) is the signal detected by CR users , s(t) is the primary user’s transmitted signal , n(t) is the additive white Gaussian noise (AWGN), and h is the channel amplitude gain between the PU and the kth CR user
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
