Techniques for improvement of qos in cognitive radio networks

Abstract

The rapid adoption of the newest wireless technologies and gadgets newlineover the past ten years has led to an increase in the demand for the wireless newlineradio spectrum. The fixed spectrum allocation policy results in inefficient newlinespectrum utilization, so that the major segment of the licensed spectrum is newlineunderutilized. Cognitive Radio (CR) is the concept which offers revolutionary newlinesolution to the forthcoming spectrum crunch issue. A cognitive radio is a newlineradio that can be automated and designed adaptively to utilize the appropriate newlinewireless channels in its proximity to evade user interference and newlineovercrowding. The vital role of cognitive radio to avert adverse interference newlinewith the licensed user and identify the unoccupied frequency spectrum for newlineefficient spectrum utilization is Spectrum Sensing (SS). newlineThe efficiency of the spectrum detection is usually assessed by the newlinespectrum sensing duration because it introduces a trade-off between the newlinethroughput efficiency and sensing capability of the secondary user network. newlineThe spectrum sensing duration should be nominal enough to make the newlinecognitive radio network effective. The sensing duration should be kept to a newlineminimum so that the Secondary User (SU) has enough time to send its data newlineand is large enough to ensure that the licensed user is not interfered with. newlineConventionally, the time allocated to sense the spectrum is fixed and newlineidentical. This research is aimed at minimising the spectrum sensing duration newlineby minimising the number of samples required to detect the Primary User newline(PU) channel, which in turn enhances the throughput of the cognitive radio newlinenetwork. newline