A Review of Spectrum Sensing Times in Cognitive Radio Networks

Abstract

The introduction of Cognitive Radio (CR) to ensure the efficient
utilization of radio spectrum resources, where the opportunistic
unlicensed user called the Secondary User (SU) jumped into a
temporary unused spectrum owned by the licensed user called the
Primary User (PU) for data transmission without causing
interference. The CR is the key enabling technology that enables next
generation communication system also known as Dynamic Spectrum
Access (DSA) networks to efficiently utilize Radio Frequency (RF)
spectrum effectively. The CR has opened more research areas among
which is the Spectrum Sensing and is the most crucial task for the
establishment of CR based communication mechanism. CR has
challenges of collision among SUs during data transmission and
single user spectrum sensing is subjected to destructive effect of
shadowing and multipath fading, which result to Hidden Terminal
Problem (HTP). Cooperative Spectrum Sensing (CSS) was deployed
to mitigate the HTP, but it also introduces an additional
communication overhead as a result of long sensing and reporting
times. The longer the sensing time, ????????, the more the communication overhead. The reduction in the communication overhead reduces the Total Error Rate (TER) and when the TER is reduced the throughput
is automatically increased. This paper presents a review of Spectrum
Sensing Times in Cognitive Radio Networks and proposes better ways
of achieving an improved Spectrum Sensing Time to efficiently utilize
the RF spectrum