Document Type : Research Paper


1 Al-Nahrain University, College of Information Engineering, Baghdad, Iraq

2 Al-Mustansiriya University, College of Engineering, Baghdad, Iraq


Cognitive Radio (CR) is a communication technology developed to solve the
problem of spectrum scarcity. One way to improve the throughput of CR is the use of
efficient decision rules of the fusion center to combine the collected information from
cooperative sensors and produce the right final decision. For this purpose, hard decision
rules like AND and OR and soft decision rules like Square Law Combination (SLC) and
Maximum Ratio Combination (MRC) can be combined to optimize the throughput
performance. In this paper, three decision rules, each consist of two decision stages (hard
and soft) are proposed to improve the throughput of CR in cooperative scenario. The
simulation results showed that the proposed rules enhance the throughput as compared
with traditional ones. They demonstrated that the first proposed rule enhances the
throughput by 106% and 58.9% at SNR equals -10 dB in Rayleigh fading channel over the
classical OR-SLC and the AND-SLC rules, respectively. Under the same simulation
conditions, the second proposed rule enhanced the throughput by 163% and 97.5%, while
the third proposed method enhances throughput by 210% and 135%, respectively.