Performance Analysis of Sequential Method for Handover in Cognitive Radio Systems

TL;DR

This paper evaluates the performance of a sequential handover method in cognitive radio systems, proposing an improved weighted handover scheme that enhances throughput and energy efficiency based on primary user activity and channel conditions.

Contribution

It introduces a weighted hand-over scheme considering channel conditions and primary user presence, improving throughput over existing methods and optimizing sensing time for energy efficiency.

Findings

Weighted hand-over scheme outperforms SMHO in throughput.

Optimal sensing time balances throughput and energy consumption.

Proposed optimization enhances spectrum utilization efficiency.

Abstract

Powerful spectrum handover schemes enable cognitive radios (CRs) to use transmission opportunities in primary users' channels appropriately. In this paper, we consider the cognitive access of primary channels by a secondary user. We evaluate the average detection time and the maximum achievable average throughput of the secondary user when the sequential method for hand-over (SMHO) is used. We assume that a prior knowledge of the primary users' presence and absence probabilities are available. When investigating the maximum achievable throughput of the secondary user, we end into an optimization problem, in which the optimum value of sensing time must be selected. In our optimization problem, we take into account the spectrum hand over due to false detection of the primary user. We also propose a weighted based hand-over (WBHO) scheme in which the impacts of channels conditions and primary users' presence probability are considered. This Spectrum handover scheme provides higher average throughput for the SU than the SMHO method. The tradeoff between the maximum achievable throughput and consumed energy is discussed, and finally an energy efficient optimization formulation for finding a proper sensing time is provided.