Impact of Secondary User Interference on Primary Network in Cognitive Radio Systems

TL;DR

This paper analyzes the impact of secondary user interference on primary network performance in cognitive radio systems by deriving analytical expressions for key metrics and validating them through simulations.

Contribution

It provides the first closed-form analytical expressions for primary user SINR, capacity, and outage probability considering peak power adaptation of secondary users.

Findings

Analytical expressions match simulation results accurately.

Interference from secondary users significantly affects primary network performance.

Dynamic interference temperature regulation can improve primary network reliability.

Abstract

Most of the research in cognitive radio field is primarily focused on finding and improving secondary user (SU) performance parameters such as bit error rate, outage probability and capacity etc. Less attention is being paid towards the other side of the network that is the primary network which is under interference from SU. Also, it is the primary user (PU) that decides upon the interference temperature constraint for power adaptation to maintain a certain level of quality of service while providing access to SUs. However, given the random nature of wireless communication, interference temperature can be regulated dynamically to overcome the bottlenecks in entire network performance. In order to do so, we need to analyze the primary network carefully. This study tries to fill this gap by analytically finding the closed form theoretical expressions for signal to interference and noise ratio (SINR), mean SINR, instantaneous capacity, mean capacity and outage probability of PU, while taking peak transmit power adaptation at SU into picture. Furthermore, the expressions generated are validated with the simulation results and it is found that our theoretical derivations are in perfect accord with the simulation outcomes