RESEARCHING AND PROPOSING AN OPTIMAL POWER CONTROL PARAMETER IN OFDM-BASED COGNITIVE RADIO SYSTEMS

Nguyen Van Vinh; Nguyen Thi Phuong Hoa

Nguyen Van Vinh Hung Yen University of Technology and Education
Nguyen Thi Phuong Hoa Hung Yen University of Technology and Education

Abstract

Cognitive Radio (CR), which aims to improve spectrum utilization by accessing the spectrum originally licensed to a primary system, is a promising concept. In cognitive radio system based on orthogonal frequency division multiplexing (OFDM), the optimized algorithms for sub-carrier power allocation share the problems of complex iterative calculation and difficult realization. In this paper, we propose power control parameter to adjust the interference threshold license users, we also establish mathematical model based on convex optimization theory, and through matlab simulation, the optimal scheme and equal ladder scheme and average scheme were compared. The results showed that when the cognitive users satisfy interference threshold of license users, it can make the cognitive users’ channel throughput at maximization.

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