Cognitive Radio Systems: Multicarrier Modulation and Power Allocation Challenges
Ahmed Sohail*, Mohammed Al-Imari, Pei Xiao and Barry G. Evans
Centre for Communication Systems Research, University of Surrey, Guildford, GU2 7XH, United Kingdom
- *Corresponding Author:
- Ahmed Sohail
Centre for Communication Systems Research
University of Surrey, Guildford
GU2 7XH, United Kingdom
Tel: 01483 68 3600
E-mail: [email protected]
Received Date: July 3, 2013; Accepted Date: October 25, 2013; Published Date: October 28, 2013
Citation: Sohail A, Al-Imari M, Xiao P, Barry G, Evans (2013) Cognitive Radio Systems: Multicarrier Modulation and Power Allocation Challenges. J Electr Electron Syst 3:116.doi:10.4172/2332-0796.1000116
Copyright: © 2013 Sohail A, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
The rapid development of modern communication services results in high data rate requirements from the end user. It is challenging to meet high data rate requirements because of prevailing issues such as spectrum scarcity and spectrum underutilization due to fixed spectrum assignment policy. Cognitive Radio (CR), being the enabler of dynamic spectrum management techniques, has the capability to tackle these issues by proficiently implementing spectrum sharing schemes using Multicarrier Modulation (MCM) techniques. In CR system, where the Primary User (PU) and the Secondary User (SU) co-exist in the same frequency band, mutual interference (i.e., from SU to PU and vice versa) is a limiting factor on the achievable capacity of both the PU and the SU. Power allocation in MCM based CR systems aims to dynamically control the transmit power on each subcarrier of the SU in order to reduce the mutual interference. Furthermore, combining multiple antennas with MCM is regarded as a very attractive solution for the CR communications to effectively enhance data rate without demanding additional bandwidth and transmit power.