Transmit Power Optimization in Cognitive Radio Networks Using Game Theoretic Approach

Abstract

One of the major challenges in design of any wireless networks is the maximum utilization of the frequency spectrum. Numerous studies on spectrum utilization show that most of the allocated spectrum is not utilized. So spectrum underutilization motivates for opportunistic spectrum access. Cognitive Radio, with its ability of opportunistic and dynamic spectrum access is a promising technology to effectively address the spectrum underutilization problem. The basic idea in cognitive radio is to permit some unlicensed (secondary) users to operate in a licensed frequency band, without causing interference to the licensed (primary) user. The cognitive radio link intelligently sense the frequency segment in the radio spectrum, and jumps into any temporarily unused spectrum rapidly without interfering the primary users. A critical design challenge for cognitive radio networks is to establish a balance between two conflicting terms, i.e. transmit power and interference. Use of power control is an efficient way to increase the total capacity of the network by allowing secondary users to intelligently transmit by controlling their power in order to make sure that qualities of service of primary users remain unaffected.