A New Power Allocation Algorithm in Cognitive Radio Networks[omnet++program]

 A New Power Allocation Algorithm in Cognitive Radio Networks

With rapid development of wireless communication technologies and their applications, the contradiction between spectrum resource scarcity and the low efficiency of traditional fixed spectrum allocation policy is more and more obvious. A New Power Allocation Algorithm in Cognitive Radio Networks In practice, Federal Communi China Communications· April cations Commission in the U.S.A shows that the underutilized licensed spectrum is due to the inflexible spectrum regulation policy. A New Power Allocation Algorithm in Cognitive Radio Networks[omnet++program]Thus the development of new kinds of flexible spectrum management mechanism becomes very important and necessary. A New Power Allocation Algorithm in Cognitive Radio Networks Since the currently emerging new cognitive radio technology can smartly, efficiently, and flexibly make use of this valuable spectrum resource, A New Power Allocation Algorithm in Cognitive Radio Networks it is one of the key methods to solve the spectrum efficiency problem in wireless systems. Power allocation is a significant issue in cognitive radio networks. A New Power Allocation Algorithm in Cognitive Radio Networks

In , a joint power control and beam-forming scheme with the objective of minimizing total transmitted power of cognitive networks such that the received interference is below a threshold at primary users Pus is presented, A New Power Allocation Algorithm in Cognitive Radio Networks while SINR requirement is guaranteed for the secondary users SUs admitted in the system. Two power allocation algorithms are proposed, A New Power Allocation Algorithm in Cognitive Radio Networks one based on weighted least square approach and the other relying on admission control for SUs to meet the strict interference protection requirement for PUs. A New Power Allocation Algorithm in Cognitive Radio Networks In , a distributed power control based on a cooperative game theoretic framework is proposed where the interference power constraints are imposed to protect transmission of PUs.

 

 A New Power Allocation Algorithm in Cognitive Radio Network

 

An interference-aware radio resource allocation based orthogonal frequency division multiple access OFDMA in cognitive radio networks is proposed aiming at maximizing cognitive throughput under the interference constraints of PU s in . A distributed power control algorithm for spectrum sharing based cognitive radio networks is given in to improve performance of the network, which does not require each cognitive user to negotiate with other cognitive users during communication. And in , a distributed algorithm for optimal resource allocation without spectrum dynamics information exchange among nodes is presented. In this algorithm, each node makes resource allocation decision according to current or past local information from neighboring nodes to satisfy the throughput requirement of each flow. All these resource allocation algorithms are based on the interference power constraint to protect PUs in cognitive radio networks.

In this paper, we propose a new criterion for SINR loss constraint which is an upper bound on the SINR loss rate. This bound does not exceed the tolerance for PUs generated by cognitive transmission. We consider power allocation problem for cognitive users to maximize throughput in OFOMA-based cognitive networks subject to the proposed SINR loss constraint and the maximum transmit power for each cognitive user. Formulating this power allocation into a nonlinear programming problem, we present a distributed algorithm based on Lagrange duality theory. The newpower allocation algorithm in the networks can guarantee stability and improve spectrum efficiency for the network. which can protect QoS of PUs. Opportunistic spectrum access must detect the idle spectrum where PU does not occupy, which means this access technique has to make use of spectrum sensing to detect transmission status of PU, so that the cognitive users can use the idle spectrum. In this paper, we will use spectrum sharing technique as a platform in cognitive radio networks. We consider T primary users in OFDMA network with K subcarriers and each.