Research Of Cognitive Wireless Network Resource Allocation Based On Cross-layer Optimization

In recent years, with the rapid growth of wireless services, almost all usable frequencies have been occupied. Meanwhile, FCC(2002) identifies that a large portion of the licensed spectrums is unused at any given time and any location. Cognitive radio offers a possible solution to increase the spectrum efficiency. In cognitive networks, the cognitive node is capable of sensing the surrounding environment and making corresponding changes in certain operating parameters in real time.Firstly, we present the cognitive wireless network and cross-layer optimization techniques. Then, we propose new cross-layer architecture of cognitive wireless network, the architecture can be proven practical and stable. Secondly, by means of studying physical layer, data link layer and the network layer, this paper firstly propose a novel cross-layer optimization which is based on ad-hoc cognitive radio physical / data link layer/network layer protocol. In order to measure the system's communications capabilities accurately, we propose the replacement of the traditional real-time channel capacity with an effective channel capacity(ECC) concept, which take into account the utilization of the channel capacity of the channel, after verification, the protocol can effectively improve the reliability and accuracy of the communication system. Finally, this paper studies the cognitive network cross-layer optimization of efficient spectrum utilization method based on the course of the study. To take cognitive radio networks commonly used NC-OFDM as the research object, we propose improvements to the traditional algorithm block priority optimization method based on genetic algorithm, the algorithm with traditional genetic algorithm and subcarriers-wise priority genetic algorithm optimization algorithm can significantly improve the utilization of the spectrum communication system resources, through the simulation, the proposed algorithm can improve the overall throughput and performance of the communication system.