Research On Cross-layer Resource Allocation In OFDM System Of Broadband Power Line Communication

The attenuation, time-varying, multipath propagation and some other transmission characteristics in power line can be eliminated by the OFDM technology used in the broadband power line communication system effectively. So the resource utilization system, quality of service, and data transmission rate will be improved accordingly, which laid the foundation for the diversified service of broadband power line communication. At present, in addition to the traditional service, the service of broadband power line communication also extended to high-speed streaming media service, such as HDTV, which put forward higher requirements for the quality of communication. Meanwhile, the efficient resource allocation which can meet the QoS of different services in OFDM communication system has become a problem.In this thesis, the cross-layer resource allocation algorithm in OFDM system of broadband power line communication is researched to solve the above problems. Firstly, the interference in OFDM communication systems is analysed by using the simulated modelling of power line channel; Secondly, the bit loading algorithm for maximizing throughput which combined channel interference power and adaptive guard interval length is proposed, and two methods to reduce the computational complexity of the algorithm are put forward. The simulation results show that the efficiency and performance of bit loading is improved effectively by this algorithm; Finally, a cross-layer resource allocation algorithm based on access control strategy is proposed, in which the scheduling strategy of access control and normalized fairness factor is used on the basis of low complexity bit loading algorithm. The simulation results show that the fairness of different services is guaranteed and the system performance is improved by using the algorithm which is proposed in this thesis.