Research On Adaptive Resource Allocation For Low-Voltage Power Line Communication System Based On OFDM

Due to the wide wiring, Power Line Communication (PLC) is regarded as a main technical mean for smart home and indoor multi-network integration. Since the power line was not originally designed to transmit signals, there exist high attenuation, time-varying and frequency selective fading phenomenon. In this regard, usually use Orthogonal Frequency Division Multiple(OFDM) to transmit information. Adaptive resource allocation technology is an important part of the OFDM technology, according to business needs, the technology can greatly improve overall system performance while saving transmission resource consumption. In addition, adaptive resource allocation techniques can overcome the adverse effects of the power line channel, so the technology has been widely applied to PLC.Firstly, this article introduced the implementation mechanism of OFDM and PLC, and then gives two low-voltage power line channel model, in which the static multipath channel model can well react power line multipath fading characteristics, and dynamic channel model can accurately describe the power line Linear Periodically Time Varying(LPTV) characteristics, previous work established a favorable foundation for the simulation of adaptive resource allocation. After that, according to the LPTV characteristics of power line channel, this paper proposed a new optimization criterion, which can enhance the overall transmission rate of the system. Under the new criterion, this paper presents a single-user resource allocation algorithm for Broadband(BB) power line, the algorithm can be divided into two steps, the first step uses Lagrange multiplier method to allocate bit and power, the second step uses binary search method for rapid iteration. The simulation results show that this algorithm can increase the bit rate and also significantly reduce computational complexity. For multi-user system, based on the current existing intelligent algorithms, combining the advantages of Particle Swarm Optimization(PSO) algorithm and Simulated Annealing(SA) algorithm, this paper proposed a SA-PSO multi-user resource allocation algorithm, the simulation shows that the the algorithm can overcome the shortcomings of local convergence of PSO. Compared to the traditional PSO and other intelligent algorithm, this algorithm can improve overall system transmission rate. So the algoritm is suitable for high-speed transmission in BB powerline communication.