Research On Resource Allocation Algorithm For Multi-users In Low-voltage Power Line Communication

With the rapid development of smart grid, expanding of traffic type and user categories, the traditional power line carrier communication technology seems unable to meet the growing transmission rate and quality of service. Currently, most carrier communication terminal has used advanced OFDM technology to improve system capacity and anti-interference performance, but the spectrum efficiency of the system is low and there is still some aspects to be improved. Dynamic resource optimize technology is an effective measure to improve the utilization of the available resource, it uses the time-varying characteristics of channels to change allocated resources dynamically in each subcarrier to maximize resource utilization. The main content of this paper is to research resource optimize technology to improve spectral efficiency and the overall network performance.Firstly, the thesis analyzed the current development of low voltage power line carrier communication, the standards for NB-PLC(narrow band powerline communications) and the application status of products with power line carrier technology at home and abroad. Based on the detailed analysis on common resource allocation algorithm and their quality of performance, it is summed up that the problems and shortcoming of current technology.Secondly, according to the analysis on transmission characteristics and noise characteristics of low voltage power line channel, and the study on attenuation and multipath effect etc., the model of transmission channel is established. And then, after comparing the different characteristics of five basic noise in power line channel, three typical noise are modeled significantly in Simulink, which lays a foundation for later research on resource allocation algorithm.Thirdly, with the power spectral density limitations in power line communication, considering the rate requirement of users with different traffic and service fairness during the communication, a dynamic resource allocation algorithm based on resource factor and proportional rate fairness is designed. By means of simulation, the impact of different resource factor on distribution results is analysed; compared with several classical resource allocation algorithm, the superiority on the system capacity and fairness in the proposed method is illustrated; the anti-interference capability of the proposed algorithm is demonstrated by adding different types of noise in the channel.Finally, a power line carrier communication system platform for multi-user is built and the hardware and software in the system is described. It is focused on the modular design of sending and receiving link in analog front end, the detailed analysis on the circuit schematic and the selection of components parameter during the hardware design. In the software, the realization of system architecture in transceiver and the main function module are given. In the end, the normal communication function is tested in laboratory environment, and the anti-interference performance is verified by observing communication success rate and bit error rate in host computer under different noise environments.