Ary Spread Spectrum Based On Low-voltage Power Line Meter Reading Technology Research

All low voltage power distribution network covers the basic human living space, thus it has a widely practicability of power line communication. It has a broad network resources Simultaneously, and the power line has great potential as communication medium for the high quality of the data transmission. In this paper,the cause of widely public concern in the low voltage power line communication application in the electric power meter reading system is studied.The multi-band methods and main performance of spread spectrum codes are deeply studied. It chooses two good performance of multi-band spread spectrum codes in detail. One is the method of binary m sequence, and using shift register produces multi-band spread spectrum codes. The other is for multivalued quantification method and using multivalued quantification method to Produce the multi-band spread spectrum codes. After Producing multi-band spread spectrum codes, and the derived respectively is analyzed by the theoretical formula and the actual spread spectrum communication system is simulated in MATLAB. The correlation, power spectrum, ber performance is analyzed and compared with binary m sequence and finally it verifies the feasibility of the two methods.It analyzes the low-voltage power line channel environment. Power line communication quality is good or bad by three decisions of the power line noise, transmission line impedance and attenuation. Upon inquiry, it is generally thought that there are five types of noise in the low voltage power line carrier communication environment, such as the colored background noise and narrowband noise, out of sync with the grid frequency periodic impulse noise, periodic impulse noise frequency synchronization with the grid, the sync pulse noise. In this paper, modeling and simulation analysis was carried out on the various noise respectively. And by test and simulation of power line channel transmission characteristics under certain grid environment, it is discussed according to the input impedance and signal attenuation characteristics. Finally it realizes the simulation of power line channel.The multi-band spread spectrum technology and power line communication channel is combined in this paper. It implements a complete remote automatic meter reading system. In the software MATLAB/Simulink platform and with the cooperation of programming, the system completes the generation of multi-band codes, carrier modulation demodulation. It spreads spectrum signal on the analog power line channel transmission and displays functions of transmission error rate. The simulation results show that the multi-band spread spectrum methods improve the ber performance of automatic meter reading system effectively It is more suitable for electric meter reading assignments.Through system simulation, the advantages of the multi-band spread spectrum technology in power transmission are validated and implemented. It has certain significance for the research of power line communication and reference.