Research On The Channel Codec Methods For Power Line Communication

With the steady improvement of the residents per capita consumption as well as the stating of strong smart grid construction strategy, modern power grid intelligent communication has become one of the national key construction projects, smart grid has gradually become an important way to reduce operating costs, improve transmission efficiency for National Electric Power Authority. Power line carrier communication technology is the key technology of intelligent power grid, the communication quality directly determines the level of overall system efficiency, therefore, many experts and scholars have devoted to the research and development of power line carrier communication.Power line carrier communication system based on power line distribution network, there is no need to erect or lay special cable or equipment, it has unparalleled advantages to improve the management level, reduce the manpower cost compared with other means of communication in the aspect of national power system. However, power line is not an ideal medium for communication, power line has more difficulties compared with twisted pair, coaxial cable or optical fiber. Attenuation, noise disturbance, time-varying and frequency selective characteristics will cause the power line communication greatly reduced if you don’t take some specific techniques and measures.Channel coding technology uses specific technology in the process of sending and receiving information, therefore, it has high error correcting retrieval and anti-jamming capability, besides, it’s also one of the most important ways to assure the efficiency and reliability for communication system. In this paper, a thorough analysis was done for coding and decoding method of repeat accumulate code, and simulation is implemented according to the characteristics of power line channel. In the coding process, this paper puts forward a design scheme of the improved interleaver, which packeted and switched the input information based on the properties and characteristics of binary tree to break the correlation between input information, not only avoids the I and II class 4-circle production of repeat accumulate codes, at the same time also substantially reduces the cost of the system. In decoding process, we improved the belief propagation algorithm for repeat accumulate codes, with the use of piecewise strategy to replace the exponential function and the tangent function in original algorithm which reduces the complexity of decoding algorithm greatly. Besides, look-up table method has reduced the system error, which ensured the reliability of power line carrier communication.In order to verify the effect of improved method in the power line communication based on the improvement of existing coding methods, this paper made simulations respectively. In coding process, simulation results show that the effect of improved interleaver communication is slightly better than S-random interleaver, in decoding process, simulation results show that although the improved decoding scheme has certain disparity than belief propagation algorithm, however, it greatly simplifies the decoding process. In addition, at the application of improvement strategy, the bit error rate of the whole system is similar with the original method, but the decoding complexity is greatly reduced, which has important theoretical and practical significance in the construction of smart grid for power line communication.Power line network is believed as the world’s largest, most extensively covered network, which has incomparable advantages cmpared with any other network, power line can transmit the power and information efficiently at this advantage. With the construction pace of the smart grid and the perfecting of power line communication, the power line carrier communication will have a more broad development prospects.