ارسال داده مخابراتي با نرخ بيت كم در خطوط قدرت

Transmission of Communication data with low bit rate in Power Lines

Daily interest to use communication services like personal communications, domestic automation, internet and other requirements cause the necessity to provide new communication channels. Considering the fact that the AC power lines pass by each building, they can be used for protecting/controlling and automation requirements. However, these lines carry terrible noise along with themselves, moreover these line are not designed for communication frequency. Therefore error correction codes are used for optimization of transmitted data over these lines. BCH codes are suitable code due to their high speed and high capability of correction. In this paper performance of block codes, turbo code and convolutional code are simulated and evaluated. Simulation results depict that BCH(15,7) and BCH(31,21) codes in addition to a fairly high coding rates, perform the best performance against the inter-network noise and burst noise of power lines. In turbo codes, code with a rate of I /2, considering the lower burst period, has a better performance and also have a higher coding rates and the more constraint length, the better code performance and proportionally the more complication of it. In a constant bit rate, the extension of the message block leads to the higher probability of burst occurrences, hence code doesnʹt have a good performance, however if an identical form of burst occurs then the code with a larger length has more performance. Simulation results show that for high bit rates, turbo code are optimum and for low bit rates BCH codes are optimum.