Evaluation and implementation of cyclic permutation coding for power line communications

Noise and attenuation, in the form of frequency disturbance, impulsive noise, additive white Gaussian noise (AWGN) and frequency selective fading, are the major setbacks in power line communications (PLC). In order to effectively combat this challenge, we thus report the development and implementation of a specially coded M-ary differential phase shift keying modulation scheme on narrowband PLC channel. The coding aspect involves the concatenation of conventional Reed Solomon (RS) code with cyclic permutation coding (CPC), resulting in what is termed RS-CPC scheme. The CPC employed in this work maps the output bits of a binary RS code onto non-binary CPC symbols, in a cyclic manner, with a view to improving the distance between two different sets of mapped symbols. For implementation over 230 V AC power line, software defined radio hardware, called the universal software radio peripherals (USRPs), were used, together with narrowband coupling circuits, to couple the signal to and receive it from the power line. Both by simulation and implementation, our scheme outperforms the conventional Reed Solomon-convolutional coding (RS-CC) specified in the G3-PLC standard. An added advantage is that our scheme is easier to implement.