Frequency mappings with hadamard transform for power line communications channel

M-FSK modulation scheme has shown its robustness in power line channel. Making benefits of certain properties of Hadamard transform, we have mapped frequencies onto the convolutional outputs to get benefit of the Viterbi decoding algorithm. Promising results show that this technique is very useful without the need of a construction, which is necessary in distance-preserving mappings technique, that is usually used to combine convolutional codes and M-FSK modulation schemes. We furthermore investigate the performance of the new designed communication system in the presence of permanent frequency disturbances, also known as narrowband noise disturbances, such as those encountered in power line communications (PLC) channel.