Error correction using IFMV9 coded overlapped PN sequence for power line SSMA

Proposes an IFMV9 coded OL(overlapped)-PN sequence as a PN sequence that is suitable for DS/SS data transmission with low spreading factor through a power line channel. The IFMV9 coded OL-PN sequence is a data stream coded according to the coding rule of IFMV9, that is one of the channel codes, in every unit period length of a PN sequence. It can provide DC free and correlation properties. This coded sequence also makes it possible to combine maximum-likelihood (ML) decoding techniques with the well-known differential decoding method at the receiver´s side. The authors investigate the error rate characteristics and the possible maximum number of simultaneous users by computer simulation. They use a model of television of which a power circuit impedance alternates rapidly and greatly, as the simulated channel. The simulated result shows the error rate improvement due to the combination of ML decoding and differential decoding at the receiving end