A parallel Reed-Solomon coding/decoding structure for an ADSL modem with increased interleaving for ATM applications

A Reed-Solomon coder/decoder combined with a trellis encoder for an ADSL modem for ATM applications is presented and its performance is studied. The proposal incorporates a faster structure for the RS coding/decoding part of the modem that exploits the single latency operation of the device. The modem, as well as the proposed changes in it, is fully compatible with the existing standard of the T1E1.4 ANSI Standard Group. The proposed structure and the results obtained confirmed the significant savings that can be achieved by its application. Here, the coding/decoding part of the modem was simulated, only. The simulation results showed an approximate 50% improvement in the speed of the RS coding/decoding operation. Due to the operation speed up, deeper interleaving or faster transmission could be achieved leading to an improvement in the performance of the whole system. For further gains, a trellis encoder was added to the RS coder in a concatenated scheme. The paper is organized as follows: first, the introduction and the proposed modem structure are given; then follow the Reed Solomon and trellis codes used in the simulations; finally, we give the simulation method, results and conclusions.