Effect of DFE error propagation on the coding gain of an interleaved Reed-Solomon code

Transmission systems based on decision feedback equalization and interleaved Reed-Solomon coding have found application in cable modem and xDSL systems. Such systems provide good performance while avoiding the complexity of an adaptive transmitter. An important performance characteristic of these systems relates to the effect of DFE error propagation on the code performance. This paper derives closed-form expressions which describe this effect. For the example rate adaptive DSL (RADSL) system studied here the impact is a coding gain loss of about 1 dB. In general, larger propagated burst lengths and/or shorter interleaving depths can result in greater loss, as described herein.