Soft decoding techniques for broadband wireless channels

This document addresses several aspects of block turbo codes (BTC) and higher order modulations, selected as the optional coding scheme for the burst modes of the IEEE 802.16.1, air interface draft standard. Compatibility, with mandatory burst modes (MODE B downstream and upstream transmissions), includes the same processes for the transmission convergence (TC) layer and physical media dependent (PMD) layer. However, the PMD sublayer is enhanced to allow for the replacement the FEC schemes based on RS variants with BTC.