Patent ID: 6353640
Filing Date: 2002-03-05
Classification: H03G,H03M,H04B,H04L

Abstract:
A radio frequency receiver system comprising:a radio frequency receiver for receiving radio frequency carrier signals that include trellis encoded modulated signals and demodulating the trellis encoded modulated digital signals including MSBs and LSBs, and digital processor means receiving the demodulated signals for decoding the trellis encoded modulated signal by removing effects of the LSBs prior to making a decision of the MSBs, wherein the digital processor includes: a Viterbi decoder including circuit means for generating a first table containing a current symbol and a previous symbol to bring the trellis to a given state, and for generating a second table containing a current symbol, a previous symbol, and a symbol previous to the previous symbol necessary to bring a trellis to a given state, and for calculating a path metric for a received signal by indexing the values of the first and second tables into a branch metric decoding calculation.