Viterbi decoding with channel and location information

An apparatus for decoding a signal, the apparatus comprising:

• means for receiving a sampled signal;
• means for making a hard decision on which constellation point the sampled signal represents;
• means for determining a sealing factor (k) corresponding to the hard decision points;
• and
• means for providing the scaling factor (k) and the hard decision to a Viterbi decoder.

A method of signal decoding comprising:

• accepting a received signal;
• quantizing the received signal to a point in a signal constellation plane, to provide a quantized point;
• making a hard decision as to which constellation point the quantized point represents;
• determining scaling factors (k's) associated with each constellation point;
• using the scaling factors and hard decision point to determine decoder metrics;
• and
• providing a decoder metrics and quantized point to a Viterbi decoder.

An apparatus comprising:

• an input for accepting a received signal;
• a quantizer that accepts the received signal from the input and quantizes the input to a point in a signal constellation plane, to provide a quantized point;
• a hard decision unit that accepts the quantized point and determines a constellation point that the quantized point represents;
• a scaling factor unit that determines scaling factors associated with the constellation point;
• and
• a metric calculator that accepts the scaling factors and the constellation points and determines branch metrics for the constellation points.