Trellis encoder and decoder based upon punctured rate ½ convolutional codes

USRE38010E1 · kind E1 · reissue

Assignee

• QUALCOMM Incorporated · US

Inventors

• Ephraim Zehavi · San Diego, US
• Jack K. Wolf · Rancho Mirage, US

Key dates

• Filing date: May 4, 1999
• Grant date: Feb 25, 2003
• Expiry date: May 4, 2019

Classification

• Technology area (CPC —): General

Abstract

An encoder for encoding data as trellis coded data and a decoder for decoding the trellis coded data. The encoder uses a rate ½ convolutional encoder punctured to a rate k/n to produce n symbols from k input bits. The symbols are converted by a converter to sets of p symbols and provided to an interleaver. In the interleaver certain ones of the symbols are delayed. Symbol sets are output from the interleaver to a 2P-ary modem for modulation and transmission. The decoder uses a modem for providing from the modulated data sets of p symbols. A deinterleaver delays certain ones of the symbols to achieve time alignment of the originally interleaved symbols. The sets of time aligned symbols are provided to metric calculators for computing signal metrics which are provided to a converter for providing n sets of metrics to a metric decoder. The metric decoder computes from the n sets of metrics an estimate of the encoded k data bits.