Ericsson Gmbh

George W Kellam

Robert A Zak

Rasaram Ramesh

A decoder for decoding a data signal using a non-binary trellis diagram by designating binary butterfly trellises within the non-binary trellis is disclosed. The decoder analyzes each designated binary butterfly trellis using the basic Viterbi binary butterfly operation to generate a pair of pathways to each node of the non-binary trellis. The pathways for each node from the basic binary butterfly operations are compared to determine the survivor path for that node.

Non-binary viterbi decoder using butterfly operations

A multi-path demodulator is provided for a mobile radiotelephone that includes a maximum likelihood sequence estimator in parallel with a symbol-by-symbol detector to demodulate the received signals. In a preferred embodiment, an adaptive equalizer is used in a dual-path demodulator in parallel with a differential detector. As each frame of data is demodulated, a determination is made from channel decoder information from each path about which demodulated bit stream to use (e.g., from either the estimator or detector). The performance of the demodulator is thus optimized for both non-time-dispersive and time-dispersive radio signals.

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Hillsborough, NC, United States of America

George W Kellam