Excavating
Patent
1993-05-26
1995-02-14
Gordon, Paul
Excavating
G06F 1110
Patent
active
053901983
ABSTRACT:
An error control decoder (44) for use in decoding signals encoded with an M-ary convolutional code and a method for decoding such a code. The error control decoder includes a branch metrics module (46) that determines differences between the correlation values of each of eight possible symbols used to represent data encoded and the largest of these correlation values. An add-compare-select module (50) determines path metric values for each of 64 states by adding selected branch metric values to prior state metrics for the two possible paths that lead to a current state metric. The minimum path metric of the two is then assigned as a new state metric, and a logic level identifying the selected path metric is stored in a path history module (62). This procedure is repeated for each of the 64 states. A minimum state metric from the prior symbol period is determined and used to normalize the current state metrics to avoid overflow. After processing data for 36 symbol periods to form the initial path history, the data are decoded by tracing back through the path history to identify a state that most likely represents the binary data originally encoded. The error control decoder is disclosed in use in a spread spectrum communication system (20).
REFERENCES:
patent: 4240156 (1980-12-01), Doland
patent: 4346473 (1982-08-01), Davis
patent: 4404674 (1983-09-01), Rhodes
patent: 4536878 (1985-08-01), Rattlingourd et al.
patent: 4837766 (1989-06-01), Yoshida
patent: 4868830 (1989-09-01), Pollara-Bozzola
patent: 4901307 (1990-02-01), Gilhousen et al.
patent: 4922507 (1990-05-01), Simon et al.
patent: 5095484 (1992-03-01), Karabed et al.
patent: 5128967 (1992-07-01), Durkin et al.
B. Trumpis, "Convolutional Coding for M-ary Channels," Abstract of the Dissertation, University of California, 1975, pp. 1-102.
Unknown, "Convolutional Code Structure and Viterbi Decoding," Chapter 6, pp. 252-265.
Gordon Paul
The Boeing Company
LandOfFree
Soft decision viterbi decoder for M-ary convolutional codes does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Soft decision viterbi decoder for M-ary convolutional codes, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Soft decision viterbi decoder for M-ary convolutional codes will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-293421