Method and apparatus for communicating digital information such as compressed video using treillis coded QAM

Patent 5321725 Issued on June 14, 1994. Estimated Expiration Date:

July 10, 2012. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Abstract Claims Description Full Text

Patent References

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Inventors

Assignee

General Instrument Corporation

Application

No. 908407 filed on 07/10/1992

US Classes:

375/265, Trellis encoder or Trellis decoder348/155, Motion detection375/240.23, Variable length coding375/339, Carrier controlling local generator714/756, Cross-interleave Reed-Solomon code (CIRC)714/784, Reed-Solomon code714/792Trellis code

Examiners

Primary: Chin, Stephen
Assistant: Phan, Hien H.

Attorney, Agent or Firm

Lipsitz; Barry R.

International Class

H04L 005/12

Abstract

A method and apparatus for communicating high definition television signals is provided. Video signals are divided into blocks of PCM data. The PCM data is processed using motion estimation and compensation to provide DPCM data. For each block, one of PCM and DPCM data is selected for transmission based on a predetermined criteria. The selected data is compressed using the discrete cosine transform to provide blocks of transform coefficients. The coefficients are quantized to improve their coding efficiency and variable length coded. The variable length coded coefficients are coded using a concatenated coding scheme with a Reed-Solomon outer code and trellis inner code to provide coded signals for transmission. The coded signals are transmitted using QAM.

Other References

Viterbi, et al., "A Pragmatic Approach to Trellis-Coded Modulation," IEEE Communications Magazine, Jul. 1989, pp. 11-19
Odenwalder, J. P., Error Control Coding Handbook, Section 7.1, "Viterbi-Decoded Convolutional Inner Code and Reed-Solomon Outer Code," Linkabit Corporation, 1976
W. Paik, "DigiCipher--All Digital, Channel Compatible, HDTV Broadcast System," IEEE Transactions on Broadcasting, vol. 36, No. 4, Dec. 1990, pp. 245-25