Method and apparatus for synchronizing a data communication syst

Details Method and apparatus for synchronizing a data communication syst Method and apparatus for synchronizing a data communication syst

1999-06-07

2000-06-27

Pham, Chi H.

Pulse or digital communications

Synchronizers

370523, 370503, H04L 700

Patent

active

060815671

ABSTRACT:
A pulse code modulation modem system is configured to transmit data from a first modem to a second modem over the public switched telephone network (PSTN). The PSTN employs robbed bit signaling (RBS) such that symbols affected by RBS arrive at the second modem in a periodic manner based on a period of six symbols. The modem system is configured such that signal segments are formatted and transmitted with six symbols per segment. After obtaining symbol synchronization, the second modem initializes a modulo-6 symbol counter such that the zero count corresponds to the first symbol of each received signal segment. Those symbols affected by RBS are identified and analyzed to determine optimized signal point constellations that may be used to compensate for the RBS on a symbol-by-symbol basis during subsequent encoding and decoding. Upon a loss of synchronization, the second modem resets its modulo-6 counter in response to the detection of the first symbol in a subsequent signal segment. In this manner, the modem system can again use the optimized signal point constellations determined previously.

REFERENCES:
patent: 4730312 (1988-03-01), Johnson et al.
patent: 5048054 (1991-09-01), Eyuboglu et al.
patent: 5398234 (1995-03-01), O'Connell et al.
patent: 5506956 (1996-04-01), Cohen
patent: 5509036 (1996-04-01), Nakata
patent: 5535244 (1996-07-01), Nakatsu et al.
patent: 5541967 (1996-07-01), Gluska et al.
patent: 5590161 (1996-12-01), Meyn et al.
patent: 5598435 (1997-01-01), Williams
patent: 5623516 (1997-04-01), Brownlie et al.
patent: 5687199 (1997-11-01), Dupuy
patent: 5729226 (1998-03-01), Betts et al.
patent: 5754594 (1998-05-01), Betts et al.
patent: 5761247 (1998-06-01), Betts et al.
patent: 5784405 (1998-07-01), Betts et al.
patent: 5812075 (1998-09-01), Betts et al.
patent: 5822359 (1998-10-01), Bruckert et al.
patent: 5822371 (1998-10-01), Goldstein et al.
patent: 5825816 (1998-10-01), Cole et al.
patent: 5825823 (1998-10-01), Goldstein et al.
patent: 5838724 (1998-11-01), Cole et al.
Analyzing Code Translation Characteristics of a PCM Channel and Communicating a Mutual PCM Code Signaling Set,Dale Walsh, TIA Committee Contribution, April 9, 1997.

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