Timing acquisition in voiceband data sets

Details Timing acquisition in voiceband data sets Timing acquisition in voiceband data sets

1981-12-30

1983-11-15

Safourek, Benedict V.

Pulse or digital communications

Repeaters

Testing

375110, H03H 1500, H04B 319, H04L 702

Patent

active

044160151

ABSTRACT:
In a multipoint data communication system using quadrature-amplitude modulation, a master modem and a plurality of tributary modems are interconnected via respective transmission channels. Adaptive equalizer circuitry in the master modem equalizes the channel from a particular tributary by multiplying samples of signals received from the tributary by an ensemble of tap coefficients associated with the tributary. The tap coefficient ensembles for each tributary are stored in a memory from which they are retrieved at the start of transmission from that tributary. Timing acquisition circuitry within the master modem adjusts the phase of the latter's sampling circuitry at the start of transmission from a given tributary so that the received signals are sampled at the correct time points. In particular, a timing acquisition signal is transmitted by the tributary. The master samples and equalizes the received timing acquisition signal to form a succession of timing acquisition equalizer outputs. Each timing acquisition equalizer output is multiplied by its complex conjugate to form a timing acquisition envelope sample. The time by which the operation of the sampling circuitry is to be advanced or retarded is determined as a trigonometric function of successive timing acquisition envelope samples.

REFERENCES:
patent: 3962637 (1976-06-01), Motley et al.
patent: 4061978 (1977-12-01), Motley et al.
patent: 4245345 (1981-01-01), Gitlin et al.
patent: 4285061 (1981-08-01), Ho
patent: 4290139 (1981-09-01), Walsh
patent: 4376309 (1983-03-01), Fenderson et al.

Affiliated with

Also associated with

Rating

Timing acquisition in voiceband data sets does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Timing acquisition in voiceband data sets, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Timing acquisition in voiceband data sets will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-162779