Digital telephone system circuits

Details Digital telephone system circuits Digital telephone system circuits

1989-12-29

1991-05-14

Olms, Douglas W.

Multiplex communications

Wide area network

Packet switching

379201, 375 41, 3701101, H04J 114

Patent

active

050162462

ABSTRACT:
A telephone system uses above voice-band ASK control and supervisory signals which are appended to digitally encoded voice by forcing the least significant bits to a selected level for transmission to the receiving end. At the receiving end, the ASK is regenerated by a circuit including special filter. To eliminate audible noise resulting from the filter action, the ASK signal is applied to a shaping circuit which shapes the leading and trailing ASK envelope into a gradually increasing and decreasing envelope. To detect the proper number of pulses in the signal, a threshold detector is used which follows the envelope, ignoring peaks of low amplitude after peaks of high amplitude.

REFERENCES:
patent: 4637016 (1987-01-01), Ciancibello
patent: 4673976 (1987-06-01), Wreford-Howard
patent: 4715045 (1987-12-01), Lewis
patent: 4829560 (1989-05-01), Evanyk
patent: 4901344 (1990-02-01), Monette et al.
Frank P. Tedeschi, The Active Filter Handbook, 1979, pp. 160-168.

Affiliated with

Also associated with

Rating

Digital telephone system circuits does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Digital telephone system circuits, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Digital telephone system circuits will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1654364