Communication system having transmitter frequency control

Details Communication system having transmitter frequency control Communication system having transmitter frequency control

1994-07-27

1996-10-22

Chin, Stephen

Pulse or digital communications

Transceivers

Loopback mode

375358, 370107, H04B 138, H04L 516

Patent

active

055685129

ABSTRACT:
A communication system is simpler and conserves power by eliminating the need for a reference frequency oscillator in the transmitter circuit. In a battery operated transceiver of the present invention, the receiver portion includes a tracking oscillator. The tracking oscillator output is used to synchronize received data and as a reference frequency source for the transmitter. In a half duplex communication system a reply signal is transmitted while no command signal is being received. Therefore, the transceiver in such a system includes circuitry for maintaining the reference frequency during transmission. Thus, the frequency accuracy of the transmission is based on the frequency accuracy of the received command signal. The tracking oscillator in one embodiment includes a phase locked loop circuit having a voltage controlled oscillator (VCO), an up-down counter, and a digital to analog converter (DAC) for determining the VCO frequency. A transparent latch in series between the counter and the DAC is used to maintain the VCO frequency as a reference frequency for transmission.

REFERENCES:
patent: 4185241 (1980-01-01), Ewanus et al.
patent: 4929918 (1990-05-01), Chung et al.
patent: 5003559 (1991-03-01), Kanai et al.
patent: 5059979 (1991-10-01), Micic et al.
patent: 5272730 (1993-12-01), Clark
patent: 5363419 (1994-11-01), Ho
patent: 5365551 (1994-11-01), Snodgrass et al.
patent: 5377232 (1994-12-01), Davidov et al.

Affiliated with

Also associated with

Rating

Communication system having transmitter frequency control does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Communication system having transmitter frequency control, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Communication system having transmitter frequency control will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2365438