Method and system for distance measurement in a low or zero...

Telecommunications – Radiotelephone system – Zoned or cellular telephone system

Reexamination Certificate

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

C455S011100, C455S067110, C455S067160, C342S118000, C342S127000

Reexamination Certificate

active

07139581

ABSTRACT:
A method and system for distance measurement in a low or zero intermediate frequency (IF) half-duplex communications loop measures the distance between two transceivers without synchronizing the local oscillators of the two transceivers. Transceiver distance may be measured in systems that use direct conversion (zero IF) or intermediate frequencies that are so low that phase noise significantly reduces the accuracy of the distance measurement. The communications loop demodulates, re-modulates and retransmits a received signal to provide a re-transmitted signal that has the same carrier and modulation frequency as the received signal. A phase-hold circuit provides an analog system for half-duplex operation that retains the frequency and phase information of the received signal for retransmission in a subsequent time slot. Alternatively, a digital implementation provides phase and frequency retention via a sample and delay system comprising an analog-to-digital conversion (ADC) subsystem, a first-in-first-out (FIFO) memory and a digital-to-analog (D/A) converter.

REFERENCES:
patent: 3676865 (1972-07-01), Strenglein
patent: 3680092 (1972-07-01), Scott
patent: 3790940 (1974-02-01), Becker
patent: 4011562 (1977-03-01), Bruce
patent: 5381444 (1995-01-01), Tajima
patent: 5546032 (1996-08-01), Yatagai
patent: 6608587 (2003-08-01), Sparrow et al.
patent: 2003/0012306 (2003-01-01), Alexander et al.

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Method and system for distance measurement in a low or zero... does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Method and system for distance measurement in a low or zero..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and system for distance measurement in a low or zero... will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-3696528

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.