Pulse or digital communications – Repeaters – Testing
Patent
1993-10-15
1995-05-02
Cain, David C.
Pulse or digital communications
Repeaters
Testing
380 34, H04K 100
Patent
active
054126878
ABSTRACT:
A digital radio transceiver uses a differential 4-ary frequency shift keying (D4FSK) modulation scheme to achieve a radio that is low cost, miniaturizable, low in power consumption, and high in spectral efficiency. An adaptive digital "slicer" looks at a digitized FM video signal produced in the receiver to determine if the data sent is a 00, 01, 10 or 11. The digitized FM video signal is first processed by a differential decoder, the output of which is input to a peak detector. The peak detector outputs a signal upon the occurrence of a three-step transition, i.e., a peak-to-peak voltage value. Two-step and three-step transitions are separately detected and used to perform digital clock recovery. A carrier detect circuit uses a digital bit filter to produce a carrier detect signal that is reliable and glitch-free. The digital radio transceiver uses frequency hopping spread spectrum transmission. A switchable loop bandwidth frequency synthesizer provides for glitch-free switching between a wide hopping bandwidth and a narrow bandwidth between hops.
REFERENCES:
patent: 4291409 (1981-09-01), Weinberg et al.
patent: 4481640 (1984-11-01), Chow et al.
patent: 4672658 (1987-06-01), Kavehrad et al.
patent: 4707839 (1987-11-01), Andren et al.
patent: 4862478 (1989-08-01), McIntosh
patent: 4930140 (1990-05-01), Cripps et al.
patent: 4964138 (1990-10-01), Nease et al.
patent: 5121408 (1992-06-01), Cai et al.
patent: 5134630 (1992-07-01), Bateman
patent: 5210770 (1993-05-01), Rice
patent: 5267271 (1993-11-01), Rice
Grau, Jr. Juan G.
Sutton Jeff R.
Cain David C.
Proxim Incorporated
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