US4660215A
Expired / Lapsed
US
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Transmitter/receiver system
Assignee: Panasonic Holdings Corp
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Filing: 1984-12-04
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Granted: 1987-04-21
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Expires: 2004-12-04
Abstract
Abstract A transmitter/receiver system for converting digital information into a multi-frequency signal for transmission. A reference frequency signal is first transmitted, then a series of frequencies having information indicative of differences with the reference signal are transmitted, and a receiver discriminates differences with the reference frequency signal to decode the information.
Inventors
- 👤 Yoshio Horiike
- 👤 Yasuo Nagaishi
- 👤 Kiyotake Fukui
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 08:42
CPC Classifications
H; H04; H04L; H04L27/00; H04L27/26
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
235 words
A transmitter/receiver system comprising: a transmitter which transmits a multi-frequency signal composed of a reference frequency signal having a reference frequency followed by at least an information signal having a frequency different from said reference frequency; and a receiver which receives said multi-frequency signal and produces an information corresponding to a frequency difference between said information signal and said reference signal, said receiver comprising: a frequency conversion means having a local oscillator for converting frequencies of said multi-frequency signal to lower frequencies; a frequency analyzing means for analyzing the lower-converted frequencies of said multi-frequency signal, which comprises a plurality of filters divided into groups each composed of at least three filters, each group being assigned to each of the lower-converted frequencies of said multi-frequency signal; a decoding means for decoding the analyzed frequencies to produce said information corresponding to said frequency difference, said decoding means controlling a local oscillation frequency of said local oscillator so that a lower-converted frequency signal corresponding to said reference frequency signal is outputted from a filter in a group assigned to said reference frequency signal in said frequency analyzing means; and a means for changing the grouping of said plurality of filters in said frequency analyzing means so that said lower-converted frequency signal corresponding to said reference frequency signal is outputted from a center filter among said at least three filters in said group assigned to said reference frequency signal.
Claim 2
Dependent Claim
235 words
A transmitter/receiver system comprising: a transmitter which transmits a multi-frequency signal composed of a reference frequency signal having a reference frequency followed by at least an information signal having a frequency different from said reference frequency; and a receiver which receives said multi-frequency signal and produces an information corresponding to a frequency difference between said information signal and said reference signal, said receiver comprising: a frequency conversion means having a local oscillator for converting frequencies of said multi-frequency signal to lower frequencies; a frequency analyzing means for analyzing the lower-converted frequencies of said multi-frequency signal, which comprises a plurality of filters divided into groups each composed of at least three filters, each group being assigned to each of the lower-converted frequencies of said multi-frequency signal; a decoding means for decoding the analyzed frequencies to produce said information corresponding to said frequency difference, said decoding means controlling a local oscillation frequency of said local oscillator so that a lower-converted frequency signal corresponding to said reference frequency signal is outputted from a filter in a group assigned to said reference frequency signal in said frequency analyzing means; and a means for changing the grouping of said plurality of filters in said frequency analyzing means so that said lower-converted frequency signal corresponding to said reference frequency signal is outputted from a center filter among said at least three filters in said group assigned to said reference frequency signal.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-04-20 | 1990-10-20 | 1991-04-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-04-20 | 1994-10-20 | 1995-04-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-04-20 | 1998-10-20 | 1999-04-21 | $7700.00 | Window Closed / Lapsed |