US4856025A
Expired / Lapsed
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Method of digital signal transmission
Assignee: Panasonic Holdings Corp
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Filing: 1986-12-29
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Granted: 1989-08-08
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Expires: 2006-12-29
Abstract
Abstract A modulation method capable of high-speed or high-quality digital data transmission under a multipath fading transmission line such as a radio transmission in an urban area is a type of differential coding phase modulation and residues in the fact that the rate of change of phase varies, or the phase is discrete, but does not employ a phase transition waveform of a constant value in a time slot which is a smallest unit for transmitting one symbol of data as in conventional methods. Phase transition waveforms in respective time slots which are spaced apart from each other by prescribed time slots are identical varying waveforms or discrete waveforms, and entirely shifted from each other by an amount according to the data transmitted. A detecting method employed is a differential detection method using a delay line for delaying a signal for a time corresponding to the prescribed time slots. In the presence of multipath propagation, a plurality of kinds of detected outputs are produced according to the multipath propagation, and the detected outputs are combined by a filter after the differential detection, producing a diversity effect for improving bit error rate characteristics. This digital signal transmission method is capable of multiphase transmission and can increase spectrum utilization efficiency.
Inventors
- 👤 Hitoshi Takai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 14:40
CPC Classifications
H; H04; H04L; H04L27/00; H04L27/18; H04L27/22; H04L27/233; H04L27/2331; H04L27/20; H04L27/2032; H04L27/2053; H04L27/206; H04L27/2067; H04L27/2085
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
132 words
A method of transmitting a digital signal, employing, in a transmission apparatus for transmitting digital data, a transmission signal having phase transition waveforms in respective continuous time slots of data, each phase transition waveform in each of the time slots having a varying rate of change of phase or at least one phase jump, wherein phase transition waveforms in any two time slots which are spaced apart from each other on a time axis by a prescribed number of time slots are identical to each other in shape irrespective of an information to be transmitted, the information to be transmitted being present in a phase difference between the phase transition waveforms in any two time slots spaced apart from each other on a time axis by the prescribed number of time slots.
Claim 2
Independent Claim
132 words
A method of transmitting a digital signal, employing, in a transmission apparatus for transmitting digital data, a transmission signal having phase transition waveforms in respective continuous time slots of data, each phase transition waveform in each of the time slots having a varying rate of change of phase or at least one phase jump, wherein phase transition waveforms in any two time slots which are spaced apart from each other on a time axis by a prescribed number of time slots are identical to each other in shape irrespective of an information to be transmitted, the information to be transmitted being present in a phase difference between the phase transition waveforms in any two time slots spaced apart from each other on a time axis by the prescribed number of time slots.
Claim 3
Dependent Claim
22 words
A method according to claim 1, wherein the phase transition waveform in each of the time slots is a raised cosine waveform.
Claim 4
Dependent Claim
21 words
A method according to claim 1, wherein the phase transition waveform in each of the time slots is a Gaussian waveform.
Claim 5
Dependent Claim
29 words
A method according to claim 1, wherein said phase difference is any one of angles obtained by equally dividing 2π by a number which is a power of 2.
Claim 6
Dependent Claim
25 words
A method according to claim 1, wherein said transmission signal is delayed and transmitted from a plurality of different antennas each with a time delay.
Claim 7
Dependent Claim
32 words
A method according to claim 1, wherein said transmission signal is detected by differential detection using a delay line capable of producing a delay corresponding to said prescribed number of time slots.
Claim 8
Dependent Claim
28 words
A method according to claim 1, wherein said phase transition waveform in each of the time slots is of a stepped pattern having at least one phase jump.
Claim 9
Dependent Claim
16 words
A method according to claim 7, wherein said stepped pattern has a plurality of phase jumps.
Claim 10
Dependent Claim
15 words
A method according to claim 7, wherein said stepped pattern has a single phase jump.
Claim 11
Dependent Claim
21 words
A method according to claim 9, wherein the phase jump occurs at the same position in each of the time slots.
Claim 12
Dependent Claim
21 words
A method according to claim 10, wherein the phase jump occurs at a center position in each of the time slots.
Claim 13
Dependent Claim
26 words
A method according to claim 9, wherein the phase jump in each of the time slots occurs at one of a plurality of kinds of positions.
Claim 14
Dependent Claim
15 words
A method according to claim 9, wherein the amount of the phase jump is π.
Claim 15
Dependent Claim
37 words
A method according to claim 9, wherein the direction of the phase jump is the same which is leading or lagging, and the amount of the phase jump is the same, in all of the time slots.
Claim 16
Dependent Claim
49 words
A method according to claim 9, wherein the direction of the phase jump is the same which is leading or lagging in all of the time slots, and the amount of the phase jump in each of the time slots is one of a plurality of kinds of amounts.
Claim 17
Dependent Claim
42 words
A method according to claim 9, wherein the direction of the phase jump is alternately leading and lagging in each adjacent two of the time slots, and the amount of the phase jump is the same in all of the time slots.
Claim 18
Dependent Claim
48 words
A method according to claim 9, wherein the direction of the phase jump is alternately leading and lagging in each adjacent two of the time slots, and the amount of the phase jump in each of the time slots is one of a plurality of kinds of amounts.
Claim 19
Dependent Claim
28 words
A method according to claim 1, wherein the phase transition waveform in each of the time slots is composed of a plurality of straight lines of different gradients.
Claim 20
Dependent Claim
13 words
A method according to claim 18, wherein said gradients are of two kinds.
Claim 21
Dependent Claim
17 words
A method according to claim 18, wherein said gradients, i.e., frequencies, are of three kinds or more.
Claim 22
Dependent Claim
21 words
A method according to claim 18, wherein said phase transition waveform in each of the time slots has a phase jump.
Claim 23
Dependent Claim
20 words
A method according to claim 18, wherein said phase transition waveform in each of the time slots changes phase continuously.
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) | 1992-08-07 | 1993-02-06 | 1993-08-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-08-07 | 1997-02-06 | 1997-08-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-08-07 | 2001-02-06 | 2001-08-08 | $7700.00 | Window Closed / Lapsed |