Patent US3746996A successfully refreshed from Google Patents.
US3746996A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Asynchronous single-sideband demodulation
Assignee: AT&T Inc
•
Filing: 1971-12-29
•
Granted: 1973-07-17
•
Expires: 1991-12-29
Abstract
Abstract Asynchronous or noncoherent demodulation, i.e., demodulation without employing a carrier wave at the receiver to multiply the incoming channel signal, of single-sideband signals is accomplished using only the instantaneous phase deviation information of the channel signal. The required receiver comprises an instantaneous phase deviation detector followed by a nonlinear, post-detection processor including a cosine generator in parallel with the tandem combination of a Hilbert transform circuit and an exponential amplifier.
Inventors
- 👤 J Peoples
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 14:10
CPC Classifications
H; H03; H03D; H03D1/00; H03D1/22; H03D1/24
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
116 words
A receiver for recovering asynchronously a baseband information signal transmitted in a single sideband modulated wave comprising means for detecting the instantaneous phase deviation of said single sideband modulated wave, means for generating a first nonlinear function of said phase deviation from said detecting means, means for producing the inverted Hilbert transform of said phase deviation from said detecting means, means for operating on said inverted Hilbert transform of said phase deviation by a second nonlinear function, and means for multiplying said first and second nonlinear functions of said phase deviation respectively produced by said generating means and said operating means to form an output signal which is a linear function of said baseband information signal.
Claim 2
Dependent Claim
116 words
A receiver for recovering asynchronously a baseband information signal transmitted in a single sideband modulated wave comprising means for detecting the instantaneous phase deviation of said single sideband modulated wave, means for generating a first nonlinear function of said phase deviation from said detecting means, means for producing the inverted Hilbert transform of said phase deviation from said detecting means, means for operating on said inverted Hilbert transform of said phase deviation by a second nonlinear function, and means for multiplying said first and second nonlinear functions of said phase deviation respectively produced by said generating means and said operating means to form an output signal which is a linear function of said baseband information signal.
Claim 3
Dependent Claim
20 words
The receiver defined in claim 1 in which said means for generating said first nonlinear function is a cosine network.
Claim 4
Dependent Claim
27 words
The receiver defined in claim 1 in which said means for producing the inverted Hilbert transform of said phase deviation is a wideband, all-pass, 90-degree phase-shifting network.
Claim 5
Dependent Claim
34 words
The receiver defined in claim 1 in which said means for operating on the inverted Hilbert transform of said phase deviation by a second nonlinear function is an amplifier with an exponential gain characteristic.
Claim 6
Dependent Claim
119 words
An asynchronous receiver for recovering an information signal from a single-sideband modulated wave comprising means for detecting the instantaneous phase deviation of said single-sideband modulated wave, means for generating the cosine function of said phase deviation obtained from said detecting means, means for phase shifting all frequency components of said phase deviation obtained from said detecting means by 90 electrical degrees without altering the amplitudes of any of them, further means for operating on the phase-shifted frequency components from said phase shifting means to derive an exponential function thereof, and means for multiplying the respective cosine and exponential functions from said generating means and from said operating means to form an output signal proportional to the desired information signal.
Claim 7
Dependent Claim
119 words
An asynchronous receiver for recovering an information signal from a single-sideband modulated wave comprising means for detecting the instantaneous phase deviation of said single-sideband modulated wave, means for generating the cosine function of said phase deviation obtained from said detecting means, means for phase shifting all frequency components of said phase deviation obtained from said detecting means by 90 electrical degrees without altering the amplitudes of any of them, further means for operating on the phase-shifted frequency components from said phase shifting means to derive an exponential function thereof, and means for multiplying the respective cosine and exponential functions from said generating means and from said operating means to form an output signal proportional to the desired information signal.
Claim 8
Independent Claim
90 words
The method of recovering a baseband information signal transmitted as a single sideband of wave energy comprising the steps of a. detecting the instantaneous phase deviation of said single sideband of wave energy, b. generating a first nonlinear function of said phase deviation, c. generating an inverted Hilbert transformation of said phase deviation, d. generating a second nonlinear function of said inverted Hilbert transformation, and e. forming the product of said first and second nonlinear functions to form a signal which is a linear function of said baseband information signal.
Claim 9
Independent Claim
90 words
The method of recovering a baseband information signal transmitted as a single sideband of wave energy comprising the steps of a. detecting the instantaneous phase deviation of said single sideband of wave energy, b. generating a first nonlinear function of said phase deviation, c. generating an inverted Hilbert transformation of said phase deviation, d. generating a second nonlinear function of said inverted Hilbert transformation, and e. forming the product of said first and second nonlinear functions to form a signal which is a linear function of said baseband information signal.
Claim 10
Dependent Claim
25 words
The method of recovering a baseband information signal according to claim 6 in which said first nonlinear function produces the cosine of said phase deviation.
Claim 11
Dependent Claim
30 words
The method of recovering a baseband information signal according to claim 6 in which said second nonlinear function produces the exponential of the inverted Hilbert transformation of said phase deviation.
References Cited (Backward Citations)
US3508155A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-07-16 | 1977-01-15 | 1977-07-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-16 | 1981-01-15 | 1981-07-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-16 | 1985-01-15 | 1985-07-17 | $7700.00 | Window Closed / Lapsed |