US4516087A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for reducing side-lobe energy in an MSK detectable signal
Assignee: Boeing North American Inc
•
Filing: 1982-04-12
•
Granted: 1985-05-07
•
Expires: 2002-04-12
Abstract
Abstract A method and apparatus for generating an MSK detectable signal with reduced side lobe energy of the type in which the MSK detectable signal has two combined orthogonal channels to transmit a data signal. A predetermined channel envelope modulation waveform pattern is selected in accordance with a group of data bits, and the respective orthogonal channels are amplitude modulated with the selected predetermined waveforms. The addition of the orthogonal channels results in a constant amplitude signal with greatly reduced energy in the higher order sidelobes.
Inventors
- 👤 Warren B. Bruene
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 14:03
CPC Classifications
H; H04; H04L; H04L27/00; H04L27/18; H04L27/20; H04L27/2003; H04L27/2007; H04L27/2017
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
219 words
Means for generating an MSK detectable signal for transmission of a binary data signal having a sequence of mark and space data bits comprising: a waveform generator for phase controlling a pair of orthogonally oriented waves in accordance with respective successive alternate data bits of said data signal and for amplitude modulating each of said orthogonally oriented waves with a waveform pair so that said modulated orthogonally oriented waves have continuously rounded phase transitions; said waveform pair being selected in accordance with the states of three successive bits of said data signal according to the following table: ______________________________________
next present previous waveform
bit bit bit pair
______________________________________
.0. .0. .0. lp-slr
.0. .0. 1 slr-hp
.0. 1 .0. lp-slr
.0. 1 1 slr-hp
1 .0. .0. slr-hp
1 .0. 1 lp-slr
1 1 .0. slr-hp
1 1 1 lp-slr
______________________________________ wherein lp is a low-peak wave having a shape defined by 2 sin 45 (1-(2/π) cos 2θ); hp is a high-peak wave having a shape defined by 2 sin θ; slr is a slope reversing wave having a shape defined by 2 sin 45 (1-(2/π) cos 2θ); slr is a sign reversing wave having a shape defined by 2 sin θ; and means for combining said amplitude modulated signals into a combined signal to form said MSK detectable signal.
Claim 2
Dependent Claim
219 words
Means for generating an MSK detectable signal for transmission of a binary data signal having a sequence of mark and space data bits comprising: a waveform generator for phase controlling a pair of orthogonally oriented waves in accordance with respective successive alternate data bits of said data signal and for amplitude modulating each of said orthogonally oriented waves with a waveform pair so that said modulated orthogonally oriented waves have continuously rounded phase transitions; said waveform pair being selected in accordance with the states of three successive bits of said data signal according to the following table: ______________________________________
next present previous waveform
bit bit bit pair
______________________________________
.0. .0. .0. lp-slr
.0. .0. 1 slr-hp
.0. 1 .0. lp-slr
.0. 1 1 slr-hp
1 .0. .0. slr-hp
1 .0. 1 lp-slr
1 1 .0. slr-hp
1 1 1 lp-slr
______________________________________ wherein lp is a low-peak wave having a shape defined by 2 sin 45 (1-(2/π) cos 2θ); hp is a high-peak wave having a shape defined by 2 sin θ; slr is a slope reversing wave having a shape defined by 2 sin 45 (1-(2/π) cos 2θ); slr is a sign reversing wave having a shape defined by 2 sin θ; and means for combining said amplitude modulated signals into a combined signal to form said MSK detectable signal.
Claim 3
Dependent Claim
30 words
The means for generating an MSK detectable signal of claim 1 further comprising a band pass filter through which said combined signal is passed to produce said MSK detectable signal.
Claim 4
Dependent Claim
21 words
The means for generating an MSK detectable signal of claim 1 wherein the MSK detectable signal is of constant envelope amplitude.
References Cited (Backward Citations)
US4135057A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-05-06 | 1988-11-05 | 1989-05-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-05-06 | 1992-11-05 | 1993-05-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-05-06 | 1996-11-05 | 1997-05-07 | $7700.00 | Window Closed / Lapsed |