Patent US4706261A successfully refreshed from Google Patents.
US4706261A
Expired / Lapsed
US
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Differential phase modulation
Assignee: BAE Systems Aerospace Inc
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Filing: 1985-03-20
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Granted: 1987-11-10
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Expires: 2005-03-20
Abstract
Abstract The amplitude of a signal to be modulated on a carrier wave is sampled every T seconds. The sampled amplitudes are converted into phase representative pulses of pulse rate 1/T. Each phase representative pulse corresponds to the difference between a first phase corresponding to the sampled amplitude and the phase of Nth previous phase representative pulse, where N is an interger greater than 1. The discrete phase representative pulses are phase modulated onto the carrier wave. Conversion is accomplished by detecting the sampled amplitudes, applying the detected amplitudes as an address to a ROM to provide corresponding differential phase information, and modulating the differential phase information onto the carrier. To demodulate the signal from the carrier wave, the carrier wave is delayed for NT seconds and the delayed signals are subtracted from the undelayed signals. The resulting signal is linearly detected by an envelope detector to develop an output signal representative of the original modulating signal.
Inventors
- 👤 Frank M. Torre
- 👤 John F. Crush
- 👤 Raymond J. Masak
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:07
CPC Classifications
H; H04; H04B; H04B14/00; H04B14/002; H04B14/006
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
143 words
A method of modulating a carrier wave with an analog signal comprising the steps of: sampling the amplitude of the analog signal every T seconds to provide sampled amplitudes corresponding to the amplitude of the analog signal every T seconds; encoding in sequential order the sampled amplitudes into digital data pulses of pulse rate 1/T, each said digital data pulse having an amplitude corresponding to the amplitude of each sampled pulse; generating phase representative digital pulse corresponding to the difference between the amplitude of each said digital data pulse and the amplitude of the digital data pulse previous to and contiguous with each said digital data pulse; phase modulating the phase representative digital pulses onto a sine wave thereby generating phase representative sine wave pulses which correspond to the analog signal; and mixing said phase representative sine wave pulses with the carrier wave.
Claim 2
Independent Claim
143 words
A method of modulating a carrier wave with an analog signal comprising the steps of: sampling the amplitude of the analog signal every T seconds to provide sampled amplitudes corresponding to the amplitude of the analog signal every T seconds; encoding in sequential order the sampled amplitudes into digital data pulses of pulse rate 1/T, each said digital data pulse having an amplitude corresponding to the amplitude of each sampled pulse; generating phase representative digital pulse corresponding to the difference between the amplitude of each said digital data pulse and the amplitude of the digital data pulse previous to and contiguous with each said digital data pulse; phase modulating the phase representative digital pulses onto a sine wave thereby generating phase representative sine wave pulses which correspond to the analog signal; and mixing said phase representative sine wave pulses with the carrier wave.
Claim 3
Dependent Claim
81 words
The method of claim 1 wherein the step of encoding comprises the steps of: converting the sampled amplitudes into a corresponding digital signal; applying the digital signal to a read-only memory to generate corresponding phase representative digital pulses; and wherein the step of phase modulating comprises the step of providing phase representative sine wave pulses of equal amplitude and of pulse rate 1/T, each successive phase representative sine wave pulse having a phase corresponding to each successive phase representative digital pulse.
Claim 4
Independent Claim
119 words
A method of demodulating a carrier wave which is modulated with phase representative sine wave pulses of pulse rate 1/T, having a phase corresponding to the difference between the amplitude of one digital data pulse of a sequence of digital data pulses and the amplitude of a digital data pulse in the sequence which is previous to and continguous with the one digital data pulse, said sequence corresponding to an analog signal to be detected, said method comprising the steps of: delaying the carrier wave for T seconds; developing a carrier wave difference signal having a phase which represents the difference between the delayed carrier wave and the undelayed carrier wave; and detecting the envelope of said difference signal.
Claim 5
Independent Claim
119 words
A method of demodulating a carrier wave which is modulated with phase representative sine wave pulses of pulse rate 1/T, having a phase corresponding to the difference between the amplitude of one digital data pulse of a sequence of digital data pulses and the amplitude of a digital data pulse in the sequence which is previous to and continguous with the one digital data pulse, said sequence corresponding to an analog signal to be detected, said method comprising the steps of: delaying the carrier wave for T seconds; developing a carrier wave difference signal having a phase which represents the difference between the delayed carrier wave and the undelayed carrier wave; and detecting the envelope of said difference signal.
Claim 6
Dependent Claim
19 words
The method of claim 3 wherein said step of detecting comprises applying said difference signal to an envelope detector.
Claim 7
Independent Claim
161 words
An apparatus for modulating a carrier wave with an analog signal comprising: (a) means for providing the signal; (b) means for sampling the amplitude of the signal every T seconds to provide sampled amplitudes corresponding to the amplitude of the analog signal every T seconds; (c) means for encoding in sequential order the sampled amplitudes into digital data pulses of pulse rate 1/T, each said digital data pulse having an amplitude corresponding to the amplitude of each sampled pulse; (d) means for generating phase representative digital pulses corresponding to the difference between the amplitude of each said digital data pulse and the amplitude of the digital data pulse previous to and contiguous with each said digital data pulse; and (e) means for phase modulating the phase representative digital pulses onto a sine wave thereby generating phase representative sine wave pulses which correspond to the analog signal; and (f) means for mixing said phase representative sine wave pulses with the carrier wave.
Claim 8
Independent Claim
161 words
An apparatus for modulating a carrier wave with an analog signal comprising: (a) means for providing the signal; (b) means for sampling the amplitude of the signal every T seconds to provide sampled amplitudes corresponding to the amplitude of the analog signal every T seconds; (c) means for encoding in sequential order the sampled amplitudes into digital data pulses of pulse rate 1/T, each said digital data pulse having an amplitude corresponding to the amplitude of each sampled pulse; (d) means for generating phase representative digital pulses corresponding to the difference between the amplitude of each said digital data pulse and the amplitude of the digital data pulse previous to and contiguous with each said digital data pulse; and (e) means for phase modulating the phase representative digital pulses onto a sine wave thereby generating phase representative sine wave pulses which correspond to the analog signal; and (f) means for mixing said phase representative sine wave pulses with the carrier wave.
Claim 9
Dependent Claim
112 words
The apparatus of claim 5 wherein said means for encoding comprises: an analog to digital converter for converting the sampled amplitudes into corresponding digital data pulses; a read-only memory (ROM) including a look-up table for defining the difference between two amplitudes applied as an address; means for applying the digital signals as an address to the ROM for generating corresponding phase representative digital pulses at the output of the ROM; and wherein said means for phase modulating comprises means for providing phase representative sine wave pulses of equal amplitude and of pulse rate 1/T, each successive phase representative sine wave pulse having a phase corresponding to each successive phase representative digital pulse.
Claim 10
Independent Claim
125 words
An apparatus for demodulating a carrier wave which is modulated with phase representative sine wave pulses of pulse rate 1/T, having a phase corresponding to the difference between the amplitude of one digital data pulse of a sequence of digital data pulses and the amplitude of a digital data pulse in the sequence which is previous to and contiguous with the one digital data pulse, said sequence corresponding to an analog signal to be detected, said apparatus comprising: (a) means for delaying the carrier wave for T seconds; (b) means for developing a carrier wave difference signal having a phase which represents the difference between the delayed carrier wave and the undelayed carrier wave; and (c) means for detecting the envelope of said difference signal.
Claim 11
Independent Claim
125 words
An apparatus for demodulating a carrier wave which is modulated with phase representative sine wave pulses of pulse rate 1/T, having a phase corresponding to the difference between the amplitude of one digital data pulse of a sequence of digital data pulses and the amplitude of a digital data pulse in the sequence which is previous to and contiguous with the one digital data pulse, said sequence corresponding to an analog signal to be detected, said apparatus comprising: (a) means for delaying the carrier wave for T seconds; (b) means for developing a carrier wave difference signal having a phase which represents the difference between the delayed carrier wave and the undelayed carrier wave; and (c) means for detecting the envelope of said difference signal.
Claim 12
Dependent Claim
13 words
The apparatus of claim 7 wherein said means for detecting comprises a diode.
Claim 13
Independent Claim
192 words
A system for transmitting audio information comprising a transmitter comprising; (a) means for providing the signal; (b) means for sampling the amplitude of the signal every T seconds; (c) means for encoding in sequential order the sampled amplitudes into digital data pulses of pulse rate 1/T, each said digital data pulse having an amplitude corresponding to the amplitude of each sampled pulse; (d) means for generating phase representative digital pulses corresponding to the difference between the amplitude of each said digital data pulse and the amplitude of the digital data pulse previous to and contiguous with each said data pulse; (e) means for phase modulating the phase representative digital pulses onto a sine wave thereby generating phase representative sine wave pulses which correspond to the analog signal; (f) means for mixing said phase representative sine wave pulses with the carrier wave; and a receiver comprising: (g) means for delaying the carrier wave for T seconds; (h) means for developing a carrier wave difference signal having a phase which represents the difference between the delayed carrier wave and the undelayed carrier wave; and (i) means for detecting the envelope of said difference signal.
Claim 14
Independent Claim
192 words
A system for transmitting audio information comprising a transmitter comprising; (a) means for providing the signal; (b) means for sampling the amplitude of the signal every T seconds; (c) means for encoding in sequential order the sampled amplitudes into digital data pulses of pulse rate 1/T, each said digital data pulse having an amplitude corresponding to the amplitude of each sampled pulse; (d) means for generating phase representative digital pulses corresponding to the difference between the amplitude of each said digital data pulse and the amplitude of the digital data pulse previous to and contiguous with each said data pulse; (e) means for phase modulating the phase representative digital pulses onto a sine wave thereby generating phase representative sine wave pulses which correspond to the analog signal; (f) means for mixing said phase representative sine wave pulses with the carrier wave; and a receiver comprising: (g) means for delaying the carrier wave for T seconds; (h) means for developing a carrier wave difference signal having a phase which represents the difference between the delayed carrier wave and the undelayed carrier wave; and (i) means for detecting the envelope of said difference signal.
Claim 15
Dependent Claim
119 words
The system of claim 9 wherein said means for encoding comprises: an analog to digital converter for converting the sampled amplitudes into corresponding digital signals; a read-only memory (ROM) including a look-up table for defining the difference between two amplitudes applied as an address; means for applying the digital signals as an address to the ROM for generating corresponding phase representative digital pulses at the output of the ROM; wherein said means for phase modulating comprises means for providing phase representative sine wave pulses of equal amplitude and of pulse rate 1/T, each successive phase representative sine wave pulse having a phase corresponding to each successive phase representative digital pulse; and wherein said means for detecting comprises a diode.
Claim 16
Independent Claim
147 words
A method of modulating a carrier with an analog signal comprising the steps of: sampling the amplitude of the analog signal every T seconds to provide sampled amplitudes corresponding to the amplitude of the analog signal every T seconds; encoding in sequential order the sampled amplitudes into digital data pulses of pulse rate 1/T, each said digital data pulse having an amplitude corresponding to the amplitude of each sampled pulse; generating phase representative digital pulses corresponding to the difference between the amplitude of each said digital data pulse and the amplitude of the digital data pulse Nth preceding each said digital data pulse where N is an integer greater than 1; phase modulating the phase representative digital pulses onto a sine wave thereby generating phase representative sine wave pulse which correspond to the analog signal; and mixing said phase representative sine wave pulses with the carrier wave.
Claim 17
Independent Claim
147 words
A method of modulating a carrier with an analog signal comprising the steps of: sampling the amplitude of the analog signal every T seconds to provide sampled amplitudes corresponding to the amplitude of the analog signal every T seconds; encoding in sequential order the sampled amplitudes into digital data pulses of pulse rate 1/T, each said digital data pulse having an amplitude corresponding to the amplitude of each sampled pulse; generating phase representative digital pulses corresponding to the difference between the amplitude of each said digital data pulse and the amplitude of the digital data pulse Nth preceding each said digital data pulse where N is an integer greater than 1; phase modulating the phase representative digital pulses onto a sine wave thereby generating phase representative sine wave pulse which correspond to the analog signal; and mixing said phase representative sine wave pulses with the carrier wave.
Claim 18
Dependent Claim
81 words
The method of claim 11 wherein the step of encoding comprises the steps of: converting the sampled amplitudes into a corresponding digital signal; applying the digital signals to a read-only memory to generate corresponding phase representative digital pulses; and wherein the step of phase modulating comprises the step of providing phase representative sine wave pulses of equal amplitude and of pulse rate 1/T, each successive phase representative sine wave pulse having a phase corresponding to each successive phase representative digital pulse.
Claim 19
Independent Claim
125 words
A method of demodulating a carrier wave which is modulated with phase representative sine wave pulses of pulse rate 1/T, having a phase corresponding to the difference between the amplitude of one digital data pulse of a sequence of digital data pulses and the amplitude of a digital data pulse in the sequence which is Nth preceding to the one digital data pulse where N is an integer greater than 1, said sequence corresponding to an analog signal to be detected said method comprising the steps of: delaying the carrier wave for NT seconds; developing a carrier wave difference signal having a phase which represents the difference between the delayed carrier wave and the undelayed carrier wave; and detecting the envelope of said difference signal.
Claim 20
Independent Claim
125 words
A method of demodulating a carrier wave which is modulated with phase representative sine wave pulses of pulse rate 1/T, having a phase corresponding to the difference between the amplitude of one digital data pulse of a sequence of digital data pulses and the amplitude of a digital data pulse in the sequence which is Nth preceding to the one digital data pulse where N is an integer greater than 1, said sequence corresponding to an analog signal to be detected said method comprising the steps of: delaying the carrier wave for NT seconds; developing a carrier wave difference signal having a phase which represents the difference between the delayed carrier wave and the undelayed carrier wave; and detecting the envelope of said difference signal.
Claim 21
Dependent Claim
19 words
The method of claim 13 wherein said step of detecting comprises applying said difference signal to an envelope detector.
Claim 22
Independent Claim
164 words
An apparatus for modulating a carrier wave with an analog signal comprising: (a) means for providing the signal; (b) means for sampling the amplitude of the signal every T seconds to provide sampled amplitudes corresponding to the amplitude of the analog signal every T seconds; (c) means for encoding in sequential order the sampled amplitudes into digital data pulses of pulse rate 1/T, each said digital data pulse having an amplitude corresponding to the amplitude of each sampled pulse; (d) means for generating phase representative digital pulses corresponding to the difference between the amplitude of each said digital pulse and the amplitude of the digital data pulse Nth preceding each said digital data pulse where N is an integer greater than 1; (e) means for phase modulating the phase representative digital pulses onto a sine wave thereby generating phase representative sine wave pulses which correspond to the analog signal; and (f) means for mixing said phase representative sine wave pulses with the carrier wave.
Claim 23
Independent Claim
164 words
An apparatus for modulating a carrier wave with an analog signal comprising: (a) means for providing the signal; (b) means for sampling the amplitude of the signal every T seconds to provide sampled amplitudes corresponding to the amplitude of the analog signal every T seconds; (c) means for encoding in sequential order the sampled amplitudes into digital data pulses of pulse rate 1/T, each said digital data pulse having an amplitude corresponding to the amplitude of each sampled pulse; (d) means for generating phase representative digital pulses corresponding to the difference between the amplitude of each said digital pulse and the amplitude of the digital data pulse Nth preceding each said digital data pulse where N is an integer greater than 1; (e) means for phase modulating the phase representative digital pulses onto a sine wave thereby generating phase representative sine wave pulses which correspond to the analog signal; and (f) means for mixing said phase representative sine wave pulses with the carrier wave.
Claim 24
Dependent Claim
111 words
The apparatus of claim 15 wherein said means for encoding comprises: an analog to digital converter for converting the sampled amplitude into corresponding digital signals; a read-only memory (ROM) including a look-up table for defining the difference between two amplitudes applied as an address; means for applying the digital signal as an address to the ROM for generating corresponding phase representative digital pulses at the output of the ROM; and wherein said means for phase modulating comprises means for providing phase representative sine wave pulses of equal amplitude and of pulse rate 1/T, each successive phase representative sine wave pulse having a phase corresponding to each successive phase representative digital pulse.
Claim 25
Independent Claim
134 words
An apparatus for demodulating a carrier wave which is modulated with phase representative sine wave pulses of pulse rate 1/T, having a phase corresponding to the difference between the amplitude of one digital data pulse of a sequence of digital data pulses and the amplitude of a digital data pulse in the sequence which is Nth preceding to the one digital data pulse where N is an integer greater than 1, said sequence corresponding to an analog signal to be detected, said apparatus comprising: (a) means for delaying the carrier wave for NT seconds; (b) means for developing a carrier wave difference signal having a phase which represents the difference between the delayed carrier wave and the undelayed carrier wave; and (c) means for detecting the envelope of said difference signal representing the difference.
Claim 26
Independent Claim
134 words
An apparatus for demodulating a carrier wave which is modulated with phase representative sine wave pulses of pulse rate 1/T, having a phase corresponding to the difference between the amplitude of one digital data pulse of a sequence of digital data pulses and the amplitude of a digital data pulse in the sequence which is Nth preceding to the one digital data pulse where N is an integer greater than 1, said sequence corresponding to an analog signal to be detected, said apparatus comprising: (a) means for delaying the carrier wave for NT seconds; (b) means for developing a carrier wave difference signal having a phase which represents the difference between the delayed carrier wave and the undelayed carrier wave; and (c) means for detecting the envelope of said difference signal representing the difference.
Claim 27
Dependent Claim
13 words
The apparatus of claim 17 wherein said means for detecting comprises a diode.
Claim 28
Independent Claim
193 words
A system for transmitting audio information comprising a transmitter comprising: (a) means for providing the signal; (b) means for sampling the amplitude of the signal every T seconds; (c) means for encoding in sequential order the sampled amplitudes into digital data pulses of pulse rate 1/T, each said digital data pulse having an amplitude corresponding to the amplitude of each sampled pulse; (d) means for generating phase representative digital pulses corresponding to the difference between the amplitude of each said digital pulse and the amplitude of the digital data pulse Nth preceding each said digital data pulse where N is an integer greater than 1; (e) means for phase modulating the phase representative digital pulses onto a sine wave thereby generating phase representative sine wave pulses which correspond to the analog signal; and (f) means for mixing said phase representative sine wave pulses with the carrier wave; and a receiver comprising: (g) means for delaying the carrier wave for NT seconds: (h) means for developing a difference signal which represents the difference between the delayed carrier wave and the undelayed carrier wave; and (i) means for detecting the envelope of said difference signal.
Claim 29
Independent Claim
193 words
A system for transmitting audio information comprising a transmitter comprising: (a) means for providing the signal; (b) means for sampling the amplitude of the signal every T seconds; (c) means for encoding in sequential order the sampled amplitudes into digital data pulses of pulse rate 1/T, each said digital data pulse having an amplitude corresponding to the amplitude of each sampled pulse; (d) means for generating phase representative digital pulses corresponding to the difference between the amplitude of each said digital pulse and the amplitude of the digital data pulse Nth preceding each said digital data pulse where N is an integer greater than 1; (e) means for phase modulating the phase representative digital pulses onto a sine wave thereby generating phase representative sine wave pulses which correspond to the analog signal; and (f) means for mixing said phase representative sine wave pulses with the carrier wave; and a receiver comprising: (g) means for delaying the carrier wave for NT seconds: (h) means for developing a difference signal which represents the difference between the delayed carrier wave and the undelayed carrier wave; and (i) means for detecting the envelope of said difference signal.
Claim 30
Dependent Claim
119 words
The apparatus of claim 19 wherein said means for encoding comprises: an analog to digital converter for converting the sampled amplitudes into corresponding digital signals; a read-only memory (ROM) including a look-up table for defining the difference between two amplitudes applied as an address; means for applying the digital signals as an address to the ROM for generating corresponding phase representative digital pulses at the output of the ROM; wherein said means for phases modulating comprises means for providing phase representative sine wave pulses of equal amplitude and of pulse rate 1/T, each successive phase representative sine wave pulse having a phase corresponding to each successive phase representative digital pulse; and wherein said means for detecting comprises a diode.
Claim 31
Dependent Claim
7 words
The system of claim 20 wherein N=2.
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