EP0256700A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Apparatus for synthesizing the modulation of a time varying waveform with a data signal
Assignee: AT&T Inc
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Filing: 1987-07-29
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Granted: —
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Expires: 2007-07-29
Abstract
Abstract A technique for digitally synthesizing the amplitude modulation of one or more carrier signals with a random digital data signal is disclosed. Pursuant to the present invention, a memory unit (118) is addressed by a plurality of binary coded digital symbols (115-1,...115-N, 117-1,...117-N) in the data signal. For each address, at least two digital representations are read out. Each representation corresponds to a different sample of the carrier signals which has been amplitude modulated by a composite of the spectrally shaped data signal. The disclosed technique can be adapted to synthesize a variety of modulation formats, and can provide compensation for fixed in-rail and cross-rail distortions.
Inventors
- 👤 Walter Debus, Jr.
- 👤 Howard Clifford Reeve Iii
- 👤 Curtis A Siller, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 13:56
CPC Classifications
H; H04; H04L; H04L27/00; H04L27/32; H04L27/34; H04L27/36; H04L27/365; H04L25/00; H04L25/02; H04L25/03; H04L25/03006; H04L25/03012; H04L25/03114; H04L25/03133; H04L27/02; H04L27/04
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
200 words
Waveform synthesizing apparatus characterized by accessing means (112, 116) for successively converting a prescribed number of bits in a binary input data signal into first and second arrays; output means (118) for outputting at least two digital representations in response to each array, each of said digital representations corresponding to the sum of one sample of a first amplitude modulated carrier signal and another sample of second amplitude modulated carrier signal that is in phase quadrature with the first carrier signal, the amplitude of one of said carrier signals having been modulated by a composite of impulse time functions temporally displaced from one another wherein each impulse time function is weighted by a predetermined number associated with different bits in said first array and the amplitude of said other one of said carrier signals having been modulated by a composite of impulse time functions temporally displaced from one another wherein each impulse time function is weighted by said predetermined number associated with the different bits in said second array, and conversion means (121) responsive to said outputting means for converting said digital representations to an analog waveform equal to the sum of said first and second amplitude modulated carrier signals.
Claim 2
Dependent Claim
200 words
Waveform synthesizing apparatus characterized by accessing means (112, 116) for successively converting a prescribed number of bits in a binary input data signal into first and second arrays; output means (118) for outputting at least two digital representations in response to each array, each of said digital representations corresponding to the sum of one sample of a first amplitude modulated carrier signal and another sample of second amplitude modulated carrier signal that is in phase quadrature with the first carrier signal, the amplitude of one of said carrier signals having been modulated by a composite of impulse time functions temporally displaced from one another wherein each impulse time function is weighted by a predetermined number associated with different bits in said first array and the amplitude of said other one of said carrier signals having been modulated by a composite of impulse time functions temporally displaced from one another wherein each impulse time function is weighted by said predetermined number associated with the different bits in said second array, and conversion means (121) responsive to said outputting means for converting said digital representations to an analog waveform equal to the sum of said first and second amplitude modulated carrier signals.
Claim 3
Dependent Claim
23 words
The apparatus of claim 1 wherein said accessing means is characterized by a plurality of delaying means (112-1,...112-N, 116-1,...116-N) for producing said array.
Claim 4
Dependent Claim
26 words
The apparatus of claim 1 wherein said accessing means is characterized by a serial to parallel converter (141) which supplies parallel bitstreams to said delaying means.
Claim 5
Dependent Claim
48 words
The apparatus of claim 1 characterized in that said input data signal has a bit rate and said outputting means output digital representations which correspond to samples of said amplitude modulated carrier signal, said carrier signal having a frequency which is a rational multiple of said bit rate.
Claim 6
Dependent Claim
48 words
The apparatus of claim 1 characterized in that said input data signal has a bit rate and said outputting means output digital representations which correspond to samples of said amplitude modulated carrier signal, said carrier signal having a frequency which is an integer multiple of said bit rate.
Claim 7
Dependent Claim
32 words
The apparatus of claim 1 characterized in that said outputting means includes arrangement means (130, 131, 132) for arranging said digital representations outputted in response to each array into a predetermined sequence.
Claim 8
Dependent Claim
21 words
The apparatus of claim 4 characterized in that said arranging means includes a counter which is connected to said outputting means.
Claim 9
Dependent Claim
14 words
The apparatus of claim 1 characterized in that said outputting means includes a memory.
Claim 10
Dependent Claim
25 words
The apparatus of claim 1 characterized in that each of said amplitude modulated carrier signals comprise distortion and said digital representations compensate for this distortion.
Claim 11
Dependent Claim
116 words
Waveform synthesizing apparatus comprising accessing means (112, 116) for successively converting a prescribed number of bits in a binary input data signal into an array; output means (118) for outputting at least two digital representations in response to each array, each of said digital representations corresponding to a different sample of an amplitude modulated carrier signal, said carrier signal amplitude having been modulated by a composite of impulse time functions temporally displaced from one another and characterized in that each impulse time function is weighted by a predetermined number associated with different bits in said array, and conversion means (121) responsive to said outputting means for converting said digital representations to said amplitude modulated carrier signal.
Claim 12
Dependent Claim
116 words
Waveform synthesizing apparatus comprising accessing means (112, 116) for successively converting a prescribed number of bits in a binary input data signal into an array; output means (118) for outputting at least two digital representations in response to each array, each of said digital representations corresponding to a different sample of an amplitude modulated carrier signal, said carrier signal amplitude having been modulated by a composite of impulse time functions temporally displaced from one another and characterized in that each impulse time function is weighted by a predetermined number associated with different bits in said array, and conversion means (121) responsive to said outputting means for converting said digital representations to said amplitude modulated carrier signal.
Claim 13
Dependent Claim
23 words
The apparatus of claim 10 characterized in that said accessing means includes a plurality of delaying means (112-1,...112-N, 116-1...116-N) for producing said array.
Claim 14
Dependent Claim
26 words
The apparatus of claim 10 characterized in that said accessing means includes a serial to parallel converter (141) which supplies parallel bitstreams to said delaying means.
Claim 15
Dependent Claim
32 words
The apparatus of claim 10 characterized in that said outputting means includes arrangement means (130, 131, 132) for arranging said digital representations outputted in response to each array into a predetermined sequence.
Claim 16
Dependent Claim
22 words
The apparatus of claim 13 characterized in that said arranging means includes a counter (131) which is connected to said outputting means.
Claim 17
Dependent Claim
48 words
The apparatus of claim 10 characterized in that said input data signal has a bit rate and said outputting means output digital representations which correspond to samples of said amplitude modulated carrier signal, said carrier signal having a frequency which is a rational multiple of said bit rate.
Claim 18
Dependent Claim
48 words
The apparatus of claim 10 characterized in that said input data signal has a bit rate and said outputting means output digital representations which correspond to samples of said amplitude modulated carrier signal, said carrier signal having a frequency which is an integer multiple of said bit rate.
Claim 19
Dependent Claim
15 words
The apparatus of claim 10 characterized in that said outputting means comprises a memory (118).
Claim 20
Dependent Claim
23 words
The apparatus of claim 1 characterized in that said amplitude modulated carrier signal includes distortion and said digital representations compensate for this distortion.
References Cited (Backward Citations)
No citation records indexed.
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