US4910474A
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Method and apparatus for generating phase and amplitude modulated signals
Assignee: Telogy Networks Inc
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Filing: 1989-02-09
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Granted: 1990-03-20
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Expires: 2009-02-09
Abstract
Abstract An improved circuit for generating phase and amplitude modulated signals in a modem. A first circuit (161) generates a first signal (163) using a 1200 Hz carrier (160) and an input data stream (162). This signal (163) is generated at the rate of 7200 samples per second. The first signal (163) is then sampled by a sampler (164) at a 3600 Hz rate (165). The sampled signal (166) contains both a 1200 Hz signal and a 2400 Hz signal. A bandpass filter (43) selects a 1200 Hz or a 2400 Hz center frequency. The resulting output (44) is a selectable 1200 Hz or 2400 Hz signal which is generated using only the data sampling points necessary to generate the first, 1200 Hz signal (163).
Inventors
- 👤 Taruna Tjahjadi
- 👤 Randy D. Nash
- 👤 Steven R. Sweitzer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 09:13
CPC Classifications
H; H04; H04L; H04L27/00; H04J; H04J3/00; H04J3/02; H04J3/06; H04J3/0602; H04J3/0605; H04L27/02; H04L27/08; H04L27/18; H04L27/20; H04L27/2032; H04L27/2053; H04L27/206; H04L27/2067; H04L27/2071; H04L27/32; H04L27/34; H04L27/36; H04L27/362; H04L7/00; H04L7/02; H04L7/033; H04L7/0334; H04L9/00; H04L9/40; H04L7/0331
Claims Analysis
Total Claims: 47
Claim 1
Independent Claim
111 words
A method for generating phase shift keyed (PSK) signals, comprising: generating an in-phase signal and a quadrature phase signal corresponding to an input data stream; selectively inverting said quadrature phase signal in response to a band select signal; generating a first PSK signal having a first carrier frequency; sampling said first PSK signal at a predetermined sampling frequency to provide a plurality of PSK signals, said plurality of PSK signals comprising said first PSK signal and a second PSK signal having a second carrier frequency; and selectively bandpass filtering said plurality of PSK signals in response to said band select signal to provide said first signal or said second PSK signal.
Claim 2
Independent Claim
111 words
A method for generating phase shift keyed (PSK) signals, comprising: generating an in-phase signal and a quadrature phase signal corresponding to an input data stream; selectively inverting said quadrature phase signal in response to a band select signal; generating a first PSK signal having a first carrier frequency; sampling said first PSK signal at a predetermined sampling frequency to provide a plurality of PSK signals, said plurality of PSK signals comprising said first PSK signal and a second PSK signal having a second carrier frequency; and selectively bandpass filtering said plurality of PSK signals in response to said band select signal to provide said first signal or said second PSK signal.
Claim 3
Dependent Claim
28 words
The method of claim 1 wherein said first carrier frequency is 1200 Hertz, said second carrier frequency is 2400 Hertz, and said predetermined sampling frequency is 3600 Hertz.
Claim 4
Dependent Claim
19 words
The method of claim 1 wherein said quadrature phase signal is inverted when said second PSK signal is selected.
Claim 5
Independent Claim
115 words
A method for generating quadrature amplitude modulated (QAM) signals, comprising: generating an in-phase signal, a quadrature phase signal, and an amplitude signal corresponding to an input data stream; selectively inverting said quadrature phase signal in response to a band select signal; generating a first QAM signal having a first carrier frequency; sampling said first QAM signal at a predetermined sampling frequency to provide a plurality of QAM signals, said plurality of QAM signals comprising said first QAM signal and a second QAM signal having a second carrier frequency; and selectively bandpass filtering said plurality of QAM signals in response to said band select signal to provide either said first QAM or said second QAM signal.
Claim 6
Independent Claim
115 words
A method for generating quadrature amplitude modulated (QAM) signals, comprising: generating an in-phase signal, a quadrature phase signal, and an amplitude signal corresponding to an input data stream; selectively inverting said quadrature phase signal in response to a band select signal; generating a first QAM signal having a first carrier frequency; sampling said first QAM signal at a predetermined sampling frequency to provide a plurality of QAM signals, said plurality of QAM signals comprising said first QAM signal and a second QAM signal having a second carrier frequency; and selectively bandpass filtering said plurality of QAM signals in response to said band select signal to provide either said first QAM or said second QAM signal.
Claim 7
Dependent Claim
28 words
The method of claim 4 wherein said first carrier frequency is 1200 Hertz said second carrier frequency is 2400 Hertz, and said predetermined sampling frequency is 3600 Hertz.
Claim 8
Dependent Claim
19 words
The method of claim 4 wherein said quadrature phase signal is inverted when said second QAM signal is selected.
Claim 9
Independent Claim
121 words
An apparatus for generating phase shift keyed (PSK) signals, comprising: first means for generating a first PSK signal in response to an input data stream, said first means including means for generating and selectively inverting a quadrature phase signal in response to a band select signal, said first PSK signal having a first carrier frequency; sampling means for providing a sampled PSK signal by sampling said first PSK signal at a predetermined sampling frequency, said sampled PSK signal comprising said first PSK signal and as second PSK signal having a second carrier frequency; and bandpass filtering means connected to said sampling means and responsive to said band select signal for selectively providing said first PSK signal or said second PSK signal.
Claim 10
Independent Claim
121 words
An apparatus for generating phase shift keyed (PSK) signals, comprising: first means for generating a first PSK signal in response to an input data stream, said first means including means for generating and selectively inverting a quadrature phase signal in response to a band select signal, said first PSK signal having a first carrier frequency; sampling means for providing a sampled PSK signal by sampling said first PSK signal at a predetermined sampling frequency, said sampled PSK signal comprising said first PSK signal and as second PSK signal having a second carrier frequency; and bandpass filtering means connected to said sampling means and responsive to said band select signal for selectively providing said first PSK signal or said second PSK signal.
Claim 11
Dependent Claim
28 words
The apparatus of claim 7 wherein said first carrier frequency is 1200 Hertz, said second carrier frequency is 2400 Hertz, and said predetermined sampling frequency is 3600 Hertz.
Claim 12
Dependent Claim
19 words
The apparatus of claim 7 wherein said quadrature phase signal is inverted when said second PSK signal is selected.
Claim 13
Independent Claim
118 words
An apparatus for generating quadrature amplitude modulated (QAM) signals, comprising: first means for generating a first QAM signal in response to an input data stream, said first means including means for generating an selectively inverting a quadrature phase signal in response to a band select signal, said first QAM signal having a first carrier frequency; sampling means for providing a sampled QAM signal by sampling said first QAM signal at a predetermined sampling frequency, said sampled QAM signal comprising said first QAM signal add a second QAM signal having a second carrier frequency; and bandpass filtering means connected to said sampling means and responsive to said band select signal for selectively providing said first QAM signal or signal.
Claim 14
Independent Claim
118 words
An apparatus for generating quadrature amplitude modulated (QAM) signals, comprising: first means for generating a first QAM signal in response to an input data stream, said first means including means for generating an selectively inverting a quadrature phase signal in response to a band select signal, said first QAM signal having a first carrier frequency; sampling means for providing a sampled QAM signal by sampling said first QAM signal at a predetermined sampling frequency, said sampled QAM signal comprising said first QAM signal add a second QAM signal having a second carrier frequency; and bandpass filtering means connected to said sampling means and responsive to said band select signal for selectively providing said first QAM signal or signal.
Claim 15
Dependent Claim
28 words
The apparatus of claim 10 wherein said first carrier frequency is 1200 Hertz, said second carrier frequency is 2400 Hertz, and said predetermined sampling frequency is 3600 Hertz.
Claim 16
Dependent Claim
19 words
The apparatus of claim 10 wherein said quadrature phase signal is inverted when said second QAM signal is selected.
Claim 17
Dependent Claim
118 words
Apparatus for generating a phase and amplitude modulated output signal responsive to a phase encoded input signal, comprising: a first predetermined number (N) or series-connected delay means for providing N delayed signals y delaying said input signal; a second predetermined number (M) of multiplying means for providing M multiplied signals, each of M-1 of said multiplied signals being product of a selected one of said N delayed signals and a selected one of M filter tap coefficients, and one of said M multiplied signals being the product of said signal and a selected one of said M filter tap coefficients; and adding means responsive to said M multiplied signals for providing said phase and amplitude modulated output signal.
Claim 18
Dependent Claim
118 words
Apparatus for generating a phase and amplitude modulated output signal responsive to a phase encoded input signal, comprising: a first predetermined number (N) or series-connected delay means for providing N delayed signals y delaying said input signal; a second predetermined number (M) of multiplying means for providing M multiplied signals, each of M-1 of said multiplied signals being product of a selected one of said N delayed signals and a selected one of M filter tap coefficients, and one of said M multiplied signals being the product of said signal and a selected one of said M filter tap coefficients; and adding means responsive to said M multiplied signals for providing said phase and amplitude modulated output signal.
Claim 19
Dependent Claim
13 words
The apparatus of claim 13 wherein N equals 3 and M equals 4.
Claim 20
Dependent Claim
18 words
The apparatus of claim 13 wherein each said delay means provides a delay time of one baud time.
Claim 21
Dependent Claim
16 words
The apparatus of claim 13 wherein each of said filter tap coefficients has P possible values.
Claim 22
Dependent Claim
9 words
The apparatus of claim 16 wherein P equals 6.
Claim 23
Dependent Claim
23 words
The apparatus of claim 16 wherein each of said M filter tap coefficients cycles through said P possible values in one baud time.
Claim 24
Dependent Claim
9 words
The apparatus of claim 18 wherein P equals 6.
Claim 25
Dependent Claim
151 words
Apparatus for generating a phase and amplitude modulated output signal responsive to an input data stream of in-phase (I) and quadrature phase (Q) component pairs, comprising: storage means for receiving said input data stream and shifting said I and Q component pairs to provide a phase encoded signal; a first predetermined number (N) of series-connected delay means for providing N delayed signals by delaying said phase encoded signal; a second predetermined number (M) of multiplying means for providing M multiplied signals, each of M-1 of said multiplied signals being the product of a selected one of said N delayed signals and a selected one of M filter tap coefficients, and one of said M multiplied signals being the product of said phase encoded signal and a selected one of said M filter coefficients; and adding means responsive to said M multiplied signals for providing said phase and amplitude modulated output signal.
Claim 26
Dependent Claim
151 words
Apparatus for generating a phase and amplitude modulated output signal responsive to an input data stream of in-phase (I) and quadrature phase (Q) component pairs, comprising: storage means for receiving said input data stream and shifting said I and Q component pairs to provide a phase encoded signal; a first predetermined number (N) of series-connected delay means for providing N delayed signals by delaying said phase encoded signal; a second predetermined number (M) of multiplying means for providing M multiplied signals, each of M-1 of said multiplied signals being the product of a selected one of said N delayed signals and a selected one of M filter tap coefficients, and one of said M multiplied signals being the product of said phase encoded signal and a selected one of said M filter coefficients; and adding means responsive to said M multiplied signals for providing said phase and amplitude modulated output signal.
Claim 27
Dependent Claim
13 words
The apparatus of claim 20 wherein N equals 3 and M equals 4.
Claim 28
Dependent Claim
18 words
The apparatus of claim 20 wherein each said delay means provides a delay time of one baud time.
Claim 29
Dependent Claim
17 words
The apparatus of claim 20 wherein each of said M filter tap coefficients has P possible values.
Claim 30
Dependent Claim
9 words
The apparatus of claim 23 wherein P equals 6.
Claim 31
Dependent Claim
23 words
The apparatus of claim 23 wherein each of said M filter tap coefficients cycles through said P possible values in one baud time.
Claim 32
Dependent Claim
9 words
The apparatus of claim 25 wherein P equals 6.
Claim 33
Dependent Claim
21 words
The apparatus of claim 20 where said storage means comprises a shift register and each said component pair represents a symbol.
Claim 34
Dependent Claim
28 words
The apparatus of claim 27 wherein said shift register has 16 bits and each said I component and said Q component of a component pair occupies 2 bits.
Claim 35
Independent Claim
102 words
A method for generating a phase and amplitude modulated output signal responsive to a phase encoded input signal, comprising the steps of: providing N delayed signals by delaying said input signal; providing M filter tap coefficients; providing M multiplied signals, each M-1 of said M multiplied signals being the product of a selected one of said N delayed signals and selected one of said M filter tap coefficients, and one of said M multiplied signals being the product of said input signal and a selected one of said M filter tap coefficients; and adding said multiplied signals to provide said output signal.
Claim 36
Independent Claim
102 words
A method for generating a phase and amplitude modulated output signal responsive to a phase encoded input signal, comprising the steps of: providing N delayed signals by delaying said input signal; providing M filter tap coefficients; providing M multiplied signals, each M-1 of said M multiplied signals being the product of a selected one of said N delayed signals and selected one of said M filter tap coefficients, and one of said M multiplied signals being the product of said input signal and a selected one of said M filter tap coefficients; and adding said multiplied signals to provide said output signal.
Claim 37
Dependent Claim
13 words
The method of claim 29 wherein N equals 3 and M equals 4.
Claim 38
Dependent Claim
46 words
The method of claim 29 wherein said N delayed signals lag said input signal by K baud times, wherein K is an integer and wherein 1≦K≦N, and each of said N delayed signals has a different K value than any other of said N delayed signals.
Claim 39
Dependent Claim
39 words
The method of claim 29 wherein each of said M filter tap coefficients has P possible values, further comprising the step of: cycling each of said M filer tap coefficients through said P possible values in one baud time.
Claim 40
Dependent Claim
9 words
The method of claim 32 wherein P equals 6.
Claim 41
Independent Claim
130 words
A method for generating a phase and amplitude modulated output signal responsive to an input data stream of in-phase (I) and quadrature phase (Q) component pairs, comprising the steps of: receiving said input data stream; shifting said I and Q component pairs to provide a phase encoded signal; providing N delay signals by delaying said phase encoded signal; providing M filter tap coefficients; providing M multiplied signals, each of M-1 of said M multiplied signals being the product of a selected one of said N delayed signals and a selected one of said M filter tap coefficients, and one of said M multiplied signals being the product of said input signal and a selected one of said M filter coefficient; and adding said multiplied signals to provide said output signal.
Claim 42
Independent Claim
130 words
A method for generating a phase and amplitude modulated output signal responsive to an input data stream of in-phase (I) and quadrature phase (Q) component pairs, comprising the steps of: receiving said input data stream; shifting said I and Q component pairs to provide a phase encoded signal; providing N delay signals by delaying said phase encoded signal; providing M filter tap coefficients; providing M multiplied signals, each of M-1 of said M multiplied signals being the product of a selected one of said N delayed signals and a selected one of said M filter tap coefficients, and one of said M multiplied signals being the product of said input signal and a selected one of said M filter coefficient; and adding said multiplied signals to provide said output signal.
Claim 43
Dependent Claim
13 words
The method of claim 34 wherein N equals 3 and M equals 4.
Claim 44
Dependent Claim
45 words
The method of claim 34 wherein said N delayed signals lag said input signal by K baud times, wherein K in an integer and wherein 1≦K≦N and each of said N delayed signals has a different value than any other of said N delayed signals.
Claim 45
Dependent Claim
39 words
The method of claim 34 wherein each of said M filter tap coefficients has P possible values, further comprising the step of: cycling each of said M filter tap coefficients through said P possible values in one baud time.
Claim 46
Dependent Claim
9 words
The method of claim 37 wherein P equals 6.
Claim 47
Dependent Claim
25 words
The method of claim 34 wherein each of said I component and each said Q component is stored and shifted as a 2 bit value.
References Cited (Backward Citations)
US4280099A
Cited
US4455661A
Cited
US4400817A
Cited
US4538119A
Cited
US4472818A
Cited
US4488294A
Cited
US4570125A
Cited
WO1985000255A1
Cited
US4620294A
Cited
EP0142302A2
Cited
EP0171856A1
Cited
JPS60167551A
Cited
US4661948A
Cited
US4680780A
Cited
US4812786A
Cited
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