Patent EP0706273A2 successfully refreshed from Google Patents.
EP0706273A2
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Method of and apparatus for demodulating a signal conveyed by multiple carriers
Assignee: Sony Corp
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Filing: 1995-10-02
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Granted: —
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Expires: 2015-10-02
Abstract
Abstract A demodulating apparatus for use with a multiple-carrier system communication system can easily remove a timing offset and a frequency offset. The demodulating apparatus for receiving and demodulating a signal transmitted by use of a plurality of carriers having different frequencies employing demodulating means for frequency-analysing a specific time waveform defined by data in one modulation symbol duration and guard times accompanying with the data to provide a demodulated time waveform, a detecting means for detecting a correlation value between a received signal and a signal spaced apart from the received signal by a period corresponding to one modulation symbol duration, an integrating circuit for integrating a correlation detected signal and a peak-position discriminating means for discriminating a peak-position of an integrated value supplied thereto from the integrating circuit, wherein a correction in a demodulation processing is carried out on the basis of peak-position information discriminated by the peak-position discriminating means.
Inventors
- 👤 Mitsuhiro c/o Sony Corporation Suzuki
- 👤 Makoto c/o Sony Corporation Natori
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 06:55
CPC Classifications
H; H04; H04L; H04L7/00; H04L7/02; H04L27/00; H04L27/26; H04L27/2601; H04L27/2647; H04L27/2649; H04L27/2653; H04L27/2655; H04L27/2657; H04L27/2668; H04L27/2673; H04L27/2676
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
198 words
A demodulating apparatus for demodulating transmitted data by receiving a transmitted signal wherein predetermined bits of said transmitted data are used as a modulation symbol, a plurality of carriers having different frequencies are modulated and a predetermined time waveform is multiplied with a modulated signal whose modulation symbol is composed of said predetermined bits, said demodulating apparatus comprising: a sampling circuit for sampling a received signal at a timing corresponding to said modulation symbol; a demodulating circuit for demodulating data by frequency-analysing said received signal output from said sampling circuit in response to said modulation symbol; a correlation detecting circuit for detecting the degree of correlation between said received signal output from said sampling circuit and a received signal which results from delaying said received signal output from said sampling circuit by a predetermined time corresponding to said modulation symbol duration; an integrating circuit for integrating a signal output from said correlation detecting circuit; and a peak-position discriminating circuit for discriminating a peak-position of a signal output from said correlation detecting circuit, wherein a correction in a demodulating process of said received signal is carried out on the basis of peak-position information discriminated by said peak-position discriminating circuit.
Claim 2
Dependent Claim
35 words
A demodulating apparatus according to claim 1, wherein a sampling timing at which said sampling circuit samples said received signal is controlled on the basis of said peak-position information discriminated by said peak-position discriminating circuit.
Claim 3
Dependent Claim
53 words
A demodulating apparatus according to claim 1 or 2, further comprising a phase information discriminating circuit for discriminating a phase of said peak-position discriminated by said peak-position discriminating circuit and wherein a frequency offset of said received signal is corrected on the basis of phase information discriminated by said phase information discriminating circuit.
Claim 4
Dependent Claim
74 words
A demodulating apparatus according to claim 3, further comprising a frequency oscillator supplied with an output signal from said phase information discriminating circuit and outputting a signal with a frequency corresponding to said output signal and a mixer supplied with said output signal from said frequency oscillator and said received signal and wherein a frequency offset of said received signal is corrected by supplying an output signal of said mixer to said sampling circuit.
Claim 5
Dependent Claim
82 words
A demodulating apparatus according to claim 3, further comprising a frequency oscillator supplied with an output signal from said phase information discriminating circuit and outputting a signal with a frequency corresponding to said output signal and a mixer supplied with an output signal from said frequency oscillator and an output signal from said sampling circuit and said received signal and wherein a frequency offset of said received signal is corrected by supplying an output signal of said mixer to said demodulating circuit.
Claim 6
Dependent Claim
53 words
A demodulating apparatus according to claim 4, wherein said phase information is normalized by dividing said phase information discriminated by said phase information discriminating circuit by a predetermined time corresponding to said modulation symbol duration and an oscillation frequency of said frequency oscillator is controlled on the basis of a normalized phase information.
Claim 7
Dependent Claim
53 words
A demodulating apparatus according to claim 5, wherein said phase information is normalized by dividing said phase information discriminated by said phase information discriminating circuit by a predetermined time corresponding to said modulation symbol duration and an oscillation frequency of said frequency oscillator is controlled on the basis of a normalized phase information.
Claim 8
Independent Claim
177 words
A method of demodulating transmitted data by receiving a transmitted signal wherein predetermined bits of said transmitted data are used as a modulation symbol, a plurality of carriers having different frequencies are modulated and a predetermined time waveform is multiplied with a modulated signal whose modulation symbol is composed of said predetermined bits, said method comprising the steps of: sampling a received signal at a timing corresponding to said modulation symbol; demodulating data by frequency-analysing said received signal output at said sampling step in response to said modulation symbol; detecting the degree of correlation between said received signal output at said sampling step and a received signal which results from delaying said received signal output from said sampling step by a predetermined time corresponding to said modulation symbol duration; integrating a signal output from said correlation detecting step; and discriminating a peak-position of a signal output from said correlation detecting step, wherein a correction in a demodulating process of said received signal is carried out on the basis of peak-position information discriminated by said peak-position discriminating step.
Claim 9
Dependent Claim
34 words
A method according to claim 8, wherein a sampling timing at which said sampling step samples said received signal is controlled on the basis of said peak-position information discriminated by said peak-position discriminating step.
Claim 10
Dependent Claim
47 words
A method according to claim 8, further comprising the step of discriminating a phase of said peak-position discriminated by said peak-position discriminating step and wherein a frequency offset of said received signal is corrected on the basis of phase information discriminated by said phase information discriminating step.
Claim 11
Dependent Claim
75 words
A method according to claim 10, further comprising a frequency-oscillating step supplied with an output signal from said phase information discriminating step and outputting a signal with a frequency corresponding to said output signal and a mixing step supplied with said output signal from said frequency-oscillating step and said received signal and wherein a frequency offset of said received signal is corrected by supplying an output signal of said mixing step to said sampling step.
Claim 12
Dependent Claim
83 words
A method according to claim 10, further comprising a frequency-oscillating step supplied with an output signal from said phase information discriminating step and outputting a signal with a frequency corresponding to said output signal and a mixing step supplied with an output signal from said frequency-oscillating step and an output signal from said sampling step and said received signal and wherein a frequency offset of said received signal is corrected by supplying an output signal of said mixing step to said demodulating step.
Claim 13
Dependent Claim
52 words
A method according to claim 11, wherein said phase information is normalized by dividing said phase information discriminated by said phase information discriminating step by a predetermined time corresponding to said modulation symbol duration and an oscillation frequency of said frequency-oscillating step is controlled on the basis of a normalized phase information.
Claim 14
Dependent Claim
52 words
A method according to claim 12, wherein said phase information is normalized by dividing said phase information discriminated by said phase information discriminating step by a predetermined time corresponding to said modulation symbol duration and an oscillation frequency of said frequency-oscillating step is controlled on the basis of a normalized phase information.
References Cited (Backward Citations)
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