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US5214391A Expired / Lapsed US ⏱️ 0.0 years remaining

Demodulation apparatus having multipath detector for selecting a first or second demodulator

Assignee: Toshiba Corp
•
Filing: 1992-06-29
•
Granted: 1993-05-25
•
Expires: 2012-06-29
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Abstract

Abstract A demodulation apparatus incorporating an adaptive equalizer, capable of realizing a highly reliable communication, lower power consumption, and a compact size. In the demodulation apparatus, an output of one of two demodulators, at least one of which including an equalizer, is selected according to a presence or absence of multipath which is determined from a non-coincidence of bit codes, eye apertures, bit error rates, or a matched filter output, while the operation of the other demodulator is stopped for reduction of power consumption, by stopping a supply of power or clock signals to the other demodulator. In a case using a frequency offset detection unit and a frequency offset memory, one of these is selected according to a convergence or divergence of an error signal from an equalizer, while the operation of the other one is stopped for reduction of power consumption.

Inventors

  • 👤 Mutsumu Serizawa
  • 👤 Minoru Namekata
  • 👤 Koji Ogura
  • 👤 Katsumi Sakakibara

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-02 17:56
CPC Classifications
H; H04; H04L; H04L27/00; H04L1/00; H04L1/0001; H04L1/20; H04L25/00; H04L25/02; H04L25/03; H04L25/03006; H04L25/03012; H04L25/03019; H04L25/03038

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 88 words
A demodulation apparatus, comprising: a distributor for distributing an input signal to a first and a second passages; a first demodulator including an equalizer capable of compensating a transmission path distortion, connected with the first passage, for demodulating the input signal; a second demodulator, connected with the second passage, for demodulating the input signal; means for detecting a presence of multipath from the input signal; and means for selectively outputting one of the outputs of the first and second demodulators according to the detected presence of the multipath.
Claim 2
Dependent Claim 88 words
A demodulation apparatus, comprising: a distributor for distributing an input signal to a first and a second passages; a first demodulator including an equalizer capable of compensating a transmission path distortion, connected with the first passage, for demodulating the input signal; a second demodulator, connected with the second passage, for demodulating the input signal; means for detecting a presence of multipath from the input signal; and means for selectively outputting one of the outputs of the first and second demodulators according to the detected presence of the multipath.
Claim 3
Dependent Claim 35 words
The apparatus of claim 1, wherein the selectively outputting means outputs an output of the first demodulator when the detecting means detects the presence of the multipath, and an output of the second demodulator otherwise.
Claim 4
Dependent Claim 36 words
The apparatus of claim 1, wherein the detecting means comprises: matched filter means for filtering the input signal; and means for determining the presence of the multipath according to an output of the matched filter means.
Claim 5
Dependent Claim 37 words
The apparatus of claim 1, further comprising means for stopping, for a prescribed period of time, a power supply to one of the first and second demodulators whose output is not selected by the selectively outputting means.
Claim 6
Dependent Claim 38 words
The apparatus of claim 1, further comprising means for stopping, for a prescribed period of time, a clock signal supply to one of the first and second demodulators whose output is not selected by the selectively outputting means.
Claim 7
Dependent Claim 13 words
The apparatus of claim 1, wherein the second demodulator includes a delay detector.
Claim 8
Dependent Claim 27 words
The apparatus of claim 1, wherein the second demodulator includes another equalizer which has a equalization characteristic different from that of the equalizer of the first demodulator.

References Cited (Backward Citations)

US3537008A Cited
US4151475A Cited
US4726073A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1996-05-24 1996-11-23 1997-05-25 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2000-05-24 2000-11-23 2001-05-25 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2004-05-24 2004-11-23 2005-05-25 $7700.00 Window Closed / Lapsed

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