JPS56140706A - Fm demodulator - Google Patents

Fm demodulator

Info

Publication number
JPS56140706A
JPS56140706A JP4361680A JP4361680A JPS56140706A JP S56140706 A JPS56140706 A JP S56140706A JP 4361680 A JP4361680 A JP 4361680A JP 4361680 A JP4361680 A JP 4361680A JP S56140706 A JPS56140706 A JP S56140706A
Authority
JP
Japan
Prior art keywords
crosses
zero
demodulation
counting
integer
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
JP4361680A
Other languages
Japanese (ja)
Other versions
JPS6121004B2 (en
Inventor
Katsumi Kobayashi
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nippon Telegraph and Telephone Corp
Original Assignee
Nippon Telegraph and Telephone Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Nippon Telegraph and Telephone Corp filed Critical Nippon Telegraph and Telephone Corp
Priority to JP4361680A priority Critical patent/JPS56140706A/en
Publication of JPS56140706A publication Critical patent/JPS56140706A/en
Publication of JPS6121004B2 publication Critical patent/JPS6121004B2/ja
Granted legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03D—DEMODULATION OR TRANSFERENCE OF MODULATION FROM ONE CARRIER TO ANOTHER
    • H03D3/00—Demodulation of angle-, frequency- or phase- modulated oscillations
    • H03D3/006—Demodulation of angle-, frequency- or phase- modulated oscillations by sampling the oscillations and further processing the samples, e.g. by computing techniques

Landscapes

  • Engineering & Computer Science (AREA)
  • Theoretical Computer Science (AREA)
  • Power Engineering (AREA)
  • Digital Transmission Methods That Use Modulated Carrier Waves (AREA)

Abstract

PURPOSE:To realize a demodulation having a reduced distortion in a wide band with elimination of the specified relation between fC and fS, by counting the number of the zero-crosses of the input sample value FM signal and then counting the reciprocal number in the time interval during which the number of the zero-crosses reaches a certain set value to carry out an FM demodulation. CONSTITUTION:The means 5 is provided to count the number (l) of the zero- crosses in which either one of the two consecutive sampled values e(kT) and e[(k- 1)T] is positive and the other is negative respectively for the FM signal e(kT) (k:an integer) of the carrier frequency fC that is sampled in the sampling period T. Then in case when (k) is defined as (i) with l=1 obtained by the means 5 and (k) is defined as (j) in the case of l=N(N: >=2 integer), (d) is obtaned which is expressed as d=e(iT) / [e(iT)-e[(j-1)T]]+(j-1-i)+e[(j-1)T]/[e[(j- 1)T]-e(jT)]. Then the arithmetic means 6 and 7 are provided to calculate (N- 1)pi/d-2pifCT.
JP4361680A 1980-04-04 1980-04-04 Fm demodulator Granted JPS56140706A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP4361680A JPS56140706A (en) 1980-04-04 1980-04-04 Fm demodulator

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP4361680A JPS56140706A (en) 1980-04-04 1980-04-04 Fm demodulator

Publications (2)

Publication Number Publication Date
JPS56140706A true JPS56140706A (en) 1981-11-04
JPS6121004B2 JPS6121004B2 (en) 1986-05-24

Family

ID=12668766

Family Applications (1)

Application Number Title Priority Date Filing Date
JP4361680A Granted JPS56140706A (en) 1980-04-04 1980-04-04 Fm demodulator

Country Status (1)

Country Link
JP (1) JPS56140706A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58207705A (en) * 1982-05-28 1983-12-03 Nippon Telegr & Teleph Corp <Ntt> Differential detecting and demodulating system
EP0099142A2 (en) * 1982-06-23 1984-01-25 Philips Patentverwaltung GmbH Method and device for the demodulation of a frequency-modulated input signal
JPS609205A (en) * 1983-06-28 1985-01-18 Matsushita Electric Ind Co Ltd Fm detection circuit
JPS60194809A (en) * 1984-03-16 1985-10-03 Toshiba Corp Demodulation circuit

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58207705A (en) * 1982-05-28 1983-12-03 Nippon Telegr & Teleph Corp <Ntt> Differential detecting and demodulating system
EP0099142A2 (en) * 1982-06-23 1984-01-25 Philips Patentverwaltung GmbH Method and device for the demodulation of a frequency-modulated input signal
JPS609205A (en) * 1983-06-28 1985-01-18 Matsushita Electric Ind Co Ltd Fm detection circuit
JPH0516204B2 (en) * 1983-06-28 1993-03-03 Matsushita Electric Ind Co Ltd
JPS60194809A (en) * 1984-03-16 1985-10-03 Toshiba Corp Demodulation circuit
JPH0262961B2 (en) * 1984-03-16 1990-12-27 Tokyo Shibaura Electric Co

Also Published As

Publication number Publication date
JPS6121004B2 (en) 1986-05-24

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