Transcript
Europaisches Patentamt European Patent Office
EUROPEAN
0 512
© Publication number:
Office europeen des brevets
PATENT
A3
APPLICATION Int. CI* H04B
© Application number: 92201159.8
606
1/16
(§) Date of filing: 24.04.92 ®
Priority: 03.05.91 EP 91201051
®
Date of publication of application: 11.11.92 Bulletin 92/46
@ Designated Contracting States: DE ES FR GB IT @ Date of deferred publication of the search report: 27.01.93 Bulletin 93/04 @ Applicant: N.V. Philips' Gloeilampenfabrieken Groenewoudseweg 1 NL-5621 BA Eindhoven(NL)
@ Inventor: Therssen, Dieter Ernest Michel c/o INT. OCTROOIBUREAU B.V. Prof. Holstlaan 6 NL-5656 AA Eindhoven(NL) Inventor: Ginderdeuren, Johan Kamiel Jozef c/o INT. OCTROOIBUREAU B.V. Prof. Holstlaan 6 NL-5656 AA Eindhoven(NL) 0
Representative: Schoonheijm, Harry Barend et al INTERNATIONAAL OCTROOIBUREAU B.V. Prof.Holstlaan 6 NL-5656 AA Eindhoven(NL)
(54) Time-discrete stereo decoder.
00 < CO o CO CM m
© A receiver having a signal path incorporating a tuner, a demodulator circuit for supplying a stereo multiplex signal comprising a baseband stereo sum signal (L + R), a 19 kHz stereo pilot and a stereo difference signal (L-R) which is double sideband amplitude-modulated on a suppressed 38 kHz subcarrier, a sampler for converting an analog signal into a time-discrete signal and a stereo decoder for time-division multiplex decoding of a time-discrete stereo multiplex signal into time-discrete left and right stereo signals. In order to realise an effective selection of the stereo multiplex signal by means of an easily integrable low-pass filter, the stereo decoder comprises a time-discrete halfband low-pass filter circuit having a finite impulse response, with a transition band which is substantially located in the frequency range of said modulated stereo difference signal and with a half-value transfer which is located at the frequency of said 38 kHz stereo subcarrier, which filter circuit has a substantially linear amplitude transfer characteristic as well as a linear phase transfer characteristic in the transition band, said receiver also including an interpolation circuit which is coupled to an output of the filter circuit for converting time-sequential even and odd sampling values of the output signal of the filter circuit into
time-sequential pairs of simultaneously occurring sampling values, and a dematrixing circuit coupled to the interpolation circuit for a linear combination of said pairs of sampling values and a compensation of the crosstalk between the left and right stereo signals caused by the filter circuit. DOS fa=76KC T FD
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European Patent Office
Application Number
EUROPEAN SEARCH REPORT EP
DOCUMENTS CONSIDERED TO BE RELEVANT Citation of document with indication, where appropriate, Relevant Category of relevant passages to claim EP-A-0 308 520 (DEUTSCHE PTT INDUSTRIES) A,D * a b s t r a c t ; claims 1-7; figures 1-5 *
92 20 1159
CLASSIFICATION Or THE APPLICATION (Int. CI.5 ) H04B1/16
TECHNICAL FIELDS SEARCHED (Int. CI.5 ) H04B H03D
The present search report has been drawn up for all claims Dale ofa»f>letioa ofthe search Place of March 20 NOVEMBER 1992 THE HAGUE CATEGORY OF CITED DOCUMENTS X: particularly relevant if taken alone Y: particularly relevant if combined with another document of the same category A: technological background O : non-written disclosure P : intermediate document
ExamMr ANDERSEN J . G .
T : theory or principle underlying the invention E : earlier patent document, but published on, or after the filing date D : document cited in the application L : document cited for other reasons A : member of the same patent family, corresponding document
