The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 11, 1995
Filed:
Dec. 02, 1991
Applicant:
Inventors:
Assignee:
British Telecommunications public limited company, London, GB;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04J / ; H04J / ;
U.S. Cl.
CPC ...
370 495 ; 370 50 ; 359123 ;
Abstract
Apparatus for converting a frequency division multiplex (fdm) signal to a time domain multiplex (tdm) signal in which a voltage control oscillator whose output is a staircase of reference frequencies is mixed by a mixer with a received fdm signal. Each received frequency is output in turn at a common intermediate frequency from a bandpass filter thereby forming a tdm signal after passing through a demodulator and low pass filter. The conversion may take place in the optical domain by mixing optical reference frequencies with an optical fdm signal in, for example, a coherent heterodyne optical receiver.