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:
Jan. 23, 1990
Filed:
Nov. 16, 1984
Applicant:
Inventor:
Paul C Millar, Felixstowe, GB;
Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04B / ;
U.S. Cl.
CPC ...
381 29 ;
Abstract
A pair of filters (H.sub.1 H.sub.2) split an input signal into two frequency sub-bands (defined by a transition frequency) which are down-sampled and coded: after sample rate restoration the signals are filtered (K.sub.1 K.sub.2) and combined. To reduce signal delays, the delay response of each filter is non-constant, having a maximum at or beyond the transition frequency. Preferably non-quadrature filter pairs are used. Filters may be cascaded for more than two sub-bands.