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:
Feb. 07, 1989
Filed:
Nov. 24, 1987
Christopher E Holt, Ipswich, GB;
John M Rollett, Ipswich, GB;
Abstract
A stereo coding system is described in which 7 kHZ bandwidth sum (L+R) and difference (L-R) signals are converted to digital form (11 and 12). The difference signal is then bandlimited (13) to 2 kHZ and downsampled (14) to 4K samples/sec prior to being encoded (16), and the sum signal is encoded (15); both are then multiplexed together (17) prior to transmission. After reception, the signal is demultiplexed (19) and the difference signal is decoded (20) upsampled (21) to its original bit rate and filtered to prevent aliasing (22), and the sum signal is delayed in a digital buffer (28) and decoded (24) prior to both being converted back to analogue form (23 and 25). The delay introduced by the digital buffer (28) equalizes the excess delay introduced into the difference signal.