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:
Mar. 19, 1991
Filed:
Jan. 29, 1990
Robert C Wang, Mendham, NJ (US);
AT&T Bell Laboratories, Murray Hill, NJ (US);
Abstract
A baseband processing unit (10) for use in a cellular telephone cell site includes a digital signal processor (20) which serves to process forward voice signals intended for transmission to a mobile unit (12) as well as process the reverse voice signals received from the mobile unit. The digital signal processor further serves to produce a first supervisory audio tone (SAT) for transmission to the mobile unit by generating successive digital SAT samples which are decoded into a continuous tone. In addition, the digital signal processor serves to detect the presence of a second SAT generated by the mobile unit by sampling and processing successive samples of the second SAT and measuring the power thereof.