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:
Sep. 01, 1992
Filed:
Jan. 25, 1991
Charles J Malek, Crystal Lake, IL (US);
James A McDonald, Buffalo Grove, IL (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
In frequency-hopping spread-spectrum systems, it is necessary to maintain frequency and bit synchronization (sync) between the transmitter and receiver in order to maintain quality data recovery at the receiver. Two transmissions in adjacent hop-time intervals may overlap because of various time delays within the system. Collision bits (203 and 207) are used to realign the transmitted messages in time. The base station (103) manufactures (401) the collision bits (203 and 207) and transmits them to the communication unit (101), which echoes back (503) the bits on its next transmission. If the bits received at the base station do not match the bits sent (407), the base station (103) initiates (409) collision maintenance such that the communication unit (101) can adjust its DPLL (331) to realign its transmissions in time.