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. 14, 1999
Filed:
Sep. 12, 1997
Randolph L Durrant, Colorado Springs, CO (US);
Mark Burbach, Peyton, CO (US);
Omnipoint Corporation, Colorado Springs, CO (US);
Abstract
A spread spectrum receiver for demodulating a CPM spread spectrum signal receives burst comprising a preamble and a data message that have been transmitted by M-ary encoding of a data signal into a single chip stream, dividing the chip stream into I and Q signal streams, independently modulating the I and Q signal streams, and superposing the resultants for transmission. The receiver detects the preamble using a non-coherent parallel correlator, and from the preamble correlation peak generates a series of integration periods for serial non-coherent correlation. A bank of non-coherent, serial correlators operate in parallel to recover the spread spectrum encoded information. For each of M spread spectrum codes, the receiver simultaneously attempts to correlate the non-preamble portion of the received spread spectrum signal by separating, the received signal into real and imaginary parts, correlating both real and imaginary parts for I and Q sequences, and combining the real I, real Q, imaginary I, and imaginary Q correlation signals into a unified correlation signal. The maximum of the unified correlation signals from the non-coherent, serial correlators dictates the content of the data stream for each integration period. The local clock reference signal in the receiver need not be frequency or phase matched with the clock of the transmitter in order to carry out the integration and recovery of the data stream.