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AN ADAPTIVE METHOD FOR THE EXTRACTION OF CHANNEL IMPAIRMENTS FROM A DIGITAL SYNCHRONIZATION PATTERN

IP.com Disclosure Number: IPCOM000009419D
Original Publication Date: 1999-Sep-01
Included in the Prior Art Database: 2002-Aug-22

Publishing Venue

Motorola

Related People

Authors:
Kevin Doberstein

Abstract

In digital modulation schemes, such as with the APCO Project 25 specified modulations CQPSK and C4M, a receiver must be able to synchronize to a transmitted waveform. Unfortunately, various impairments induced by inaccuracies in transmitters and also the RF channel cause degradations in the received synchronization pattern. It is the responsi- bility of the receiver to acquire synchronization under these conditions and after synchronization is acquired, it is also the receiver's responsibility to estimate several parameters required to recover the data. These parameters include the amount of cani- er offset, the amount of gain in the symbols, and the position of the symbol center in the received waveform.