A unified approach to optimum frame synchronization and reduced-complexity CPM receiver
Abstract
This thesis has two parts: (1) Optimum Fume Synchronization and (2) Reduced-Complexity Demodulation of CPM. The problem of frame synchronization is to locate the boundaries between frames at the receiver. Such information is necessary, for example, in communication systems with block-based error-control coding and pilot-symbol assisted modulation (PSAM). In our study, the optimum decoder-assisted frame synchronizer is proposed for Markov modulations in AWGN channels. The proposed frame synchronizer can be applied for time-varying channels with slow-fading or phase/frequency instabilities, when combined with per-survivor-processing. The time-varying channel is jointly estimated by per-survivor-processing as frame synchronization proceeds. The proposed frame synchronizer is robust to channel variation and shows performance improvement due to coding gain. Continuous phase modulation (CPM) allows the transmission of many bits per symbol while providing both good bit error probability (BER) and bandwidth performance. We develop a class of suboptimal symbol-by-symbol demodulators for continuous phase modulated (CPM) signals. The proposed demodulators provide soft-outputs to the outer code and offer a reduced-complexity symbol-by-symbol detection in which the numbers of matched filters and states are appreciably reduced. We also apply the proposed demodulation scheme to iterative decoding of serially concatenated CPM.
Degree
Ph.D.
Advisors
Krogmeier, Purdue University.
Subject Area
Electrical engineering
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