Title :
Maximum-likelihood based rapid carrier acquisition architectures
Author :
Ramakrishnan, Balasubramanian
Author_Institution :
MITRE Corp., Bedford, MA
Abstract :
Modern codes such as turbo and LDPC codes operate at low signal-to-noise ratios, which makes carrier synchronization a challenging problem. This paper first develops a new Monte-Carlo based method to derive Cramer-Rao lower bounds for non-data aided carrier synchronization. Using these theoretical results, it is shown that carrier frequency can in theory be acquired much more rapidly than existing techniques for the DVB-S2 waveform, a commercial satellite waveform, which has also been adopted for use in military satellite communications. The paper then develops practical realizations of the maximum-likelihood carrier synchronizers for non-data aided carrier synchronization. The proposed simplified architecture is also shown to have significantly lower acquisition times and better tracking performance than commonly used carrier synchronizers for DVB-S2.
Keywords :
Monte Carlo methods; digital video broadcasting; direct broadcasting by satellite; maximum likelihood estimation; military communication; parity check codes; synchronisation; turbo codes; Cramer-Rao lower bounds; DVB-S2 waveform; LDPC codes; Montem Carlo based method; carrier frequency; commercial satellite waveform; low density parity check codes; maximum-likelihood based carrier acquisition architectures; military satellite communications; nondata aided carrier synchronization; signal-to-noise ratios; turbo codes; Artificial satellites; Digital video broadcasting; Frequency synchronization; Military satellites; Military standards; Modulation coding; Parity check codes; Quadrature phase shift keying; Signal to noise ratio; Timing;
Conference_Titel :
Military Communications Conference, 2008. MILCOM 2008. IEEE
Conference_Location :
San Diego, CA
Print_ISBN :
978-1-4244-2676-8
Electronic_ISBN :
978-1-4244-2677-5
DOI :
10.1109/MILCOM.2008.4753266