학술논문

Joint LDPC decoding and timing recovery using code constraint feedback
Document Type
Periodical
Source
IEEE Communications Letters IEEE Commun. Lett. Communications Letters, IEEE. 10(3):189-191 Mar, 2006
Subject
Communication, Networking and Broadcast Technologies
Parity check codes
Timing
Feedback
Iterative decoding
Frequency estimation
Circuits
Phase estimation
Phase locked loops
Tracking loops
Delay effects
Language
ISSN
1089-7798
1558-2558
2373-7891
Abstract
Timing recovery and channel decoding are traditionally performed independently. However, we show here that the information generated during the iterative decoding of low-density parity-check (LDPC) coded data can be fed back to the timing recovery circuit to enable accurate estimation of frequency and phase errors without the need for any pilot symbols. We describe a method capable of handling large offsets with complexity that grows linearly with offset size. Combining the LDPC constraint node observations with a properly calibrated phase locked loop allows successful tracking of a constant time delay, a frequency offset and a random phase walk.