Center-Tap Tracking Algorithms for Timing Recovery
- 12 November 1987
- journal article
- website
- Published by Institute of Electrical and Electronics Engineers (IEEE) in AT&T Technical Journal
- Vol. 66 (6), 63-78
- https://doi.org/10.1002/j.1538-7305.1987.tb00305.x
Abstract
Fractionally spaced adaptive equalizers can readily compensate for timing-phase variations between the transmitter and receiver clocks that are on the order of several symbol intervals. When there is a frequency difference between these clocks, the equalizer compensates for the accumulated timing-phase difference by shifting the equalizer tap weights in the appropriate direction along the delay line. Performance, as measured by the mean-squared error, is not degraded until the center (largest) tap migrates toward one end of the equalizer. In this paper, we demonstrate how the spatial distribution of the equalizer coefficients can be used to lock the receiver sampling frequency to that of the transmitter. Replacing the standard envelope-derived timing recovery system with a closed-loop center-tap tracking algorithm offers significantly improved performance for narrow roll-off or severely-attenuated systems, reduced complexity, and a structure appropriate for all-digital receivers.Keywords
This publication has 8 references indexed in Scilit:
- The Tap-Leakage Algorithm: An Algorithm for the Stable Operation of a Digitally Implemented, Fractionally Spaced Adaptive EqualizerBell System Technical Journal, 1982
- Fractionally-Spaced Equalization: An Improved Digital Transversal EqualizerBell System Technical Journal, 1981
- On the Required Tap-Weight Precision for Digitally Implemented, Adaptive, Mean-Squared EqualizersBell System Technical Journal, 1979
- Fractional Tap-Spacing Equalizer and Consequences for Clock Recovery in Data ModemsIEEE Transactions on Communications, 1976
- Jointly Adaptive Equalization and Carrier Recovery in Two-Dimensional Digital Communication SystemsBell System Technical Journal, 1976
- Timing Recovery and Scramblers in Data TransmissionBell System Technical Journal, 1975
- Passband Equalization of Differentially Phase-Modulated Data SignalsBell System Technical Journal, 1973
- A Note on a Special Class of One-Sided Distribution SumsBell System Technical Journal, 1965