Timing Recovery in Digital Subscriber Loops

Tradeoffs in the design of the timing recovery functions in a subscriber loop receiver are analyzed. The techniques considered are applicable to both the echo cancellation (EC) and time compression multiplexing (TCM) methods of full duplex transmission. Emphasis is on those techniques that lend themselves to implementation in MOSLSI technology, where the objective requirement is that timing recovery be implemented on a sampled-data signal (with the minimum possible sampling rate where EC is used). The wave difference method (WDM) for timing recovery appears to be the best candidate. A detailed study of its performance is carried out analytically and by computer simulation for the case of binary and alternate mark-inversion (AMI) line coding. A closed form expression describing the binary jitter performance of the WDM and its continuous time counterpart, the spectral line technique, is used to compare the two techniques. Analytical and simulation results for recovered phase and jitter are presented for various cable pulse responses carefully chosen to represent worst-case or nearly worst-case conditions. Two methods for including frequency detection in the WDM, the quadricorrelator and the rotational detector, are also simulated.

[1]  W. Bennett.  Statistics of regenerative digital transmission , 1958 .

[2]  K. Mueller,et al.  Timing Recovery in Digital Synchronous Data Receivers , 1976, IEEE Trans. Commun..

[3]  D. C. Bunday.  Digital Communications: Satellite/Earth Station Engineering , 1983 .

[4]  L. Franks,et al.  Carrier and Bit Synchronization in Data Communication - A Tutorial Review , 1980, IEEE Transactions on Communications.

[5]  Toshiro Suzuki,et al.  Line Equalizer for a Digital Subscriber Loop Employing Switched Capacitor Technology , 1982, IEEE Trans. Commun..

[6]  David D. Falconer,et al.  Optimal reception of digital data over the Gaussian channel with unknown delay and phase jitter , 1977, IEEE Trans. Inf. Theory.

[7]  R. D. Gitlin,et al.  Timing recovery and scramblers in data transmission , 1975, The Bell System Technical Journal.

[8]  W. U. Lee,et al.  Statistical Properties of Timing Jitter in a PAM Timing Recovery Scheme , 1974 .

[9]  Robert W. Brodersen,et al.  Computer Generation of Digital Filter Banks , 1986, IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems.

[10]  L. Franks,et al.  Statistical Properties of Timing Jitter in a PAM Timing Recovery Scheme , 1974, IEEE Trans. Commun..

[11]  G. G. Stokes.  "J." , 1890, The New Yale Book of Quotations.

[12]  David G. Messerschmitt,et al.  Echo Cancellation in Speech and Data Transmission , 1984, IEEE J. Sel. Areas Commun..

[13]  David Falconer,et al.  Adaptive Reference Echo Cancellation , 1982, IEEE Trans. Commun..

[14]  P. van Gerwen,et al.  Digital echo cancellation for baseband data transmission , 1979 .

[15]  David E. Muller,et al.  Application of Boolean algebra to switching circuit design and to error detection , 1954, Trans. I R E Prof. Group Electron. Comput..

[16]  S. Nader,et al.  Optimal data transmission filters , 1979 .

[17]  David G. Messerschmitt.  Frequency Detectors for PLL Acquisition in Timing and Carrier Recovery , 1979, IEEE Trans. Commun..

[18]  J. E. Mazo.  Jitter comparison of tones generated by squaring and by fourth-power circuits , 1978, The Bell System Technical Journal.

[19]  H. Andrews,et al.  Hadamard transform image coding , 1969 .

[20]  D. L. Duttweiler,et al.  The jitter performance of phase-locked loops extracting timing from baseband data waveforms , 1976, The Bell System Technical Journal.

[21]  G. Ungerboeck,et al.  Fractional Tap-Spacing Equalizer and Consequences for Clock Recovery in Data Modems , 1976, IEEE Trans. Commun..

[22]  Burton R. Saltzberg,et al.  Timing recovery for synchronous binary data transmission , 1967 .

[23]  D. Lyon.  Timing Recovery in Synchronous Equalized Data Communication , 1975, IEEE Trans. Commun..

[24]  David G. Messerschmitt,et al.  Nonlinear Echo Cancellation of Data Signals , 1982, IEEE Trans. Commun..

[25]  Richard D. Gitlin,et al.  Timing recovery in PAM systems , 1971 .

[26]  Floyd M. Gardner,et al.  Phaselock techniques , 1984, IEEE Transactions on Systems, Man, and Cybernetics.