Symbol synchronizer using modified early/punctual/late gate technique

A symbol synchronizer in a telecommunications device, comprising:

• a plurality of filters, receiving a sequence of incoming pairs of in-phase and quadrature signals in accordance with a symbol timing, each of the pair of matched filters outputting an early signal, a punctual signal, and a late signal, the early signal and the late signal indicating an error in synchronization between the symbol timing of the received signals and the timing of the matched filter, and the punctual signal being an information bearing signal indicating the contents of the received in-phase and quadrature signals;
• a symbol synchronizing estimator, connected to the plurality of matched filters, receiving from each of the pair of matched filters the early signal and the late signal and outputting an interpolation signal to the pair of matched filters;
• and
• means for adjusting the relative delay of the matched filters with regard to the symbol timing of the received signal in accordance with the interpolation signal;
• wherein the symbol synchronizing estimator includes suppression means for suppressing the interpolation signal when the received signals fall below a predetermined signal to noise ratio, thereby enabling the symbol synchronizer to "flywheel" through signal fades;
• wherein the suppression means is a constant value in a normalizer for normalizing a sum and a difference signal based on the received in-phase and quadrature signals.

A symbol synchronizer in a telecommunications device, comprising:

• a plurality of filters, receiving a sequence of incoming pairs of in-phase and quadrature signals in accordance with a symbol timing, each of the pair of matched filters outputting an early signal, a punctual signal, and a late signal, the early signal and the late signal indicating an error in synchronization between the symbol timing of the received signals and the timing of the matched filter, and the punctual signal being an information bearing signal indicating the contents of the received in-phase and quadrature signals;
• a symbol synchronizing estimator, connected to the plurality of matched filters, receiving from each of the pair of matched filters the early signal and the late signal and outputting an interpolation signal to the pair of matched filters;
• and
• means for adjusting the relative delay of the matched filters with regard to the symbol timing of the received signal in accordance with the interpolation signal wherein the adjusting means includes means for switching between a plurality of sets of filter coefficients in the matched filters;
• wherein each matched filter has eight sets of coefficients, the timing of each set differing by one eighth of a sample.