| 摘要 |
A quadrature amplitude modulated (QAM) data signal transmitted at T symbols per second is sampled in a data receiver at a rate of 2/T samples per second and applied to a transversal-type equalizer structure (25, 46, 34, 35) having taps spaced at T/2 second intervals. A demodulated equalized signal (aj, bj), generated once every T seconds, is quantized to form a decision (aj*, bj*) as to the value of the original modulating data symbol. An error signal (ej, ej) is formed in response to the pre- and post-quantized values of the demodulated equalized signal. Tap coefficients (ci(j), ci(j)) used in generating the equalized signals are updated in response to (a) a correction term which is a function of the error signal and (b) a predetermined tap leakage term which has a constant magnitude. The introduction of the tap leakage term maintains the coefficient values at minimum levels. |
