Adaptive digital equaliser for data receiver - includes self adjusting digital filter with calculator determining sampled signal phase and amplitude, from controlled reference generator

摘要

The circuit includes an adjusting digital filter receiving the sampled low frequency signal. This is followed by an interpolator network and a phase and amplitude calculating circuit. The outputs of the amplitude and phase calculator are applied at first and second decision blocks respectively. The outputs of the two decision blocks are connected to the inputs of an AND-gate. The AND-gate output is connected to the validation input of a digital filter coefficient control circuit. The main input of this circuit is connected to the output of a subtractor circuit whose inputs are connected to the output of the digital filter and the outputs of a reference signal generating circuit. This is itself connected to the phase output of the calculator.