Transversal type automatic phase and amplitude equalizer
AssigneeNippon Electric Co., Ltd.
InventorsShin'ichi Koike, Seijiro Hayashi, Michio Takayama
Life of this patent
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Abstract
A transversal type automatic equalizer includes circuits for differentiating the equalized signal, sampling the equalized signal under the control of a timing signal, and generating an error signal from the sampled signal. The differentiated and error signals are multiplied together and a variable phase shifter phase shifts the timing signal in response to their product to provide optimum equalization.
Claims6
In a transversal type automatic equalizer for automatically equalizing an input multilevel signal, comprising tapped delay means for receiving said input multilevel signal and producing a plurality of delayed outputs, variable tap weighting means for weighting the delayed outputs appearing at the taps of said delay means, coupling means for algebraically summing the outputs of said tap weighting means, sampling means for sampling the output of said coupling means in response to a sampling control signal, identification means connected to receive the output of said sampling means for providing an identified signal as the output of said automatic equalizer, error means for comparing the input and output signals of said identification means to provide an error signal representative of the difference between said input and output signals, and first multiplication means for multiplying said delayed outputs by said error signal in order to provide said tap control signals to said variable tap weighting means;
- the improvement wherein said transversal type automatic equalizer further comprises:
- differentiating means for differentiating the output of said coupling means;
- second multiplication means for receiving said error signal and the output of said differentiating means, said multiplication means having an output signal corresponding to the product of said received signals;
- integrating means for integrating the output of said second multiplication means;
- and
- control means for providing said sampling control signal to said sampling means in response to the output of said integrating means.
Dependencies are inferred from the claim text.