Equalizer circuit, communication system, and method that is adaptive to varying launch amplitudes for reducing receiver error

A communication system, comprising:

• a communication path;
• a transmitter coupled to forward a communication signal into the communication path, the forwarded communication signal having a launch amplitude;
• and
• a receiver having an equalizer circuit coupled to receive the communication signal from the communication path, the received communication signal having an attenuated amplitude, wherein said equalizer circuit includes:
• means for detecting the launch amplitude and for modifying the attenuated amplitude to match the launch amplitude by using a first loop and a second loop in the equalizer circuit, wherein the first loop comprises a first filter, a slicer circuit, and an integrator and the second loop comprises a second filter, a voltage peak detector, and the slicer circuit;
• wherein the slicer circuit has an adjustable output;
• the first filter comprising an inverse filter coupled to receive the communication signal from the communication path having the attenuated amplitude;
• the second filter comprises a low pass filter having a frequency response that allows a determination of the launch amplitude;
• the voltage peak detector is coupled to retain the launch amplitude and to modify an adjustable output to match the launch amplitude;
• and
• the integrator is coupled to modify a gain of the inverse filter depending on a difference between an output of the inverse filter and an output from the slicer circuit.

A method for reducing errors at the output of a receiver, comprising:

• applying a communication signal to the receiver;
• generating a communication signal amplitude and an error signal indicative of the communication signal;
• generating a first logic value when the communication signal amplitude exceeds a threshold voltage and a second logic value when the communication signal amplitude does not exceed the threshold value;
• adjusting a plurality of filter weights according to the error signal;
• detecting a peak-to-peak amplitude of the communication signal during a time when the communication signal exhibits a first frequency, which is less than a threshold frequency amount;
• feeding back the peak-to-peak amplitude to modify the output from the receiver by adjusting magnitudes of the first and second logic values to substantially match the peak-to-peak amplitude;
• and
• integrating the modified receiver output to provide an output that substantially matches the peak-to-peak amplitude.