Patent ID: 7512191
Filing Date: 2009-03-31
Classification: H04L

Abstract:
1. A method for implementing channel equalization on a digital communications path, the method comprising: in a transmitter, converting an outgoing bit stream into symbols to be sent, compensating for a channel distortion with a Tomlinson-Harashima precoder in the transmitter, sending precoded symbols to a communications channel, a signal represented by the precoded symbols constituting a channel output signal at a destination end of the communication channel, and in a receiver, forming estimated symbol values on the basis of the channel output signal and recovering the bit stream on the basis of the estimated symbol values, wherein, during a data transmission state, the method further comprises: performing adjustment of tap coefficients of the Tomlinson-Harashima precoder based on content values of a delay line of the Tomlinson-Harashima precoder and a value of an error variable that is dependent on the difference between a signal measurable in the receiver and one of the following: wherein said measurable signal is measured in the receiver at a point where an absolute value of said difference is minimized when the adjustment is in a steady state, and synchronizing the error variable with the content values of the delay line of the Tomlinson-Harashima precoder with the aid of line frame synchronization information.