Patent ID: 7512191

Claim:
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: a sent precoded symbol value if the value of the error variable is calculated in the transmitter, and an estimated symbol value used by the receiver to recover the bit stream if the value of the error variable is calculated in the receiver, 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.