Patent ID: 8848811

Claim:
Precoder for a communication system arranged to provide transmission blocks (t (i) ) for transmission over a transmission channel based on inputted symbol blocks (x (1) ) having a length N, said precoder being arranged to pre-distort each symbol block (x (1) ) based on an estimate of characteristics of the transmission channel so that a corresponding transmission block (t (i) ) appears to be undistorted after transmission over the transmission channel, wherein the precoder comprises: a memory; and a processor coupled to the memory and configured to retrieve pre-computed parameters from the memory, wherein the processor is arranged to use the retrieved pre-computed parameters to provide a first measure vector corresponding to predistortion so as to remove intrasymbol interference and a second measure (q) vector corresponding to predistortion so as to remove intersymbol interference, wherein the processor is configured to form a pre-distorted symbol block by applying Tomlinson-Harashima precoding on a sum vector formed as a sum of the first measure vector and the second measure vector (q), wherein the Tomlinson-Harashima precoding is performed N times on the sum vector starting with k=N and down to k=1, wherein N is an integer and wherein for each of the N times, the first measure vector is updated, and wherein the processor is configured to form a corresponding transmission block (t (i) ) from the pre-distorted symbol block.