Precoder for a communication system and methods used in said communication system

摘要

The present invention relates to a precoder for a communication system arranged to provide transmission blocks for transmission over a transmission channel based on inputted symbol blocks. The precoder is arranged to pre-distort each symbol block based on an estimate of the characteristics of the transmission channel so that the corresponding transmission block appears to be undistorted after transmission over the transmission channel. In accordance therewith, the precoder is arranged to apply Tomlinson-Harashima precoding on a sum of a first measure corresponding to predistortion so as to remove intrasymbol interference and a second measure corresponding to predistortion so as to remove intersymbol interference. The present invention further relates to a method for providing transmission blocks for transmission over a transmission channel in a communication system.

主权项

1. 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.