Method for processing a digital input signal of a channel equalizer

A method of processing a baseband digital signal block at an output of a filter matched to a radio transmission channel and at an input of a channel equalizer, wherein the baseband signal is fed to a whitening filter estimated for the block by a procedure comprising the steps of:

• estimating a noise sequence included in the baseband signal block and superimposed on a known signal sequence;
• calculating an autocorrelation vector of the estimated noise sequence;
• estimating a noise autocorrelation vector in the form of a sum of predetermined vectors weighted by respective coefficients, the predetermined vectors comprising a first vector representative of an autocorrelation of a useful signal in a first frequency band, at least one second vector representative of a correlation of the useful signal with a disturbance from at least one channel situated in a second frequency band adjacent to the first band and a third vector representative of a correlation of the useful signal with a thermal noise component, said coefficients being chosen to minimize a deviation between the calculated autocorrelation vector and said estimated noise autocorrelation vector;
• estimating coefficients of the whitening filter from the estimated noise autocorrelation vector;
• applying the estimated coefficients to the whitening filter;
• and
• filtering the baseband signal.

A device for processing a baseband digital signal in a radiocommunication receiver, comprising a whitening filter for receiving the baseband signal at an output of a filter matched to a transmission channel and for supplying a filtered signal to a channel equalizer, and means of estimation of the whitening filter for a block of the baseband signal, wherein the means of estimation of the whitening filter comprise:

• means for calculating an autocorrelation vector of the baseband signal;
• means for determining an estimated autocorrelation vector as a sum of predetermined vectors weighted by respective coefficients, the predetermined vectors comprising a first vector representative of an autocorrelation of a useful signal in a first frequency band, at least one second vector representative of a correlation of the useful signal with a disturbance from at least one channel situated in a second frequency band adjacent to the first band and a third vector representative of a correlation of the useful signal with a thermal noise component, said coefficients being chosen to minimize a deviation between the calculated autocorrelation vector and said estimated autocorrelation vector;
• means of estimation of a noise autocorrelation vector by differencing between the estimated autocorrelation vector and the first vector multiplied by an energy estimation of the useful signal;
• and
• means of estimation of the coefficients of the whitening filter from the estimated noise autocorrelation vector.

A device for processing a baseband digital signal in a radiocommunication receiver, comprising a whitening filter for receiving the baseband signal at an output of a filter matched to a transmission channel and for supplying a filtered signal to a channel equalizer, and means of estimation of the whitening filter for a block of the baseband signal, wherein the means of estimation of the whitening filter comprise:

• means of estimation of a noise sequence included in the baseband signal block and superimposed on a known signal sequence;
• means for calculating an autocorrelation vector of the estimated noise sequence;
• means of estimation of a noise autocorrelation vector in the form of a sum of predetermined vectors weighted by respective coefficients, the predetermined vectors comprising a first vector representative of an autocorrelation of a useful signal in a first frequency band, at least one second vector representative of a correlation of the useful signal with a disturbance from at least one channel situated in a second frequency band adjacent to the first band and a third vector representative of a correlation of the useful signal with a thermal noise component, said coefficients being chosen to minimize a deviation between the calculated autocorrelation vector and said estimated noise autocorrelation vector;
• and
• means of estimation of coefficients of the whitening filter from the estimated noise autocorrelation vector.