Method and system for interference assessment and reduction in a wireless communication system

1. A method for reducing interference in a wireless communication system utilizing an antenna array, the antenna array using at least one or more channels for communicating with one or more mobile terminals, comprising:

assigning at least one channel as an empty channel in which no desired signal is carried so as to provide a representation of all relevant interference;

analyzing a spatial signature of the channels based on the interference received on the empty channel and the desired signals received on at least one signal channel; and

reducing the interference on the signal channel by utilizing the analyzed spatial signature and the representation of all relevant interference, wherein the analyzing further includes:

estimating data covariance matrices, R x and R in , wherein R in is a covariance matrix of the empty channel and the R x is a covariance matrix of the signal channel;

estimating the spatial signature of the signal channels by finding a generalized principal eigenvector of a matrix pencil {R x , R in }; and

obtaining a nulling weight vector for the signal channel based on the spatial signature and R in .

2. The method of claim 1 further includes:

determining a beamforming vector based on the nulling weight vector;

detecting the desired signals from the beamforming vector;

further determining the spatial signature; and

repeating the above steps until a predetermined condition is satisfied.

3. The method of claim 2 wherein the predetermined condition is the convergence of the detected desired signals.

4. The method of claim 2 wherein the predetermined condition is a predetermined number of iterations.

5. A wireless communication system for reducing interference utilizing an antenna array, the antenna array using one or more signal channels for communicating with one or more mobile terminals, comprising means for:

assigning at least one channel as an empty channel in which no desired signal is carried so as to provide a representation of all relevant interference;

analyzing a spatial signature of the signal channels based on the interference received on the empty channel and the desired signals received on at least one signal channel; and

reducing the interference on the signal channels by utilizing the analyzed spatial signature and the representation of all relevant interference, wherein the analyzing further includes:

estimating data covariance matrices, R in and R x , wherein R in is a covariance matrix of the empty channel and R x is a covariance matrix of the signal channel;

estimating the spatial signature of the signal channel by finding a generalized principal eigenvector of a matrix pencil {R x , R in }; and

obtaining a nulling weight vector for the signal channels based on the spatial signature and R in .

6. The system of claim 5 further includes:

determining a beamforming vector based on the nulling weight vector;

detecting the desired signals from the beamforming vector;

further determining the spatial signature; and

repeating the above steps until a predetermined condition is satisfied.

7. The system of claim 6 wherein the predetermined condition is the convergence of the detected desired signals.

8. The system of claim 6 wherein the predetermined condition is a predetermined number of iterations.

9. The system of claim 6 wherein the obtaining further includes using a training sequence in the signal channel for better estimating the spatial signature.

10. A method for reducing interference in a wireless communication system utilizing an antenna array, the antenna array using one or more channels for communicating with one or more mobile terminals, comprising:

assigning at least one channel as an empty channel in which no desired signal is carried so as to provide a representation of all relevant interference;

analyzing a spatial signature of the channels based on the interference received on the empty channel and signals of a training sequence received on at least one signal channel; and

reducing the interference on the signal channels by utilizing the analyzed spatial signature and the representation of all relevant interference, wherein the analyzing further includes:

estimating the spatial signature of the signal channel by finding a generalized principal eigenvector of a matrix pencil {R x , R in };

obtaining a nulling weight vector for the signal channel based on the spatial signature and the covariance matrix of the signal channel;

determining a beamforming vector based on the nulling weight vector;

detecting the signals of the training sequence from the beamforming vector; and

repeating the above four steps until a predetermined condition is satisfied.