Multi-component digital predistortion

Abstract

Various examples are directed to systems and methods for operating a plurality of power amplifiers. A predistortion circuit may pre-distort an input signal according to a predistortion configuration to generate a pre-distorted signal for the plurality of power amplifiers. An adaption circuit may receive a first feedback signal from a first power amplifier of the plurality of power amplifiers and generate predistortion correlation data describing a correlation between parameters of a model describing the plurality of power amplifiers. The adaption circuit may receive a first feedback signal from a second power amplifier of the plurality of power amplifiers and update the predistortion correlation data to generate updated predistortion correlation data using the first feedback signal from the second power amplifier. The adaption circuit may also generate the predistortion configuration using the updated predistortion correlation data.

What is claimed is: 
     
         1 . A system for operating a plurality of power amplifiers, the system comprising:
 a predistortion circuit configured to pre-distort an input signal according to a predistortion configuration to generate a pre-distorted signal for the plurality of power amplifiers;   an adaption circuit, configured to generate the predistortion configuration based at least in part on a first feedback signal from a first power amplifier of the plurality of power amplifiers and a first feedback signal from a second power amplifier of the plurality of power amplifiers; and   a beamforming circuit, configured to perform operations comprising:
 applying a first amplitude modification and a first phase shift to the pre-distorted signal to generate a first modified pre-distorted signal, the first modified pre-distorted signal being provided to the first power amplifier; and 
 applying a second amplitude modification and a second phase shift to the pre-distorted signal to generate a second modified pre-distorted signal, the second modified pre-distorted signal being provided to the second power amplifier. 
   
     
     
         2 . The system of  claim 1 , the generating of the predistortion configuration comprising:
 receiving a first feedback signal from a first power amplifier of the plurality of power amplifiers;   generating predistortion correlation data describing a correlation between parameters of a model describing the plurality of power amplifiers;   receiving a first feedback signal from a second power amplifier of the plurality of power amplifiers;   updating the predistortion correlation data to generate updated predistortion correlation data, the updating using the first feedback signal from the second power amplifier; and   generating the predistortion configuration using the updated predistortion correlation data.   
     
     
         3 . The system of  claim 2 , wherein generating the predistortion correlation data comprises:
 generating a first basis matrix using the first feedback signal of the first power amplifier and the pre-distorted signal;   generating a first error vector using the first feedback signal of the first power amplifier and the pre-distorted signal;   generating an autocorrelation matrix using the first basis matrix; and   generating a cross-correlation vector using the first error vector.   
     
     
         4 . The system of  claim 3 , wherein updating the predistortion correlation data comprises:
 generating a second basis matrix using the first feedback signal of the second power amplifier and the pre-distorted signal;   generating a second error vector using the first feedback signal of the second power amplifier and the pre-distorted signal;   generating an updated autocorrelation matrix using the second basis matrix and the autocorrelation matrix; and   generating an updated cross-correlation vector using the second error vector and the cross-correlation vector.   
     
     
         5 . The system of  claim 4 , wherein generating the predistortion configuration is based at least in part on the updated autocorrelation matrix and the updated cross-correlation vector. 
     
     
         6 . The system of  claim 4 , wherein generating the predistortion configuration is based at least in part on a previous predistortion configuration, the updated autocorrelation matrix, and the updated cross-correlation vector. 
     
     
         7 . The system of  claim 1 , the first amplitude modification and the first phase shift being based on a first down tilt angle and a first horizontal scan angle, the second amplitude modification and the second phase shift also being based on the first down tilt angle and the first horizontal scan angle. 
     
     
         8 . The system of  claim 1 , the beamforming circuit comprising:
 a first mixer to apply the first amplitude modification and the first phase shift to the pre-distorted signal; and   a second mixer to apply the second amplitude modification and the second phase shift to the pre-distorted signal.   
     
     
         9 . The system of  claim 1 , further comprising an antenna array, the antenna array comprising:
 a first antenna electrically coupled to receive an output of the first power amplifier; and   a second antenna electrically coupled to receive an output of the second power amplifier.   
     
     
         10 . A method for operating a plurality of power amplifiers, the method comprising:
 pre-distorting an input signal according to a predistortion configuration to generate a pre-distorted signal for a plurality of power amplifiers;   generating the predistortion configuration based at least in part on a first feedback signal from a first power amplifier of the plurality of power amplifiers and a first feedback signal from a second power amplifier of the plurality of power amplifiers;   applying a first amplitude modification and a first phase shift to the pre-distorted signal to generate a first modified pre-distorted signal, the first modified pre-distorted signal being provided to the first power amplifier; and   applying a second amplitude modification and a second phase shift to the pre-distorted signal to generate a second modified pre-distorted signal, the second modified pre-distorted signal being provided to the second power amplifier.   
     
     
         11 . The method of  claim 10 , the generating of the predistortion configuration comprising:
 receiving a first feedback signal from a first power amplifier of the plurality of power amplifiers;   generating predistortion correlation data describing a correlation between parameters of a model describing the plurality of power amplifiers;   receiving a first feedback signal from a second power amplifier of the plurality of power amplifiers;   updating the predistortion correlation data to generate updated predistortion correlation data, the updating using the first feedback signal from the second power amplifier; and   generating the predistortion configuration using the updated predistortion correlation data.   
     
     
         12 . The method of  claim 11 , wherein generating the predistortion correlation data comprises:
 generating a first basis matrix using the first feedback signal of the first power amplifier and the pre-distorted signal;   generating a first error vector using the first feedback signal of the first power amplifier and the pre-distorted signal;   generating an autocorrelation matrix using the first basis matrix; and   generating a cross-correlation vector using the first error vector.   
     
     
         13 . The method of  claim 12 , wherein updating the predistortion correlation data comprises:
 generating a second basis matrix using the first feedback signal of the second power amplifier and the pre-distorted signal;   generating a second error vector using the first feedback signal of the second power amplifier and the pre-distorted signal;   generating an updated autocorrelation matrix using the second basis matrix and the autocorrelation matrix; and   generating an updated cross-correlation vector using the second error vector and the cross-correlation vector.   
     
     
         14 . The method of  claim 13 , wherein generating the predistortion configuration is based at least in part on the updated autocorrelation matrix and the updated cross-correlation vector. 
     
     
         15 . The method of  claim 13 , wherein generating the predistortion configuration is based at least in part on a previous predistortion configuration, the updated autocorrelation matrix, and the updated cross-correlation vector. 
     
     
         16 . The method of  claim 10 , the first amplitude modification and the first phase shift being based on a first down tilt angle and a first horizontal scan angle, the second amplitude modification and the second phase shift also being based on the first down tilt angle and the first horizontal scan angle. 
     
     
         17 . A system for operating a plurality of power amplifiers, the system comprising:
 means for pre-distorting an input signal according to a predistortion configuration to generate a pre-distorted signal for the plurality of power amplifiers;   means for generating the predistortion configuration based at least in part on a first feedback signal from a first power amplifier of the plurality of power amplifiers and a first feedback signal from a second power amplifier of the plurality of power amplifiers;   means for applying a first amplitude modification and a first phase shift to the pre-distorted signal to generate a first modified pre-distorted signal, the first modified pre-distorted signal being provided to the first power amplifier; and   means for applying a second amplitude modification and a second phase shift to the pre-distorted signal to generate a second modified pre-distorted signal, the second modified pre-distorted signal being provided to the second power amplifier.   
     
     
         18 . The system of  claim 17 , the first amplitude modification and the first phase shift being based on a first down tilt angle and a first horizontal scan angle, the second amplitude modification and the second phase shift also being based on the first down tilt angle and the first horizontal scan angle. 
     
     
         19 . The system of  claim 17 , the generating of the predistortion configuration comprising:
 receiving a first feedback signal from a first power amplifier of the plurality of power amplifiers;   generating predistortion correlation data describing a correlation between parameters of a model describing the plurality of power amplifiers;   receiving a first feedback signal from a second power amplifier of the plurality of power amplifiers;   updating the predistortion correlation data to generate updated predistortion correlation data, the updating using the first feedback signal from the second power amplifier; and   generating the predistortion configuration using the updated predistortion correlation data.   
     
     
         20 . The system of  claim 19 , wherein generating the predistortion correlation data comprises:
 generating a first basis matrix using the first feedback signal of the first power amplifier and the pre-distorted signal;   generating a first error vector using the first feedback signal of the first power amplifier and the pre-distorted signal;   generating an autocorrelation matrix using the first basis matrix; and   generating a cross-correlation vector using the first error vector.