Patent ID: 11863210
Assignee: NANOSEMI, INC.
Field: Basic communication processes (Electrical engineering)
Classification: CPC H | IPC H

Claim 24:
25. The method of claim 16, wherein the digital predistorter configured to generate the digitally predistorted output, v, is configured to:
generate the digitally predistorted output, v, based on the input signal u and the time-varying signal, e, according to:, v
      ⁡
      
        [
        t
        ]
      
    
    =
    
      
        u
        ⁡
        
          [
          t
          ]
        
      
      +
      
        
          ∑
          
            k
            =
            1
          
          n
        
        ⁢
        
          
            x
            k
          
          ⁢
          
            
              B
              k
            
            ⁡
            
              (
              
                
                  
                    q
                    u
                  
                  ⁡
                  
                    [
                    t
                    ]
                  
                
                ,
                
                  
                    q
                    e
                  
                  ⁡
                  
                    [
                    t
                    ]
                  
                
              
              )
            
          
        
      
    
  

  with

  
    
      
        q
        u
      
      ⁡
      
        [
        t
        ]
      
    
    =
    
      [
      
        
          
            
              u
              ⁡
              
                [
                
                  t
                  +
                  l
                  -
                  1
                
                ]
              
            
          
        
        
          
            
              u
              ⁡
              
                [
                
                  t
                  +
                  l
                  -
                  2
                
                ]
              
            
          
        
        
          
            ⋮
          
        
        
          
            
              u
              ⁡
              
                [
                
                  t
                  +
                  l
                  -
                  τ
                
                ]
              
            
          
        
      
      ]
    
  

  
    and
    ⁢
    
      
    
    ⁢
    with
  

  
    
      
        q
        e
      
      ⁡
      
        [
        t
        ]
      
    
    =
    
      [
      
        
          
            
              e
              ⁡
              
                [
                
                  t
                  +
                  
                    s
                    ⁡
                    
                      (
                      
                        l
                        -
                        1
                      
                      )
                    
                  
                
                ]
              
            
          
        
        
          
            
              e
              ⁡
              
                [
                
                  t
                  +
                  
                    s
                    ⁡
                    
                      (
                      
                        l
                        -
                        2
                      
                      )
                    
                  
                
                ]
              
            
          
        
        
          
            ⋮
          
        
        
          
            
              e
              ⁡
              
                [
                
                  t
                  +
                  
                    s
                    ⁡
                    
                      (
                      
                        l
                        -
                        τ
                      
                      )
                    
                  
                
                ]
              
            
          
        
      
      ]
    
  

wherein Bk are basis functions, qu[t] and qe[t] are stacks of recent baseband and envelope input samples, respectively, s is a time scale separation factor representative of a ratio of time constants of the power amplifier and the power supply modulator powering the power amplifier, and xk are computed coefficients to weigh the basis functions.