Patent ID: 11862194
Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
Field: Audio-visual technology (Electrical engineering)
Classification: CPC G | IPC G

Claim 11:
12. The data storage system of claim 1, further comprising a data-dependent noise variance calculator configured to estimate a data-dependent noise variance from the metric input signal, each of the one or more branch metric calculations comprising:, m
    k
   
   =
   
    
     ln
     ⁡
     (
     
      σ
      2
     
     )
    
    +
    
     
      
       [
       
        
         (
         
          
           y
           k
          
          -
          
           
            s
            ˆ
           
           k
          
         
         )
        
        ⁢
        
         (
         
          1
          -
          
           
            
             ∑
              
            
            
             i
             =
             1
            
            J
           
           ⁢
           
            p
            i
           
           ⁢
           
            D
            i
           
          
         
         )
        
       
       ]
      
      2
     
     /
     
      σ
      2
     
    
   
  
  ,, where mk is the branch metric, σ is the data-dependent noise variance, yk is the signal input to the estimator, ŝk is the estimated signal, J is a highest order of the applicable noise whitening filter, pi are filter parameters of the applicable noise whitening filter, and D represents a delay corresponding to a bit duration.