Patent ID: 11881971
Assignee: INSPUR SUZHOU INTELLIGENT TECHNOLOGY CO., LTD.
Field: Digital communication (Electrical engineering)
Classification: CPC H | IPC H

Claim 19:
20. The adaptive PAM4 decision feedback equalization circuit according to claim 1, wherein an adaptive adjustment of the adaptive PAM4 decision feedback equalization circuit is implemented based on eye pattern monitoring and an adaptive algorithm, wherein the adaptive algorithm is a least mean square (LMS) algorithm, and
coefficients in the LMS algorithm are updated as follows:, C
    i
   
   (
   
    n
    +
    T
   
   )
  
  =
  
   
    
     C
     i
    
    (
    n
    )
   
   +
   
    2
    ⁢
    
     μ
     ·
     
      e
      ⁡
      (
      n
      )
     
     ·
     
      x
      ⁡
      (
      n
      )
     
    
   
  
 

wherein n is a currently sampling moment, T is a sampling period, e(n) is an error signal, x(n) is an equalization signal, and μ is a time constant,
after integral transformation, division by T, and transposition, the following formula is obtained:, C
      i
     
     (
     
      n
      +
      T
     
     )
    
    -
    
     
      C
      i
     
     (
     n
     )
    
   
   T
  
  =
  
   
    
     2
     ⁢
     μ
    
    T
   
   ⁢
   
    e
    ⁡
    (
    n
    )
   
   ⁢
   
    x
    ⁡
    (
    n
    )
   
  
 

as T approaches zero, the tap coefficient Ci(n) is expressed as, according to the calculus definition:, C
    i
   
   (
   n
   )
  
  =
  
   
    1
    
     τ
     int
    
   
   ⁢
   
    
     ∫
     0
     t
    
    
     
      e
      ⁡
      (
      n
      )
     
     ⁢
     
      x
      ⁡
      (
      n
      )
     
     ⁢
     dn
    
   
  
 

wherein, τ
   int
  
  =
  
   T
   /
   2
   ⁢
   μ, is a time constant of an integrator.