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Chapter 14  Signal Processing

 

 

 

 

 

 

Quality of Estimation

 

 

 

 

 

Classical PSD Estimation

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Quality of Estimation

 

   Why not take the Theoretical result?

       It's perfect, ideal, accurate ...  ,

         so it's physically unavailable! L

 

 

   What is Estimation?

      All measurements are Random Processes,

      the approximations to the Theoretical results.

     

 

                                 

 

 

 

      Observation = Theoretical Value + Noise

            x[n] = θ + w[n]

 

      A simplest Estimation:

                

 

 Mean , Variance, MSE(均方误差):

                

                   

 

 

   Biaslessness(无偏性)

            

 

 

   Effectiveness(有效性)

           

 

 

   Consistency(一致性)

       

            

      It is equivalent to:

             

    

 

 

  Other Estimations

 

        Least MSE Estimation will minimize the MSE.

 

 

 

        Bayes Estimation will minimize the Mean of

         the following Cost:

            ,  or   

  

 

 

        Maximum Likelihood Estimation (MLE) will maximize

         the Likelihood Probability Density Function:

              f(x1, x2, ...,  xN|θ )

          

        Least Square Estimation (LSE) minimizes the

          sum of square of residual:

                    where  

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Classical PSD Estimation

 

   Autocorrelation自相关 method

          Wiener-Khinchin Theorem

        

          

 

 

   Periodogram周期图 method

         

             

 

   Averaged平均Periodogram method

         

                

 

   Smoothed Periodogram method

        

        

 

           w[m]: Anti-Leakage Window

 

 

 

 

 

   More Methods:

            Matlab Signal Processing Toolbox