1. A Synchronization Technique to Model Output Behavior of Wide Bandwidth Signals Efrain Zenteno & Magnus Isaksson Center for RF measurement Technology, University of Gävle, Sweden Signal Processing Lab, The Royal Institute of Technology, KTH, Stockholm, Sweden RFMTC 2011, Gävle, October, 2011

2. Agenda Introduction (Why is synchronization needed it?) Challenges when modeling large bandwidth signals Approach Results Conclusions

3. Introduction 1.Larger bandwidths are required for newer communication systems. 2.Weakly non-linear devices cause spectrum widening ……( larger for larger bandwidths) 3.Larger bandwidths poses challenges into the measurement systems, modeling and validation.

4. Set up Description

5. Synchronization ? Adquisition in different time. (periodic signals) Sub-sample.

6. Defining.. Fourier Transform: Measured output Error : that produces the lowest modelling error.

7. Model Gp’s are FIR systems

8. Approach “Including the estimation of the delay (  ) into the identification procedure ” Problems: Nonlinear. High dimensionality.

9. The problem: Linear model parameters Nonlinear delay estimation. (separable least squares) Now use this solution The error function depends of only one variable (  ).

10. Effect of 

11. Newton Search 1.Initial Cross-correlation search (integer D) 2.Newton search on D + k, k = -5, -4, -3,…, 3, 4, 5

12. Results

15. Conclussions A synchronization technique to model output behavior of parallell Hammerstein system is presented. With the same model complexity, the search method, performs better (in NMSE) than similar methods to find the synchronization.

16. Thanks Questions ?