1. Turbo-synchronization

2. Friday, March 19 2004 Sébastien de la Kethulle de Ryhove – Turbo-synchronization Introduction Communication systems based on the turbo principle Remarkable performances Ideal synchronization

3. Friday, March 19 2004 Sébastien de la Kethulle de Ryhove – Turbo-synchronization Transmission System

4. Friday, March 19 2004 Sébastien de la Kethulle de Ryhove – Turbo-synchronization The Turbo Principle Compute soft information on the transmitted symbols using an iterative receiver

5. Friday, March 19 2004 Sébastien de la Kethulle de Ryhove – Turbo-synchronization Soft / Hard Information Hard approach Soft approach

6. Friday, March 19 2004 Sébastien de la Kethulle de Ryhove – Turbo-synchronization The Turbo Principle Applicable to a wide variety of problems: –Decoding: Turbo-decoding –Decoding + equalization: Turbo-equalization –Decoding + demodulation: Turbo-demodulation –… Turbo detection

7. Friday, March 19 2004 Sébastien de la Kethulle de Ryhove – Turbo-synchronization Example: Turbo-demodulation Transmitter

8. Friday, March 19 2004 Sébastien de la Kethulle de Ryhove – Turbo-synchronization NSC Encoder

9. Friday, March 19 2004 Sébastien de la Kethulle de Ryhove – Turbo-synchronization Grouping and Mapping

10. Friday, March 19 2004 Sébastien de la Kethulle de Ryhove – Turbo-synchronization Example: Turbo-demodulation Receiver – Exchange of soft information

11. Friday, March 19 2004 Sébastien de la Kethulle de Ryhove – Turbo-synchronization Synchronization Find estimates for –The carrier frequency –The carrier phase –The sampling time

12. Friday, March 19 2004 Sébastien de la Kethulle de Ryhove – Turbo-synchronization Synchronization Classical receiver

13. Friday, March 19 2004 Sébastien de la Kethulle de Ryhove – Turbo-synchronization Turbo-synchronization Soft receiver

14. Friday, March 19 2004 Sébastien de la Kethulle de Ryhove – Turbo-synchronization Soft Synchronization – Example Traditional DD synchronization Soft DD synchronization

15. Friday, March 19 2004 Sébastien de la Kethulle de Ryhove – Turbo-synchronization Algorithm: Soft Phase Synchronization Initialize /* many possibilities */ do { Correct the phase of the received sequence Perform one soft det./dec. iteration on the corrected sequence Find a new estimate for using the newly obtained soft information } while ( changes a lot) /* Continue with detection / decoding */

16. Friday, March 19 2004 Sébastien de la Kethulle de Ryhove – Turbo-synchronization BER Performance Phase offset [degrees] BER BER Performance vs. Phase Offset for a Turbo Coded system

17. Friday, March 19 2004 Sébastien de la Kethulle de Ryhove – Turbo-synchronization Mean Estimated Phase Offset Phase offset [degrees] Mean Estimated Phase Offset [degrees]

18. Friday, March 19 2004 Sébastien de la Kethulle de Ryhove – Turbo-synchronization Estimator Variance Phase offset [degrees] Estimator Variance [degrees 2 ]

19. Friday, March 19 2004 Sébastien de la Kethulle de Ryhove – Turbo-synchronization BER Performance Phase offset [degrees] BER

20. Friday, March 19 2004 Sébastien de la Kethulle de Ryhove – Turbo-synchronization Estimator Variance Phase offset = 30 degrees Estimator Variance [degrees 2 ] E b / N 0 [dB]

21. Friday, March 19 2004 Sébastien de la Kethulle de Ryhove – Turbo-synchronization Performances – Acquisition BER Preamble: 7 16-QAM symbols E b / N 0 [dB]

22. Friday, March 19 2004 Sébastien de la Kethulle de Ryhove – Turbo-synchronization Conclusions Performance enhancement –Synchronization algorithms –Overall system Encouraging results