1. ADSL Equalization Van Herck Hans Verheyden Jonas

2. Content Implementation of theoretical schematic Optimisation algorithm (LMS) Simulation results

3. QAM demod decoder S/P quadrature amplitude modulation (QAM) encoder mirror data and N -IFFT P/S D/A + transmit filter N -FFT and remove mirrored data S/P TRANSMITTER RECEIVER N/2 subchannelsN real samples N/2 subchannels receive filter + A/D 00110 Bits P/S

4. QAM demod decoder S/P quadrature amplitude modulation (QAM) encoder mirror data and N -IFFT add cyclic prefix P/S D/A + transmit filter N -FFT and remove mirrored data S/P remove cyclic prefix TRANSMITTER RECEIVER N/2 subchannelsN real samples N/2 subchannels receive filter + A/D 00110 Bits channel P/S

5. Real channel

6. QAM demod decoder invert channel = FEQ S/P quadrature amplitude modulation (QAM) encoder mirror data and N -IFFT add cyclic prefix P/S D/A + transmit filter N -FFT and remove mirrored data S/P remove cyclic prefix TRANSMITTER RECEIVER N/2 subchannelsN real samples N/2 subchannels receive filter + A/D 00110 Bits channel P/S

7. QAM demod decoder invert channel = FEQ S/P quadrature amplitude modulation (QAM) encoder mirror data and N -IFFT add cyclic prefix P/S D/A + transmit filter N -FFT and remove mirrored data S/P remove cyclic prefix TRANSMITTER RECEIVER N/2 subchannelsN real samples N/2 subchannels time domain equalizer (FIR filter) receive filter + A/D 00110 Bits channel P/S

8. Transmitter

9. Channel and TEQ

10. Receiver

11. TEQ Determine W and B through different algorithms Choose length W and B Goal: h ∗ w shorter than h z-z- h + w b - xkxk rkrk ekek nknk + TIR TEQCIR

12. Least Mean Squares z-z- h + w b - xkxk rkrk ekek nknk + TIR TEQCIR

13. Simulation results More or less ideal channel

14. Simulation results Real channel

15. Simulation results Influence CP

16. Optimised LMS (FSTEQ) Every iteration step: B = FFT(b) Check if B lies between boundaries Scale if needed New b = IFFT(B)

17. Conclusion Implementing TEQ doesn’t reduce error percentage, but does increase efficiency Still errors in received symbols: error coding is needed

18. Questions?