Presentation is loading. Please wait.

Presentation is loading. Please wait.

An Initial Study on the Convergence of DVB-H and DTMB in the Physical Layer Feng Yang, Jian Song, Changyong Pan, Hui Yang, Kewu Peng, Jun Wang, Zhixing.

Similar presentations


Presentation on theme: "An Initial Study on the Convergence of DVB-H and DTMB in the Physical Layer Feng Yang, Jian Song, Changyong Pan, Hui Yang, Kewu Peng, Jun Wang, Zhixing."— Presentation transcript:

1 An Initial Study on the Convergence of DVB-H and DTMB in the Physical Layer Feng Yang, Jian Song, Changyong Pan, Hui Yang, Kewu Peng, Jun Wang, Zhixing Yang Dept. EE Tsinghua University

2 ChinaCom2007 ShangHai 2 Brief Introduction of MING-T MING-T = Multistandard Integrated Network convergence for Global Mobile and Broadcast Technologies Main Objectives of the Project … Incorporate both DVB-H and DTMB into the multi- standard framework.... from project management handbook Convergence of DVB-H and DTMB

3 ChinaCom2007 ShangHai 3 Brief Introduction of MING-T (Contd) Prototype using two demodulators However, single chip is more attractive!

4 ChinaCom2007 ShangHai 4 Comparisons of DTMB & DVB-H Randomization Similarities The same PRBS, the same initial state Differences Sync byte: DVB (untouched) DTMB (Randomized) Reset: DVB (every 8 TS) DTMB (every signal frame)

5 ChinaCom2007 ShangHai 5 Comparisons of DTMB & DVB-H (Contd) Forward Error Correcting (FEC) coding DVB-H : RS + Convolutional code RS(204,188) derived from RS(255,239) Convolutional codes : 1/2, 2/3, 3/4, 5/6, 7/8 DTMB : BCH + LDPC BCH(762,752) derived from BCH(1023,1013) LDPC with 3 code rates as the inner code

6 ChinaCom2007 ShangHai 6 Comparisons of DTMB & DVB-H (Contd) Interleaving Convolutional interleaving DTMB: B=52 M=240/720 DVB-H: B=12 M=17

7 ChinaCom2007 ShangHai 7 Comparisons of DTMB & DVB-H (Contd) Interleaving Block interleaving DVB-H in-depth interleaver (8k) DTMB frequency interleaver (4k)

8 ChinaCom2007 ShangHai 8 Comparisons of DTMB & DVB-H (Contd) Frame Structure C-OFDM : Process in Frequency domain Parameter refresh : 1ms; Signal lock : 100ms TDS-OFDM : Process in Time/Frequency domain Channel estimation : 0.56 ms; Signal lock : 5ms PN Data PN Data Signal Frame 500μs TDS-OFDM Copy CP Data+Pilot CP Data+Pilot Copy OFDM Symbol C-OFDM

9 ChinaCom2007 ShangHai 9 Comparisons of DTMB & DVB-H (Contd) Summary TDS-OFDM vs C-OFDM, Using PN brings Higher spectrum efficiency Faster channel synchronization BCH+LDPC vs RS+Convolutional code for better coding gain, therefore, lower E b /N 0 required for the same BER Larger coverage Better availability Long time-domain interleaver Better immunization to impulsive noise

10 ChinaCom2007 ShangHai 10 Receiver Algorithms & Convergence Considerations Synchronization Correlation approach DTMB: correlating with the known PN sequence DVB-H: guard interval correlation (pre-FFT syn.)

11 ChinaCom2007 ShangHai 11 Receiver Algorithms & Convergence Considerations (Contd) Channel estimation & equalization DVB-H: 8k FFT DTMB: 8k FFT (channel estimation) 3780 FFT (equalization)

12 ChinaCom2007 ShangHai 12 Receiver Algorithms & Convergence Considerations (Contd) De-interleaving Convolutional de-interleaver DTMB: B=52, M=720 DVB-H: B=12, M=17 Block de-interleaver DVB-H: 8K DTMB: 4K

13 ChinaCom2007 ShangHai 13 Receiver Algorithms & Convergence Considerations (Contd) FEC decoder DVB-H Convolutional code: Viterbi Algorithm (VA) RS code: syndrome computation, key-equation solver, Chien search and error evaluator DTMB (LDPC) Hard-decision : Bit-Flipping (BF) Soft-decision : Sum-Product Algorithm (SPA)

14 Thank you for your attention!


Download ppt "An Initial Study on the Convergence of DVB-H and DTMB in the Physical Layer Feng Yang, Jian Song, Changyong Pan, Hui Yang, Kewu Peng, Jun Wang, Zhixing."

Similar presentations


Ads by Google