3 : ATSC 3.0 (Jeongchang Kim et al.: Study on Synchronization Using Bootstrap Signals for ATSC 3.0 Systems) (Special Paper) 21 6, (JBE Vol. 21

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1 3: ATSC 3.0 (Jeongchang Kim et al.: Study on Synchronization Using Bootstrap Signals for ATSC 3.0 Systems) (Special Paper) 21 6, (JBE Vol. 21, No. 6, November 2016) ISSN (Online) ISSN (Print) ATSC 3.0 a), a), b), b) Study on Synchronization Using Bootstrap Signals for ATSC 3.0 Systems Jeongchang Kim a), Hyeongseok Kim a), Sung Ik Park b), and Heung Mook Kim b) ATSC 3.0 (bootstrap). ATSC 3.0. ATSC 3.0., (signal-to-noise ratio). Abstract In ATSC 3.0 systems, a bootstrap signal is located at the start of each frame. In this paper, we propose an initial synchronization scheme for ATSC 3.0 systems using the bootstrap signal. The bootstrap signal of ATSC 3.0 has several repetition patterns in the time domain. By utilizing the repetition patterns within the bootstrap, the proposed scheme can obtain an initial synchronization at the receiver. Also, simulation results show that the proposed scheme can obtain an initial synchronization at very low signal-to-noise ratios. Keyword : Advanced Television Systems Committee (ATSC) 3.0, bootstrap, orthogonal frequency division multiplexing (OFDM), synchronization a) (Division of Electronics and Electrical Information Engineering, Korea Maritime and Ocean University) b) (Broadcasting Systems Research Department, Electronics and Telecommunications Research Institute (ETRI)) Corresponding Author : (Jeongchang Kim) jchkim@kmou.ac.kr Tel: ORCID: [R ( )] Manuscript received September 12, 2016; Revised November 7, 2016; Accepted November 16, Copyright 2016 Korean Institute of Broadcast and Media Engineers. All rights reserved. This is an Open-Access article distributed under the terms of the Creative Commons BY-NC-ND ( which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited and not altered.

2 (JBE Vol. 21, No. 6, November 2016)., [1-3] ATSC (Advanced Television Systems Committee) 2013 ATSC 3.0 [1][2] ATSC 3.0 System Discovery and Signaling (A/321) [4], ATSC 3.0 (A/322) [5]. ATSC 3.0 (bootstrap) (preamble) (subframe). ATSC 3.0.,. ATSC 3.0 ATSC 3.0. ATSC 3.0 (initial synchronization). [6] [7]., [6]. DVB-T2 P1 2 (correlator). [7] [6] (fractional frequency offset)., [6] [7] (correlation length) (signal-to-noise ratio: SNR). ATSC (correlation peak) (phase)..,. SNR.. 2 ATSC 3.0, 3. 4, ATSC 3.0 [3]. Zadoff-Chu (ZC) (pseudo-noise: PN). ZC (1)., ZC root (major version), ZC.

3 3: ATSC 3.0 (Jeongchang Kim et al.: Study on Synchronization Using Bootstrap Signals for ATSC 3.0 Systems) Sequence Generator root seed ZC Generator PN Generator Subcarrier Mapping & Zero Padding IFFT Cyclic Shift & Termination CAB & BCA Structure Construction 1. ATSC 3.0. Fig. 1. ATSC 3.0 bootstrap sequence generator. 2. Fig. 2. Pseudo-noise sequence generator PN 2 =16 linear feedback shift register (LFSR). PN seed (minor version) PN 1. PN Table 1. Initial register state of the PN sequence generator for bootstrap minor versions Initial register state Bootstrap minor version Binary Hexadecimal x019D x00ED x01E x00E x00FB x x x00EC. 0 PN 1. ZC PN (subcarrier) DC 749., DC 0., 749 (negative) 749 (positive). ATSC ZC., PN , 749 PN 749 ZC., PN DC 749 ZC..

4 (JBE Vol. 21, No. 6, November 2016) otherwise, PN IFFT (inverse fast Fourier transform). (cyclic shift) termination., CAB BCA. 2. ATSC OFDM (or- thogonal frequency division multiplexing).,. IFFT (=log ). (relative cyclic shift) (absolute cyclic shift).., (5) (Gray code mapping).. mod., (6)., 0. mod, ATSC 3.0., FFT. IFFT, (7). mod., DC ATSC 3.0 OFDM. 3 A IFFT, B C A. A, B, C, 500.

5 3: ATSC 3.0 (Jeongchang Kim et al.: Study on Synchronization Using Bootstrap Signals for ATSC 3.0 Systems) 2. OFDM Table 2. OFDM parameters Item Value FFT Size ( ) 2048 Length of parts A, B and C 2048 / 504 / 520 Guard subcarriers 550 (including DC subcarrier) Used subcarriers 1498 OFDM sample duration ( ) 1/6.144 MHz ( ) Subcarrier spacing ( ) Occupied bandwidth OFDM symbol duration (a) 3 khz 4.5 MHz 0.5 ms (8)., OFDM., 3(b) BCA. A IFFT. A 520 A C, A (C 504 ) B. (9). 3 B C.. (b) 3.. (a) CAB (b) BCA. Fig. 3. Structures of bootstrap symbols in the time domain. (a) CAB structure (b) BCA structure 3(a) CAB. A 520 C, 504 (C 504 ) + B., 3 khz. (local oscillator)., (Doppler shift). OFDM..,.

6 (JBE Vol. 21, No. 6, November 2016), (additive white Gaussian noise: AWGN). (auto-correlation) [8-10]. 3 CAB BCA B C., CAB BCA. 4., 4(a). A C. 4(b). (a) (b) (c) 4.. (a) (b) (c) Fig. 4. Repetition patterns of the bootstrap signal in the time domain. (a) sample distance (b) sample distance (c) sample distance

7 3: ATSC 3.0 (Jeongchang Kim et al.: Study on Synchronization Using Bootstrap Signals for ATSC 3.0 Systems) A B., C B. 4(c). C B., A (, BCA A B ) B. 4 SNR., 4 (timing metric). 5 4., 5 4(a). A (11).. Received samples r( k) (NA) ( ) * Moving Average (NC) CorrA( m) (NSYM) Summation (NSYM) (NSYM+NB) CorrS, A( m) 1/4 ( ) * Corr2( m) Ð j 2 f t e p D (NB) ( ) * Moving Average (NB) Corr ( ) B m (NSYM) - Summation (NSYM) (2NB) CorrS, B ( m) 1/4 (NA) ( ) * (NC-NB) Corr1( m) (NA+NB) ( ) * Moving Average (NB) CorrA + B ( m) (NSYM) - Summation (NSYM) (NA+2NB) CorrS,A + B ( m) 1/4 5. Fig. 5. Structure of correlators for an initial synchronization

8 (JBE Vol. 21, No. 6, November 2016) (11) 4(a) C.. C CAB BCA.,,, 5 summation 4 4 SNR. (12) (12). 5 4(b). A C (13). (13) 4(b) B.. 4(b), CAB B A., BCA B C.,,, 5 summation 4 4 SNR. (14) (14)., BCA B A.,

9 3: ATSC 3.0 (Jeongchang Kim et al.: Study on Synchronization Using Bootstrap Signals for ATSC 3.0 Systems). 5 4(c). C A (15). (15) 4(c) B..,, CAB B C., BCA B A.,,, 5 summation 4 4 SNR. (16) (16) (12) (14)., (14).,,,,.,., (17).,. (11), (12).,., (18)

10 (JBE Vol. 21, No. 6, November 2016).,.,.,.,.. 6(a) AWGN SNR=-3dB,,.. 6(b) AWGN SNR=-13dB,,. SNR=-13dB.,, 520, 504, 504 SNR SNR. 7 AWGN,,. 4 4 SNR.,, 6(a),, 7(a)., 6(b) 7(b) SNR. (a) (b) 6.,,, AWGN. (a) SNR=-3dB (b) SNR=-13dB Fig. 6. Snapshot of correlator outputs,,, AWGN. (a) SNR=-3dB (b) SNR=-13dB

11 3: ATSC 3.0 (Jeongchang Kim et al.: Study on Synchronization Using Bootstrap Signals for ATSC 3.0 Systems) (a) (b) 7.,,, AWGN. (a) SNR=-3dB (b) SNR=-13dB Fig. 7. Snapshot of correlator outputs,,, AWGN. (a) SNR=-3dB (b) SNR=-13dB (a) (b) 8.,,, AWGN. (a) SNR=-3dB (b) SNR=-13dB Fig. 8. Snapshot of correlator outputs,,, AWGN. (a) SNR=-3dB (b) SNR=-13dB 8 AWGN (17), (18) [6][7],,. DVB-T2 P1 CAB. [6] [7] 5 (21). 8(a),,. SNR=-3dB

12 (JBE Vol. 21, No. 6, November 2016) (peak-to-average ratio: PAR),, PAR=47.9, 87.6, PAR. 8(b) SNR=-13dB,,. SNR=-13dB. SNR Rayleigh (RL20) [11] SNR=-3dB,,.,, PAR=34, 67.8, 19. PAR., AWGN PAR. 9.,,, RL20, SNR=-3dB. Fig. 9. Snapshot of correlator outputs,,, RL20, SNR=-3dB. 10 AWGN RL20 [7] (mean square error: MSE). MSE. (a) (b) 10. (a) AWGN (b) RL20 Fig. 10. Mean square error of the estimated FFO (a) AWGN (b) RL20

13 3: ATSC 3.0 (Jeongchang Kim et al.: Study on Synchronization Using Bootstrap Signals for ATSC 3.0 Systems) SNR.. ATSC 3.0. ATSC 3.0..,. SNR. (References) [1] A global approach to the future of terrestrial television broadcasting, Future of Broadcast television (FoBTV) Summit Joint Declaration, Nov. 11, [2] ATSC Technology Group 3.0, Call for proposals for ATSC 3.0 physical layer a terrestrial broadcast standard, Mar. 26, [3] J. Kim, S. I. Park, and H. M. Kim, A study on performance analysis for terrestrial cloud transmission systems, Journal of Broadcasting Engineering, vol. 20, no. 2, pp , Mar [4] ATSC, ATSC Standard: A/321, System Discovery and Signaling, Doc. A/321:2016, 23 March [5] ATSC, ATSC Standard: Physical Layer Standard (A/322), Doc. A/322:2016, 7 Sept [6] K.-S. Ok, I.-W. Kang, H. J. Kim, Y. Kim, J. H. Seo, H. M. Kim, and H.-N. Kim, Frame synchronization method by detecting bootstrap signal for ATSC 3.0, in Proc. of KICS 2015 Autumn, pp , Nov [7] H. J. Kim, J.-Y. Lee, I.-W. Kang, K.-S. Ok, Y. Kim, J. H. Seo, H. M. Kim, and H.-N. Kim, Estimation fractional-frequency offset in the ATSC 3.0 systems using bootstrap symbol, in Proc. of KICS 2016 Winter, pp , Jan [8] S. I. Park, H. M. Kim, Y. Wu, L. Zhang, N. Hur, and J. Kim, Robust synchronization for the OFDM-based cloud transmission system, in Proc. of BMSB 2013, London, UK, June [9] T. M. Schmidl and D. C. Cos, Robust frequency and timing synchronization for OFDM, IEEE Trans. Commun., vol. 45, no. 12, pp , Dec [10] J. C. Kim, S. I. Park, and H. M. Kim, Initial timing acquisition algorithm for terrestrial cloud transmission systems, in Proc. of KICS, vol. 39C, no. 9, pp , Sep [11] L. Polak and T. Kratochvil. "Simulation and measurement of the transmission distortions of the digital television DVB-T/H Part 3: Transmission in fading channels," Radioengineering, vol. 19, no. 4, pp , Dec : () : () : () ~ : ~ : ~ : ~ : - ORCID : - :,,, MIMO

14 (JBE Vol. 21, No. 6, November 2016) : () - ORCID : - :,, IoT : () : () : () ~ : ~ : IEEE Transactions on Broadcasting ~ : IEEE Distinguished Lecturer - :,, : () : () : () ~ : ~ : ~ : - ORCID : - : RF,, DTV