DTTB System Multipath Character Drawing on both the

DTTB System Multipath Character • Drawing on both the Field Trial data and the Laboratory test data this presentation seeks to explain some DTTB questions, particularly in the areas of static and dynamic multipath character. These questions are : (1) What is the minimum C/N required at various levels of echoes ? (2) What effect does Rx NF have on the C/N requirement ? (3) How does Flutter modify the C/N requirements ? (4) How does Impulse noise modify the requirements ? 1 1/10/2022 WTD

DTTB System Static Multipath Character (Conditions: Static multipath, Equal Rx NF, No Co-channel or impulse interference) C/N Threshold (d. B) Indoor Antenna 35 8 VSB COFDM (64 QAM, 2/3, 1/8) Picture (above curve) 19 15 0 1/10/2022 Outdoor Antenna 3 15 Multipath Level ( - d. B) WTD 30 No Picture (Below curve) 2 W. T. Dickson 29 March 98

Field Trial Multipath Character (Conditions: Static multipath, Equal Rx NF, No Co-channel or impulse interference) C/N Threshold (d. B) Indoor Antenna 35 8 VSB COFDM (64 QAM, 2/3, 1/8) 19 15 Picture (above curve) SYDNEY FIELD TRIAL TESTS 0 1/10/2022 Outdoor Antenna 3 15 Multipath Level ( - d. B) WTD 30 No Picture (Below curve) 3 W. T. Dickson 29 March 98

DTTB System Multipath Character - Unequal NF (Conditions: Static multipath, Unequal Rx NF, No Co-channel or impulse interference) C/N Threshold (d. B) Indoor Antenna 35 (31) 8 VSB With NF=(X+4)d. B COFDM With NF=Xd. B Picture (above curve) (64 QAM, 2/3, 1/8) 19 (15) 0 1/10/2022 Outdoor Antenna 3 15 Multipath Level ( - d. B) WTD 30 No Picture (Below curve) 4 W. T. Dickson 29 March 98

DTTB System Dynamic Multipath Character (Conditions: Dynamic multipath (flutter), Equal Rx NF, No Co-channel or impulse interference) C/N Threshold (d. B) Indoor Antenna 35 8 VSB w/o flutter 8 VSB with flutter Dependent upon flutter level (amplitude and doppler shift) COFDM (64 QAM, 2/3, 1/8) With or without flutter 19 15 0 1/10/2022 Outdoor Antenna 3 15 Multipath Level ( - d. B) WTD 30 Picture (above curve) No Picture (Below curve) 5 W. T. Dickson 29 March 98

DTTB System Impulse Noise Character (Conditions: Static multipath, Equal Rx NF, No Co-channel, but with impulse interference) C/N Threshold (d. B) Indoor Antenna 35 8 VSB COFDM With impulse noise Dependent upon level and character of impulse noise (up to 10 d. B higher than 8 VSB) Picture COFDM (above curve) (64 QAM, 2/3, 1/8) 19 15 0 1/10/2022 Outdoor Antenna 3 15 Multipath Level ( - d. B) WTD 30 No Picture (Below curve) 6 W. T. Dickson 29 March 98

DTTB System Multipath Performance Improvement (Conditions: Static multipath, Equal Rx NF, No Co-channel or impulse interference) C/N Threshold (d. B) Indoor Antennas 35 8 VSB COFDM (64 QAM, 2/3, 1/8) (Nov. 1997) COFDM Current implementations (April 1998) 19 15 0 1/10/2022 Outdoor Antennas 3 15 Multipath Level ( - d. B) WTD 30 Picture (above curve) No Picture (Below curve) 7 W. T. Dickson 16 April 98