Philippine digital television (DTV) transition: Technical challenges based on actual digital and analog terrestrial television transmission scenario

The main factor in television broadcast system planning is the accurate estimation of the received signal strength with deep understanding of the characterization of the channel. The planning based on actual scenario through field measurements is required for more reliable characterization. This paper presents path loss models based on characterization conducted for antenna heights of 10m and 2m both for fixed reception of analog and digital TV signals around Metro Manila. Actual field measurements were done to 42 locations. 7 TV channels were considered in the study including 3 digital channels (32, 42 and 43) and 4 analog channels (31, 33, 37 and 41). Field strength as well as bit error rate (BER) for digital channels were captured to help for the characterization of the given channels. Curve fitting, using fminsearch algorithm, and multiple regression were used to derive the statistical model and come up with the model, Path Lloss= - 963 + 40.1 log distance (km) + 377 log Frequency (MHz) - 0.988 Antenna height (m). Compared to other outdoor models such as COST-321, ECC-33 and Free Space Path Loss, the derived statistical model has better prediction performance arriving with smallest value of root mean square error equal to 14.98 and 10.87 mean absolute percentage error. Also, protection ratio has been determined between adjacent digital TV channels in order to prevent possible adjacent channel interference. Curve fitting of BER vs. Protection ratio was used to come up with the Protection Ration equal to -10.26 dB. The result of this research can be used by TV broadcasters as well as the government regulating agency (NTC) in planning transmitter location during transition to Digital Television