Digital terrestrial broadcasting has characteristics that provide a robust resistance to noise and disturbances caused by reflected radio waves, which would look like ghost images in the case of analog broadcasting. These features, together with digital signal processing, allow us to make reception feasible at locations where reception would otherwise have been difficult due to interference, and to receive HDTV signals in a car.
Long-delay multipath equalization technology
While digital terrestrial broadcasting signals have good resistance to multiple interference waves coming from single frequency network (SFN) stations or reflected waves (multipath), an interference wave arrival time difference in excess of the signal tolerance (guard interval) drastically increases the error rate, sometimes making reception impossible. To solve this problem, this reception system is equipped with a function that equalizes any long-delay multipath that may be included in the received signal. It properly receives broadcast waves by detecting and equalizing multipath waves that arrive after the guard interval. (Figure 1)
Diversity reception system for mobile reception
We are developing a technology that will allow a user to receive broadcasting services designed for a home receiver on a mobile receiver instead. Multiple antennas can be installed on the roof of a car to receive and appropriately combine the received HDTV broadcasting signals. Although its reception coverage area will be slightly smaller, due to the weaker radio waves received at the lower car antennas in comparison with a building's rooftop antenna, it is expected to be a technology that will further enhance the attractiveness of digital broadcasting. (Figure 2)
