The core technology of the system is COFDM Coded Orthogonal Frequency Division Multiplexing modulation and demodulation techniques, namely multi-carrier modulation and demodulation technology. This is a new digital modem technology. Its the most prominent feature is to ensure the stability transmission in the high-speed mobile and multi-path interference (The mobile speed is up to 170 km / h). The terrestrial digital video and audio signal can transmit without interference and distortion as the same as optical fiber or cable. With the different amplifiers, it can transfer 20km to 50km under the conditions .
COFDM signal is composed of a number of orthogonal carriers. Each carrier is modulated COFDM signal has a longer cycle compared with the same data rate the single-carrier technology. So the technology has a strong anti-multipath the decline of performance. The signal can ensure the higher transmission quality in the complex environment (a high-rise building, city) .
