This research improves both capacity and reliability for Digital Terrestrial Television Broadcasting (DTTB) systems. In order to realize 4K ultra high definition television for wireless broadcasting, a higher transmission capacity and additional bandwidth spectrum are essential. However, an issue of spectrum scarcity will be realize because of the existence of first generation Integrated Services Digital Terrestrial Broadcasting - Terrestrial (ISDB-T). To solve the problem, the researcher proposed a Layered Division Multiplexing (LDM) scheme to simultaneously transmit ISDB-T stream and secondary data stream for the next generation DTTB over a common frequency band.
An additional contribution was realized by the proposal of low complexity compressed sensing (CS) based channel estimation (CE) with virtual oversampling for ISDB-T. The proposed CE is prone to fractional delay, and only requires less computational cost in estimating the channel. Fractional delay is common issue due to sampling imperfection of channel delay time and can only be detected using oversampling. However, oversampling can increase the signal bandwidth. In this scheme, the increase of signal bandwidth can be avoided because it is only "virtual oversampling".
With these contributions, it is expected to realize an additional transmission capacity enough for 4K transmission of next generation DTTB system without requiring additional bandwidth. In addition, the reliability improvement can be achieve where bit error rate (BER) performance of the proposed system is less error compared to conventional channel estimator for DTTB system. Numerical analysis of BER and computational complexity are given to verify the effectiveness of the proposed scheme.