A Study on Frequency Diversity Using Lower Layer of LDM-BST-OFDM Transmission Scheme

• Main Authors: YAMAMOTO, Hiroto, NAKAMUR, Akira, ITAMI, Makoto
• Format: Conference Proceeding
• Language: English
• Subjects: Broadcasting; Diversity reception; Frequency diversity; OFDM; Receivers; UHDTV
• ISSN: 2158-4001
• DOI: 10.1109/ICCE46568.2020.9043078

Recently, the next-generation DTTB(Digital Terrestrial Television Broadcasting) for UHDTV (Ultra-High Definition Television) broadcasting is being researched and developed in the world. For the Japanese next-generation DTTB for UHDTV broadcasting, LDM-BST-OFDM(Layered Division Multiplexing - Band Segmented Transmission - Orthogonal Frequency Division Multiplexing) transmission scheme is proposed. Although LDM-BST-OFDM transmission scheme can be achieved good band utilization, dedicated receivers that can demodulate LDM-multiplexed symbols are required. Therefore, frequency diversity using lower layer of LDM-BST-OFDM transmission scheme is proposed in this paper. In the proposed scheme, coded bits for fixed reception which are transmitted in 26 segments excluding the central 9 segments are duplicated. After that, duplicated bits are modulated and LDM-multiplexed in the partial reception band. In the conventional fixed receivers which cannot demodulate LDM-multiplexed symbols, the stream for fixed reception can be decoded without LDM-multiplexed symbols. On the other hand, the performance is improved by maximum ratio combining using LDM-multiplexed symbols in the proposed receivers which can demodulate LDM-multiplexed symbols. In this paper, the reception characteristics of the proposed scheme is evaluated by computer simulations. As the results of the simulations, the required CNR(Carrier to Noise Ratio) of fixed reception can be improved by the proposed scheme.