Masafumi Saito

Transmission System for ISDB-T

The Association of Radio Industries and Businesses in Japan decided the specifications for a digital terrestrial broadcasting system called ISDB-T in 1998. The ISDB-T transmission system is recommended in ITU-R Recommendation BT.1306. Planning criteria of the ISDB-T system are recommended in ITU-R Recommendation BT.1368. This paper describes the transmission scheme of the ISDB-T system. First, it explains features of the ISDB-T system. Second, it describes transmission systems such as modulation, error correction, orthogonal frequency division multiplexing framing, transmission and multiplexing configuration control, guard interval, etc. Finally, it concludes discussion of the ISDB-T transmission system and describes transmission parameters used in Japan.

A digital modulation method for terrestrial digital TV broadcasting using trellis coded OFDM and its performance

OFDM (orthogonal frequency division multiplexing) is regarded as an excellent digital modulation method for various future digital broadcasting systems, including digital audio broadcasting (DAB). The scope of applications of the OFDM can be further expanded by combining it with TCM (trellis coded modulation). This TCM-OFDM system can transmit a much larger number of data than conventional OFDM, causing almost no degradation of bit error rate performance within the same frequency bandwidth. The concept of the TCM-OFDM system for terrestrial digital TV broadcasting and a system configuration that needs no carrier recovery at the receiver and gives simulation results of the bit error rate performances under various receiving conditions are described.<<ETX>>

A Hierarchical OFDM System for Mobile Reception and Single Frequency Networks

It is desirable that digital terrestrial broadcasting systems provide services not only to fixed receivers through single frequency networks (SFN) but also services to mobile receivers. This paper studies suitable values for the OFDM parameters of SFNs and mobile receivers respectively, and it proposes a new OFDM technique called MSL-TDM (Multi-Symbol-Length Time Division Multiplexing) which multiplexes symbols of different lengths for mobile and fixed reception. By using MSL-TDM, we can construct both large scale SFNs and mobile receivers simultaneously on a single transmission channel. This paper presents the concept of MSL-TDM and it provides an outline of an experimental modem. It also describes some results obtained from indoor experiments. These indicate that the system works well in both Gaussian and Rayleigh channels. There was no difference in results measured by one hierarchical transmission and two hierarchical transmission.