Transmission parameters of ISDB-T, such as the modulation scheme and the coding rate of the inner code, are described in TMCC (Transmission and Multiplexing Configuration Control). So the transmission performance of TMCC is required to be superior to that of program signals. This paper describes the results of field transmission experiments of TMCC signal for ISDB-T in mobile condition. And we compare the transmission performance of TMCC with that of program signals. The results show that the TMCC decoding by using five all carriers in single segment acquires sufficient performance in model 1 of the narrow band ISDB-T system.
Video signals re-transmission or re-distribution systems using a millimeter-wave band has been studied recently. However, in the millimeter-wave band it is still difficult to create a stable local oscillator with low phase noise. Therefore it has been difficult to transfer signals with high-efficient digital modulation format like multi-point QAM signals. To solve such problems, we have proposed and developed the millimeter-wave self-heterodyne communication system. This paper reports the results of the experiment of 60GHz band transmission of a terrestrial digital broadcasting signal using the developed millimeter-wave self-heterodyne communication system.
Digital Terrestrial Television Broadcasting (DTTB) system adopted in Japan, uses Orthogonal Frequency Division Multiplexing (OFDM) modulation, and Spectrum Mask for OFDM modulation waves is defined. This Spectrum Mask is defined to coexist with adjacent analog television signal and adjacent digital television signal. When applied to the transmission network for relay system, the spectrum mask must be more stringent in performance depending on the required transmission characteristics. The effect exerted by the spectrum mask on the transmission characteristics of the adjacent channel is represented by the equivalent C/N. The relationship between the required transmission characteristics and the spectrum mask is studied, and findings obtained are described below.
It is important to clarify the manner in which the C/N degrades because of multi-step connection of the transmitters for construction of Digital Terrestrial Television Broadcasting network. It is well known that simple summing up of noise power suffices the purpose when there is Gaussian noise only. As far as the inter-modulation (IM) noise is concerned, it depends largely on the non-linearity of the transmitters to be multi-step connected. The relationship between the IM and C/N through multi-step connection is simulated. Findings from the simulation are described below.