Yoichi Suzuki

Performance evaluation of transmission system for 8K Super Hi-Vision satellite broadcasting

We developed a new transmission system for 8K Super Hi-Vision satellite broadcasting in Japan. This system has a transmission capacity of over 100 Mbps in a single 34.5MHz satellite transponder. The key technical feature of the new system are lowering roll-off factor to 0.03 and using 16APSK and LDPC code with a coding rate of 7/9. To confirm the transmission performance in a satellite channel, we conducted indoor transmission tests and transmission tests using Japanese communication and broadcasting satellites. This paper shows the transmission performance of this system and similar performance was obtained in indoor-transmission and satellite-transmission tests.

Comparison of Measured Rain Attenuation in the 12-GHz Band with Predictions by ITU-R Methods

The rain attenuation in the 12-GHz band and one-minute-rain rate were measured in Tokyo over a four-year period (2000-2003). The statistical characteristics of this data are presented. The one-minute-rain rates at 0.01% of time percentage of year in Tokyo and Osaka are compared to other past and recent values. The comparison of measured rain attenuation in the 12-GHz band in Tokyo and Osaka with prediction by ITU-R methods is conducted. The root-mean-square prediction error of rain attenuation for the prediction by ITU-R Rec.P.618 is evaluated. Convective rain cell effects can be seen in the scatter diagram of one-minute-rain rate and rain attenuation. However, it is found that the effect is not properly accounted for by the slant path length adjustment factor of P.618-8. A reliable rain attenuation prediction requires some revisions of the slant path length adjustment factor with taking local weather characteristics into account for the P.618-8.

Study on equalization system using transponder characteristics to compensate for non-linear distortion

In a new satellite broadcasting standard (ARIB STD-B44 ver.2.0) in 2014, 16APSK modulation schemes and a roll-off factor of 0.03 were adopted. Aiming at improving the transmission performance for 16APSK over satellite, we have developed an equalization technique using satellite transponder characteristics. We report the effect of this technique for 16APSK at each Output Back Off.

Development of a wide-band modem for a 21-GHz band satellite broadcasting system

A next-generation satellite broadcasting system using the 21-GHz band (21.4-22.2 GHz) allocated for satellite broadcasting is expected to provide large-capacity advanced broadcasting services. To use the 21-GHz band, higher output power to compensate for rain attenuation and protection of the radio astronomy band are required. We report the design and prototype of a 300-MHz class wide-band modulator-demodulator (modem) for use with the 21-GHz band satellite broadcasting system. The prototype modem is evaluated for signal characteristics and transmission performance with intermediate frequency connection.

Study on non-linear compensation technique based on signal point error estimation over satellite transponder

We are studying 16APSK and 32APSK, which can transmit more HDTV programs per channel or be applied for high quality services beyond HDTV. Multi-level modulations such as these APSK schemes are vulnerable to the non-linear distortion of a satellite transponder. We propose a compensation technique for estimating the signal point error vectors over a satellite simulator in advance and compensating for the error vectors of each signal point at the transmitter. We report on both 16APSK and 32APSK performances in terms of the required C/N and optimum operating point of the traveling wave tube amplifier (TWTA) by using a computer simulation on the effect of this compensation technique.

A Study of Adaptive Equalizer for APSK in the Satellite Broadcasting System

By making use of LDPC codes and a smaller roll-off factor, the advanced satellite broadcasting system proposed by us has a 30% higher transmission channel capacity in comparison with the current ISDB-S system. In addition, the transmission channel capacity can be more increased by using multi-level amplitude phase shift keying (M-APSK) modulation. However, the APSK signal is more sensitive to the non-linear distortion. Hence, a careful consideration for APSK should be paid for transmission over a satellite channel. In this paper, we report on adaptive equalizers that are designed for APSK transmission over a satellite channel. We also report on computer simulation results of equalized 16/32APSK performances under a satellite channel model and discuss the equalization effect for the advanced ISDB-S system transmission format.