Cristiano Akamine

Results of the ISDB-T system tests, as part of digital TV study carried out in Brazil

Since the year 2000, Mackenzie Presbyterian University has been carrying out lab and field tests to evaluate the performance of current DTV systems, with the aim of providing backing for the Brazilian Governments decision on the standard to be adopted. This paper presents the results of tests using the Japanese DTV system ISDB-T. Initially, the tests were done using a first generation prototype of the ISDB-T DTV set-top box. When DTV transmissions began in Japan in November 2003, the Brazilian tests were repeated using several new commercial set-top boxes. The main tests accomplished in 2000 were: measurement of the C/N ratio, behavior of the signal with multipath, Doppler effect and immunity to impulse noise. In 2003/2004, these tests were repeated using new receivers to analyze the evolution of the system. Furthermore, two new tests were introduced: resilience to phase noise and simultaneous transmission of two types of modulation in the same TV channel, in order to evaluate the band segmentation. Also, a one-segment DTV receiver (1STV) in a portable handset was tested in the laboratory.

Re-Multiplexing ISDB-T BTS Into DVB TS for SFN

The Single Frequency Network (SFN) allows a single TV channel to cover a great area in the same frequency, increasing the spectrum efficiency and signal quality. In this case, all the programs are re-multiplexed into a Transport Stream (TS) and distributed to the re-transmitter stations. The Integrated Digital Services Broadcasting-Terrestrial (ISDB-T) has been projected to operate in SFN, and uses a TS-adapted version called Broadcast Transport Stream (BTS). The BTS has a constant bit rate and packet size of 204 bytes. Owing to these characteristics, most network adapters are non compliant with this signal type. This article proposes a new re-multiplexer algorithm of the BTS signal that allows the encapsulation of the BTS into the Digital Video Broadcasting Transport Stream (DVB TS) and vice versa. This technique makes the BTS distribution possible through satellite, allowing the large SFN construction and accomplishing lesser bit rate than the original BTS.

Digital signal disturbed by impulsive noise

This paper presents and comments on test results and measurement procedures carried out mainly in the laboratory to investigate the degree of immunity of DTV reception in the presence of impulse noise. The objective of these tests was to compare the resilience to this type of noise provided by the DTV standards: ATSC, DVB-T and ISDB-T. The field test in the city of Sa/spl tilde/o Paulo, Brazil, showed a high and unforeseen rate of places presenting considerable degradation caused by impulsive noise. Previous studies do not reflect the reality of the impulse noise found in the Brazilian environment. Under these circumstances, a need arises for simulating interference conditions caused by ignition motors, hairdryers, blenders, etc, in the laboratory. Our laboratory tests utilized an impulse noise generator that was constructed especially to emulate ignition noise, but which was shown to be equally satisfactory in emulating other kinds of impulse noise. This paper also describes the operating principles and specifications of the impulse noise generator.

Field trial for Brazilian DTV using space diversity

This paper presents field tests results of High Definition Television (HDTV) mobile reception performance of an Integrated Services Digital Broadcasting-Terrestrial version B (ISDB-TB) receiver with space diversity. The diversity receiver hardware uses a commercial chip with a four branch maximal ratio combining (MRC) system. The tests were performed at the center of the UHF band using 64-QAM in urban, suburban, rural, and highway areas. During the tests the diversity receiver and a standard receiver performances were compared and the results showed that diversity reception would make HDTV mobile reception possible.

Field measurements for ISDB-T B in the VHF band

This paper presents field tests and analysis of the results of the fixed and mobile reception of Integrated Services Digital Broadcasting-Terrestrial version B (ISDB-TB) in the VHF band. A comparative analysis of DTV reception behavior in the VHF and UHF bands is presented.

Performance evaluation of Brazilian DTV mobile reception

This paper presents the tests of Brazilian Digital TV System (SBTVD) carried out to evaluate the performance on mobile reception conditions. The majority of digital television stations in Sao Paulo is configured with hierarchical modulation (one High Definition (HD) program and one Low Definition (LD) program). Considering these two programs, the main areas of São Paulo city area were evaluated and mapped, in order to show the places where the signal needs to be improved.

A proposal for the next generation of ISDB-Tb using FBMC in a SDR implementation on GNU radio environment

Digital TV standards are continuously evolving in order to provide users with livelier experiences. Nowadays, the trend in digital TV is to investigate the evolution of present systems to enable the transmission of 8K video programs. In order to do so, the physical layer of the system has to be adapted to be able to transmit the required bit rate. On the other hand, the modulation technique Filter Bank Multi Carrier (FBMC) has been widely studied in many communication systems, like 5G and WiMax, as a viable alternative to Orthogonal Frequency Multiplexing (OFDM). This fact stems from the better utilization of bandwidth (greater spectral efficiency) and more robustness to interferences in FBMC. This paper presents a study of the use of FBMC in Integrated Services Digital Broadcasting Terrestrial B (ISDB-TB), developing a complete software radio model on GNURadio, and accomplishing comparisons with the OFDM system. The GNURadio has been an important tool in order to simulate communications system, due to fact that it is a free and open source software, that allows analyzes and measurements in real time.

A proposal to use cloud transmission technique into the ISDB-T system

Cloud Transmission is a new broadcasting system, proposed to be used as the physical layer in the next-generation digital television, especially for the Advanced Television Systems Committee (ATSC) 3.0 system. Its principal benefits are spectral efficiency, robustness against noise, multipath and co-channel interference, besides maintaining compatibility with actual and future systems. Cloud Transmission is based on Layer-Division-Multiplexing (LDM), which provides to the system an increase of its robustness keeping the same data rates. This paper presents a performance analysis of an LDM transmitter/receiver, implemented in Software Defined Radio (SDR), using the same channel coder, interleavers, modulation and OFDM frame structure of Integrated Digital Services Broadcasting-Terrestrial (ISDB-T).

Implementation of ISDB-T LDM broadcast system using LDPC codes

This paper presents the scenario of terrestrial broadcast services, the challenges and needed adaptations for the next generation television. It shows promising technologies such as LDM, LDPC, NUC and their advantages in terms of increase of transmission rate, robustness and efficient use of spectrum. It also proposes an adapted ISDB-T system that uses LDM, LDPC, NUC and SDR technologies to increase performance and useful bit rate to DTV applications, while using a layer that would still be compatible with traditional ISDB-T system.

Comparison of Terrestrial DTV Systems: ISDB-TB and DVB-T2 in 6 MHz

The present paper completely discusses the ISDB-TB and the DVB-T2 systems. There are demonstrated the differences and similarities since BTS data entrance to ISDB-TB as well T2-MI to DVB-T2, up to base band generation. Tests for both broadcast television systems have been performed using 6 MHz of bandwidth. The tests procedure in laboratory used TOV (Threshold of Visibility) criteria under different transmissions parameters to ISDB-TB and DVB-T2. It was analyzed the TV interferences as sensibility performance, C/N threshold, Impulsive Noise and Multipath.