Kazuyuki Takahashi

The ATSC Link-layer Protocol (ALP): Design and Efficiency Evaluation

In this paper, a novel data link layer protocol adopted in the ATSC 3.0 terrestrial broadcast standard is described. The data link layer is a protocol layer between the physical layer and the network layer. The data link layer transports data from the network layer to the physical layer at the sending side and transports data from the physical layer to the network layer at the receiving side. The data link layer protocol in ATSC 3.0 is called the ATSC link-layer protocol (ALP). The major function of ALP is to take multiple input formats, not only IP packets but also legacy broadcast formats such as MPEG-2 TS packets, and output them in a common format to the physical layer. ALP provides overhead reduction mechanisms to achieve efficient transmission, particularly the compression of IP/UDP packet headers. The protocol and operation of ALP, as well as efficiency analysis and evaluation of ALP are presented.

Development of a plastic objective Lens for BD/DVD/CD compatibility

We have developed a single plastic objective lens compatible with BD/DVD/CD systems. This objective lens has a self NA control function and shows favorable reading characteristics.

Terrestrial broadcast system using preamble and frequency division multiplexing

Broadcast systems based on FDM (Frequency Division Multiplex) have the advantage of near continuous demodulation of the broadcast signal, allowing accurate and continuous tracking of channel conditions which is particularly useful for mobile reception. This has been employed in the ISDB-T standard used in Japan, Brazil and other countries. However, as designed in ISDB-T the broadcast signal lacks the ability to send system parameters such as FFT size, GI size and so on before the receiver begins demodulation. The receiver must blindly estimate such system parameters before it can read the other detailed parameter information using the TMCC pilot carriers. This takes time, usually one frame or longer. This paper proposes a next generation FDM system which enables the original advantages of FDM to be retained, while allowing additional advantages by employing an additional small signal (Preamble 1) which imparts essential information such as FFT size, GI size and pilot pattern to the receiver to enable immediate demodulation of the broadcast signal based on known parameters rather than blind estimation. Following demodulation of the first preamble, demodulation of the second preamble (Preamble 2) allows immediate knowledge of the all subsequent parameters contributing to faster demodulation of the overall signal.