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Wenting CHANG Jintao WANG Changyong PAN Zhixing YANG
In order to realize multi-service in TDS-OFDM system, a novel multiplexing scheme based on space time block code is proposed along with the corresponding demultiplexing method with low complexity. Simulations show the presented scheme can not only achieve full diversity gain, but also effectively improve the system capacity.
Hideo KAWATA Hirotaka NAKAMURA Toshihiko SUGIE
This paper proposes the technology of wide passband wavelength-division multiplexing (WWDM) for access networks offering multiplexed services. The technology greatly relaxes the wavelength setting accuracy requirements of the WDM light source and the multiplexer/demultiplexer (MUX/DEMUX) compared to dense WDM (DWDM) technology. A WWDM optical converter that offers the Internet protocol (IP) service is implemented and its performance assessed at temperatures ranging from 0C to 45C. In addition, we assess three channel transmission (cable television (CATV) and IP services) in the 1.5 µm region as a multiplexed service example. Using the proposed WWDM, we confirm the feasibility of a service multiplexing system that offers simultaneous CATV and IP services in access networks. This WWDM technology is expected to provide cost effective service multiplexing systems for access networks.
Naoki KAWAI Kouji OHSAKI Takeshi KIMURA Seiichi NAMBA
We discuss ISDB (Integrated Services Digital Broadcasting) which has a transport structure to meet the technical requirements such as the flexibility and the extensibility of broadcasting in the future. The basic configuration of the ISDB transmission signal for distribution into various transmission channels is shown. Hybrid multiplexing, which uses common fixed-length packets and structured transmission units called "slots," is introduced to construct a transmission signal for low-cost signal processing in ISDB receivers. We show that a fixed packet length of 40-240 bytes results in high transmission efficiency in a diverse range of service arrangements. Furthermore, we use transmission control methods, which show the relationship between programs and packet IDs, to select the desired program with certainty and ease.