19-GHz high-speed wireless LAN system; VJ25 system

This paper describes a new high-speed wireless LAN system in the 19-GHz band based on the RCR STD-34A Japanese radio system standard. This system consists of a control module (CM) and some user modules (UMs). One CM can communicate with up to 10 UMs. This system features a maximum throughput of 15.2 Mbit/s, which is faster than Ethernet's. To achieve high speed wireless data transmission, this system adopts GSMA (Global Scheduling Multiple Access), in which all data transmission is managed in the CM, and DQPSK is used as a modulation scheme. This GSMA has both short-length and long-length frames, and performs well with light traffic and heavy traffic with minimal delay. In addition, as a countermeasure to shadowing and multipath fading, the CM has an omni-beam antenna and each UM uses a 12-sector antenna, and sector selection diversity is carried out at the UM.