Siemens RUGGEDCOM WiN5100, Руководство пользователя, Страница: 16 / 114

Chapter 2
Product Description
RUGGEDCOM WiN5100/WiN5200
User Guide
8 Space-Time Coding
Figure 3: MIMO Antenna System
Section 2.3.1.1
Space-Time Coding
Space-Time Coding (STC) is a technique for implementing transmission diversity. Mobile WiMAX uses transmit
diversity in the downlink direction to provide spatial diversity to enhance the signal quality to a specific subscriber
located anywhere within the range of the antenna beam. Although providing less signal gain than beam-forming,
transmit diversity is more robust for mobile users as it does not require prior knowledge of the path characteristics
of a subscriber’s particular frequency channel. One such STC technique, known as the Alamouti Code, was
published in 1998[4] is incorporated in the WiMAX 16e standard.