Anritsu Spectrum Master MS2720T, Руководство пользователя

Страница: 844 / 1035

3GPP2 MG PN: 10580-00235 Rev. D 3-1
Chapter 3 — EVDO Signal Analyzer
3-1 Introduction
The instrument offers three EVDO measurement options:
• CDMA2000 1xEV-DO RF measurements
• CDMA2000 1xEV-DO Demodulator, Rev. A compatible
• CDMA2000 1xEV-DO OTA measurements, requires Option 31
CDMA2000 1xEVDO has a chip rate of 1.2288 MHz, the same as cdmaOne and CDMA2000
1xRTT. Each chip lasts for a duration of 0.8138 microseconds. In downlink, an EVDO signal
can be time-divided into “half slots.” Each half slot has 1024 chips.
The 1024 chips in a half slot can be further time-divided into three different channels:
Pilot, MAC, and Data. The Pilot Channel provides synchronization for the EVDO Access
Terminals (for example, cell phones, laptops, and so forth.). The MAC (Medium Access
Control) Channel controls the overall EVDO traffic. The Data Channel transmits data to
various users.
The Pilot and MAC Channels are always active in an EVDO signal, but the Data Channel
may sometimes transmit no data. When no data is transmitted, the half slot is considered
idle. Otherwise, it is called an active slot.
The instrument can measure EVDO signals over the air (OTA) by connecting the antenna to
the unit or by directly connecting to the base station.
3-2 General Measurement Setup
Please refer to the User Guide for information on selecting the EVDO Signal Analyzer mode,
setting up frequency, amplitude, power loss for compensating external loss, limit lines,
markers, and file management.
ООО "Техэнком" Контрольно-измерительные приборы и оборудование www.tehencom.com