Instrument Design and Function Description CMU
1100.4903.82 3.16 E-4
Option CDMA (IS95) Signalling Unit CMU-B81
The CDMA (IS95) Signalling Unit is a module of the CMU200 providing signalling and measuring
support for the CDMA IS-95 cellular phone network.
With the use of analog and digital hardware and firmware, this module uses the down converter and a
signal generator in the CMU200 to establish a link with a CDMA mobile station.
Design
The CDMA (IS95) Signalling Unit is a plug-in module with a complete
aluminum shell providing optimal electrical shielding of the module.
Cooling system
Ventilation holes on the right and left of the shell produces a large cooling
flow through the module by means of the instrument fan.
Control and supply
The MOTHERBOARD 1 provides bus lines, the voltage supply, and controls
the CDMA (IS95) Signalling Unit via two 96-pin connectors and one 48-pin
connector. Further interfaces for testing and debugging are provided on the
top of the module.
Function
The CDMA (IS95) Signalling Unit contains the hardware for signal
demodulation and signal generation of a CDMA system. See Figure 3-1 for
a simplified block diagram.
A micro processor with peripheral equipment and three programmable logic
devices (Xilinx 1, 2, and 3) on the board control all the processes on the
module.
An RS232 interface is available for debugging and data input and output.
An AT-bus interface is used for control and data communication with the
front module computer.
CMU Platform
CDMA LinkHandler
CDMA Signal
Generation
CDMA
Demodulation
LinkHandler
Processor / Memory
Clock / Trigger
System
AWGN
Generator
External
Interfaces
CMU
Internal
Interfaces
Internal
Interfaces
Expansion Interfaces
Output Signal
Conditioning
Digital
Up / Down
Conversion
RxTx
Board
FrontEnd
Board
System Clock
Generation
Measurement
DSP
Synchronization
RF
CMU ControllerFront / Rear Panel
Triggers
NetClock
I
Q
Dig. I & Q
CDMASupport
Vocoder
Interface
Figure 3-1: CDMA (IS95) Signalling Unit block diagram
To Next Page
Loading...
Need help?
General
