Annual Report 2011-2012

Annual Research Report 2011-2012
Design and Implementation of a New Baseband Modem for
SEM400 Radio Modem
Research Department : Communication
Research Center: Power Systems Control & Dispatching
Producer : Sazgan Ertebat Company
Introduction:
Today, power distribution companies are pursuing systems of the distribution
automation, for the sake of increasing efficiency, producing reliable power and
decreasing the costs of the maintenance and use. It is obvious that reaching to the
mentioned aims is not practical without using reliable and fast communication
networkS.In comparison, radio links from the perspective of cost, and simplicity of
installation and use is better than other ways of communicationS.According to large
benefits and applications of radio systems for transforming data, a sample model of
UHF radio modem (NRM 400 model) designed and produced as a research project in
Niroo research institute (NRI) and after performing initial tests, it was abdicated private
part. NRM400 modem radio was industrialized during new project as support and
supervision of radio modem industrial productioN.This modem consists of two parts,
base band part and RF part, which separately and together passed all of standard
testS.This modem is now produced by Sazegan-Ertebat Company entitled SEM400.
However, the Baseband block of SEM400 has several drawbacks as follows:
• Obsolete parts
• High bandwidth consumption
• Low processing power for more complex tasks
So new project of design and implementation base band modem is approved as a
research and producing project in NRI. We use strong digital processor in this project.
The main characteristics of the radio modem:
• Low cost.
• Simple installation, operation and application.
• Tuning ability of the system parameters by software:
- operation frequency limit: 403-419 MHz
- output power limit of the transmitter:0.5-6 watt
- transmitted bit rate: 9600 bit per second
• Reading and adjusting the parameters of the system, testing the radio link and
transmitting and receiving data by every standard software of the serial port
(Hyper terminal,Term 95)
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