05-03-2013, 12:31 PM
AUTOMATIC MODULATION RECOGNITION
AUTOMATIC MODULATION.ppt (Size: 1.12 MB / Downloads: 33)
ABSTRACT
Automatic Modulation Recognition (AMR) is a technique to identify the type of modulation done to the signal being received automatically. It is the intermediate step between signal detection and demodulation.
Uses of AMR
To decode the enemy signals during peace/war
Optimizing the recording media by switching on the recording based on modulation.
Applications
Military applications COMMINT (Communication intelligence)
Civil applications
Spectrum management
Network traffic administration
Signal confirmation
Software radios
Intelligent modems etc.,
EXISTING SYSTEM
Modulation Recognition is done manually.
A Two Receiver model is in use.
One receiver which continuously scans the received signal for the spectrum analysis.
Other is manually operated for fine tuning and adjusting the parameters for accurate recognition.
In this system the accuracy is up to 80% as there may be human errors.
SYSTEM UNDER DEVELOPMENT
A system for automatic detection of modulation is being developed.
An RF modulated signal received from the antenna is given to two receivers which convert the signal to IF frequency range for processing.
The Analysis module consists of the software for the automatic recognition of modulation which automatically checks the features of the received signal.
This signal is given to an Integrated high speed POWER PC processor for processing the signal for efficient recognition of the modulation type.
STUDY OF ALGORITHM
An algorithm developed by Azzouz and Nandi for the classification of various modulation techniques is being implemented by using MATLAB software.
Many algorithms in this regard are studied and found that they are capable of recognizing the modulation types having SNR≥15 to 20 dB.
Where as Azoouz and Nandi’s algorithm is capable of recognizing the modulation types having the SNR≥6 to 10 dB which is vey much preferable for practical scenario.