01-08-2012, 11:11 AM
RADIO COMMUNICATION DESIGN TO IDENTIFY FRIEND OR FOE
[attachment=29798]
WHAT IS IFF
Identification of friend or foe (IFF)
used to identify aircraft, vehicles, or forces as friendly or foe.
secondary surveillance radar (SSR).
The SSR interrogates, from ground and the transponder equipment in aircraft will respond to the coded pulses. As the interrogation and reply pulses are coded it provides discrete targets identification.
MODULATION/DEMODULATION
•. Modulation - process of translation of the baseband message signal to Bandpass (modulated carrier) signal at frequencies that are very high compared to the baseband frequencies
• Demodulation is the process of extracting the
baseband message back from the modulated carrier.
ERROR CONTROL CODING
• Channel is noisy
• Channel output prone to error
• ⇒ we need measure to ensure correctness of the bit stream
Transmitted
Error control coding aims at developing methods for coding to
check the correctness of the bit stream transmitted.
The bit stream representation of a symbol is called the codeword of
that symbol.
Different error control mechanisms:
• Linear Block Codes
• Repetition Codes
• Convolution Codes
Encryption/decryption
Encryption is the conversion of data into a form, that cannot be easily understood by unauthorized people.
Decryption is the process of converting encrypted data back into its original form, so it can be understood.
[attachment=29798]
WHAT IS IFF
Identification of friend or foe (IFF)
used to identify aircraft, vehicles, or forces as friendly or foe.
secondary surveillance radar (SSR).
The SSR interrogates, from ground and the transponder equipment in aircraft will respond to the coded pulses. As the interrogation and reply pulses are coded it provides discrete targets identification.
MODULATION/DEMODULATION
•. Modulation - process of translation of the baseband message signal to Bandpass (modulated carrier) signal at frequencies that are very high compared to the baseband frequencies
• Demodulation is the process of extracting the
baseband message back from the modulated carrier.
ERROR CONTROL CODING
• Channel is noisy
• Channel output prone to error
• ⇒ we need measure to ensure correctness of the bit stream
Transmitted
Error control coding aims at developing methods for coding to
check the correctness of the bit stream transmitted.
The bit stream representation of a symbol is called the codeword of
that symbol.
Different error control mechanisms:
• Linear Block Codes
• Repetition Codes
• Convolution Codes
Encryption/decryption
Encryption is the conversion of data into a form, that cannot be easily understood by unauthorized people.
Decryption is the process of converting encrypted data back into its original form, so it can be understood.