Phase compensation is the correction of phase error
Ultra High Frequency (UHF) band 300 MHz – 3 GHz binary phase shift keying (BPSK) C/A code is only modulated onto the L1 carrier while the P(Y) code is modulated onto both the L1 and the L2 carrier
Pulse Repetition Frequency (PRF) is the number of pulses transmitted per second the duty cycle is the fraction of time that a system is in an &quot;active&quot; state D=t/T where t :is the duration that the function is non-zero T:is the period of the function.
Why Fuzzy: * Fuzzy techniques are powerful tools for knowledge representation and processing * Fuzzy techniques can manage the vagueness and ambiguity efficiently
Band-Limit White Noise: Introduce white noise into a continuous system Frequency Modulation varying its frequency .
This block models multiband noise using four different band limited white noise blocks, each one with its own power and time scale. A first order low pass filter with a selectable cut off frequency is applied to the last three noises (have look under the mask).The output sampling time has to be multiple of the first sample time. A low-pass filter is a filter that passes low- frequency signals but attenuates (reduces the amplitude of) signals with frequencies higher than the cutoff frequency Phase compensation is the correction of phase error (i.e., the difference between the actually needed phase and the obtained phase). Rate Transition: Handle transfer of data between blocks operating at different rates ,1/Z: Acts as a unit delay
by Mohamed Loey Ramadan Improving the Performance of Anti-GPS Signal
5.2.2 Anti-GPS Fuzzy Controller Rules 1. If (GPSErrorSiganl is not Good) then (JammingSignal is NotAffect) 2. If (GPSErrorSignal is Good) and (Frequency is Same) and (pulseRepetitionFrequency is Medium) and (Duty is Medium) and (JammingSignalRatio is Medium) and FrequencyOffset is Inside) then (JammingSignal is Affect) 3. If (PulseRepetitionFrequency is VerySmall) or (DutyCycle is VerySmall) Then (JammingSignal is NotAffect) 4. If (PulseRepetitionFrequency is VeryLarge) or (DutyCycle is VeryLarge) Then (JammingSignal is Continues)
5.2.2 Anti-GPS Fuzzy Controller Rules 5. If (FrequencyOffect is not Inside) then (JammingSignal is NotAffect) 6. If (JammingSignalRatio is Low) then (JammingSignal is NotAffect) 7. If (JammingSignalRatio is High) then (JammingSignal is NotAffect) 8. If (Frequecy is High) then (JammingSignal is NotAffect) 9. if (Frequency is Low) then (JammingSignal is NotAffect)
5.6 Test Results Multi-Band limit white noise Frequency modulation Band –limit white noise Comparisons Medium High Low Noise Power Medium Low High Jamming Power Hard Too Hard Easy Jamming Detection High Medium Low Data Destroy Too Hard Hard Easy Anti-Jamming
HESHAM N. ELMAHDY and MOHAMED L. Ramadan, “Improving the Performance of Anti-GPS Signal,”, In Proceedings of WSEAS SIP 09: The 8 th World Scientific and Engineering Academy and Society international conference on Signal Processing , Istanbul, Turkey, June 2009.