Identification Friend Or Foe System Research Articles

Fuzzy FMEA risk assessment approach for IFF system in military helicopters using Matlab R2022A

In this article, the author reviews the fuzzy Failure Mode and Effect Analysis (fuzzy FMEA) as one of the effective methods of risk assess- ment. Using the fuzzy logic toolbox of the MATLAB R2022a software, the Identification Friend or Foe (IFF) system of military helicopters is analysed in a case study, during which the fuzzy risk priority numbers (F-RPN) for this system of military helicopters is created. Finally, the author of this paper summarizes the results obtained.

Research on MSK Demodulation Method for M-Sequence in IFF System

M-Sequence, short for Maximum Linear Feedback Shift Register Sequence, is widely used in identification friend or foe (IFF) system because of its good equalization and autocorrelation characteristics, and Minimum Shift Keying (MSK) signal has been paid more attention in military communication field because of its excellent signal characteristics. A new demodulation method for MSK modulation signal of M-Sequence is studied. The MSK signal is sampled by A/D converter, and an integration circuit is designed in the FPGA. The same M-Sequence is generated by the same M-Sequence source polynomial as the integrator coefficient. The peak value of the integrated signal is judged to determine the M-Sequence. When the symbol rate is 1 Mbps and the carrier rate is 1 Mbps and M-Sequence is 5 bits, the recognition time of the new method is less than 1 us, which is less than one fifth of the recognition time of the traditional demodulation method. This method simplifies the demodulation process and is easy to implement. It improves the recognition speed of M-Sequence in MSK modulation signal and provides some reference value for the development of IFF system.

Prediction of Equipment-to-Equipment Coupling Through Antennas Mounted on An Aircraft

Modern military and civil aircraft have various radar and communication equipments placed on them for different actions. Electromagnetic interference (EMI) can be easily coupled through various antennas which are mounted on the aircraft. It is therefore desirable to exactly predict their effect on one another as much as possible. In this paper the equipment-to-equipment coupling (ETEC) is proposed which is suitable to accurately determine the electromagnetic compatibility (EMC) safety margin of the aircraft radio system. By employing the microwave network theory the equivalent circuit model of the Identification Friend or Foe System (IFFS) and the Ground-to-Air (GTA) communication system of the aircraft can be obtained and then the ETEC is accurately calculated. In this way the electromagnetic coupling level between the two subsystems can be easily determined. Basing on the accurate coupling, it is allowed to simply and exactly evaluate the electromagnetic interference safety margin of the receiver.