A.V. Pitrin1, A.S. Popov2, M.S. Vorona3, A.A. Kovalskiy4

1-4 Military Space academy named after A.F. Mozhaisky (Saint-Petersburg, Russia)

To ensure the stability of information transmission using a radio channel, the influence of noise and interference is of great importance. In systems with relative (differential) phase manipulation (OFM), the so-called "reverse operation" mode is excluded. These signals are not inferior in noise immunity to phase-manipulated (FM) signals.

In addition, incoherent reception (demodulation) is possible, which greatly simplifies the receiving device. The use of such signals and incoherent reception is preferable in cases where the phase of the carrier oscillation changes dynamically and/or randomly and tracking it is difficult, especially in the presence of structural interference of various types.

To calculate the probabilities of bit errors, we determine the models of the radio signal and interference.

We derive formulas for calculating the average probabilities of bit errors of incoherent reception of a radio signal from OFM-2 in the presence of harmonic interference.

The output of the final formula for calculating the probabilities of bit errors is averaged through the transition probabilities over the phases of the signal and interference (s), taking them as random variables evenly distributed within (-T, T).

Thus, the probabilities of bit errors are calculated when transmitting the signal and accepted and vice versa.

We plot the dependence of the average probability of an incoherent reception bit error with OFM-2 on the signal level in the presence of harmonic interference when the frequencies of the carrier oscillations coincide, which shows that in order to achieve the required value of the bit error probability, it is necessary to increase the signal level by the amount determined by the graph.

And also a graph of the dependence of the average and probability of bit reception error on the magnitude of the frequency shift k of the interference relative to the signal at fixed levels.

The developed technique allows us to qualitatively or conditionally quantify the effects of harmonic interference on the reliability of transmitted information in the radio channel when the frequency of interference is shifted.

Pitrin A.V., Popov A.S., Vorona M.S., Kovalskiy A.A. The method of calculating the noise immunity of incoherent reception of signals with binary relative phase manipulation (OFM-2) with harmonic interference. Nonlinear World. 202 3. V. 21. № 1. P. 13-20. DOI: https://doi.org/10.18127/j20700970-202301-02 (In Russian)

1. Kulikov G.V., Nguen Van Zung, Do Chung Tien. Pomehoustojchivost' avtokorreljacionnogo demoduljatora signalov s differencial'noj fazovoj manipuljaciej pri nalichii releevskih zamiranij i garmonicheskoj pomehi. Rossijskij tehnologicheskij zhurnal. 2020. № 8(3). S. 48–58.
2. Okunev Ju.B. Cifrovaja peredacha informacii fazomanipulirovannymi signalami. M.: Sovetskoe radio. 1991. 296 s.
3. Fink L.M. Teorija peredachi diskretnyh soobshhenij. Izd. 2-e, pererab. i dop. M: Sovetskoe radio. 1970. 728 s.
4. Zvonarev V.V., Popov A.S., Pitrin A.V. Metodika rascheta verojatnostej bitovyh oshibok priema radiosignalov s QPSK-moduljaciej pri neskol'kih garmonicheskih pomehah. Radiotehnika. 2022. T. 86. № 8. S. 84-95.
5. Zvonarev V.V., Pimenov V.F., Popov A.S. Metodika vychislenija verojatnostej simvol'nyh i bitovyh oshibok dlja QPSK-signalov pri nalichii garmonicheskoj pomehi so sdvigom chastity. Trudy Voenno-kosmicheskoj akademii imeni A.F. Mozhajskogo. 2021. Vyp. 677. S. 50-61.
6. Zvonarev V.V., Popov A.S. Potencial'naja pomehoustojchivost' kogerentnogo priema chetyrehpozicionnogo fazomanipulirovannogo radiosignala v prisutstvii kogerentnoj garmonicheskoj pomehi. Informacionno-upravljaju-shhie sistemy. 2021. № 1. S. 45–54.
7. Fuqin Xiong. Digital modulation techniques. Second edition. Artech House Telecommunications Library. 2006. 1039 p.