S.V. Dvornikov1, A.R. Bestugin2, S.S. Dvornikov3, I.A. Kirshina4

1-4 St. Petersburg State University of Aerospace Instrument Engineering (St. Petersburg, Russia)

1,3 The Military Academy of Communications n.а. Marshal of the Soviet Union S.M. Budyonny (St. Petersburg, Russia)

1 practicdsv@yandex.ru; 2 fresguap@mail.ru; 3 dvornic92@mail.ru; 4 ikirshina@mail.ru 

In optical receivers, diodes are usually used to implement signal heterodyning procedures both at the formation stage and at reception. Diodes as electronic devices are characterised by internal noise, which limits the sensitivity of reception. The nature of internal noise of electronic devices is determined by thermal processes and shot effect, which, in their turn, are determined not only by the temperature of the surrounding background, but also by the frequency of received radiations.

The aim is to evaluate the threshold sensitivity of diode mixers in heterodyning paths of optical receivers.

Expressions for calculating the internal noise level of an optical mixer are presented. An approach of shot noise estimation characterising the threshold sensitivity from the position of noise temperature is proposed. Simplified expressions of dependence of threshold sensitivity as a function of radiation frequency at a given temperature are obtained. Noise values in terms of temperature for different frequencies are calculated. A practical method of measuring the noise temperature, which characterises the sensitivity of reception, based on the measurement of the output voltage when receiving signals from sources with known temperatures of emitters, is substantiated. The values of the signal-to-noise ratio of the threshold sensitivity for different frequency ranges are presented and the sensitivity evaluation of the estimation of heterodyne receiver mixers is assessed.

From the presented analytical expressions it follows that it is reasonable to choose the frequency range of 0.1-1 THz, as it is characterised by a relatively low noise temperature, but at the same time is able to provide a high rate of message transmission.

Dvornikov S.V., Bestugin A.R., Dvornikov S.S., Kirshina I.A. Evaluation of the sensitivity of receiving signals used in LoRa technology. Radiotekhnika. 2024. V. 88. № 8. P. 18−25. DOI: https://doi.org/10.18127/j00338486-202408-02 (In Russian)

1. LoRa Modulation Basics. Semtech. Archived from the original on 2019-07-18. Retrieved 2020-02-05.
2. RP002-1.0.3 LoRaWAN Regional Parameters. lora-alliance.org. Retrieved 9 June 2021.
3. LoRaWAN recognized as ITU International LPWAN standard. eenewswireless. 8 December 2021. Retrieved 2021-12-31.
4. Adelantado Ferran, Vilajosana Xavier, Tuset-Peiro Pere, Martinez Borja, Melia-Segui Joan, Watteyne Thomas. Understanding the Limits of LoRaWAN. IEEE Communications Magazine. 2017. V. 55. № 9. Р. 34–40. DOI:10.1109/mcom.2017.1600613.
5. Grebeshkov A.Ju., Daraev D.M. Razrabotka intellektual'nogo sensornogo uzla na baze tehnologii Lora. Infokommunikacionnye tehnologii. 2021. T. 19. № 2. S. 179-186. DOI: 10.18469/ikt.2021.19.2.06 (In Russian).
6. Kirichek R.V. Issledovanie peredachi izobrazhenij na baze tehnologii LoRa. Jelektrosvjaz'. 2017. № 7. S. 31-38 (In Russian).
7. Roenkov D.N., Jaronova N.V. Osnovy tehnologii LoRa. Perspektivy ee primenenija. Avtomatika, svjaz', informatika. 2017. № 4.
   S. 31-35 (In Russian).
8. Nasser S.S.S., Ljachek Ju.T., Mutanna M.S.A. i dr. Jenergosberegajushhij algoritm dlja tehnologii LoRa: realizacija prototipa. Izvestija SPbGJeTU LJeTI. 2020. № 10. S. 45-49 (In Russian).
9. Nosov A.F. Primenimost' sistem peredachi dannyh s ispol'zovaniem tehnologii LoRaWAN. Doklady Tomskogo gos. un-ta sistem upravlenija i radiojelektroniki. 2023. T. 26. № 3. S. 83-88. DOI: 10.21293/1818-0442-2023-26-3-83-88 (In Russian).
10. Netesov E.Ju., Zacepina V.I. Postroenie vnutricehovoj sistemy ucheta jelektrojenergii na baze seti lorawan. Sb. trudov konf. «Cifrovaja transformacija v jenergetike». Tambov: Izdatel'stvo Pershina R.V. 2020. S. 308-311 (In Russian).
11. Bankov D., Khorov E., Lyakhov A. On the Limits of LoRaWAN Channel Access. 2016 International Conference on Engineering and Telecommunication (EnT). November 2016. Р. 10–14. DOI:10.1109/ent.2016.011.
12. What are LoRa® and LoRaWAN®? LoRa Developer Portal. Retrieved 7 July 2021.
13. Liando J.C., Gamage A., Tengourtius A.W., Li M. Known and Unknown Facts of LoRa: Experiences from a Large-Scale Measurement Study. ACM Transactions on Sensor Networks. 2019. V. 15. № 2. Article No. 16. Р. 1–35. DOI: 10.1145/3293534.
14. Margelis G. et al. Low Throughput Networks for the IoT: Lessons learned from industrial implementations. In: 2015 IEEE 2nd World Forum on Internet of Things (WF-IoT). 2015. Р. 181–186.
15. Reynders B., Pollin S. Chirp spread spectrum as a modulation technique forlong range communication. In: 2016 Symposium on Communications and Vehicular Technologies (SCVT). 2016. Р. 1–5.
16. Dvornikov S.V., Markov E.V., Manoshi Je.A. Povyshenie pomehozashhishhennosti peredach dekametrovyh radiokanalov v uslovijah neprednamerennyh pomeh. T-Comm: Telekommunikacii i transport. 2021. T. 15. № 6. S.4-9. DOI: 10.36724/2072-8735-2021-15-6-4-9 (In Russian).
17. Gordienko D.Ju., Dvornikov S.V. Korreljacionnyj priem chastotno-manipulirovannyh signalov v rezhime s psevdosluchajnoj perestrojkoj rabochej chastoty. T-Comm: Telekommunikacii i transport. 2022. T. 16. № 3. S. 18-22. DOI: 10.36724/2072-8735-2022-16-3-18-22 (In Russian).
18. Ferré G., Giremus A. LoRa Physical Layer Principle and Performance Analysis. In: 2018 25th IEEE International Conference on Electronics, Circuits and Systems (ICECS). 2018. Р. 65–68.
19. Dvornikov S.V., Balykov A.A. Predlozhenija po upravleniju skorost'ju peredachi i pomehoustojchivost'ju signalov s perestanovochnoj chastotnoj moduljaciej. T-Comm: Telekommunikacii i transport. 2020. T. 14. № 6. S. 20-26. DOI: 10.36724/2072-8735-2020-14-6-20-26 (In Russian).
20. Dvornikov S.S., Zheglov K.D., Dvornikov S.V. SSB signals with controlled pilot level. T-Comm. 2023. V. 17. № 3. P. 41-47. DOI: 10.36724/2072-8735-2023-17-3-41-47.
21. SX1272 Datasheet (http://www.semtech.com/apps/filedown/down.php?file=sx1272.pdf)
22. SX1276 Datasheet (http://www.semtech.com/apps/filedown/down.php?file=sx1276.pdf)
23. Simonov A.N., Volkov R.V., Dvornikov S.V. Osnovy postroenija i funkcionirovanija uglomernyh sistem koordinatometrii istochnikov radioizluchenij: Ucheb. posobie. SPb: VAS. 2017. 248 s. (In Russian).
24. Dvornikov S.V. Bilinejnye raspredelenija s ponizhennym urovnem interferencionnogo fona v chastotno-vremennom prostranstve (prodolzhenie obzora). Trudy uchebnyh zavedenij svjazi. 2018. T. 4. № 2. S. 69-81 (In Russian).
25. Dvornikov S.V., Ovchinnikov G.R., Balykov A.A. Programmnyj simuljator ionosfernogo radiokanala dekametrovogo diapozona. Informacija i kosmos. 2019. № 3. S. 6-12 (In Russian).