Method of Automatic Parameters Estimation of Radio Signals Generated According to LoRa Standard

Authors

Keywords:

method, radio signal, LoRa, linear frequency modulation, parameter, bandwidth, spreading factor, automation

Abstract

Radio signals generated according to the LoRa standard (hereinafter referred to as LoRa radio signals) are widely used in telecommunication systems for both civil and military purposes, which is due primarily to their high immunity to interference.

The mathematical model of the LoRa radio signal is presented in the article. The relationship between radio signal modulation parameters, coding parameters, data transmission speed and interference immunity is shown. The characteristics of modern radio electronic components that support LoRa technology are analyzed, and the limits of modulation parameters ranges that can be used in a radio signal are determined. A method of automatic estimation of LoRa radio signal parameters is proposed, which consists of 4 stages. At the first stage, the carrier frequency and bandwidth are calculated by using characteristics of the signal amplitude-frequency spectrum. At the second stage, the information symbol duration is calculated by analyzing the features of the autocorrelation function. The obtained modulation parameters are rounded to the nearest constant values according to the minimum metric method. At the third stage, the spreading factor is calculated, which is analytically related to the bandwidth and the information symbol duration. At the fourth stage, the direction of the LoRa radio signal frequency change is determined. For this, two matched filters (for up-chirp and down-chirp symbols) are synthesized, the settings of which correspond to the LoRa radio signal parameters calculated in the previous three stages. The decision on the frequency change direction is made according to maximum signals amplitude at the output of the matched filters. The proposed method efficiency was verified by modeling in the MATLAB software and technical analysis of known LoRa data transmission protocols radio signals. It is shown that the method allows to correctly estimate the LoRa radio signals parameters with a probability close to 1 when the signal-to-noise ratio is greater than -5 dB.

References

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Published

2024-03-30

How to Cite

Нагорнюк , О. А. (2024) “Method of Automatic Parameters Estimation of Radio Signals Generated According to LoRa Standard”, Visnyk NTUU KPI Seriia - Radiotekhnika Radioaparatobuduvannia, (95), pp. 23-30. Available at: https://radap.kpi.ua/radiotechnique/article/view/1979 (Accessed: 22April2024).

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Section

Telecommunication, navigation, radar systems, radiooptics and electroacoustics