Anti-interference method, device and system suitable for orthogonal frequency division multiple access reflection communication

Abstract

The invention provides an anti-interference method suitable for orthogonal frequency division multiple access reflection communication. The anti-interference method comprises the steps of S1, modifying a pure carrier into a standard chirp signal; S2, using the generated subcarriers for frequency shift of the standard chirp signal; and S3, de-spreading the reflection signal by using the standard chirp signal, and then carrying out fast Fourier transform on the signal after de-spreading to complete demodulation. According to the invention, the narrowband subcarrier signal is modulated into the broadband chirp signal, the narrowband interference is effectively avoided, the influence of the environmental noise on the signal is greatly reduced, the signal polluted by the noise can be normally demodulated, and the anti-interference capability of the orthogonal frequency division multiple access reflection communication system is improved. According to the invention, the pure carrier part is modified into the standard chirp signal, and the transmitter does not need to be additionally modified, so that the maintenance of the orthogonal frequency division multiple access reflection communication system is facilitated. Meanwhile, the transmitter bears power consumption for generating the standard chirp signal, and the low-power-consumption characteristic of a tag can be kept.

Description

Technical field [0001] The present invention relates to communication technologies, and in particular, relates to one for an orthogonal frequency division multiple access communication system in reflection interference method and apparatus system. Background technique [0002] Communication system reflecting an orthogonal frequency division multiple access technique based on spectrum resource by dividing a frequency band into a plurality of sub-carriers orthogonal to each other and assigned to different users, the concurrent increase of the system. However, for a single subcarrier, since it occupies only a small band, and therefore very vulnerable to environmental noise interference (narrow-band interference), when it covers a small noise band, information carried on a subcarrier will be difficult demodulation subcarriers become unavailable. [0003] Is an effective way to overcome spreading narrowband interference, spread spectrum communications technique is commonly chirp sprea...

AI Technical Summary

Problems solved by technology

However, the disadvantage of this prior art is that it is impossible to despread the radio frequency signal, so that demodulation cannot be achieved

However, although patent document 3 uses the orthogonal demodulation technology to realize the extraction of time delay, which avoids the phase ambiguity and spectrum leakage phenomenon in the traditional time delay detection process, it still does not solve how to effectively avoid narrow-band interference and cannot solve the problem of noise pollution. The technical problem of how the signal is normally demodulated

[0007] Therefore, there is an urgent need to develop and design a system and method that can solve the problem of poor anti-interference ability of existing OFDMA reflective communication systems

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