Radio frequency self-interference eliminating system applied to same-time and same-frequency full-duplex system

Abstract

The invention provides a radio frequency self-interference eliminating system applied to a same-time and same-frequency full-duplex system. The radio frequency self-interference eliminating system comprises a direct modulation laser device, a variable optical delay line, a variable optical attenuator, and a balanced receiver, wherein the upper branch of the direct modulation laser device is connected with the first input end of the balanced receiver, while the lower branch of the direct modulation laser device is connected with the second input end of the balanced receiver via the variable optical attenuator and the variable optical delay line in sequence; the variable optical delay line is used for matching time delays generated by a self-interference signal passing through different paths; the variable optical attenuator is used for matching the magnitude of the self-interference signal; and the balanced receiver is used for receiving two optical signals from the upper branch and lower branch of the direct modulation laser device, performing subtraction, obtaining the available optical signals and then converting into corresponding electrical signals to output. According to the system, the radio frequency signal is modulated by using the direct modulation laser device with low cost, the self-interference signal is eliminated by the balanced receiver, and the good interference eliminating performance and inhibiting performance are obtained in a relatively wide frequency band range.

Description

technical field [0001] The present invention relates to the technical field of communication and wireless communication, in particular to a radio frequency self-interference elimination system applied to a simultaneous and same-frequency full-duplex system. Background technique [0002] With the continuous application of novel Internet of Things services and big data services in mobile communication systems, users' demand for transmission capacity of wireless communication systems has increased sharply. In order to adapt to the rapid growth of mobile Internet services and meet users' requirements for future new services , the future wireless communication system needs to have ultra-high-speed transmission capabilities, large-density network access scale, real-time local operations, and ubiquitous broadband access capabilities. In terms of wireless transmission technology, in order to meet the exponential growth of mobile communication services and user bandwidth requirements...

AI Technical Summary

Problems solved by technology

This scheme is limited by the modulation bandwidth of the electro-absorption modulator, and the

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