Anti-narrow band interference adaptive filter, system and adaptive filtering method

Abstract

The invention belongs to the satellite navigation signal processing technical field and discloses an anti-narrow band interference adaptive filter, an anti-narrow band interference adaptive system and an adaptive filtering method. The filter includes an interference amplitude calculation which is used for calculating interference amplitude y according to a weight w (n) and inputted reference interference signals u (n), a subtracter used for removing the interference amplitude y from digital intermediate-frequency signals d to obtain output signals e, and a weight calculation module used for calculating the weight w (n) according to the inputted reference interference signals u (n) and the output signals e. The filtering method includes the following steps that: first step, the reference interference signals u (n) are inputted to the interference amplitude calculation module and the weight calculation module, and the digital intermediate-frequency signals d are inputted to the wideband tunable subtractor; second step, the interference amplitude calculation module calculates the interference amplitude y according to the weight w (n); third step, the wideband tunable subtractor removes the interference amplitude y from the digital intermediate-frequency signals d to obtain the interference-filtered out output signals e, and outputs the output signals to a baseband in real time; and fourth step, the weight calculation model updates the weight w (n) according to the output signals e and the reference interference signals u (n) and transmits the weight w (n) to the interference amplitude calculation module, and the calculation of the second step, the third step and the fourth step is cycled.

Description

technical field [0001] The invention belongs to the technical field of satellite navigation signal processing, and in particular relates to an adaptive filter and an adaptive filtering method for resisting narrow-band interference. Background technique [0002] Due to the relatively small power of the satellite navigation signal transmitted by the Beidou / GPS satellite, the receiving power of the signal after transmission to the ground is very weak, and it is transmitted at a fixed frequency, coupled with the complex electromagnetic environment near the earth, the Beidou / GPS receiver is easily subject to in-band interference The interference signal will block the receiver's reception and demodulation of the satellite signal. For interference signals with an interference-to-signal ratio of less than 15dB and Beidou / GPS signals with a bandwidth of 2MHz, the receiver signal processing can effectively suppress the interference after despreading, but for interference signals with ...

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Problems solved by technology

[0002] Due to the relatively small power of the satellite navigation signal transmitted by the Beidou / GPS satellite, the receiving power of the signal after transmission to the ground is very weak, and it is transmitted at a fixed frequency, coupled with the complex electromagnetic environment near the earth, the Beidou / GPS receiver is easily subject to in-band interference The interference signal will block the receiver's reception and demodulation of the satellite signal

For interference signals with an interference-to-signal ratio of less than 15dB and Beidou / GPS signals with a bandwidth of 2MHz, the receiver signal processing can effectively suppress the interference after despreading, but for interference signals with strong power, the Beidou / GPS receiver will have poor performance. Decline, even unable to capture and track Beidou / GPS satellite signals

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