Method for inhibiting MPSK narrowband interference of direct sequence spread spectrum system (DSSS)

Abstract

The invention relates to a method for inhibiting MPSK narrowband interference of a direct sequence spread spectrum system (DSSS), and belongs to the technical field of anti-interference of communication. In the method, a main lobe and a side lobe of a MPSK narrowband interference signal are inhibited respectively by adopting a method of combining a frequency domain and a time domain. The method comprises the following steps of: by adopting a method of segmentation overlay processing, inhibiting the main lobe of the MPSK narrowband interference signal as many as possible, and simultaneously ensuring that the energy loss of the useful signal is reduced as much as possible by using the difference between the noise characteristics of the DSSS communication signal in the frequency domain and the energy focusing characteristics of the MPSK narrowband interference signal; and inhibiting the side lobe of the MPSK narrowband interference signal in the time domain so as to effectively separate the interference signal from the useful signal, achieve high performance of bit error rate and guarantee reliable communication of the DSSS by using the characteristics that the frequency spectrum of the side lobe of the MPSK narrowband shows an impulse form. In addition, the method has low computational complexity and is easily implemented by the system in real time.

Description

technical field [0001] The invention relates to an MPSK narrow-band interference suppression method used in a direct spread system, and belongs to the technical field of communication anti-interference. Background technique [0002] The direct sequence spread spectrum system (referred to as direct spread system) has unique advantages such as strong anti-interference ability, concealment of information signal, easy encryption, arbitrary site selection, and easy networking. Therefore, direct spread technology is currently widely used in communication equipment, such as the current The CDMA communication system and GPS navigation system used are all direct spread systems. Due to its own coding gain and processing gain, the spread spectrum system has a certain anti-interference ability, but the complexity of the transmitter / receiver and the available bandwidth limit the upper limit of the processing gain. When there is strong interference, the performance of the spread spectrum...

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Problems solved by technology

[0006] In the direct sequence spread spectrum system, in order to solve the problem that the traditional method is difficult to completely suppress narrow-band interference signals with large side lobes such as MPSK, resulting in a high bit error rate and a decrease in system performance, the present invention proposes a direct spread system The MPSK narrowband interference suppression method adopts the combination of frequency domain suppression and time domain suppression to effectively suppress MPSK narrowband interference, that is, first suppresses the main lobe energy of the MPSK narrowband interference signal in the frequency domain, and then suppresses its side lobe energy in the time domain , to reduce the bit error rate and ensure the reliable communication of the direct sequence spread spectrum system

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