A Detection Method of Direct Spread Signal with Low Noise Ratio

Abstract

The invention belongs to the technical field of communication and discloses a low signal to noise ratio direct spread signal detection method. The detection method comprises the steps of 1, carrying out time domain detection processing on a received signal through utilization of a local frequency domain sequence of a target terminal probe signal, thereby obtaining a calibrated time domain probe signal, carrying out power spectrum operation on the received signal, judging whether a target exists or not through utilization of a power spectrum feature, entering a second step if the target signal exists, and repeating the first step if the target signal does not exist; and 2, carrying out coarse estimation on a carrier through the power spectrum feature, taking a coarse estimation result as a detection signal, taking the power spectrum of the detection signal as detection spectrum, and carrying out bandpass filtering according to the detection spectrum, thereby obtaining a baseband signal of the signal. According to the method, the signal can be detected relatively accurately, whether the signal exists or not can be judged, and the detection accuracy of the probe signal is achieved.

Description

technical field [0001] The invention specifically relates to a detection method of a low-noise-ratio direct-spread signal, which belongs to the technical field of communication. Background technique [0002] The detection and identification of communication signals is one of the key technologies in the field of single satellite electronic reconnaissance. The task of signal detection and identification is to determine whether there is a useful signal in the received signal, and to identify the modulation mode of the signal. The detection and recognition process may be disturbed by noise, and some modulation information needs to be known. Effective detection and identification can provide a basis for follow-up work such as demodulation, analysis, or interference. Most of the early detection and identification methods were to change the received high-frequency signal to intermediate frequency, and then input it into different demodulators to obtain observable signals, and fin...

AI Technical Summary

Problems solved by technology

But this kind of method also has some problems. For these methods, the conventional communication signal and the direct spread signal have similar characteristics, so although these methods can detect whether the signal exists, they cannot distinguish whether the target signal is a conventional signal or a direct spread signal. Signals, which means that methods of this class are susceptible to regular signals