Adaptive threshold controller and control method, direct sequence spread spectrum signal detection method and circuit

Abstract

The invention discloses an adaptive threshold controller and a control method, a direct sequence spread spectrum signal detection method and a circuit. The adaptive threshold control method comprises the following steps: making a statistic of the number N of signals to be detected of a current group; calculating shift correlation values of the N signals to be detected and a local spread spectrum sequence; judging whether the shift correlation values exceed the threshold, and making a statistic of the number n of the shift correlation values exceeding the threshold; based on the number N of the signals to be detected and the number n of the correlation values exceeding the threshold, selecting a sign function epsilon; and modifying the threshold based on the sign function epsilon, and taking the modified threshold as the threshold of the signals to be detected of a next group. The adaptive threshold control method provided by the invention can make a false alarm probability tend to 0 and a detection probability tend to 1 under the circumstance that the dynamic range of an input signal amplitude is very wide, so that the acquisition performance of a system can be improved.

Description

technical field [0001] The invention relates to the technical field of signal detection, in particular to an adaptive threshold controller and a control method, a direct spread signal detection method and a circuit. Background technique [0002] Due to its outstanding advantages in anti-interference, confidentiality, and increased system capacity, spread spectrum communication is widely used in civil, commercial, and military fields. [0003] Among the various spread spectrum methods, the most widely used is the direct sequence spread spectrum method, which uses the PN code and the binary information digital sequence modulo 2 to form a composite code to modulate the carrier. The spread spectrum signal must be synchronized with the local PN code at the receiving end before the information can be extracted, and thus the spread spectrum gain can be obtained to reduce the bit error rate. In order to realize the digital receiver, the received signal can be despread by using digi...

AI Technical Summary

Problems solved by technology

In order to achieve a low false alarm probability, the CFAR detection technology makes the threshold too high, which will make the detection probability very small and the capture performance will decrease; moreover, the most important thing is that the CFAR detection needs to obtain the adaptive threshold by estimating the interference or noise power, and the engineering realization quite complicated

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