Fast acquisition system and fast acquisition method suitable for multipath random access signals

Abstract

The invention discloses a fast acquisition system and a fast acquisition method suitable for multipath random access signals. An intermediate frequency signal received by a message communication receiver is input to a digital down conversion module after AD sampling for digital down conversion to obtain a zero intermediate frequency signal, the zero intermediate frequency signal is sent to a low-pass filter, and the data processed by low-pass filtering through the low-pass filter is sent to a capture module for capture operation. Aiming at the characteristics of multipath random access signals, the capture module uses a mode of ping-pong RAM buffer to extract, store and calculate the data, which realizes continuous search of inbound signals. The fast acquisition system and fast acquisitionmethod suitable for multipath random access signals solve the problem of fast capture of the multipath random access signals. In the case of limited on-board resources, the multipath random access signals can be quickly captured according to different satellite PRN number configurations and different pseudo-code initial phases. At any time, the capture probability of the inbound signals is greater than 99%, and the capture time is shorter.

Description

technical field [0001] The invention relates to a fast acquisition system and method suitable for multi-channel random access signals, belonging to the field of satellite-borne Beidou communication, in particular to a multi-channel random access spread spectrum signal in a large-scale field programmable gate array (FPGA) The quick capture method on . Background technique [0002] The message communication receiver project requires that it can receive multiple random access message communication signals at the same time, and the false alarm capture and capture probability meet the project requirements. In order to achieve fast capture, a sync header sequence is inserted before the message signal. The acquisition module uses the synchronization header sequence to quickly realize the acquisition and synchronization, and complete the estimation of the carrier and phase. The synchronous head is composed of periodic short codes, and the data is all "1" or all "0" modulation. At...

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Problems solved by technology

[0003] The technical problem to be solved by the present invention is: aiming at the characteristics of multi-channel random access signals, a fast capture system and method suitable for multi-channel random access signals is proposed. Continuous search for station signals; the present invention solves the problem of fast acquisition of multi-channel random access signals. In the case of limited space-borne resources, multi-channel random access can be realized according to different satellite PRN number configurations and different pseudo-code initial phases Fast signal capture, the capture probability of inbound signals at any time is greater than 99%, and the capture time is short

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