Fully-digital direct sequence spread spectrum communication system and rapid pseudo code capturing method thereof

A technology of direct sequence spread spectrum and communication system, which is applied in the field of all-digital direct sequence spread spectrum communication system and its pseudocode fast acquisition, can solve the problems of reducing acquisition time and search times, and achieves reduction of acquisition time and power consumption. and complexity, the effect of simplifying the design

CN102571137AActive Publication Date: 2012-07-11ZHEJIANG UNIV
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2012-07-11

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Abstract

The invention discloses a fully-digital direct sequence spread spectrum communication system and a rapid pseudo code capturing method thereof. A digital signal is processed by using an FPGA (Field Programmable Gate Array) which comprises a pseudo code capturing module, a sampling signal of an ADC (Analog To Digital Converter) is subjected to frequency mixing with a signal of a local carrier NCO (Numerically Controlled Oscillator) and filtered to obtain a baseband signal, residual carrier Doppler frequency is eliminated from the baseband signal by adopting a differential multiplying mode, thus the phase deviation of a receiving signal and a local pseudo code is further obtained through an FFT (Fast Fourier Transform) algorithm without scanning on a carrier frequency domain; and when the phase deviation of the pseudo code is obtained, a local pseudo code phase is modified and is subjected to correlation degree of dissociation with the receiving signal, and the carrier Doppler frequency is figured out by using the FFT algorithm, and is compensated to a carrier NCO and a pseudo code NCO, thus carrier frequency capturing and pseudo code capturing are realized.
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Description

technical field

[0001] The invention relates to the fields of radio frequency communication and digital signal processing, in particular to an all-digital direct-sequence spread-spectrum communication system and a pseudo-code rapid acquisition method applied under Doppler conditions. Background technique

[0002] Direct sequence spread spectrum communication has gradually become the main technology of modern communication because of its strong anti-interference ability, strong anti-interception ability, confidentiality, and easy realization of multiple access communication.

[0003] The principle of spread spectrum communication is to use a high-speed spread spectrum sequence to spread the spectrum of the signal at the transmitter, and use the same spread spectrum code sequence to despread at the receiver to restore the expanded spread spectrum signal to the original signal. The direct sequence spread spectrum method is to directly use the pseudo-noise sequence to modulate t...

Examples

Embodiment Construction

[0027] The present invention will be described in detail below in conjunction with the embodiments and accompanying drawings, but the present invention is not limited thereto.

[0028] like figure 1 As shown, an all-digital direct-sequence spread spectrum communication system includes a radio frequency filter, a low-noise amplifier, a frequency synthesizer, a mixer, an intermediate frequency filter, an AGC (automatic gain control circuit), and an AD analog-to-digital converter in hardware. And FPGA (Field Programmable Gate Array, Field Programmable Gate Array). Among them, the radio frequency filter is connected to the low noise amplifier, the output of the low noise amplifier and the output of the frequency synthesizer are connected to the two inputs of the mixer, and the mixer, IF filter, AGC, AD analog-to-digital converter and FPGA are sequentially connected.

[0029] The analog circuit includes radio frequency filter, low noise amplifier, frequency synthesizer, mixer, in...