Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

PN code FFT parallel acquisition method based on majority decision

A decision and large number technology, applied in the field of PN code FFT parallel acquisition and decision, can solve the problems of high channel noise sensitivity, single synchronization acquisition decision criteria, synchronization acquisition, etc., to achieve the effect of improving robustness

Inactive Publication Date: 2014-04-09
UNIV OF ELECTRONICS SCI & TECH OF CHINA
View PDF2 Cites 2 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0019] 1. Synchronous acquisition judgment is highly sensitive to channel noise. In engineering applications, with the real-time change of channel noise, it is easy to cause wrong judgment of synchronous acquisition;
[0020] 2. Synchronous capture decision criterion is too simple: the criterion for successful synchronous capture is only related to the threshold value V T A single comparison is performed once the threshold V T There is a large error in the calculation, that is, it is easy to cause wrong judgment of synchronous capture

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • PN code FFT parallel acquisition method based on majority decision
  • PN code FFT parallel acquisition method based on majority decision
  • PN code FFT parallel acquisition method based on majority decision

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0047] The FFT parallel pseudo-code acquisition method of this embodiment is performed under the condition that the receiver has extracted the transmitter carrier frequency fc, where:

[0048] The number of cascade stages of short pseudo codes: G=4 (4 same short pseudo codes);

[0049] The short pseudo code spreading factor is: l=256 (M sequence);

[0050] Short pseudo code generator polynomial: [8 4 3 2 0], initial state: -1;

[0051] Baseband modulation mode: two-phase phase shift keying (BPSK) modulation (carrier frequency is f c =10MHz);

[0052] Wireless channel environment: Rayleigh channel;

[0053] Channel SNR range: [-20:10]dB;

[0054] Capture technology: FFT parallel pseudo code capture;

[0055] Large number judgment threshold: g=3;

[0056] The specific method is as follows:

[0057] Transmitter A

[0058] Step A-1. Short pseudo-code set generation: The transmitter converts the long pseudo-code (long M sequence) with a spreading factor of 1024 in the background technology into a ...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention discloses a PN code FFT parallel acquisition method in wireless communication techniques. The method includes the steps of generation of a short pseudo code set of a transmitting end, generation of a base band modulating signal, up-conversion processing and signal transmission, generation of a short pseudo code set of a receiving end, signal receiving and down-conversion processing, frequency domain matching and correlation solving, and majority decision. According to the method, a long pseudo code is converted into G short pseudo codes, all the short pseudo codes are connected in a cascading mode to generate the short pseudo code sets, the short pseudo code sets in the same cascading mode are adopted in a receiver at the same time so as to carry out frequency domain matching coherent processing, and then majority decision based on chip delay is carried out; in this way, the method has the advantages that the sensitivity to channel noise is low, accurate channel estimation is not needed during acquisition, acquisition accuracy is high, and the robustness of decision criteria is improved as well due to the adoption of majority decision. A required signal-to-noise ratio in a Rayleigh channel is -13dB or so when the acquisition probability of the method is 95%, and the gain of the signal-to-noise ratio is improved by 12dB or so when compared with the required signal-to-noise ratio of -1dB in background technologies.

Description

Technical field [0001] The invention belongs to the field of wireless communication technology, and specifically relates to a PN code FFT (Fast Fourier Transform) parallel acquisition decision method based on large number decision in a direct sequence spread spectrum (DSSS) communication system. Background technique [0002] In a spread spectrum communication system, in order to perform despreading correctly, pseudo code synchronization must be performed, that is, a pseudo code synchronized with the sender is generated at the receiving end and changes with the pseudo code of the sending end (that is, the phase and rate are the same) . Pseudo-code synchronization is the key to a spread spectrum system. It is divided into two stages: acquisition (coarse synchronization) and tracking (fine synchronization). Among them, acquisition is the most difficult problem to solve in the synchronization problem. Its performance directly determines the reliability and effectiveness of the sprea...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(China)
IPC IPC(8): H04B1/7075H04L27/38
Inventor 杜洋董彬虹杨枫
Owner UNIV OF ELECTRONICS SCI & TECH OF CHINA
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products