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

LFM-PC signal and ambiguity function optimization method thereof

A technology of LFM-PC and ambiguity function, applied in the direction of radio wave reflection/re-radiation, using re-radiation, measuring devices, etc., can solve the problem of the reduction of the main-side lobe ratio of the filter output signal, the high-peak side-lobe of the waveform, and the research results Not many problems, to achieve the effect of increasing Doppler tolerance, good anti-interference performance, and Doppler tolerance

Active Publication Date: 2018-05-04
NANJING UNIV OF AERONAUTICS & ASTRONAUTICS
View PDF6 Cites 3 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The phase-encoded signal has a thumbtack-type ambiguity function, so it has good autocorrelation characteristics, but it is also sensitive to Doppler. Once the echo signal does not match the filter, the main-side lobe ratio of the filter output signal will decrease rapidly.
[0004] At present, many studies have been carried out on optimizing fuzzy functions, but the research results are not many
An optimization method based on minimizing the integrated sidelobe energy can be used. However, since the objective function is the integrated sidelobe energy, the optimized waveform may have a higher peak sidelobe

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
  • LFM-PC signal and ambiguity function optimization method thereof
  • LFM-PC signal and ambiguity function optimization method thereof
  • LFM-PC signal and ambiguity function optimization method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0039] like figure 1 Shown, a kind of LFM-PC signal and its ambiguity function optimization method, comprise the following steps:

[0040] (1) The LFM-PC signal is obtained by modulating the LFM signal with the phase-encoded signal, and in the time domain, the two signals are directly multiplied; according to the definition of the ambiguity function, the ambiguity function χ of the LFM-PC signal u (τ,ξ) is

[0041]

[0042] Among them, τ is time, ξ is Doppler frequency, u PC (t) is the phase encoding signal, K=B L / T p is the FM slope, B L , T p are the bandwidth and duration of the LFM signal respectively; P is the code length, is the value of the nth sub-pulse, is a rectangular pulse p k (t) and p l The mutual ambiguity function of (t) can be expressed as:

[0043]

[0044] In the formula, t b is the sub-pulse width, and T p = Pt b ,

[0045] (2) Introduce vector and the sub-pulse mutual ambiguity function matrix H, where ψ is a 1×P-dimensional ve...

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 an LFM-PC signal and an ambiguity function optimization method thereof. The method comprises the steps that an optimization model is established based on a minimum peak sidelobe level criterion, the ambiguity function is optimized by adopting a sequential quadratic programming method, and the practicability of the method is examined through simulation. According to the LFM-PC signal and the ambiguity function optimization method thereof, a set of orthogonal phase-encoded signals are used as radar transmitted signals to improve anti-jamming performance of an SAR; compared with an LFM, the new signal has better anti-jamming performance, and compared with the phase-encoded signal, the new signal has a larger Doppler tolerance; the minimum peak sidelobe level criterionis adopted, and the ambiguity function is optimized by adopting the sequential quadratic programming method, so that the Doppler tolerance of the signal is enlarged.

Description

technical field [0001] The invention relates to the technical field of waveform optimization design, in particular to a linear frequency modulation and phase code composite modulation LFM-PC signal and an optimization method for its ambiguity function. Background technique [0002] The LFM signal is easy to generate and process and is not sensitive to Doppler, making it the most commonly used radar transmission signal. After decades of research and development, SAR imaging technology based on LFM signals has become mature and perfect. However, the anti-interference performance of LFM signal is poor, and it is impossible to achieve good imaging effect in today's increasingly fierce electronic countermeasures. [0003] Using a group of orthogonal phase coded signals as the radar transmission signal can improve the anti-jamming performance of SAR. The phase-encoded signal has a thumbtack-type ambiguity function, so it has good autocorrelation characteristics, but it is also s...

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): G01S7/36G01S13/90
CPCG01S7/36G01S13/904
Inventor 张劲东陈婉迎张超徐乃清
Owner NANJING UNIV OF AERONAUTICS & ASTRONAUTICS
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

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com