Code multiplexing differential chaotic modulator-demodulator for integrated code subscript modulation

A modem and modulator technology, which is applied in the modulation carrier system, digital transmission system, electrical components, etc., can solve the problems of low energy efficiency and spectrum efficiency, and achieve the effects of saving energy consumption, increasing bandwidth, and increasing bandwidth

Inactive Publication Date: 2017-03-29
XIAMEN UNIV
View PDF5 Cites 8 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0008] The present invention is based on the code multiplexing differential chaotic shift keying modulation (CS-DCSK), aiming at the disadvantages of low energy efficiency and spectrum ef

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
  • Code multiplexing differential chaotic modulator-demodulator for integrated code subscript modulation
  • Code multiplexing differential chaotic modulator-demodulator for integrated code subscript modulation
  • Code multiplexing differential chaotic modulator-demodulator for integrated code subscript modulation

Examples

Experimental program
Comparison scheme
Effect test

Embodiment

[0031] The implementation method of the present invention is further described below based on the computer simulation process. Suppose the chaotic carrier is generated by discrete Logistic mapping, and the sampling frequency of the signal is set to f s = 1000 times / second, the duration of the chaotic carrier T c = 0.008 seconds, the corresponding chaotic sampling number is θ=8, and the time to complete one transmission is T=NT c , the corresponding signal sampling point is β=Nθ. The mapping equation of the chaotic signal generator is When given the initial value x(0), by iterative formula x(i+1)=1-2×x 2 (i), i=0,....,i,....,θ-1, can generate a chaotic carrier sequence of length θ The construction method of the Nth order Walsh code matrix is: W m =[W m-1 ,W m-1 ;W m-1 ,-W m-1 ], W 1 =[+1,+1;+1,-1], where In the Walsh code matrix, we select the first row w of the matrix R As the modulation code of the reference signal, select the Walsh code of M=N / 2 row as the alt...

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 code multiplexing differential chaotic modulator-demodulator for integrated code subscript modulation and relates to modulation and demodulation in a communication system. The code multiplexing differential chaos modulator-demodulator comprises a modulator and a demodulator. The modulator comprises a binary/decimal converter, a serial/parallel converter, a natural number/combinatorial number mapper, a Walsh code selection controller, a chaotic signal generator, Q+1 Walsh code generators, a multiplier, a time delay unit, a shift switch and an adder. The combinatorial comprises a receiver, a multiplier, a square wave generator, an accumulator, an absolute value resolver, a comparison and selection controller, the shift switch, a decision device, the natural number/combinatorial number mapper and the binary/decimal converter. Transmitted information bits are mapped on selection of a Walsh code, a transmission data rate is improved, the bandwidth is increased, the energy efficiency is improved, and the bit error rate performance under an AWGN channel and a multi-path Rayleigh fading channel is equal to or better than that under conventional DCSK (Differential Chaotic Shift Keying). The modulator-demodulator is competitive in a short-distance communication application.

Description

technical field [0001] The invention relates to modulation and demodulation in a communication system, in particular to a code multiplexing differential chaotic modem with fusion code subscript modulation. Background technique [0002] Differential Chaotic Shift Keying (DCSK: Differential Chaotic Shift Keying) is a kind of digital modulation and demodulation technology with chaotic signal as carrier. The wide spectrum of chaotic signals makes DCSK have both modulation and spread spectrum functions, and is a low-cost alternative to traditional spread spectrum communication systems. In addition, DCSK technology has strong competitiveness in anti-multipath interference and low-cost ultra-wideband communication system, and also has good application prospects in the field of short-distance wireless communication. Code multiplexing differential chaotic shift keying (CS-DCSK) is a variant of DCSK. It uses orthogonal codes to replace the delay circuit in the original DCSK to achiev...

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
IPC IPC(8): H04L27/00
CPCH04L27/001
Inventor 许芳徐位凯王琳
Owner XIAMEN UNIV
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

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

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap