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

Improved T/2 fractional spaced coordinate transforming blind equalization method

A technology of coordinate transformation and fractional interval, applied in the field of blind equalization algorithm of inter-symbol interference, which can solve the problems of slow convergence speed and large residual error, and achieve the effect of fast convergence speed, small residual error, and real-time signal recovery.

Inactive Publication Date: 2013-02-27
NANJING UNIV OF INFORMATION SCI & TECH
View PDF0 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to aim at the disadvantages of slow convergence speed and large residual error in the fractional interval blind equalization method (T / 2-FSE-CMA) for equalizing high-order QAM signals. By analyzing the distribution characteristics of the 16QAM signal constellation diagram, a method is invented. Improved Blind Equalization Method for T / 2 Fractional Interval Coordinate Transformation (T / 2-FSE-RCTCMA)

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
  • Improved T/2 fractional spaced coordinate transforming blind equalization method
  • Improved T/2 fractional spaced coordinate transforming blind equalization method
  • Improved T/2 fractional spaced coordinate transforming blind equalization method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0064][Embodiment 1] Adopt mixed-phase underwater acoustic channel c=[0.3132-0.10400.89080.3134]; transmit signal is 16QAM, equalizer weight length is 32, signal-to-noise ratio is 25dB, and the weight length of each sub-channel equalizer is 16 , the weight vector is initialized as the center tap, and the step size μ of the three methods T / 2-FSE , μ T / 2-FSE-CTCMA , μ T / 2-FSE-RCTCMA They are 0.000006, 0.00003, and 0.0009 respectively. 5000 Monte Carlo simulation results, such as Figure 4 shown.

[0065] Figure 4 (a) simulation result shows, on steady-state error, the method T / 2-FSE-RCTCMA of the present invention has reduced 2dB than T / 2-FSE-CTCMA method, than T / 2-FSE-CMA method, has reduced 5dB; in terms of convergence speed, the T / 2-FSE-RCTCMA method of the present invention has the fastest convergence, which is nearly 2000 steps faster than the T / 2-FSE-CMA method. Figure 4 (b) shows that under different signal-to-noise ratios, the root mean square error of the method ...

Embodiment 2

[0066] [Embodiment 2] Time-varying channel c 1 The transfer function of c 1 =[0.9656-0.0906 0.0578 0.2368], when the transmitter transmits 5000 signal points, the channel changes to channel c 2 , whose transfer function is c 2 =[-0.35 0 0 1], transmit 10000 signal points, the channel changes to channel c 3 , whose transfer function is c 3 =[0.3132-0.1040 0.8908 0.3134]. With the sampling of the transmitted signal at different times, the channel zero-pole distribution changes, so as to simulate the time-varying characteristics of the channel.

[0067] The transmitted signal is 16QAM, the weight length of the equalizer is 32, the signal-to-noise ratio is 25dB, the weight length of each sub-channel equalizer is 16, and the weight vector is initialized as the center tap. In the time-varying channel, the step size parameters of the three methods As shown in Table 1. 500 Monte Carlo simulation results, such as Figure 5 shown.

[0068] Table 1 Simulation parameters of three ...

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 improved T / 2 fractional spaced coordinate transforming blind equalization method (T / 2-FSE-RCTCMA). Aiming at the defects of low convergence speed and large remainder error of a fractional spaced blind equalization method (T / 2-FSE-CMA) during equalizing a higher order QAM signal, the improved method adopts the following steps: separately equalizing a real part and an imaginary part of an input signal of a fractional spaced blind equalizer by analyzing the distribution characteristic of a 16QAM signal constellation diagram; transforming output signals onto the same circle by utilizing coordinate transformation so as to obtain a constant modulus error function after the coordinate transformation; and using the error function to adjust weight vectors of each path ofblind equalizers of the T / 2 fractional spaced blind equalizer. The improved method effectively overcomes erroneous judgments of the T / 2 FSE CMA method to multi-modulus higher order QAM signals duringequalizing. The T / 2-FSE-RCTCMA method has high convergence speed and small mean square error.

Description

technical field [0001] The invention relates to an improved blind equalization method for T / 2 fractional interval coordinate transformation, and belongs to the technical field of blind equalization algorithms for overcoming inter-symbol interference (Inter-Symbol Interference, ISI) caused by multipath fading of underwater acoustic channels. Background technique [0002] In underwater acoustic communication, the blind equalization technique that does not require training sequences is the main means to eliminate Inter-Symbol Interference (ISI), (see literature [1]: Dabeer 0, Masry E. Convergence analysis of the constant modulus algorithm [J]. IEEE Transactions on Information Theory, 2003, 49(6): 1447-1464). Among them, the Porter interval normal mode equalizer (see literature [2]: Qiu Tianshuang, et al. Adaptive Signal Processing in Communication. Electronic Industry Press. 2005) has a simple structure, but slow convergence speed and large steady-state error; Fractionally-Spa...

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 Patents(China)
IPC IPC(8): H04L1/00H04B13/02
Inventor 郭业才赵雪清
Owner NANJING UNIV OF INFORMATION SCI & TECH
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