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A symbol detection method for pam-dmt system

A PAM-DMT and detection method technology, applied in the field of visible light wireless communication, can solve the problems of not fully considering the internal structure of the real part of the transmitted signal, etc., and achieve the effect of improving symbol detection performance, easy implementation, and improving signal-to-noise ratio

Active Publication Date: 2018-04-03
SOUTHEAST UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0008] Purpose of the invention: for the defect that the existing PAM-DMT system symbol detection method does not fully consider the internal structure of the real part of the transmitted signal, the present invention provides a method for decoding by extracting effective information in the clipping noise and utilizing two-way combination, thereby Symbol detection method for recovering transmitted symbol sequence and improving detection performance

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  • A symbol detection method for pam-dmt system
  • A symbol detection method for pam-dmt system
  • A symbol detection method for pam-dmt system

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Embodiment 1

[0033] The transmission block diagram of the PAM-DMT system involved in the present invention is as figure 1 As shown, the block diagram of the symbol detection method at the receiving end is as follows image 3 shown. Specific parameters are given as follows: the transmitted bits are not channel coded, the modulation method is 4-PAM, the number of subcarriers is N=64, and the transmission channel is an optical line-of-sight transmission (LOS, Line-of-Sight) channel, that is, additive Gaussian white For a noise (AWGN, Addictive White Gaussian Noise) channel, the frequency domain equalizer adopts a zero-forcing (ZF, Zero Forcing) equalization criterion, and a two-way combination coefficient α=0.5.

[0034] Concrete implementation steps of the present invention are as follows:

[0035] Step 1. The receiving end performs the decyclic prefix operation on the received electronic domain symbol sequence to obtain the time domain sequence y(n) to be detected, n=0, 1, ..., 63;

[00...

Embodiment 2

[0047] The transmission block diagram of the PAM-DMT system involved in the present invention is as figure 1 As shown, the block diagram of the symbol detection method at the receiving end is as follows image 3 shown. The given specific parameters are as follows: the transmitted bits are not channel coded, the modulation method is 16-PAM, the number of subcarriers is N=64, and the transmission channel is a non-line-of-sight optical diffuse reflection channel (scattering / reflective channel), that is, the frequency selectivity is more channel, the frequency domain equalizer adopts the Minimum Mean Square Error (MMSE, Minimum Mean Square Error) criterion, and the diversity combining ratio α=0.45.

[0048] Concrete implementation steps of the present invention are as follows:

[0049] Step 1. The receiving end performs the decyclic prefix operation on the received electronic domain symbol sequence to obtain the time domain sequence y(n) to be detected, n=0, 1, ..., 63;

[0050...

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Abstract

The invention discloses a symbol detecting method of a PAM (pulse-amplitude modulation)-DMT (discrete multi-tone modulation) system, and belongs to the field of visual light wireless communication. The method comprises the steps of performing FFT operation for a received symbol y (n) to obtain a frequency domain symbol Y (k); performing single-tap balancing for the Y (k) to obtain Yc (k); loading the real part of the Yc (k) to the real part of a sub-carrier and loading an imaginary part to the imaginary part of the sub-carrier; respectively performing the IFFG operation to obtain a time domain real part symbol yRe (n) and an imaginary symbol yIm (n); creating a new real part symbol yRe according to the polarity of the real part symbol and the absolute value of the imaginary part symbol; combining yRe, new (n) and yIm (n) into a signal with large single-to-noise ratio as shown in the specification by the double-channel combining method; performing FFT for the signal; extracting the imaginary part; multiplying by 2; determining the symbol; demodulating; recovering the bit for sending. According to the method, the double-channel combining method is carried out, and meanwhile, an imaginary part signal and a real part signal are utilize for symbol detecting, so that the effective signal-to-noise ratio of a received signal can be increased, and as a result, the symbol detection performance can be improved.

Description

technical field [0001] The invention belongs to the field of visible light wireless communication, and in particular relates to a symbol detection method of a PAM-DMT system. Background technique [0002] Visible light wireless communication (VLC, Visible Light Communication) is an emerging wireless communication technology that uses visible light source to transmit information. It is expected to be used in future indoor ultra-high-speed wireless communication, positioning and Internet of Vehicles and other fields. Since the bandwidth of the visible light frequency band reaches nearly 500THz, which is much larger than the bandwidth of the current mainstream radio frequency electromagnetic wave communication, it is considered as a new type of large-capacity spectrum resource and becomes an important part of the fifth-generation cellular mobile communication (5G) technology. In the realization of visible light wireless communication link, light emitting diode (LED, Light Emit...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H04L27/26
CPCH04B10/116H04B10/516H04B10/60
Inventor 党建项楠张在琛吴亮
Owner SOUTHEAST UNIV