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A Noise Suppression Method for UWB Wireless Communication System Based on Time Reversal

A wireless communication system, noise suppression technology, applied in the field of communication, can solve problems such as increase and deterioration of bit error rate

Inactive Publication Date: 2019-03-05
UNIV OF ELECTRONICS SCI & TECH OF CHINA
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0013] At present, the modulation techniques used in ultra-wideband (UWB) wireless communication systems are mainly pulse position modulation (PPM) and pulse amplitude modulation (PAM); among them, PPM can remove the energy peak of UWB spectrum, make the power spectrum flatter, and realize multiple However, the study found that in the time-reversal UWB communication system that only uses PPM modulation, the noise level of the received signal will increase as the number of bits sent increases. The more bits the transmitter sends at one time, the higher the noise level. The signal-to-sidelobe ratio will gradually deteriorate, resulting in an increase in the bit error rate; and so far, there is no effective processing method to solve this problem

Method used

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  • A Noise Suppression Method for UWB Wireless Communication System Based on Time Reversal
  • A Noise Suppression Method for UWB Wireless Communication System Based on Time Reversal
  • A Noise Suppression Method for UWB Wireless Communication System Based on Time Reversal

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Embodiment 1

[0055] Using the finite difference time domain method (FDTD) to conduct full-wave electromagnetic simulation research on an indoor environment (in the simulation, a two-dimensional plane model is used instead of three-dimensional simulation, and the boundary is set as the electromagnetic characteristics of the wall), four dipole antennas with uniform spacing As a time reversal mirror, the target point is located at (288, 244), which is near the center of the entire space. The simulation structure is as follows Figure 4 shown;

[0056] There is a binary data of 5 bits, bits=[11010], the data is generated by a random function; the modulation code mapped to the direct modulation pulse position is: mod-code=[0101100110], such as Figure 5 Shown; the channel impulse response after flipping between the four units of the time reversal mirror and the target point is as follows Image 6 As shown, after the pulse position modulation is performed with the modulation code mod-code, the ...

Embodiment 2

[0061] Taking the 20bits signal again as an example, a 20bit data signal is randomly generated such as Figure 10 As shown, according to the mapping relationship, the modulation code of the modulated pulse is obtained as Figure 11 As shown, the signals to be transmitted by each TRM are as follows Figure 12 As shown, it is imported into FDTD for simulation, and the received signal of the target point is obtained as Figure 13 As shown, the previous accumulation is carried out, and the result is as follows Figure 14 As shown, it can be seen that the result is consistent with the twenty-bit modulation code; the initial received signal, the demodulated pulse signal and the sidelobe signal are as follows Figure 15 shown.

[0062] By comparing the unprocessed signal waveforms with those processed by the present invention, it can be seen intuitively that the present invention can significantly improve the time-focusing performance of the time-reversal signal. The Signal-to-Si...

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Abstract

The invention belongs to the field of communication, and provides a method for suppressing noise in an ultra-wideband wireless communication system based on time inversion. According to the noise distribution characteristics of time inversion received signals, the method compares the value of the current item in the discrete-time signal sequence received by the receiver with the value of The values ​​of all the previous items are accumulated to obtain the sum formula, and then the sum formula is output as the received signal of the item; each item of the received discrete signal is superimposed in turn to obtain the processed received signal, and then the signal is Perform normal signal demodulation. The present invention effectively reduces the noise level at the receiving end and increases the length of the time-reversal communication frame by preprocessing the received signal, thereby improving the signal transmission quality and transmission rate, that is, improving the communication performance of the time-reversal communication system.

Description

technical field [0001] The invention belongs to the communication field and relates to a noise suppression method for an ultra-wideband wireless communication system based on time reversal. Background technique [0002] Time reversal (Time Reversal, TR) was originally a signal processing technology in acoustics, which enables the sound waves propagating in homogeneous and non-uniform media to achieve simultaneous focusing in time and space; in 2004, time reversal technology was introduced into electromagnetic In the field of science, people began to explore the application of time reversal technology in electromagnetic wave systems. The study found that the use of time reversal technology can realize the time and space synchronous focusing of electromagnetic waves. This unique physical property makes time reversal electromagnetics widely used in many fields of electronic information science and technology, such as high-speed and large-capacity Wireless data transmission, sp...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H04B14/02H04B14/04
CPCH04B14/026H04B14/046
Inventor 杨雪松吴迪院琳王秉中
Owner UNIV OF ELECTRONICS SCI & TECH OF CHINA