WO2018113456A1

WO2018113456A1 - Terahertz digital communication system and method based on polarization coding

Info

Publication number: WO2018113456A1
Application number: PCT/CN2017/111226
Authority: WO
Inventors: 杨彬; 郑渚; 丁庆
Original assignee: 深圳市太赫兹科技创新研究院; 华讯方舟科技有限公司
Priority date: 2016-12-22
Filing date: 2017-11-16
Publication date: 2018-06-28
Also published as: KR20180088384A; CN106603156B; KR102023907B1; CN106603156A

Abstract

The present invention relates to a terahertz digital communication system and method based on polarization coding. The system respectively controls two pulse terahertz sources according to a digital signal to be transmitted; the two pulse terahertz sources respectively generate pulse signals at the moment when signals are 0 and 1, and then respectively form the two signals into linear polarization signals by means of a polarization unit, the polarization directions being orthogonal; the two linear polarization signals are synthesized by a polarization beam splitter into one signal and are then transmitted; after a receiving end receives the signal, the signal is restored to two signals by means of the polarization beam splitter; and then, the signal 0 and the signal 1 are respectively demodulated by a terahertz detector to complete data transmission. The present invention has the advantages of not occupying a bandwidth resource, direct and fast modulation and simple implementation, and is a new supplement to an existing terahertz communication scheme. The rate of communication is determined by the rate of a pulse terahertz source, the pulse instantaneous energy of the pulse terahertz source is high, the power can be made relatively large, and the anti-fading capability is stronger than that of a continuous wave.

Description

Terahertz digital communication system and method based on polarization coding

Technical field

The communication field of the present invention relates in particular to a terahertz digital communication system based on polarization coding, and to a terahertz digital communication method based on polarization coding.

Background technique

The increased demand for unallocated idle spectrum resources will inevitably lead to the development of wireless communication system operating frequencies to higher frequency terahertz (THz) bands. The instantaneous transmission of big data will use a higher carrier frequency to meet the high transmission rate requirements. A large number of studies have shown that the application of terahertz communication technology in the field of communication has many advantages compared with the more mature microwave communication and optical fiber communication, such as high transmission rate, good directionality, high security, small scattering, and Good penetration and so on.

At present, the coding scheme of terahertz communication mainly has (ASK, OOK) binary modulation method and (MQAM, MPSK) multiple orthogonal modulation. Although the binary modulation method is simple in implementation and high in power efficiency, it requires a large bandwidth for high-speed data transmission and is sensitive to nonlinear characteristics of the device. It is difficult to implement complex algorithms to adapt to the channel environment in practical applications; MPSK and Higher-order modulation methods such as MQAM are more efficient than binary modulation, but they are complex to implement. Consider the THz local oscillator phase noise, analog-to-digital converter (ADC) sampling rate, and power amplifier nonlinearity in a coherent receiver.

Summary of the invention

Based on this, it is necessary to provide a new type of terahertz digital communication system based on polarization coding for the problem of high bandwidth occupied by the existing coding scheme of terahertz communication.

A terahertz digital communication system based on polarization coding, comprising a signal transmitting end and a signal receiving end, the signal transmitting end comprising: a digital signal generating unit, configured to generate a digital signal consisting of 0 and 1 according to data to be transmitted a first pulse terahertz source for receiving the digital signal and transmitting a first terahertz signal at each moment when the digital signal is zero; a second pulse terahertz source for receiving the digital signal and Transmitting a second terahertz signal at each moment of signal 1; a first polarization unit for The first terahertz signal emitted from the first pulse terahertz source is converted into a linearly polarized signal and then emitted to the first polarization beam splitter; and the second polarization unit is used to output a second terahertz from the second pulse terahertz source Translating the signal into a linearly polarized signal and outputting to the first polarizing beam splitter; the linearly polarized signal converted by the first terahertz signal and the polarization direction of the linearly polarized signal converted by the second terahertz signal form a positive direction The first polarizing beam splitter is configured to combine the two-path polarized signals into one signal and then output the signal to the transmitting unit; the transmitting unit is configured to transmit the signal; and the signal receiving end includes: a receiving unit, Receiving a signal transmitted by the transmitting unit; and a second polarization beam splitter for reducing the signal received by the receiving unit into two terahertz signals corresponding to the first terahertz signal and the second terahertz signal respectively; the first terahertz a detector disposed on an outgoing path of a signal corresponding to the first terahertz signal of the second polarization beam splitter, generating a response when receiving the terahertz signal and transmitting the signal to the demodulation list a second terahertz detector, disposed on an outgoing path of the second polarization beam splitter corresponding to the second terahertz signal, generating a response when the terahertz signal is received and transmitting to the demodulation unit; The demodulation unit demodulates the signal 0 upon receiving the response of the first terahertz detector and demodulates the signal 1 upon receiving the response of the second terahertz detector.

In one embodiment, the first polarization beam splitter is configured to reflect one of the two route polarization signals and the other channel to transmit a signal, and the second polarization beam splitter receives the received signal from the receiving unit. The mutually orthogonal components of the signal are reflected and transmitted, respectively, to be reduced to two terahertz signals.

In one embodiment, the first polarizing beam splitter reflects a linearly polarized signal of a first terahertz signal and transmits a linearly polarized signal of a second terahertz signal, the second polarizing beam splitter Transmitting a component of the first terahertz signal to reflect a component of the second terahertz signal, the first terahertz detector being a detector of a reflection path of the second polarization beam splitter, the second The Hertz detector is a detector for the transmission path of the second polarization beam splitter.

In one of the embodiments, the firing unit comprises a focusing lens.

In one of the embodiments, the receiving unit comprises a focusing lens.

It is also necessary to provide a terahertz digital communication method based on polarization coding.

A terahertz digital communication method based on polarization coding, comprising: generating a digital signal consisting of 0 and 1 according to data to be transmitted; transmitting a first terahertz signal at each moment when the digital signal is 0, Transmitting a second terahertz signal at each moment when the digital signal is 1; converting the first terahertz signal into a linearly polarized signal and then outputting to the first polarization beam splitter; converting the second terahertz signal into a linearly polarized signal Exiting to the first polarizing beam splitter; the linearly polarized signal converted by the first terahertz signal is orthogonal to a polarization direction of a linearly polarized signal converted by the second terahertz signal; the first polarization The beam splitter combines the two-path polarization signals into one signal to transmit the signal; the receiving end receives the transmitted signal, and reduces the received signal to two terahertz signals through the second polarization beam splitter, respectively corresponding to the first a Hertzian signal and a second terahertz signal; signal detection by a first terahertz detector disposed on an exit path of a signal corresponding to the first terahertz signal of the second polarization beam splitter, and detecting terahertz Generating a response when the signal is generated; performing signal detection by a second terahertz detector disposed on an exit path of a signal of the second polarization beam splitter corresponding to the second terahertz signal And generating a response when a terahertz signal is detected; a signal 0 is demodulated each time the first terahertz detector generates a response, and a signal 1 is demodulated each time the second terahertz detector generates a response.

In one embodiment, the step of transmitting the first terahertz signal at each moment when the digital signal is 0 is to transmit a first terahertz signal by a first pulse terahertz source, wherein the digital signal is The step of transmitting the second terahertz signal at each instant of 1 is to transmit a second terahertz signal through the second pulse terahertz source.

In one embodiment, the first polarization beam splitter combines the two-path polarization signals into one signal and then transmits the signal, and the signal is transmitted through the first focus lens and then transmitted; the receiving end receives the transmitted signal. The step of signaling includes focusing the received signal onto the second polarizing beam splitter by a second focusing lens.

In one embodiment, the first polarization beam splitter combines the two-path polarization signals into one signal and then transmits the signal, and the first polarization beam splitter reflects one of the two-path polarization signals. And synthesizing a signal after another transmission, wherein the second polarization beam splitter reduces the received signal into two terahertz signals, and the second polarization beam splitter transmits the received signal The mutually orthogonal components are reflected and transmitted, respectively, to be reduced to two terahertz signals.

In one embodiment, the first polarizing beam splitter reflects a linearly polarized signal of a first terahertz signal and transmits a linearly polarized signal of a second terahertz signal, the second polarizing beam splitter Is to reflect the components of the first terahertz signal and transmit the components of the second terahertz signal. The first terahertz detector is a detector of a reflection path of a second polarization beam splitter, and the second terahertz detector is a detector of a transmission path of a second polarization beam splitter.

The above-mentioned terahertz digital communication system based on polarization coding has the advantages of not occupying bandwidth resources, directly and rapidly modulating, and realizing simplicity, and is a completely new supplement to the existing terahertz communication scheme. The rate of communication is determined by the rate of the pulsed terahertz source. The pulsed terahertz source has a high pulse instantaneous energy, and the power can be made larger, and the attenuation resistance is stronger than that of the continuous wave.

DRAWINGS

1 is a schematic structural diagram of a terahertz digital communication system based on polarization coding in an embodiment;

2 is a flow chart of a terahertz digital communication method based on polarization encoding in an embodiment.

detailed description

In order to facilitate the understanding of the present invention, the present invention will be described more fully hereinafter with reference to the accompanying drawings. Preferred embodiments of the invention are given in the drawings. However, the invention may be embodied in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and comprehensive.

It should be noted that when an element is referred to as being "fixed" to another element, it can be directly on the other element or the element can be present. When an element is considered to be "connected" to another element, it can be directly connected to the other element or. The terms "vertical," "horizontal," "left," "right," and the like, as used herein, are for illustrative purposes only.

All technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, unless otherwise defined. The terminology used in the description of the present invention is for the purpose of describing particular embodiments and is not intended to limit the invention. The term "and/or" used herein includes any and all combinations of one or more of the associated listed items.

1 is a schematic structural diagram of a terahertz digital communication system based on polarization coding, including a signal transmitting end 100 and a signal receiving end 200, wherein the signal transmitting end 100 includes a digital signal generating unit 110 and a first pulse terahertz source. 122, a second pulse terahertz source 124, a first polarization unit 132, The second polarization unit 134, the first polarization beam splitter 140, and the emission unit 150.

When the above-described polarization encoding-based terahertz digital communication system performs communication, the digital signal generating unit 110 first generates a digital signal composed of 0 and 1 based on the data to be transmitted. The pulses generated by the first pulse terahertz source 122 and the second pulse terahertz source 124 are controlled by the digital signal: the first pulse terahertz source 122 transmits the first terahertz signal at each moment when the digital signal is zero, after the first polarization The unit 132 is converted to a linearly polarized signal and then emitted to the first polarizing beam splitter 140; the second pulsed terahertz source 124 emits a second terahertz signal at each moment when the digital signal is 1, and converted to linear polarization by the second polarizing unit 134. The signal is also emitted to the first polarization beam splitter 140. The linearly polarized signal into which the first terahertz signal is converted is orthogonal to the polarization direction of the linearly polarized signal converted by the second terahertz signal (eg, the angle of the first terahertz signal is 90 degrees, and the angle of the second terahertz signal It is 0 degrees). The first polarization beam splitter 140 synthesizes two orthogonal linearly polarized signals into one terahertz signal and then outputs them to the transmitting unit 150, and the transmitting unit 150 transmits the terahertz signal into the propagation path.

The signal receiving end 200 includes a receiving unit 250, a second polarizing beam splitter 240, a first terahertz detector 232, a second terahertz detector 234, and a demodulating unit 220.

The terahertz signal reaches the signal receiving end 200 via the propagation path, is received by the receiving unit 250, and is transmitted to the second polarization beam splitter 240. The second polarization beam splitter 240 restores the signal to two terahertz signals, which correspond to the first terahertz signal and the second terahertz signal, respectively. A first terahertz detector 232 is disposed on an outgoing path of a signal corresponding to the first terahertz signal of the second polarization beam splitter 240, and a signal of the second polarization beam splitter 240 corresponding to the second terahertz signal is emitted. A second terahertz detector 234 is provided on the route, each of which generates a response upon transmission of the terahertz signal and transmits it to the demodulation unit 220. The demodulation unit 220 demodulates the signal 0 upon receiving the response of the first terahertz detector 232, and demodulates the signal 1 upon receiving the response of the second terahertz detector 234. In one embodiment, the first terahertz detector 232 and the second terahertz detector 234 are detectors employing Schottky barrier diodes (SBD).

The above-mentioned terahertz digital communication system based on polarization coding has the advantages of not occupying bandwidth resources, directly and rapidly modulating, and realizing simplicity, and is a completely new supplement to the existing terahertz communication scheme. A pulsed terahertz source directly modulated with a digital signal is used as a source of communication, and the rate of communication is determined by the rate of the pulsed terahertz source. Since the pulse instantaneous energy of the pulse terahertz source is high, the transmitting power of the transmitting unit 150 The rate can be made larger and the anti-attenuation ability is stronger than the continuous wave.

In one embodiment, the first polarization unit 132 and the second polarization unit 134 are polarizers.

In one embodiment, the firing unit 150 includes a focusing lens 150 that condenses the signal emitted by the first polarizing beam splitter 140 into a propagation space. The receiving unit 250 is also provided with a focusing lens, and the signal is collected by the focusing lens and transmitted to the second polarization beam splitter 240.

Referring to FIG. 1, the first polarization beam splitter 140 reflects one of the two-path polarization signals and the other channel transmits the signals, and the second polarization beam splitter 240 positively signals the signals received by the receiving unit 250. The intersecting components are reflected and transmitted separately to be reduced to two terahertz signals.

In the embodiment shown in FIG. 1, the first polarization beam splitter 140 reflects the linearly polarized signal of the first terahertz signal to transmit the linearly polarized signal of the second terahertz signal; the second polarization beam splitter 240 The component of the first terahertz signal in the received signal is reflected, and the component of the second terahertz signal is transmitted. The first terahertz detector 232 is disposed on the reflection path of the second polarization beam splitter 240, and the second terahertz detector 234 is a transmission path disposed on the second polarization beam splitter 240.

2 is a flow chart of a terahertz digital communication method based on polarization coding in an embodiment, including the following steps:

S110, generating a digital signal consisting of 0 and 1 according to the data to be transmitted.

If the data to be transmitted is itself a digital signal, it can be used directly.

S120, transmitting a first terahertz signal at each moment when the digital signal is 0, and transmitting a second terahertz signal at each moment when the digital signal is 1.

In this embodiment, two pulse terahertz sources are provided, and the pulse signals generated by the two pulse terahertz sources are respectively controlled according to the digital signals, wherein the time at which the first pulse terahertz source generates a signal is a digital signal of 0. At each time, the time at which the second pulse terahertz source generates a signal is the time at which the digital signal is 1.

S130. Convert the first terahertz signal into a linearly polarized signal and then exit to the first polarizing beam splitter.

S140. Convert the second terahertz signal into a linearly polarized signal and then exit to the first polarizing beam splitter.

The linearly polarized signal converted by the first terahertz signal is orthogonal to the polarization direction of the linearly polarized signal converted by the second terahertz signal. In this embodiment, polarizers are respectively disposed on the signal exit routes of the first and second pulse terahertz sources, and the first and second terahertz signals respectively pass through the respective polarizers. Import the first polarizing beam splitter.

S150. The first polarization beam splitter combines the two-path polarization signals into one signal to perform signal transmission.

Steps S110 to S150 are steps performed by the signal transmitting end. In one embodiment, the signal is transmitted through the first focusing lens and into the propagation space of the terahertz signal.

S160. The receiving end receives the transmitted signal, and reduces the received signal to two terahertz signals through the second polarizing beam splitter.

In one embodiment, the received signal is focused onto the second polarizing beam splitter by a second focusing lens.

S170: Perform signal detection by the first and second terahertz detectors, and generate a response when the terahertz signal is detected.

Signal detection is performed by a first terahertz detector disposed on an exit path of a signal of the second polarization beam splitter corresponding to the first terahertz signal, and a response is generated when the terahertz signal is detected. Signal detection is performed by a second terahertz detector disposed on an exit path of a signal of the second polarization beam splitter corresponding to the second terahertz signal, and a response is generated when the terahertz signal is detected.

S180, demodulating the signal 0 whenever the first terahertz detector generates a response, and demodulating the signal 1 whenever the second terahertz detector generates a response.

Steps S160 to S180 are steps performed by the signal receiving end.

In one embodiment, in step S150, one of the two polarization signals is reflected by the first polarization beam splitter, and the other is transmitted to form a signal. In step S160, the components orthogonal to each other in the received signals are respectively reflected and transmitted by the second polarization beam splitter, thereby being reduced to two terahertz signals.

In one embodiment, step S150 is to reflect the linearly polarized signal of the first terahertz signal by the first polarization beam splitter and to transmit the linearly polarized signal of the second terahertz signal. In step S160, the components of the first terahertz signal are reflected by the second polarization beam splitter to transmit the components of the second terahertz signal. The first terahertz detector is a detector of the reflection path of the second polarization beam splitter, and the second terahertz detector is a detector of the transmission path of the second polarization beam splitter.

The technical features of the above-described embodiments may be combined in any combination. For the sake of brevity of description, all possible combinations of the technical features in the above embodiments are not described. However, as long as these techniques are There is no contradiction in the combination of the technical features, and should be considered as the scope of the description.

The above-described embodiments are merely illustrative of several embodiments of the present invention, and the description thereof is more specific and detailed, but is not to be construed as limiting the scope of the invention. It should be noted that a number of variations and modifications may be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, the scope of the invention should be determined by the appended claims.

Claims

A terahertz digital communication system based on polarization coding, comprising a signal transmitting end and a signal receiving end, wherein the signal transmitting end comprises:

a digital signal generating unit, configured to generate a digital signal consisting of 0 and 1 according to the data to be transmitted;

a first pulse terahertz source for receiving the digital signal and transmitting a first terahertz signal at each moment when the digital signal is zero;

a second pulse terahertz source for receiving the digital signal and transmitting a second terahertz signal at each moment when the digital signal is one;

a first polarization unit for converting a first terahertz signal emitted from the first pulse terahertz source into a linearly polarized signal and then outputting to the first polarization beam splitter;

a second polarization unit for converting a second terahertz signal emitted from the second pulse terahertz source into a linearly polarized signal and then outputting to the first polarization beam splitter; the first terahertz signal is converted into a line The polarization signal is orthogonal to a polarization direction of the linearly polarized signal converted by the second terahertz signal;

The first polarization beam splitter is configured to combine the two-path polarization signals into one signal and then output to the transmitting unit;

The transmitting unit is configured to transmit a signal;

The signal receiving end includes:

a receiving unit, configured to receive a signal transmitted by the transmitting unit;

a second polarization beam splitter, configured to restore the signal received by the receiving unit to two terahertz signals corresponding to the first terahertz signal and the second terahertz signal, respectively;

a first terahertz detector, disposed on an outgoing path of a signal corresponding to the first terahertz signal of the second polarization beam splitter, generating a response when receiving the terahertz signal and transmitting the signal to the demodulation unit;

a second terahertz detector, disposed on an outgoing path of a signal corresponding to the second terahertz signal of the second polarization beam splitter, generating a response when receiving the terahertz signal and transmitting the signal to the demodulation unit;

The demodulation unit demodulates the signal 0 upon receiving the response of the first terahertz detector and demodulates the signal 1 upon receiving the response of the second terahertz detector.
A polarization encoding based terahertz digital communication system according to claim 1 The first polarizing beam splitter is configured to reflect one of the two-path polarized signals and the other to transmit a signal, and the second polarizing beam splitter is orthogonal to the signals received by the receiving unit. The components are reflected and transmitted separately to be reduced to two terahertz signals.
The polarization encoding-based terahertz digital communication system according to claim 2, wherein said first polarization beam splitter reflects a linearly polarized signal of said first terahertz signal and transmits a second terahertz signal The linearly polarized signal is transmitted, the second polarizing beam splitter reflects a component of the first terahertz signal, and transmits a component of the second terahertz signal, the first terahertz detector is a second polarization A detector of a reflection path of the beam splitter, the second terahertz detector being a detector of a transmission path of the second polarization beam splitter.
A polarization encoding based terahertz digital communication system according to claim 1 wherein said transmitting unit comprises a focusing lens.
A polarization-coded terahertz digital communication system according to claim 1, wherein said receiving unit comprises a focus lens.
A terahertz digital communication method based on polarization coding, comprising:

Generating a digital signal consisting of 0 and 1 according to the data to be transmitted;

Transmitting a first terahertz signal at each moment when the digital signal is 0, and transmitting a second terahertz signal at each moment when the digital signal is 1.

Converting the first terahertz signal into a linearly polarized signal and then exiting to the first polarizing beam splitter;

Converting a second terahertz signal into a linearly polarized signal and outputting to the first polarizing beam splitter; converting the linearly polarized signal converted by the first terahertz signal and the linearly polarized signal converted by the second terahertz signal The polarization directions form orthogonal;

The first polarization beam splitter combines the two-path polarization signals into one signal and then transmits the signal;

The receiving end receives the transmitted signal, and reduces the received signal to two terahertz signals through the second polarizing beam splitter, corresponding to the first terahertz signal and the second terahertz signal, respectively;

Generating a signal by a first terahertz detector disposed on an exit path of a signal corresponding to the first terahertz signal of the second polarization beam splitter, and generating a response when the terahertz signal is detected;

Generating a signal by a second terahertz detector disposed on an exit path of a signal corresponding to the second terahertz signal of the second polarization beam splitter, and generating a response when the terahertz signal is detected;

Signal 0 is demodulated each time the first terahertz detector generates a response, and signal 1 is demodulated each time the second terahertz detector generates a response.
The polarization encoding-based terahertz digital communication method according to claim 6, wherein said step of transmitting a first terahertz signal at each time when said digital signal is 0 is through a first pulse terahertz source A first terahertz signal is transmitted, and the step of transmitting the second terahertz signal at each moment when the digital signal is one is to transmit a second terahertz signal through the second pulse terahertz source.
The terahertz digital communication method based on polarization encoding according to claim 6, wherein the step of synthesizing the two polarization signals by combining the two polarization signals into one signal and transmitting the signal is to pass the signal The first focusing lens is then re-transmitted; the receiving end receiving the transmitted signal includes focusing the received signal onto the second polarizing beam splitter by a second focusing lens.
The terahertz digital communication method based on polarization encoding according to claim 6, wherein the first polarization beam splitter combines the two-path polarization signals into one signal and then transmits the signal, the A polarization beam splitter reflects one of the two-path polarized signals and the other transmits a signal, and the second polarizing beam splitter reduces the received signal into two terahertz signals. The second polarization beam splitter reflects and transmits components orthogonal to each other in the received signal, thereby being reduced to two terahertz signals.
The polarization encoding-based terahertz digital communication method according to claim 9, wherein the first polarization beam splitter reflects the linearly polarized signal of the first terahertz signal and the second terahertz signal The linearly polarized signal is transmitted, the second polarizing beam splitter reflects a component of the first terahertz signal, and transmits a component of the second terahertz signal, the first terahertz detector is a second polarization A detector of a reflection path of the beam splitter, the second terahertz detector being a detector of a transmission path of the second polarization beam splitter.