阅读说明：本技术 一种基于开环霍尔传感器的全息irs表面及通信系统 (Holographic IRS surface and communication system based on open-loop Hall sensor ) 是由 罗文宇 马怡乐 翟亚坤 丁泽奇 邵霞 于 2021-03-05 设计创作，主要内容包括：一种基于开环霍尔传感器的全息IRS表面,由N个小单元等距排列构成,所述小单元包括PIN二极管、直流电源、扼流电感、保护电阻和开环霍尔传感器,其中PIN二极管的阳极与扼流电感的一端连接,扼流电感的另一端与直流电源的正极连接,直流电源DC的负极接地,PIN二极管的阴极与保护电阻的一端连接,保护电阻的另一端接地,开环霍尔传感器置于扼流电感与PIN二极管之间的回路中。本发明的全息IRS表面可以通过全息成像的方式将携带用户信息的物光波和基站发射的参考波在IRS表面上形成全息图,而后再次从基站发射参考波即可完成显象,即还原为成像过程中用户发向IRS表面的物光波,据此可在无需信道估计的情况下完成整个通信过程。(The utility model provides a holographic IRS surface based on open-loop Hall sensor, is arranged by the little unit equidistance of N and constitutes, little unit includes PIN diode, DC power supply, choke inductance, protection resistance and open-loop Hall sensor, and wherein the positive pole of PIN diode is connected with choke inductance's one end, and choke inductance's the other end is connected with DC power supply's positive pole, and DC power supply DC's negative pole ground connection, PIN diode's negative pole and protection resistance's one end are connected, and protection resistance's the other end ground connection, open-loop Hall sensor arranges in the return circuit between choke inductance and the PIN diode. The holographic IRS surface of the invention can form a hologram on the IRS surface by the object light wave carrying user information and the reference wave emitted by the base station in a holographic imaging mode, and then the reference wave is emitted from the base station again to finish visualization, namely, the object light wave is restored to the object light wave emitted to the IRS surface by the user in the imaging process, thereby the whole communication process can be finished without channel estimation.)

1. A holographic IRS surface based on open-loop Hall sensor which characterized in that: the high-voltage power supply is formed by arranging N small units at equal intervals, wherein each small unit comprises a PIN diode (D1), a direct-current power supply (DC), a choke inductor (L1), a protection resistor (R1) and an open-loop Hall sensor, the anode of the PIN diode (D1) is connected with one end of the choke inductor (L1), the other end of the choke inductor (L1) is connected with the anode of the direct-current power supply (DC), the cathode of the direct-current power supply (DC) is grounded, the cathode of the PIN diode (D1) is connected with one end of the protection resistor (R1), the other end of the protection resistor (R1) is grounded, and the open-loop Hall sensor is arranged in a loop between the choke inductor (L1) and the PIN diode (D1).

2. The open-loop hall sensor based holographic IRS surface of claim 1, wherein: the two states of the switch of the PIN diode (D1) correspond to the two coupled phase states of the small cell.

3. The open-loop hall sensor based holographic IRS surface of claim 1, wherein: the open-loop Hall sensor is used for measuring the magnitude of high-frequency current induced by the small unit in two states of switching, and after comparison, the state of the PIN diode switch with larger high-frequency current is reserved and fed back to the controller.

4. A communication system based on the open-loop hall sensor based holographic IRS surface according to any of claims 1 to 3, characterized in that: the device comprises a base station, a controller, a user, a holographic IRS surface, a signal splitter and a signal reflector, wherein a radio frequency signal transmitted by the base station is divided into two paths of signals, namely a signal 1 and a signal 2, the first beam of signal 1 reaches the user, the user needing communication can reflect a signal 3 to the holographic IRS surface, the second beam of signal 2 enters the holographic IRS surface after being reflected by the signal reflector, two beams of signal waves interfere on the holographic IRS surface to form a hologram, a plurality of small units on the holographic IRS surface record a holographic pattern through two coupling phase states, and the on-off state of a PIN diode in each unit on the holographic IRS surface is fed back to the controller and stored to complete a training part; after training is finished, when a user needs to communicate, a beam of signal 2 is directly sent to the surface of the holographic IRS from the base station, the controller restores the switch state of a built-in PIN diode of the unit array on the surface of the holographic IRS to the state recorded by the controller when training is finished, and the phase state of a plurality of small units on the surface of the holographic IRS is a holographic pattern formed by interference of two beams of waves; the hologram can record the basic information of interference waves, and after the base station transmits a signal 2, the holographic IRS surface can reflect a beam of signal 4 to a user, so that the actual communication process is completed.

5. The open-loop hall sensor based holographic IRS surface communication system of claim 4, characterized in that: the controller comprises a single chip microcomputer and an FPGA programmable controller, voltage output by the open-loop Hall sensor is transmitted to the single chip microcomputer after analog-to-digital conversion, the single chip microcomputer can be simultaneously connected to comparison circuits inside open-loop Hall sensor units on the surfaces of the plurality of holographic IRSs, programmable voltage and programmable data are generated after centralized processing and fed back to the FPGA controller, and the FPGA controller sends instructions to control the phase state of the single small unit.

Technical Field

The invention relates to the technical field of optical communication, in particular to a holographic IRS surface based on an open-loop Hall sensor and a communication system.

Background

An Intelligent Reflective Surface (IRS) technology is a technology for realizing wireless signal transmission in a wireless network. IRS is able to dynamically change the wireless channel to improve communication performance by skillfully adjusting signal reflection through a large number of low-cost passive reflective elements, and hybrid wireless networks (including active and passive elements) assisted by IRS are expected to be highly promising for realizing cost-effective sustainable capacity growth in the future. Despite its great potential, IRS faces new challenges in efficiently integrating into wireless networks, the most significant challenge being the channel estimation problem of the communication system formed by IRS.

Because the IRS surface is formed by combining a plurality of passive small units. Because the number of small units is large, the conventional channel estimation is very complex to solve the IRS channel problem, and the passive characteristic thereof reduces the power consumption of the receiver but cannot actively process signals, which is why the channel estimation in the conventional model is not suitable for the channel estimation of the IRS surface communication system.

From the start of modern mobile communications, the radio channel between the transmitting end and the receiving end is usually modeled as a random process. In the conventional communication channel estimation, a pilot frequency is usually transmitted to calculate channel information between a user and a base station, but for a novel communication system including an IRS surface, a channel process of a cascade channel of a "base station-IRS surface-user" is too complex, and how to acquire a three-dimensional coordinate of the user at an unknown position to obtain an optimal effect of beamforming is also a difficult problem. However, the way in which the passive element in the IRS reflects the arriving signal determines that the IRS does not include a transmitter module, and cannot process the acquired signal, and naturally, cannot actively calculate the channel information.

The use of the surface of the current novel metamaterial for communication is still in the development and initiation stage. On the most remarkable channel estimation problem, researchers usually assume that the positions of users participating in communication are known, and a signal transmission model of the whole communication system is divided into a sending module and a receiving module according to a traditional channel estimation scheme under the condition that three-dimensional coordinates are known. The sending module is composed of three small modules of 'user-IRS surface receiving', 'IRS surface receiving-IRS surface transmitting', 'IRS surface transmitting-base station receiving', and then wireless channel parameters are obtained by a traditional channel estimation scheme. In the receiving module, the channel estimation of three small modules of 'base station-IRS surface-user' is cascaded, so that the channel estimation of the communication system in which the IRS surface participates can be the multi-stage cascaded channel estimation, but the calculation difficulty is still severe because the number of small units is very large.

Or by utilizing the principle of compressed sensing, through developing the sparseness of the signal, under the condition of far less than the Nyquist sampling rate, the discrete samples of the signal are obtained by random sampling, and then the signal is perfectly reconstructed through a nonlinear reconstruction algorithm. However, the principle of compressed sensing is not mature, the requirement on signals is high, the method is suitable for sparse signals, and the limitation is large in actual communication.

Existing processing schemes for IRS surface channel estimation include multi-stage cascaded channel estimation and channel estimation schemes relying on the compressed sensing principle. The existing disadvantages of these two solutions are as follows:

(1) the design complexity is high;

(2) the investment and use cost is high;

(3) the calculation amount is large, the time delay is long, and the real-time performance of communication cannot be guaranteed.

Disclosure of Invention

In order to solve the problems, the holographic IRS surface and the communication system based on the open-loop Hall sensor are provided.

The object of the invention is achieved in the following way:

a holographic IRS surface based on an open-loop Hall sensor is formed by N small units which are arranged at equal intervals, wherein each small unit comprises a PIN diode D1, a direct-current power supply DC, a choke inductor L1, a protection resistor R1 and the open-loop Hall sensor, the anode of the PIN diode D1 is connected with one end of the choke inductor L1, the other end of the choke inductor L1 is connected with the anode of the direct-current power supply DC, the cathode of the DC power supply DC is grounded, the cathode of the PIN diode D1 is connected with one end of the protection resistor R1, the other end of the protection resistor R1 is grounded, and the open-loop Hall sensor is arranged in a loop between the choke inductor L1 and the PIN diode D1.

The two states of the switch of PIN diode D1 correspond to the two coupled phase states of the small cell.

The open-loop Hall sensor is used for measuring the magnitude of high-frequency current induced by the small unit in two states of switching, and after comparison, the state of the PIN diode switch with larger high-frequency current is reserved and fed back to the controller.

A communication system based on a holographic IRS surface of an open-loop Hall sensor comprises a base station, a controller, a user, the holographic IRS surface, a signal splitter and a signal reflector, wherein a radio-frequency signal emitted by the base station is divided into two paths of signals through the signal splitter, the two paths of signals are respectively signal 1 and signal 2, the first beam of signal 1 reaches the user, the user needing communication can reflect a signal 3 to the holographic IRS surface, the second beam of signal 2 enters the holographic IRS surface after being reflected by the signal reflector, two beams of signal waves are interfered on the holographic IRS surface to form a hologram, a plurality of small units on the holographic IRS surface record a holographic pattern through two coupling phase states, and at the moment, the on-off state of a PIN diode in each unit on the holographic IRS surface is fed back to the controller and stored, and a training part is completed; after training is finished, when a user needs to communicate, a beam of signal 2 is directly sent to the surface of the holographic IRS from the base station, the controller restores the switch state of a built-in PIN diode of the unit array on the surface of the holographic IRS to the state recorded by the controller when training is finished, and the phase state of a plurality of small units on the surface of the holographic IRS is a holographic pattern formed by interference of two beams of waves; the hologram can record the basic information of interference waves, and after the base station transmits a signal 2, the holographic IRS surface can reflect a beam of signal 4 to a user, so that the actual communication process is completed.

The controller comprises a single chip microcomputer and an FPGA programmable controller, voltage output by the open-loop Hall sensor is transmitted to the single chip microcomputer after analog-to-digital conversion, the single chip microcomputer can be simultaneously connected to comparison circuits inside open-loop Hall sensor units on the surfaces of the plurality of holographic IRSs, programmable voltage and programmable data are generated after centralized processing and fed back to the FPGA controller, and the FPGA controller sends instructions to control the phase state of the single small unit.

The invention has the beneficial effects that: compared with the prior art, the invention combines the holographic principle, the Hall effect and the IRS surface. Firstly, the holographic IRS surface can form a hologram on the IRS surface by using an object light wave carrying user information and a reference wave emitted by a base station in a holographic imaging mode, and then the reference wave is emitted from the base station again to finish visualization, namely, the visualization is restored to the object light wave emitted to the IRS surface by a user in the imaging process, so that the whole communication process can be finished without channel estimation. The participation of the open-loop Hall sensor enables the two beams of signals to form a complete interference pattern on the surface of the holographic IRS. The invention has the advantages that:

(1) the flow design is simple;

(2) the IRS small unit and the open-loop Hall sensor are both low-cost materials, so that the product cost is low;

(3) the complex channel estimation can be avoided by a simple holographic principle, and the real-time performance of the communication system is greatly improved;

(4) the holographic imaging principle is utilized to record electromagnetic signals, the reduction degree is high, the positioning is accurate, and the accuracy of communication is ensured.

Drawings

FIG. 1 is a training block diagram of the holographic IRS surface communication system of the present invention.

FIG. 2 is a practical communication block diagram of the holographic IRS surface communication system of the present invention.

FIG. 3 is a schematic diagram of a narrow band beam injection holographic IRS super-surface element.

FIG. 4 is a unit circuit diagram of a holographic IRS surface.

Fig. 5 is a circuit diagram of an internal comparison circuit of the open-loop hall sensor unit in the circuit diagram of the unit in fig. 4.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the disclosure as claimed. Unless defined otherwise, all technical and scientific terms used herein have the same technical meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise, and it should be further understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of the stated features, steps, operations, devices, components, and/or combinations thereof.

In the present invention, terms such as "fixedly connected", "connected", and the like are to be understood in a broad sense, and mean either a fixed connection or an integrally connected or detachable connection; may be directly connected or indirectly connected through an intermediate. The specific meanings of the above terms in the present invention can be determined according to specific situations by persons skilled in the relevant scientific or technical field, and are not to be construed as limiting the present invention.

As shown in FIG. 3, the holographic IRS surface based on the open-loop Hall sensor is formed by arranging N small units at equal intervals, wherein each small unit comprises a PIN diode D1, a direct current power supply DC, a choke inductor L1, a protection resistor R1 and the open-loop Hall sensor, the anode of the PIN diode D1 is connected with one end of the choke inductor L1, the other end of the choke inductor L1 is connected with the anode of the direct current power supply DC, the cathode of the direct current power supply DC is grounded, the cathode of the PIN diode D1 is connected with one end of the protection resistor R1, the other end of the protection resistor R1 is grounded, and the open-loop Hall sensor is arranged in a loop between the choke inductor L1 and the PIN diode D1.

The two states of the switch of PIN diode D1 correspond to the two coupled phase states of the small cell.

The open-loop Hall sensor is used for measuring the magnitude of high-frequency current induced by the small unit in two states of switching, and after comparison, the diode switching state with larger high-frequency current is reserved and fed back to the controller.

The communication system in which the present invention participates is divided into two parts, namely a training part and an actual communication part. When a signal is injected into a small cell, the high frequency signal received at the cell will create a loop of high frequency current in the cell circuit. The built-in PIN diode 'on' and 'off' states of each small unit are different, so that the set phases of the unit are also divided into two states, the signal intensity received by the small unit in different phase states can be different (determined by the incident direction), and the reference signal and the object light signal can be interfered on the surface of the holographic IRS to form an interference pattern, thereby completing the training part. When the user communicates, the base station is controlled to send a reference signal to the holographic IRS surface, so that a communication signal to the user can be obtained through a development principle, and an actual communication part is completed.

The training part consists of six modules, namely a base station, a signal splitter, a signal reflector, a user, a holographic IRS surface and a controller. The radio frequency signal transmitted by the base station is divided into two paths of signals (reference waves) by a signal splitter. A first beam of signal 1 arrives at a user, the user needing communication can reflect a signal 3 (object wave) to the holographic IRS surface, a second beam of signal 2 enters the holographic IRS surface after being reflected by a signal reflector, two beams of signal waves interfere on the holographic IRS surface to form a hologram, a plurality of small units on the holographic IRS surface record a holographic pattern through two coupling phase states, and at the moment, the switch state of a PIN diode in each unit on the holographic IRS surface is fed back to a controller and stored.

As shown in fig. 1, after the training work is completed, when the user at the position needs to communicate, the controller controls the base station to send a beam of signal 2 from the base station to the surface of the holographic IRS. The controller restores the switch states of the built-in PIN diodes of the unit array on the surface of the holographic IRS to the training completion state, and at the moment, the phase states of a plurality of small units on the surface of the holographic IRS are the holographic patterns formed by interference of two beams of waves. The hologram can record the basic information of interference waves, and after the base station transmits a signal 2, the holographic IRS surface can reflect a beam of signal 4 to a user, so that the actual communication process is completed.

As shown in fig. 2, the present invention is based on the basic principles of holographic imaging and combines the communication advantages of a new type of IRS surface. By using an open-loop Hall sensor to solve the problem of how to enable the built-in PIN diode of each small unit to be in a correct switching state in the training process, a correct holographic pattern is obtained: the built-in PIN diodes of the small units correspond to two different reflection phases, and because the receiving capacity of each small unit for incident waves under different reflection phases is different, the influence strength of the incident waves on the small units is different, more received waves can generate larger high-frequency current in the internal circuit of the small unit, and otherwise, smaller high-frequency current is generated. After measuring and comparing the high frequency current magnitude in the switching state, we can determine in which state the cell's built-in PIN diode should be in case of a signal emitted from a certain location, and control the cell in this phase state, so that a holographic pattern is formed on the holographic IRS surface as a whole. And finally, converting the on-off state of the PIN diode in each unit into programmable data and transmitting the programmable data back to the controller, and recording and storing the programmable data by the controller.

When a signal is incident on the holographic IRS surface, we take the holographic IRS surface made of small units of "4 × 4" as an example, where each unit is arranged at equal distance, where d is the distance between units. Assume that the narrowband reference signal "r" is at an azimuth angle θ^aziE [0, 2 π) and elevation angle θ^ele∈[0，π/2]The three-dimensional coordinate system is impacted on the holographic IRS surface, so that the receiving capacity of each small unit to the narrow-band signal waveform is not the same, and after the induced high-frequency current generated in the switching state of the PIN diode built in each unit is compared, the large-current state is adopted, and the switching state of the PIN diode built in each unit on the holographic IRS surface of the 4 x 4 can be determined. As shown in fig. 3, for convenience of understanding in fig. 3, we take 16 super-surface small units in a "4 × 4" discrete arrangement as the study object. Among holographic IRS surfaces, since eachThe IRS small units are all passive, so the advantages of low power consumption and low manufacturing cost can be realized by arranging the IRS small units on the surface as much as possible, the distance d → 0 between every two units can obtain the maximum antenna aperture, and the holographic IRS surface can also be regarded as a quasi-continuous state of a common IRS surface.

The internal circuit diagram of the small unit is shown in fig. 4, and the small unit consists of five parts, namely a PIN diode D1, a direct-current power supply DC, a choke inductor L1, a protection resistor R1 and an open-loop hall sensor. The two states of the switch of PIN diode D1 correspond to the two phase states of the small cell, with different phase states having different effects on receiving signals. A DC 3.3V supply DC supplies the circuit with a bias voltage for a controllable diode. The choke inductor L1 functions as a direct current to alternating current (dc to ac) inductor, which does not function when the diode is powered by a dc power supply; when the small unit is influenced by a signal to generate high-frequency alternating current, the choke inductor L1 can prevent the alternating current from flowing outwards so as to ensure the accuracy of the measured result. The open-loop Hall sensor can be placed in a loop between the choke inductor and the PIN diode, and plays an important connection role in measuring the high-frequency current and feeding back the high-frequency current to the controller.

The invention applies the open-loop Hall sensor to the unit circuit of the holographic IRS surface. The open-loop Hall sensor has the advantages of simple structure, large impact current resistance, small size and the like. In the training step of the communication system with the participation of the holographic IRS, an open-loop Hall sensor with flexible requirements on installation space can be connected to each small unit, and the advantage of large bearing current peak value can enable the open-loop Hall sensor to measure high-frequency current generated in the communication process.

Voltage V _ s output by the open-loop hall sensor in fig. 5 is transmitted to the 80C51 single chip microcomputer after analog-to-digital conversion, the 80C51 single chip microcomputers with a plurality of interfaces can be simultaneously connected to internal comparison circuits of a plurality of holographic IRS units, and programmable voltage PV and programmable data PD generated after centralized processing are fed back to the FPGA controller.

And the FPGA controller sends an instruction to control the phase state of each small unit so as to achieve the optimal effect of imaging two beams of signals on the surface of the holographic IRS, and thus, the training process is completely finished.

The invention has the following advantages:

(1) the flow design is simple;

(2) the IRS small unit and the open-loop Hall sensor are both low-cost materials, so that the product cost is low;

(3) the complex channel estimation can be avoided by a simple holographic principle, and the real-time performance of the communication system is greatly improved;

(4) by utilizing the holographic imaging principle, the method has the advantages of high reduction degree, accurate positioning and capability of ensuring the accuracy of communication.

The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Although the embodiments of the present invention have been described with reference to the accompanying drawings, it is not intended to limit the scope of the present invention, and it should be understood by those skilled in the art that various modifications and variations can be made without inventive efforts by those skilled in the art based on the technical solution of the present invention.