阅读说明：本技术 一种基于可重构全息超表面的通信接收机系统 (Communication receiver system based on reconfigurable holographic super surface ) 是由 邓若琪 张雨童 张浩波 于 2021-08-30 设计创作，主要内容包括：本发明涉及一种基于可重构全息超表面的通信接收机系统。该系统包括：可重构全息超表面、数字波束成形接收模块和偏置电压控制模块。可重构全息超表面进行全息接收波束成形,将获取的空间自由电磁波转化为电磁波,并对电磁波的收集能量进行调节以产生能量不同的电磁波；数字波束成形接收模块处理和分离不同用户的发射信号；偏置电压控制模块预设偏置电压调节间隔,以使可重构全息超表面依据预设偏置电压调节间隔对电磁波的收集能量进行调节。基于该结构,在多用户通信中,能够使用户的总数据速率达到最大。并且,可重构全息超表面辅助多用户通信还具有功耗低,硬件成本低的特点,能够解决现有天线体积大、功耗高、硬件成本高等问题。(The invention relates to a communication receiver system based on a reconfigurable holographic super surface. The system comprises: the device comprises a reconfigurable holographic super surface, a digital beam forming receiving module and a bias voltage control module. The reconfigurable holographic super surface is used for carrying out holographic receiving beam forming, converting the acquired space free electromagnetic waves into electromagnetic waves, and adjusting the collected energy of the electromagnetic waves to generate electromagnetic waves with different energies; the digital beam forming receiving module processes and separates the transmitting signals of different users; the bias voltage control module presets a bias voltage regulation interval so that the reconfigurable holographic super surface regulates the collected energy of the electromagnetic waves according to the preset bias voltage regulation interval. Based on this structure, in multi-user communication, the total data rate of users can be maximized. Moreover, the reconfigurable holographic super-surface assisted multi-user communication has the characteristics of low power consumption and low hardware cost, and can solve the problems of large volume, high power consumption, high hardware cost and the like of the conventional antenna.)

1. A reconfigurable holographic-based hyper-surface communication receiver system, comprising:

the reconfigurable holographic super surface is used for carrying out holographic receiving beam forming and adjusting the collected energy of the received electromagnetic waves in free space to generate electromagnetic waves with different energies;

the digital beam forming receiving module is connected with the reconfigurable holographic super surface and is used for processing and separating the transmitting signals of different users;

and the bias voltage control module is connected with the reconfigurable holographic super surface and is used for presetting a bias voltage regulation interval so that the reconfigurable holographic super surface regulates the collected energy of the electromagnetic waves according to the preset bias voltage regulation interval.

2. The reconfigurable holographic-based super surface communication receiver system of claim 1, wherein the reconfigurable holographic super surface comprises: the system comprises a feed source, a parallel plate waveguide and a metamaterial receiving unit array;

the feed source and the metamaterial receiving unit array are arranged on the parallel plate waveguide; the metamaterial receiving unit array comprises a plurality of metamaterial receiving units;

the metamaterial receiving unit adjusts the collected energy of the received electromagnetic waves in the free space to generate electromagnetic waves with different energies, then the generated electromagnetic waves with different energies are transmitted to the feed source through the parallel plate waveguide to be collected, and the feed source converts the collected electromagnetic waves into high-frequency current.

3. The reconfigurable holographic-based hyper-surface communication receiver system of claim 2, wherein the metamaterial receiving unit comprises: the metal bottom plate, the dielectric layer and the microstrip line etched with the complementary inductance-capacitance resonance ring;

the dielectric layer is arranged on the metal bottom plate; the microstrip line is arranged on the dielectric layer;

the complementary inductance capacitance resonance ring comprises a variable capacitance diode and a complementary inductance capacitance resonance ring resonator; the variable capacitance diode is connected with the complementary inductance capacitance resonance ring resonator; the voltage value of the variable capacitance diode changes along with the bias voltage value, so that the mutual inductance of the complementary inductance-capacitance resonance ring resonator changes.

4. The reconfigurable holographic super surface based communication receiver system of claim 3, wherein the complementary LC resonant ring resonator comprises: a metal patch;

the metal patch is arranged in the etching groove of the microstrip line; the longest edge of the metal patch is provided with a T-shaped groove.

5. The reconfigurable holographic-based super surface communication receiver system according to claim 2, wherein the number of the metamaterial receiving element arrays is plural;

a feed source is arranged between the two metamaterial receiving unit arrays to form an electromagnetic wave transmission-receiving module;

the reconfigurable holographic super surface is provided with a plurality of electromagnetic wave transmission-receiving modules.

6. The reconfigurable holographic-based hyper-surface communication receiver system of claim 2, further comprising an incident beam channel determination module;

the incident beam channel determining module is used for determining a transmission channel between each metamaterial receiving unit and a user.

Technical Field

The invention relates to the field of wireless communication devices, in particular to a communication receiver system based on a reconfigurable holographic super surface.

Background

In order to implement ubiquitous intelligent information networks, the upcoming sixth generation (6G) wireless communications put stringent requirements on antenna technology, such as capacity enhancements and low power hardware components. Among the existing antenna technologies, the holographic antenna is a small-sized, low-power-consumption planar antenna, and is receiving increasing attention due to its multi-beam control capability with low manufacturing cost and low hardware cost. Specifically, the holographic antenna uses a metal patch to construct a holographic pattern on the surface, and records the interference between a reference wave and a target wave according to the interference principle. The radiation characteristics of the reference wave can then be varied by means of the holographic pattern to produce the desired radiation direction.

However, with the explosive growth of mobile devices, conventional holographic antennas face a great challenge because once the holographic pattern is established, the radiation pattern of the conventional holographic antennas is fixed, and the requirements of mobile communication cannot be met at all. Due to the controllability of metamaterials, emerging Reconfigurable Holographic Surface (RHS) technology shows great potential in the aspect of improving the defects of traditional holographic antennas. The RHS is an ultra-light thin plane antenna, and a plurality of metamaterial receiving units are embedded on the surface of the antenna. In particular, the RHS is excited by a reference wave generated by the antenna feed in the form of an electromagnetic wave, making it possible to manufacture the RHS with a compact structure based on Printed Circuit Board (PCB) technology. According to the hologram pattern, each radiation element can generate a desired radiation direction by electrically controlling the radiation amplitude of the reference wave. Therefore, compared with the traditional dish antenna and the traditional phased array antenna, the RHS can realize dynamic beam forming without a heavy mechanical movement device and a complex phase shift circuit, can greatly save the manufacturing cost and the power loss of the antenna, and is very convenient to install due to a light and thin structure.

However, prior research efforts in existing RHS have focused largely on RHS hardware component design and radiation direction control. Most studies only demonstrate the feasibility of the RHS to achieve dynamic multi-beam control. At present, no work is done to study the influence of a transmitting device and a holographic beam forming scheme of multi-user communication under the assistance of RHS on the performance of a communication system.

Disclosure of Invention

The invention aims to provide a communication receiver system based on a reconfigurable holographic super surface, which can maximize the total data rate of users in multi-user uplink communication assisted by the reconfigurable holographic super surface.

In order to achieve the purpose, the invention provides the following scheme:

a reconfigurable holographic hypersurface-based communication receiver system comprising:

the reconfigurable holographic super surface is used for carrying out holographic receiving beam forming and adjusting the collected energy of the received electromagnetic waves in free space to generate electromagnetic waves with different energies;

the digital beam forming receiving module is connected with the reconfigurable holographic super surface and is used for processing and separating the transmitting signals of different users;

and the bias voltage control module is connected with the reconfigurable holographic super surface and is used for presetting a bias voltage regulation interval so that the reconfigurable holographic super surface regulates the collected energy of the electromagnetic waves according to the preset bias voltage regulation interval.

Preferably, the reconfigurable holographic super surface comprises: the system comprises a feed source, a parallel plate waveguide and a metamaterial receiving unit array;

the feed source and the metamaterial receiving unit array are arranged on the parallel plate waveguide; the metamaterial receiving unit array comprises a plurality of metamaterial receiving units;

the metamaterial receiving unit adjusts the collected energy of the received electromagnetic waves in the free space to generate electromagnetic waves with different energies, then the generated electromagnetic waves with different energies are transmitted to the feed source through the parallel plate waveguide to be collected, and the feed source converts the collected electromagnetic waves into high-frequency current.

Preferably, the metamaterial receiving unit includes: the metal bottom plate, the dielectric layer and the microstrip line etched with the complementary inductance-capacitance resonance ring;

the dielectric layer is arranged on the metal bottom plate; the microstrip line is arranged on the dielectric layer;

the complementary inductance capacitance resonance ring comprises a variable capacitance diode and a complementary inductance capacitance resonance ring resonator; the variable capacitance diode is connected with the complementary inductance capacitance resonance ring resonator; the voltage value of the variable capacitance diode changes along with the bias voltage value, so that the mutual inductance of the complementary inductance-capacitance resonance ring resonator changes.

Preferably, the complementary inductor capacitor resonant ring resonator comprises: a metal patch;

the metal patch is arranged in the etching groove of the microstrip line; the longest edge of the metal patch is provided with a T-shaped groove.

Preferably, the number of the metamaterial receiving unit arrays is multiple;

a feed source is arranged between the two metamaterial receiving unit arrays to form an electromagnetic wave transmission-receiving module;

the reconfigurable holographic super surface is provided with a plurality of electromagnetic wave transmission-receiving modules.

Preferably, the method further comprises an incident beam channel determination module;

the incident beam channel determining module is used for determining a transmission channel between each metamaterial receiving unit and a user.

According to the specific embodiment provided by the invention, the invention discloses the following technical effects:

according to the communication receiver system based on the reconfigurable holographic super surface, the reconfigurable holographic super surface is adopted to adjust the collection energy of electromagnetic waves, and then the total data rate of users can be maximized in multi-user communication. Moreover, the reconfigurable holographic super-surface assisted multi-user communication has the characteristics of low power consumption and low hardware cost, and can solve the problems of large volume, high power consumption, high hardware cost and the like of the conventional antenna with the beam forming capability.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without inventive exercise.

FIG. 1 is a schematic structural view of a reconfigurable holographic metasurface provided by the present invention;

FIG. 2 is a schematic illustration of wave propagation on a parallel plate waveguide according to the present invention;

FIG. 3 is a schematic structural diagram of a metamaterial receiving unit provided in the present invention;

fig. 4 is a schematic structural diagram of a complementary lc resonant ring according to the present invention.

Description of the labeling:

the device comprises a feed source 1, a parallel plate waveguide 2, a metamaterial receiving unit 3, a metal bottom plate 4, a dielectric layer 5, a microstrip line 6, a varactor diode 7 and a metal patch 8.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The invention aims to provide a communication receiver system based on a reconfigurable holographic super surface, which can maximize the total data rate of users in multi-user uplink communication assisted by the reconfigurable holographic super surface.

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.

The invention provides a communication receiver system based on a reconfigurable holographic super surface, which comprises: the device comprises a reconfigurable holographic super surface, a digital beam forming receiving module and a bias voltage control module.

The reconfigurable holographic super surface is used for carrying out holographic receiving beam forming, and the collected energy of the electromagnetic waves in the received free space is adjusted to generate electromagnetic waves with different energies.

And the digital beam forming receiving module is connected with the reconfigurable holographic super surface and is used for processing and separating the transmitting signals of different users so as to eliminate the interference between the signals of the different users.

The bias voltage control module is connected with the reconfigurable holographic super surface and used for presetting a bias voltage regulation interval so that the reconfigurable holographic super surface regulates the collected energy of the electromagnetic waves according to the preset bias voltage regulation interval.

As shown in FIG. 1, the reconfigurable holographic super surface used in the present invention comprises: a feed source 1, a parallel plate waveguide 2 and a plurality of metamaterial receiving unit arrays.

The feed source 1 and the metamaterial receiving unit array are arranged on the parallel plate waveguide 2. A feed source 1 is arranged between the two metamaterial receiving unit arrays to form an electromagnetic wave transmission-receiving module. The reconfigurable holographic super surface is provided with a plurality of electromagnetic wave transmission-receiving modules. The metamaterial receiving unit array includes a plurality of metamaterial receiving units 3.

The metamaterial receiving unit 3 adjusts the collected energy of the received electromagnetic waves in the free space to generate electromagnetic waves with different energies, then the generated electromagnetic waves with different energies are transmitted to the feed source 1 through the parallel plate waveguide 2 to be collected, and the feed source 1 converts the collected electromagnetic waves into high-frequency current. In which an electromagnetic wave propagating on the parallel plate waveguide 2 is as shown in fig. 2.

The specific working principle is as follows: electromagnetic waves in free space hit the reconfigurable holographic super surface and are converted into electromagnetic waves with different energies which are transmitted on the reconfigurable holographic super surface through the metamaterial receiving unit 3 on the reconfigurable holographic super surface. The metamaterial receiving unit 3 can realize the adjustment of the collected energy of the electromagnetic waves, namely the adjustment of the amplitude of the electromagnetic waves by adjusting the bias voltage of the power supply in the metamaterial receiving unit 3. The bias voltage value and the amplitude value of the electromagnetic wave generated on the metamaterial receiving unit 3 have a one-to-one correspondence relationship, finally the electromagnetic wave is collected to the feed source 1 capable of reconstructing the holographic super surface, and the feed source 1 converts the electromagnetic wave into high-frequency current.

In order to further increase the tunable performance of the metamaterial receiving unit 3, as shown in fig. 3, the metamaterial receiving unit 3 adopted by the present invention includes: a metal bottom plate 4, a dielectric layer 5 and a microstrip line 6 etched with a complementary inductance-capacitance resonance ring.

A dielectric layer 5 is provided on the metal base plate 4. The microstrip line 6 is disposed on the dielectric layer 5.

The complementary inductance capacitance resonance ring comprises a varactor 7 and a complementary inductance capacitance resonance ring resonator. The varactor diode 7 is connected to a complementary inductor-capacitor resonant ring resonator. The voltage value of the variable capacitance diode 7 changes with the bias voltage value, so that the mutual inductance of the complementary inductance-capacitance resonance ring resonator changes.

For symmetry, the two varactors are connected by gaps that separate the central metal portion of the complementary lc resonant ring from the microstrip line 6. By applying a bias voltage to the varactor diode 7, the capacitance value of the varactor diode 7 changes with the applied bias voltage value, and the mutual inductance of the complementary inductor-capacitor resonant loop can be changed, so that the metamaterial receiving unit 3 can be tuned.

As shown in fig. 4, a closed loop is formed by etching an annular groove on the microstrip line 6, and is combined with the metal patch 8 (i.e. the metal patch 8 is disposed in the etched groove of the microstrip line 6), so as to prepare the complementary lc resonant ring resonator. The metal patch 8 is a rectangular metal patch. The middle of each long side of the rectangular metal patch is provided with a T-shaped groove so as to improve the design freedom degree. Specifically, by adjusting the geometry of the complementary LC resonance loop, the resonance frequency of the complementary LC resonance loop and the energy collection efficiency of the device can be changed.

Further, the communication receiver system based on the reconfigurable holographic super surface provided by the invention also comprises an incident beam channel determination module. The incident beam channel determination module is used for determining a transmission channel between each metamaterial receiving unit 3 and a user.

Next, a holographic receive beamforming design that maximizes the total communication data rate for all users is described based on the specific structure of the reconfigurable holographic-super-surface based communication receiver system provided above:

for convenience of description, the variables in the wireless communication scenario and the transmitting device are expressed and assumed alphabetically:

considering that a base station (receiving device) equipped with a Reconfigurable Holographic Surface (RHS) with K feed sources is to receive data from L mobile users, the positions of the L mobile users relative to the receiving device are the directions of the transmission beams required by the receiving device. It is assumed that the RHS consists of M × N metamaterial receiving units. Transmission channel between each receiving unit and each user of RHSThe total channel matrix between the base station and each user l is represented by H_lThis dimension is represented by MN × 1. Suppose that user l sends a signal s to the base station_l. The base station firstly performs holographic receiving beam forming based on RHS on signals sent to users, and then performs digital beam forming on the signals to demodulate the signals of each user, so that the signals of each user finally recovered by the base station are as follows:

where V is a digital beamforming matrix of size LxK, V_lIs the l-th line of V, M is an elementForming a matrix of size K × MN, K_sIs the propagation vector of the reference wave propagating on the surface of the RHS,is the distance vector, z, from the kth feed source to the (m, n) th metamaterial receiving unit_lIs white gaussian noise in the channel.

The problem of maximizing the total transmission rate of the user is as follows:

s.t.0≤M_m,n≤1,

step 1: the RHS-based holographic beam forming scheme is designed as follows:

the digital beamforming scheme is first initialized by introducing an auxiliary variable gamma_l,δ_lThe user rate maximization problem can be rewritten as:

definition ofIs composed ofThe subscript m and the subscript n are vectorized to obtain an MN-dimensional column vectorCan be expressed asWhere eta_lIs a matrix Re (b)_l)[Re(b_l)]^T+Im(b_l)[Im(b_l)]^TIs determined by the maximum characteristic value of the image,is corresponding to η_lThe (m-1) N + N-th component of the feature vector of (1).

By passingCan obtain the optimal gamma_l,δ_lThe specific expression is as follows:

by introducing lagrange multiplier lambda_m,nLoosely constrained to an objective function, and in each round of Lagrange iteration, the optimal holographic beam forming schemeThis can be obtained by solving the following system of linear equations:

the complete holographic beamforming optimization algorithm is summarized as follows:

(1) initialization M_m,n。

(2) Is calculated by the formula (a) and the formula (b)And

(3) is calculated by the formula (c)

(4) Updating lambda by a sub-gradient method_m,n。

(5) Checking whether the algorithm is converged, if not, returning to the step (2) to continue iteration, and if so, receivingConvergence, the algorithm ends to get the optimal one

Step 2: digital beamforming receive module design

According to the radiation amplitude M of the metamaterial receiving unit initially optimized in the step 1_m,nChannel matrix H_lIn order to maximize the total data rate of all users, the digital beamforming reception scheme can be expressed as:

wherein Q ═ MH₁,MH₂,…,MH_L)，P＝diag{p₁,p₂,…,p_LIs a diagonal matrix representing the power allocated by the base station to process the signal for each user, optimallyμ_lIs (Q)^HQ)^-1Q^HThe first diagonal element of (v) is such that the equation is satisfied

And step 3: iterative optimization of digital beamforming and holographic beamforming schemes using a computer

On the basis of the algorithms provided in the steps 1 and 2, the invention designs a receiving beam forming joint optimization algorithm, and solves the problem of maximizing the total data rate of the user in an iterative manner. Specifically, with the digital beamforming scheme V scheme kept fixed, the holographic beamforming receive optimization algorithm proposed in step 1 is used to pair { M }_m,nAnd (6) optimizing. Then by the formulaA digital beamforming scheme V is obtained. The optimized sum of the holographic beamforming receiver and the digital beamformer is used as an initial solution. In each subsequent iteration, the two sub-problems are solved alternately. Until the value difference of the user total data rate between two adjacent iterations is smaller than a predefined threshold, the iterations are completed to obtain the optimal holographic beam forming receiving schemeAnd digital beam forming receiving scheme V^*RHS and digital beamforming modules are respectively based onAnd V^*The received signal may be processed.

In summary, the communication receiver system based on the reconfigurable holographic super surface provided by the invention has the following advantages compared with the prior art:

1) the traditional dish antenna controls the rotation of the antenna through a heavy mechanical device, thereby realizing a beam control mode, and has the defects of high later maintenance cost and the like. The RHS has small size, is made to be compact and light by using the PCB technology, greatly reduces the manufacturing cost, is easy to be directly installed on the transmitting device, and can achieve good dynamic multi-beam control effect by adopting an electric control mode, so the RHS can be suitable for multi-user mobile communication.

2) The RHS has low power consumption and low hardware cost: although the phased array antenna also controls the beam direction by using electricity, the phased array relies on a large number of phase shifters to control the phase of electromagnetic waves in each antenna, and a large number of power amplifiers are also required, so that the phased array antenna requires a complicated phase shifting circuit, and has large power loss and high hardware cost. Compared with the prior art, the RHS does not need a phase shifter and a complex phase shifting circuit, and the variable capacitance diodes are used for controlling different electromagnetic wave energy radiated by each metamaterial receiving unit, namely, the wave beam control can be completed in an amplitude modulation mode, so that the RHS is used for assisting multi-user communication, the power consumption is low, the hardware cost is low, and the RHS has great advantages compared with a phased array antenna.

3) By adopting the holographic receiving beam forming design method based on the reconfigurable holographic super surface, the total data rate of the user can be maximized in the RHS-assisted multi-user communication process with the advantages of lightness, thinness, low cost, low power consumption and the like.

The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other.

The principles and embodiments of the present invention have been described herein using specific examples, which are provided only to help understand the method and the core concept of the present invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed. In view of the above, the present disclosure should not be construed as limiting the invention.