CN110996338A - Information transmission method of environment backscattering communication system with optimal energy efficiency - Google Patents

Information transmission method of environment backscattering communication system with optimal energy efficiency Download PDF

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CN110996338A
CN110996338A CN201911203016.1A CN201911203016A CN110996338A CN 110996338 A CN110996338 A CN 110996338A CN 201911203016 A CN201911203016 A CN 201911203016A CN 110996338 A CN110996338 A CN 110996338A
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antenna
node
energy
relay node
communication system
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冀保峰
陈珍珍
陈苏丹
李玉琦
韩影
张雪茹
包海东
李春国
曹翔宇
王又可
武自鹏
张高远
马华红
韩瑽琤
文红
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Henan University of Science and Technology
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W24/00—Supervisory, monitoring or testing arrangements
    • H04W24/02—Arrangements for optimising operational condition
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B17/00—Monitoring; Testing
    • H04B17/30—Monitoring; Testing of propagation channels
    • H04B17/309—Measuring or estimating channel quality parameters
    • H04B17/336—Signal-to-interference ratio [SIR] or carrier-to-interference ratio [CIR]
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B17/00—Monitoring; Testing
    • H04B17/30—Monitoring; Testing of propagation channels
    • H04B17/391—Modelling the propagation channel
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/14—Relay systems
    • H04B7/15—Active relay systems
    • H04B7/155—Ground-based stations
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W28/00—Network traffic management; Network resource management
    • H04W28/16—Central resource management; Negotiation of resources or communication parameters, e.g. negotiating bandwidth or QoS [Quality of Service]
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W52/00—Power management, e.g. TPC [Transmission Power Control], power saving or power classes
    • H04W52/02—Power saving arrangements
    • H04W52/0209—Power saving arrangements in terminal devices
    • H04W52/0261—Power saving arrangements in terminal devices managing power supply demand, e.g. depending on battery level
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
    • Y02D30/00—Reducing energy consumption in communication networks
    • Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks

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Abstract

The invention discloses an information transmission method of an environment backscattering communication system with optimal energy efficiency, and relates to the technical field of communication of the Internet of things. The invention has the beneficial effects that: under the energy efficiency maximization criterion, the collected energy can be used for realizing remote and efficient transmission of environmental backscatter communication of the future Internet of things.

Description

Information transmission method of environment backscattering communication system with optimal energy efficiency
Technical Field
The invention belongs to the technical field of communication of the Internet of things, and particularly relates to an information transmission method of an environment backscatter communication system with optimal energy efficiency.
Background
With the progress of information technology and the intellectualization of equipment, people are not satisfied with the communication between people, and the concept of the Internet of Things (IOT) is generated along with the progress of the information technology, aiming at realizing the interconnection between people and objects and between objects and everything. The Internet of things serves as a bridge for connecting the physical world and the human society, and portable interaction between people and everything becomes possible. Although the rapid development of the internet of things and the wide application of the radio frequency identification technology bring great convenience to daily life of people, the radio frequency identification technology cannot meet the communication requirements of the current emerging industry due to the defects of short communication distance and the like, the problem is solved by the technical proposal of environmental backscattering (Ambient Backscatter), and new blood is injected for the development of the internet of things.
Ambient backscatter techniques provide a carrier signal to a tag by using a radio frequency signal of the surrounding environment, which may be a wireless signal such as a TV signal, FM signal, conventional cellular signal, and Wi-Fi signal, instead of a carrier generator. The new technology is characterized in that the label can utilize the environment radio frequency signal to complete the active communication between the reader-writer and the label without the supply of special energy, and has better energy saving performance.
The emergence of the environmental backscattering technology has important research value for the intelligent industry and the application thereof. The traditional backscattering technology needs to reflect information to a reader-writer through a tag to realize information transmission, and radio frequency identification has the defects of short communication distance and instability, so that the communication range and the application field of a reflective tag or a hot spot are limited. The Backscatter technology relying on the environment radio frequency source signals (television towers, base stations and the like) has wider scientific research space and value, but the acquisition of the radio frequency energy of the television towers, the base stations and the like is unstable and the acquirable quantity is small, and a plurality of sensors are powered by batteries and cannot be charged, so that the communication range is limited. Resource allocation is a main method for solving short-distance communication and avoiding energy waste, and is subject to important research in academic circles, and especially joint optimization is easier to save resources.
Therefore, the information transmission method of the environment backscatter communication system with optimal energy efficiency is provided, and the transmission of the environment backscatter communication system with higher energy efficiency and low error rate can be realized.
Disclosure of Invention
The invention aims to solve the technical problem of providing an information transmission method of an environment backscatter communication system with optimal energy efficiency, and solving the problems of limited communication distance and power, high manufacturing cost, low resource utilization rate and the like of the traditional backscatter technology in the prior art.
The technical scheme adopted by the invention for solving the technical problems is as follows: the information transmission method of the environment backscatter communication system with optimal energy efficiency comprises the following specific steps that:
(1) in the first stage, a single-antenna sensor relay node receives a signal y sent by a multi-antenna source end nodeRComprises the following steps:
Figure BDA0002296329410000021
wherein, PsIs the transmit power of a multi-antenna source end node; w is a precoding matrix
Figure BDA0002296329410000022
Carrying out normalization processing on the sending signal; h-CN (0, m) is a wireless channel from the multi-antenna source end node to the single-antenna sensor relay node, and x is a transmitting signal of the multi-antenna source end node;
Figure BDA0002296329410000023
is additive white gaussian noise at the single antenna sensor relay node.
(2) In the second stage, after the relay node of the single-antenna sensor receives the signals from the multi-antenna source end node, the energy y is collected by adopting a power splitting methodR,E：
Figure BDA0002296329410000024
Where 0 < ρ < 1 is a power splitting factor; wireless signal y received by relay node of single antenna sensor after power splittingR,IComprises the following steps:
Figure BDA0002296329410000025
wherein
Figure BDA0002296329410000026
Is the conversion noise from radio frequency to baseband at the single antenna sensor relay node;
signal transmitted from single antenna sensor relay node
Figure BDA0002296329410000027
Comprises the following steps:
Figure BDA0002296329410000028
(3) in the third stage, the wireless information y received by the single-antenna electronic tag BIAnd energy y collected by information user nodeERespectively as follows:
Figure BDA0002296329410000029
Figure BDA0002296329410000031
wherein g-CN (0,1) is a wireless channel from a single-antenna sensor relay node to a single-antenna electronic tag B, f-CN (0,1) is a wireless channel from a single-antenna sensor relay node to an information user node, and nEIs white Gaussian noise at the information user node, and
Figure BDA0002296329410000032
the wireless information transmission model that the multi-antenna source end node reaches the single-antenna electronic tag B through the single-antenna sensor relay node is as follows:
Figure BDA0002296329410000033
wherein n isIIs white Gaussian noise at the single-antenna electronic tag B, and
Figure BDA0002296329410000034
(4) based on the wireless information transmission model in the step (3), the SNR of the single-antenna electronic tag B can be obtainedIThe expression of (a) is:
Figure BDA0002296329410000035
(5) under the condition that the minimum energy collected by a user is met, an optimization model for maximizing the energy efficiency of the environmental backscatter communication system is established as follows, and the model is solved to obtain an optimal solution, namely the environmental backscatter communication system information transmission method with the optimal energy efficiency:
Figure BDA0002296329410000036
Figure BDA0002296329410000037
wherein, γ0If the energy is more than 0, the energy is a preset threshold value, namely the minimum energy collected by the user in the environment backscattering communication system; a > 0 and b > 0 are power consumption model factors of power conversion efficiency and hardware circuit power consumption cost.
The invention has the beneficial effects that: the invention develops an environment backscatter communication system combined optimization system in order to solve the problems of limited communication distance and power, high manufacturing cost, low resource utilization rate and the like of the traditional backscatter technology, can better solve resource allocation during label/hot spot excitation reflection, effectively improves the energy efficiency of the whole system and reduces the error rate. Under the energy efficiency maximization criterion, the collected energy can be used for realizing remote and efficient transmission of environmental backscatter communication of the future Internet of things.
Drawings
FIG. 1 is a schematic diagram of an environmental backscatter communication scenario in accordance with an embodiment of the invention;
FIG. 2 is a diagram illustrating an exemplary implementation scenario;
fig. 3 is a simulation diagram of the system energy efficiency and the minimum energy variation function required by the energy collecting user when a is 10 and b is 300 according to the present invention;
fig. 4 is a simulation diagram of energy efficiency comparison of the joint optimization and transmit power only optimization scheme of the present invention.
Detailed Description
Firstly, a source end node configured with multiple antennas adopts a maximum ratio transmission precoding method, namely, the same bit stream is respectively provided for each transmitting antenna after being processed by different weights, the selection of a transmitting weight vector is determined by a channel state, and excitation signals are transmitted to a multi-channel electronic tag/sensor by utilizing recoded signals. At this moment, the electronic tag is in a dormant state generally for saving energy, and the electronic tag is internally provided with an induction antenna and a corresponding circuit, can absorb a signal of a radio frequency transmission source end node, converts the signal into energy for self work and stores the energy. When the energy accumulated by the electronic tag reaches a certain threshold value, the electronic tag is awakened to start communication. In order to maximize the energy efficiency of the system, the sensor relay node collects energy by adopting a power splitting method to complete information transmission (as shown in fig. 2). After the resource allocation is completed, the information and the energy are respectively sent to other electronic tags for receiving the information and users for collecting the energy through normalization. Based on an energy efficiency maximization criterion, joint optimization processing of energy efficiency maximization is carried out on the sending power, the sending antenna and the power splitting factor, and a joint optimization optimal solution of multiple parameters, namely an environment backscatter communication system information transmission method with optimal efficiency, is obtained.
The following description of specific embodiments (examples) of the present invention are provided in conjunction with the accompanying drawings to enable those skilled in the art to better understand the present invention.
As shown in fig. 2, the environmental backscatter communication system based on internet of things energy collection includes a multi-antenna source end node, a single-antenna sensor relay node (electronic tag a), a single-antenna electronic tag B, a user node for collecting energy, and the like, and the invention performs joint optimization on transmission power, transmission antenna, and power splitting factor in the system, so as to improve the energy efficiency of the whole system and reduce the error rate of the system, specifically:
in the first stage, a signal transmitted by a multi-antenna source end node and received by a single-antenna sensor relay node (electronic tag a) is represented as:
Figure BDA0002296329410000041
wherein P issIs the transmit power of the source node, w is the precoding matrix
Figure BDA0002296329410000051
Normalizing the transmitted signal, h-CN (0, m) is a wireless channel from the transmitting source node to the sensor relay node (electronic tag A), x is the transmitted signal,
Figure BDA0002296329410000052
is additive white gaussian noise at the sensor relay node (electronic tag a).
In the second stage, after the single-antenna sensor relay node (electronic tag A) receives signals, energy is collected by adopting a power splitting method:
Figure BDA0002296329410000053
where ρ < 1 is a power splitting factor, and a wireless signal received by the single-antenna sensor relay node (electronic tag a) after power splitting may be represented as:
Figure BDA0002296329410000054
wherein
Figure BDA0002296329410000055
Is the conversion noise from RF to baseband.
Signal transmitted from the single antenna sensor relay node (electronic tag a):
Figure BDA0002296329410000056
wherein y isR,IThe wireless signals are received by the sensor relay node (electronic tag A) after power division.
In the third stage, the wireless information received by the electronic tag B and the energy collected by the information user node are respectively as follows:
Figure BDA0002296329410000057
Figure BDA0002296329410000058
mathematical model for wireless information transmission from source node S to electronic tag B through sensor relay node (electronic tag A)
Figure BDA0002296329410000059
Based on a wireless information transmission mathematical model, the signal-to-noise ratio expression of the electronic tag B is obtained as follows:
Figure BDA0002296329410000061
further, under the condition that the minimum energy collected by the user is met, the optimization problem of maximizing the energy efficiency of the environmental backscatter communication system is represented as the following model, and the optimal solution of the model is the information transmission method of the environmental backscatter communication system with the optimal energy efficiency:
Figure BDA0002296329410000062
Figure BDA0002296329410000063
wherein, γ0> 0 is a preset threshold, i.e. the minimum energy collected by a user in an ambient backscatter communication system. a > 0 and b > 0 are power consumption model factors of power conversion efficiency and hardware circuit power consumption cost.
One solution to the optimization problem model that maximizes the energy efficiency of the environmental backscatter communication system is:
the signal-to-noise ratio of electronic tag B can be approximately expressed as:
Figure BDA0002296329410000064
further, the optimization problem to maximize the energy efficiency of an ambient backscatter communication system can be rewritten as:
Figure BDA0002296329410000065
Figure BDA0002296329410000066
further, the problem is represented as follows:
Figure BDA0002296329410000067
Figure BDA0002296329410000068
the above problem is represented by the lagrange function as follows:
Figure BDA0002296329410000069
the simplification is as follows:
Figure BDA0002296329410000071
resulting transmit power optimum solution
Figure BDA0002296329410000072
Similar to the above steps, the asymptotic optimal transmitting antenna of the source end node is obtained as
Figure BDA0002296329410000073
Further, the optimal solution of the power splitting factor is:
Figure BDA0002296329410000074
finally, the optimal transmitting power, the number of the antennas and the power splitting factor of the antennas can be conveniently obtained by using an iteration method.
The invention is suitable for a transmission system with large-scale nodes, and is particularly suitable for long-distance transmission and the like of a backscattering communication system in the future environment.

Claims (1)

1. The information transmission method of the environment backscatter communication system with optimal energy efficiency is characterized by comprising the following steps: the communication system comprises a multi-antenna source end node, a single-antenna sensor relay node, a single-antenna electronic tag B and a user node for collecting energy, and the specific method comprises the following steps:
(1) in the first stage, a single-antenna sensor relay node receives a signal y sent by a multi-antenna source end nodeRComprises the following steps:
Figure FDA0002296329400000011
wherein, PsIs the transmit power of a multi-antenna source end node; w is a precoding matrix
Figure FDA0002296329400000012
Carrying out normalization processing on the sending signal; h-CN (0, m) is a wireless channel from the multi-antenna source end node to the single-antenna sensor relay node, and x is a transmitting signal of the multi-antenna source end node;
Figure FDA0002296329400000013
is additive white gaussian noise at the single antenna sensor relay node;
(2) in the second stage, after the relay node of the single-antenna sensor receives the signals from the multi-antenna source end node, the energy y is collected by adopting a power splitting methodR,E：
Figure FDA0002296329400000014
Where 0 < ρ < 1 is a power splitting factor; wireless signal y received by relay node of single antenna sensor after power splittingR,IComprises the following steps:
Figure FDA0002296329400000015
wherein
Figure FDA0002296329400000016
Is the conversion noise from radio frequency to baseband at the single antenna sensor relay node;
signal transmitted from single antenna sensor relay node
Figure FDA0002296329400000017
Comprises the following steps:
Figure FDA0002296329400000018
(3) in the third stage, the wireless information y received by the single-antenna electronic tag BIAnd energy y collected by the user nodeERespectively as follows:
Figure FDA0002296329400000019
Figure FDA00022963294000000110
wherein g-CN (0,1) is a wireless channel from a relay node of the single-antenna sensor to the single-antenna electronic tag B, and f-CN (0,1) is single-antenna transmissionWireless channel from sensor relay node to user node, nEIs white Gaussian noise at the user node, and
Figure FDA0002296329400000021
the wireless information transmission model that the multi-antenna source end node reaches the single-antenna electronic tag B through the single-antenna sensor relay node is as follows:
Figure FDA0002296329400000022
wherein n isIIs white Gaussian noise at the single antenna tag, and
Figure FDA0002296329400000023
(4) based on the wireless information transmission model in the step (3), the SNR of the single-antenna electronic tag B can be obtainedIThe expression of (a) is:
Figure FDA0002296329400000024
(5) under the condition that the minimum energy collected by a user is met, an optimization model for maximizing the energy efficiency of the environmental backscatter communication system is established as follows, and the model is solved to obtain an optimal solution, namely the environmental backscatter communication system information transmission method with the optimal energy efficiency:
Figure FDA0002296329400000025
Figure FDA0002296329400000026
wherein, γ0If the energy is more than 0, the energy is a preset threshold value, namely the minimum energy collected by the user in the environment backscattering communication system; a > 0 and b > 0 are power consumption model factors of power conversion efficiency and hardware circuit power consumption cost.
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CN114285504A (en) * 2021-12-22 2022-04-05 西安邮电大学 Large-scale wireless energy supply backscattering communication network transmission performance research method

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