WO2023071023A1 - Transmission method and apparatus based on combination of sending end and relay node selection, and terminal - Google Patents

Abstract

A transmission method and apparatus based on the combination of a sending end and relay node selection, and a terminal. The method comprises: according to information carried when a sending node sends information to a receiving node, determining a transmission mode used by information transmission; calculating the total transmission rate and the total power consumption of all nodes during information transmission according to the transmission mode and information of a channel used by the information transmission; establishing, according to the total transmission rate and the total power consumption, an objective function and a constraint condition aiming at the maximum energy efficiency; optimizing the objective function; and solving the objective function according to the constraint condition to obtain an optimal power distribution mode, an optimal time allocation factor and an optimal relay selection mode.

Description

Transmission method, device and terminal for joint sending end and relay point selection

This patent application claims priority to Chinese Patent Application No. CN 202111265723.0 filed on October 28, 2021. The disclosure of the prior application is incorporated by reference in its entirety into this application.

technical field

The present application relates to the technical field of wireless communication, and in particular to a transmission method, device and terminal for joint selection of a sending end and a relay point.

Background technique

The transmission of wireless signals carries energy as well as information. It has been proven feasible to use wireless signals for energy supply, and energy collection based on wireless electromagnetic waves is more stable. The wireless energy transmission technology enables wireless devices in the network to meet energy requirements by collecting energy in wireless radio frequency signals. Wireless energy transmission technology can effectively reduce network operating costs and improve communication performance. In order to provide nodes with higher information transmission rate and better service quality, while providing energy to prolong network life, wireless information transmission technology and energy transmission technology can be reasonably combined, and energy-efficient wireless information and energy transmission (Simultaneously Wireless Information and Power Transfer, SWIPT) program came into being.

SWIPT technology enables nodes to collect energy contained in wireless signals while receiving information normally, and store the energy in batteries. However, the dual transmission of wireless information and energy of nodes in the system using the SWIPT scheme may lead to uneven resource allocation between the two, resulting in low energy efficiency, which in turn leads to energy waste or failure to meet system information transmission requirements, reducing network life.

technical problem

The purpose of the present application is to provide a transmission method, device and terminal for joint transmission end and relay point selection, aiming to solve the problem of uneven resource allocation caused by information transmission and energy transmission, resulting in reduced network life.

technical solution

In the first aspect, the embodiment of the present application provides a transmission method for joint sending end and relay point selection, including:

Determine the transmission mode used for information transmission according to the information carried when the sending node sends information to the receiving node;

Calculate the total transmission rate and total power consumption of all nodes during the information transmission process according to the transmission mode and the channel information used for the information transmission;

Establishing an objective function and constraint conditions aiming at maximizing energy efficiency according to the total transmission rate and the total power consumption;

optimizing the objective function;

According to the constraints, the objective function is solved to obtain an optimal power allocation mode, an optimal time allocation factor and an optimal relay selection mode.

In the second aspect, the embodiment of the present application provides a transmission device for joint sending end and relay point selection, including:

A calculation module, configured to determine the transmission mode adopted for information transmission according to the information carried when the sending node sends information to the receiving node;

The calculation module is also used to calculate the total transmission rate and total power consumption of all nodes during the information transmission process according to the transmission mode and the information of the channel used for information transmission;

A model establishment module, configured to establish an objective function and constraint conditions aiming at maximizing energy efficiency according to the total transmission rate and the total power consumption;

An optimization module, configured to optimize the objective function;

The calculation module is further configured to solve the objective function according to the constraints to obtain an optimal power allocation mode, an optimal time allocation factor and an optimal relay selection mode.

In a third aspect, an embodiment of the present application provides a terminal, including a memory, a processor, and a computer program stored in the memory and operable on the processor, and the computer program is implemented when the processor executes the computer program. The steps of the method described in the above first aspect or any possible implementation manner of the first aspect.

Beneficial effect

Compared with the prior art, the beneficial effect of the transmission method for joint sending end and relay point selection provided by this application lies in:

The transmission method provided in this application determines the transmission mode and the total transmission rate and total power consumption of all nodes in the process of information transmission, so as to establish the objective function and constraint conditions with the goal of maximizing energy efficiency. According to the constraints, the objective function is solved to obtain an optimal power allocation mode, an optimal time allocation factor and an optimal relay selection mode. Furthermore, through optimized transmission power, duration of information and energy collection, and relay selection strategy, the lifetime of the network as a whole can be improved, so that more information can be transmitted while consuming the same amount of energy. In addition, the transmission method provided by the present application can avoid the situation of always using the same node for information transmission through the selection of relay nodes, so as to balance the energy efficiency of the entire network.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the accompanying drawings that need to be used in the descriptions of the embodiments or the prior art will be briefly introduced below. Obviously, the accompanying drawings in the following description are only for the present application For some embodiments, those of ordinary skill in the art can also obtain other drawings based on these drawings without paying creative efforts.

Fig. 1 is the implementation flow diagram of the transmission method of joint sending end and relay point selection provided by the embodiment of the present application;

FIG. 2 is a schematic diagram of an energy-constrained wireless sensor network provided by an embodiment of the present application;

FIG. 3 is a schematic diagram of a transmission structure provided by an embodiment of the present application;

FIG. 4 is a schematic diagram of convergence analysis based on different maximum transmission powers in the main loop iteration process provided by the embodiment of the present application;

Fig. 5 is a schematic diagram of the relationship between the inter-cluster distance and energy efficiency provided by the embodiment of the present application;

Fig. 6 is a schematic diagram of the relationship between the maximum capacity limit and energy efficiency provided by the embodiment of the present application;

Fig. 7 is a schematic diagram of the remaining capacity comparison provided by the embodiment of the present application;

FIG. 8 is a schematic structural diagram of a transmission device for joint sending end and relay point selection provided by an embodiment of the present application;

FIG. 9 is a schematic diagram of a terminal provided by an embodiment of the present application.

Embodiment of this application

In the following description, specific details such as specific system structures and technologies are presented for the purpose of illustration rather than limitation, so as to thoroughly understand the embodiments of the present application. It will be apparent, however, to one skilled in the art that the present application may be practiced in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present application with unnecessary detail.

In order to make the purpose, technical solution and advantages of the present application clearer, specific embodiments will be described below in conjunction with the accompanying drawings.

Fig. 1 is the realization flow diagram of a kind of transmission method of joint sending end and relay point selection provided by the embodiment of the present application, detailed description is as follows:

Step 101, according to the information carried by the sending node when the receiving node receives the information, determine the transmission mode adopted for information transmission.

Fig. 2 is a schematic diagram of an energy-constrained wireless sensor network. The network shown in Figure 2 is composed of K wireless sensor clusters located in different areas. The network shown in Figure 2 includes four types of nodes: common nodes (circled circles), cluster-head nodes S, relay nodes R and sink nodes. In Fig. 2, solid circles represent candidate relay nodes. Ordinary nodes are the most numerous nodes in each cluster, and are used to send information to the cluster head nodes in the cluster to which they belong. Each cluster includes a cluster head node, and the cluster head node is a node in a cluster that communicates with other nodes in the cluster. Relay nodes are located at the edge of two adjacent clusters and are used to forward information between cluster-head nodes. The aggregation node may be a base station, and is used to receive information of all nodes.

In the process of information aggregation, clusters that are far away from the aggregation node need to help forward information through clusters that are closer to the aggregation node, so as to transmit the information to the aggregation node. That is, a cluster head node (sending node S) can transfer the collected information to the adjacent cluster head node (target node D), and the target node is the cluster head node of the cluster closest to the sink node. If the cluster head node of the adjacent cluster is also far away from the sink node, node S can choose other suitable cluster nodes (such as relay node R) around it as relay assistant to complete the information transmission process from S to D. In the network, cluster-head nodes can send information and energy at the same time, and the principle of transmission follows "whoever helps to forward will receive energy compensation". Relay nodes can receive energy supplies. At the same time, the target node D also performs energy collection during the energy transmission stage. The transmission structure is shown in Figure 3. In the inter-cluster communication process, the transmission period is T, and the information transmission in each transmission period includes intra-cluster communication and inter-cluster communication. During inter-cluster communication, the receiving node adopts a time switching (Time Switching, TS) mode for receiving. The node is in a certain proportion of time (for example, in

time) to receive information, another part of the time (for example, in

time) for energy harvesting.

Optionally, in this embodiment, the sending node is an ordinary node, a relay node or a cluster head node in the wireless sensor network. The receiving node is the cluster head node, relay node or target node in the wireless sensor network. When the sending node is an ordinary node, the receiving node is a cluster head node. When the sending node is a cluster head node, the receiving node is another cluster head node, a relay node or a target node. When the sending node is a relay node, the receiving node is a cluster head node or a target node.

At present, many energy-constrained wireless sensor networks are applied in areas far away from active nodes, so the limited network lifetime caused by the passivity of the entire system has become a key issue in transmission design. In the process of uplink information aggregation (that is, the process of nodes transmitting information to the aggregation node, where the aggregation node can be a base station), the energy consumption of the nodes closer to the aggregation node is due to the task of forwarding the data of the farther nodes. higher. The network that is far away from the sink node is mainly used to collect information in the area and upload it to the sink node. Optimizing the energy efficiency of the network can minimize the energy consumption of the entire network when transmitting the same amount of data. On the other hand, nodes distributed at the intersection of two cluster areas often act as relay nodes for cooperative transmission, which also makes them consume more energy than other nodes. When the nodes and relay nodes that are closer to the sink node are excessively consumed, the network will not be able to effectively transmit information, causing network paralysis. Therefore, the selection of relay nodes and the energy supply strategy have become the key research contents of cooperative transmission. Applying wireless information and energy transmission technology to the network can effectively deal with the problem of excessive energy consumption of a single node. In the transmission design process, the imbalance between information transmission and energy consumption will lead to low energy efficiency. This application optimizes energy efficiency and proposes a relay node selection method to achieve a balance between information transmission and energy consumption in a wireless sensor network, reducing the energy consumed by the entire network.

In step 101, according to the information carried when the sending node sends information to the receiving node, the transmission mode adopted for information transmission is determined, which may include:

According to the channel gain information and noise information carried when the sending node sends information to the receiving node, the normalized channel gain w _TD between the sending node and the receiving node and the normalized channel gain between the relay node and the receiving node are calculated w _RD and the normalized channel gain w _TR between the sending node and the relay node;

When the minimum value between w _TR and w _RD is greater than or equal to w _TD , the use of relay nodes can make the effective transmission rate faster, and it is determined that the second stage of information transmission adopts the relay transmission mode; when between w _TR and w _RD When the minimum value of is less than w _TD , it is determined that the second-stage information transmission adopts the direct transmission mode;

According to the transmission mode and the channel information and transmission power information carried by the sending node, the corresponding transmission rate is determined.

optional, according to

Compute the normalized channel gain. Among them, h represents the channel gain, and ^σ2 represents the noise variance. It should be noted that when w _TD is calculated, it is based on the channel gain and noise variance between the sending node and the receiving node. When calculating w _RD , it is based on the channel gain and noise variance between the relay node and the receiving node. When calculating w _TR , according to the channel gain and noise variance between the sending node and the relay node.

When determining the transmission mode, we can determine the transmission mode used for the next information transmission according to the current normalized channel gain.

Optionally, determining the corresponding transmission rate according to the transmission mode and the channel information and transmission power information carried by the sending node may include:

Determine the transmission rate of the direct transmission mode according to R _TD1 =Blog(1+w _{TD PT} );

according to

Determine the transmission rate of the relay transmission mode;

Among them, R _TD1 represents the transmission rate of the direct transmission mode, B represents the baseband transmission bandwidth, _PT represents the transmission power of the sending node, and T represents the length of the transmission cycle; R _TD2 represents the transmission rate of the relay transmission mode, and _PR represents the relay node the sending power.

Referring to FIG. 1 , in step 102 , calculate the total transmission rate and total power consumption of all nodes during the information transmission process according to the transmission mode and the channel information used for information transmission.

Assuming that the wireless sensor network includes K clusters that need to send information to the cluster head node of another cluster, under the conditions that the clustering has been determined and the transmission path is clear, the total transmission rate of the system is the rate of each target node in a unit time The sum of the amount of data transferred. The total transmission rate of the system can be calculated according to the following formula

in,

Indicates the total transmission rate of all nodes in the process of information transmission,

represents the time allocation factor,

Indicates the information transmission time allocation factor corresponding to the tth sending node,

Indicates the energy time allocation factor corresponding to the tth sending node,

Indicates the power allocation strategy,

P _t represents the transmission power of the tth sending node, K represents the number of clusters that need to send information to the cluster head node of another cluster,

Indicates the relay selection condition,

χ _t represents the t-th relay node, when the node is selected as a relay node, χ _t =1, otherwise χ _t =0. R _td represents the information transmission rate from the tth sending node to the dth destination node. In the direct transmission mode, w _t =w _td represents the normalized channel gain between the t-th sending node and the d-th target node. In the forwarding mode, w _t =w _tr represents the normalized channel gain between the t-th sending node and the r-th relay node.

The total power consumed by the system can be calculated according to the following formula:

in,

Indicates the total power consumption of all nodes in the process of information transmission, _PCT indicates the circuit power consumption of cluster-head nodes, _PCR indicates the circuit power consumption of relay nodes, and P _sum indicates the power consumed by nodes in the process of sending and receiving information.

Continuing to refer to FIG. 1 , in step 103 , according to the total transmission rate and total power consumption, an objective function and constraint conditions aiming at maximizing energy efficiency are established.

Energy efficiency is defined as the ratio of system transmission information rate to energy consumption, which means the amount of information that can be transmitted per unit energy, and the unit is bits/Joule (bits/Joule). Alternatively, energy efficiency can also be defined as the ratio of spectral efficiency to energy consumption, in units of bits/Hz/Joule (bits/Hz/Joule). It balances the spectrum efficiency and energy consumption of the system, and is an important parameter to measure the green communication standard.

In this example we adopt the first definition, namely

Our purpose is to get the optimal power allocation method, the optimal time allocation factor and the optimal relay selection method, namely

maximize the energy efficiency of the system. Therefore the problem can be modeled as

That is the objective function we need to establish.

The constraints are

Among them, η ^* represents the maximum energy efficiency of the system, ε represents the amplification factor of energy consumption in the whole transmission process, w _rd represents the normalized channel gain between the rth relay node and the dth destination node,

Indicates the energy time allocation factor corresponding to the r-th relay node, E(P _t h _tr ) represents the amount of nonlinear energy received, h _tr represents the channel gain between the t-th sending node and the r-th relay node, h _td represents the channel gain between the t-th sending node and the d-th target node; E _r,0 represents the initial power of the relay node,

Indicates the minimum energy consumption of relay nodes,

Represents the maximum information rate sent by the sending node, M _t represents the maximum energy accommodated by the sending node,

Indicates the minimum information rate sent by the sending node.

Among them, the function

Ψ _k represents the input energy

N _k represents the highest charging power that the receiving node can accommodate, Ω _k represents the energy receiving capacity coefficient of the node, a _k and b _k represent parameters determined by hardware such as the sensitivity of the node circuit and the degree of leakage.

Continue referring to FIG. 1, step 104, optimize the objective function.

In this step, the established energy efficiency optimization problem is equivalently transformed into an optimization problem in the form of an equation, that is, the objective function is optimized. can be based on

Transform the objective function into an equation; where,

Respectively represent the optimal time allocation factor, the optimal power allocation mode and the optimal relay selection mode.

Then, according to the iterative algorithm adopted in this embodiment, an equivalent transformation is performed on the energy efficiency optimization problem, as follows:

Based on the preset η and the objective function, the calculation makes

established

based on obtained

detection

Whether it holds true, where, η represents the energy efficiency of the system,

Indicates the error threshold at convergence;

when

established, determined

for

and

when

established according to

Determine the new η, and jump to the calculation based on the preset η and the objective function

established

The steps continue until it is determined

and η ^* end, or the number of iterations reaches the maximum number of iterations.

It should be noted that before iterative processing, parameters involved in the iterative algorithm need to be initialized, including initializing the number of iterations i, setting i=1; initializing energy efficiency η, setting η=0. Then enter the maximum number of iterations to limit the number of iterations of the iterative algorithm, enter the value of energy efficiency, infinitesimal and the number of iterations i.

After the iterative algorithm starts, for i=1 and η=0, when i is less than the maximum number of iterations, the main loop is performed. For a given η, solve

and make

maximize. get

After, detect

Whether it is established, when it is not established, set

And update the number of iterations according to i=i+1. When the number of iterations reaches the maximum number of iterations, or get

and η ^* when the end, the final output determined

and η ^* .

See Figure 4, the schematic diagram of the convergence analysis based on different maximum transmission powers during the main loop iteration process. Hold the maximum value.

When optimizing the objective function in this step, the energy efficiency optimization problem is transformed into a given η, and the solution

and make

problem of maximization.

Continue to refer to FIG. 1 , step 105 , solve the objective function according to the constraint conditions, and obtain the optimal power allocation mode, the optimal time allocation factor and the optimal relay selection mode.

After the objective function is optimized into an equation according to the optimization method in step 104, the equation can be solved. In this embodiment, a distributed solution algorithm is used to solve the equation.

Optionally, according to the constraints, the objective function is solved to obtain the optimal power allocation mode, the optimal time allocation factor and the optimal relay selection mode, including:

According to the constraints, the energy efficiency optimization problem corresponding to the objective function is set as a convex optimization problem, and the Lagrangian dual processing is used to obtain the closed-form solutions of each power allocation method, time allocation factor and relay selection method;

The Lagrange operator is substituted into each closed-form solution to calculate the optimal power distribution method, the optimal time distribution factor and the optimal relay selection method.

When setting the energy efficiency optimization problem as a convex optimization problem, set the value of χ _t in the constraints to 0 or 1, and set it to 0≤χ _t ≤1. χ _t can be understood as the tenth factor of the relay r used by the t-th sending node, and it is assumed that the transmission is under the condition of high signal-to-noise ratio, so that the energy efficiency optimization problem is transformed into a convex optimization problem.

From the Lagrangian duality, we get

Among them, ω, μ, ν, υ, φ represent Lagrangian multipliers respectively, ω=[ω _t ,t=1,...,K] ^T , μ=[μ _t ,t=1,.. .,K] ^T , ν=[ν _t ,t=1,...,K] ^T and υ=[ν _t,d ,t,d=1,...,K] ^T .

Since the original problem is a convex optimization problem, each condition satisfies the (Karush-Kuhn-Tucker, KKT) condition. Then the closed-form solutions are as follows

The power allocation strategy is

The time allocation strategy is

in

N _d represents the highest charging power accommodated by the d-th target node, N _r represents the highest charging power accommodated by the r-th relay node, e ^* represents an exponential function, a _r and b _r represent the sensitivity of the circuit of the r-th relay node degree and leakage degree and other hardware-determined parameters, a _d , b _d represent hardware-determined parameters such as the sensitivity and leakage degree of the d-th target node circuit, and a _tr represents the t-th sending node to the r-th relay node The parameters determined by hardware such as the sensitivity and leakage degree of the circuit between , a _rd represent the parameters determined by hardware such as the sensitivity and leakage degree of the circuit between the r-th relay node and the d-th target node, and a _t represents Parameters determined by hardware such as the sensitivity and leakage degree of the t-th sending node circuit.

The relay node allocation strategy is

in,

Represents the relay selection criterion function.

can be regarded as the relay benefit function when the jth candidate node is selected as the relay;

In the relay selection process, the benefit is compared with the criterion function, and the node corresponding to the benefit closest to the criterion function will be selected as the relay node. The expression in the formula is to calculate the difference between the two, and make the difference The value is the smallest.

Finally, the Lagrangian multipliers are updated and substituted into the above three closed-form solutions to update to obtain the final transmission strategy.

The above-mentioned transmission method selected by the joint sending end and relay point is simulated, and the simulation parameters used are not limited. In this embodiment, only the simulation parameters shown in Table 1 below are used.

Table I

Through the simulation with the parameters shown in Table 1, the simulation results shown in Figure 5 to Figure 7 are obtained. Figure 5 shows the relationship between inter-cluster distance and energy efficiency. It can be seen from Figure 5 that no matter in the relay transmission mode or the direct transmission mode, the energy efficiency of the system decreases with the increase of the inter-cluster distance. This is mainly due to the attenuating characteristics of wireless channels. Further, it can be seen that the energy efficiency performance of the system in the relay transmission mode is better than that in the direct transmission mode.

See Figure 6 which shows the relationship between the maximum energy limit and energy efficiency. It can be seen from FIG. 6 that the energy efficiency of the transmission method adopted by the present application for joint transmission and relay point selection is obviously higher than other methods. Other methods here refer to single-relay auxiliary strategy, parallel strategy and multi-relay cooperative strategy.

Refer to Figure 7 for a schematic diagram of residual energy comparison. In terms of overall energy consumption, the sending node S consumes the most energy, followed by the relay node R, and the destination node D consumes the least. On the other hand, under the strategies proposed in this application, no matter whether it is a sending node, a relay node or a target node, the remaining energy exceeds the energy corresponding to the other three strategies. At the same time, the balance of the consumption of various nodes is also the best, that is, the remaining power between different types of nodes is the closest, which prolongs the life of the network. Especially for the relay node R, the advantage of using the method provided by this application is the most obvious. This is because during the transmission process, after using the method provided by this application, the relay node collects more energy, so that the energy cost of its auxiliary transmission is greatly reduced.

This application provides a transmission method for the selection of the joint sender and relay point. By determining the transmission mode used for information transmission and the total transmission rate and total power consumption of all nodes in the information transmission process, the goal of maximizing energy efficiency is established. The objective function and constraint conditions; and according to the constraint conditions, the objective function is solved to obtain the optimal power allocation mode, the optimal time allocation factor and the optimal relay selection mode; The duration of power, information and energy collection and relay selection strategy to improve the network life of the overall network, so that more information can be transmitted while consuming the same energy. In this application, through the selection of relay nodes, it is avoided to use the same node for information transmission all the time, so that the energy efficiency of the overall network can be balanced.

It should be understood that the sequence numbers of the steps in the above embodiments do not mean the order of execution, and the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiment of the present application.

The following are device embodiments of the present application, and for details that are not exhaustively described therein, reference may be made to the above-mentioned corresponding method embodiments.

FIG. 8 shows a schematic structural diagram of a transmission device for joint sending end and relay point selection provided by an embodiment of the present application. For ease of description, FIG. 8 only shows the parts related to the embodiment of the present application, and the details are as follows:

As shown in FIG. 8 , the transmission device for joint sending end and relay point selection includes: a calculation module 801 , a model building module 802 and an optimization module 803 .

Calculation module 801, configured to determine the transmission mode adopted for information transmission according to the information carried when the sending node sends information to the receiving node;

The calculation module 801 is further configured to calculate the total transmission rate and total power consumption of all nodes during the information transmission process according to the transmission mode and the channel information used for information transmission;

A model establishment module 802, configured to establish an objective function and constraint conditions aiming at maximizing energy efficiency according to the total transmission rate and the total power consumption;

An optimization module 803, configured to optimize the objective function;

The calculation module 801 is further configured to solve the objective function according to the constraint conditions to obtain an optimal power allocation mode, an optimal time allocation factor and an optimal relay selection mode.

Optionally, the sending node is an ordinary node, a relay node or a cluster head node in the wireless sensor network, and the receiving node is the cluster head node, the relay node or a target node in the wireless sensor network node;

When the sending node is the normal node, the receiving node is the cluster head node; when the sending node is the cluster head node, the receiving node is other cluster head nodes, the relay node or the target node; when the sending node is the relay node, the receiving node is the cluster head node or the target node;

The common node is a node that sends information to the cluster head node of the cluster to which it belongs; the cluster head node is a node that communicates with nodes in other clusters in a cluster; the relay node is located at the edge of two adjacent clusters, and used for forwarding information between cluster head nodes; the target node is the cluster head node in the cluster closest to the sink node.

In an embodiment, when the calculation module 801 determines the transmission mode used for information transmission according to the information carried when the sending node sends information to the receiving node, it can be used for:

According to the channel gain information and noise information carried when the sending node sends information to the receiving node, the normalized channel gain w TD between the sending node and the receiving node, the normalized channel gain w _TD between the relay node and the receiving node, and The normalized channel gain w _RD of and the normalized channel gain w _TR between the sending node and the relay node;

When the minimum value between w _TR and w _RD is greater than or equal to w _TD , it is determined that the information transmission of the second stage adopts the relay transmission mode;

When the minimum value between w _TR and w _RD is less than w _TD , it is determined that the second stage information transmission adopts the direct transmission mode;

Determine the corresponding transmission rate according to the transmission mode and the channel information and transmission power information carried by the sending node.

In an embodiment, when the calculation module 801 determines the corresponding transmission rate according to the transmission mode and the channel information and transmission power information carried by the sending node, it can be used for:

Determine the transmission rate of the direct transmission mode according to R _TD1 =Blog(1+w _{TD PT} );

according to

Determine the transmission rate of the relay transmission mode;

Among them, R _TD1 represents the transmission rate of the direct transmission mode, B represents the baseband transmission bandwidth, _PT represents the transmission power of the sending node, T represents the length of the transmission cycle, R _TD2 represents the transmission rate of the relay transmission mode, and _PR represents the relay node the sending power.

In an embodiment, when the calculation module 801 calculates the total transmission rate and total power consumption of all nodes in the process of information transmission according to the transmission mode and the information of the channel used for information transmission, it can be used for:

When the clustering has been determined and the transmission mode is determined, according to

Calculate the total transmission rate of all nodes in the process of information transmission;

according to

Calculate the total power consumption of all nodes during information transmission;

in,

Indicates the total transmission rate of all nodes in the process of information transmission,

represents the time allocation factor,

Indicates the information transmission time allocation factor corresponding to the tth sending node,

Indicates the energy time allocation factor corresponding to the tth sending node,

Indicates the power allocation strategy,

P _t represents the transmission power of the tth sending node, K represents the number of clusters that need to send information to another cluster head node,

Indicates the relay selection condition,

χ _t represents the t-th relay node, R _td represents the information transmission rate from the t-th sending node to the d-th target node, in the direct transmission mode, w _t =w _td , means that the t-th sending node and the The normalized channel gain between d target nodes, in forwarding mode, w _t =w _tr , represents the normalized channel gain between the t-th sending node and the r-th relay node;

Indicates the total power consumption of all nodes in the process of information transmission, _PCT indicates the circuit power consumption of cluster-head nodes, _PCR indicates the circuit consumption of relay nodes, and P _sum indicates the power consumed by nodes in the process of sending and receiving information.

In one embodiment, the objective function is

The constraints are

Among them, η ^* represents the maximum energy efficiency of the system, ε represents the amplification factor of energy consumption in the whole transmission process, w _rd represents the normalized channel gain between the rth relay node and the dth destination node,

Indicates the energy time allocation factor corresponding to the r-th relay node, E(P _t h _tr ) represents the amount of nonlinear energy received, h _tr represents the channel gain between the t-th sending node and the r-th relay node, h _td represents the channel gain between the tth sending node and the dth target node; e _{r, 0} represents the initial power of the receiving node,

Indicates the minimum energy consumption of the receiving node,

Indicates the maximum information rate sent by the sending node, M _t indicates the maximum energy accommodated by the node,

Indicates the minimum information rate sent by the sending node.

In an embodiment, when the optimization module 803 optimizes the objective function, it may be used for:

according to

Transform the objective function into an equation; where,

Respectively represent the optimal time allocation factor, the optimal power allocation method and the optimal relay selection method;

Based on the preset η and the objective function, the calculation makes

established

based on obtained

detection

Whether it holds true, where, η represents the energy efficiency of the system,

Indicates the error threshold at convergence;

when

established, confirmed

for

and

when

established according to

Determine the new η, and jump to the calculation based on the preset η and the objective function using

established

The steps continue until it is determined

and η ^* end, or the number of iterations reaches the maximum number of iterations.

In an embodiment, the calculation module 801 solves the objective function according to the constraints to obtain the optimal power allocation mode, the optimal time allocation factor, and the optimal relay selection mode. Used for:

According to the constraints, the energy efficiency optimization problem corresponding to the objective function is set as a convex optimization problem, and Lagrangian dual processing is used to obtain closed-form solutions for each power allocation mode, time allocation factor, and relay selection mode;

The Lagrangian operator is substituted into each closed-form solution, and the optimal power allocation mode, the optimal time allocation factor and the optimal relay selection mode are calculated.

The transmission device selected by the above joint sending end and relay point determines the transmission mode used for information transmission and the total transmission rate and total power consumption of all nodes in the information transmission process through the calculation module, so that the model building module is established with the maximum energy efficiency as The objective function and constraint conditions of the target; and according to the constraint conditions, the optimization module solves the objective function to obtain the optimal power allocation mode, the optimal time allocation factor and the optimal relay selection mode; and then can By optimizing the transmission power, the duration of information and energy collection, and the relay selection strategy, the network life of the overall network can be improved, so that more information can be transmitted while consuming the same energy. In this application, through the selection of relay nodes, it is avoided to use the same node for information transmission all the time, so that the energy efficiency of the overall network can be balanced.

FIG. 9 is a schematic diagram of a terminal provided by an embodiment of the present application. As shown in FIG. 9 , the terminal 9 of this embodiment includes: a processor 90 , a memory 91 , and a computer program 92 stored in the memory 91 and operable on the processor 90 . When the processor 90 executes the computer program 92, it realizes the steps in the above embodiments of the transmission method for joint sending end and relay point selection, for example, step 101 to step 105 shown in FIG. 1 . Alternatively, when the processor 90 executes the computer program 92, it realizes the functions of the modules/units in the above-mentioned device embodiments, for example, the functions of the modules/units 801 to 803 shown in FIG. 8 .

Exemplarily, the computer program 92 can be divided into one or more modules/units, and the one or more modules/units are stored in the memory 91 and executed by the processor 90 to complete this application. The one or more modules/units may be a series of computer program instruction segments capable of accomplishing specific functions, and the instruction segments are used to describe the execution process of the computer program 92 in the terminal 9 . For example, the computer program 92 may be divided into modules/units 801 to 803 shown in FIG. 8 .

The terminal 9 may be a computing device such as a desktop computer, a notebook, a palmtop computer, or a cloud server. The terminal 9 may include, but not limited to, a processor 90 and a memory 91 . Those skilled in the art can understand that FIG. 9 is only an example of the terminal 9 and does not constitute a limitation to the terminal 9. It may include more or less components than shown in the figure, or combine some components, or different components, such as The terminal may also include an input and output device, a network access device, a bus, and the like.

The so-called processor 90 can be a central processing unit (Central Processing Unit, CPU), and can also be other general-purpose processors, digital signal processors (Digital Signal Processor, DSP), application specific integrated circuits (Application Specific Integrated Circuit, ASIC), Field-Programmable Gate Array (Field-Programmable Gate Array, FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor, or the processor may be any conventional processor, or the like.

The storage 91 may be an internal storage unit of the terminal 9 , such as a hard disk or memory of the terminal 9 . The memory 91 can also be an external storage device of the terminal 9, such as a plug-in hard disk equipped on the terminal 9, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, Flash card (Flash Card), etc. Further, the memory 91 may also include both an internal storage unit of the terminal 9 and an external storage device. The memory 91 is used to store the computer program and other programs and data required by the terminal. The memory 91 can also be used to temporarily store data that has been output or will be output.

Those skilled in the art can clearly understand that for the convenience and brevity of description, only the division of the above-mentioned functional units and modules is used for illustration. In practical applications, the above-mentioned functions can be assigned to different functional units, Completion of modules means that the internal structure of the device is divided into different functional units or modules to complete all or part of the functions described above. Each functional unit and module in the embodiment may be integrated into one processing unit, or each unit may exist separately physically, or two or more units may be integrated into one unit, and the above-mentioned integrated units may adopt hardware It can also be implemented in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the protection scope of the present application. For the specific working process of the units and modules in the above system, reference may be made to the corresponding process in the foregoing method embodiments, and details will not be repeated here.

In the above-mentioned embodiments, the descriptions of each embodiment have their own emphases, and for parts that are not detailed or recorded in a certain embodiment, refer to the relevant descriptions of other embodiments.

Those skilled in the art can appreciate that the units and algorithm steps of the examples described in conjunction with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed by hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art may use different methods to implement the described functions for each specific application, but such implementation should not be regarded as exceeding the scope of the present application.

In the embodiments provided in this application, it should be understood that the disclosed device/terminal and method may be implemented in other ways. For example, the device/terminal embodiments described above are only illustrative. For example, the division of the modules or units is only a logical function division. In actual implementation, there may be other division methods, such as multiple units or Components may be combined or integrated into another system, or some features may be omitted, or not implemented. In another point, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces, and the indirect coupling or communication connection of devices or units may be in electrical, mechanical or other forms.

The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, each unit may exist separately physically, or two or more units may be integrated into one unit. The above-mentioned integrated units can be implemented in the form of hardware or in the form of software functional units.

If the integrated module/unit is realized in the form of a software function unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments in the present application can also be completed by instructing related hardware through computer programs. The computer programs can be stored in a computer-readable storage medium, and the computer When the program is executed by the processor, the steps of the above embodiments of the transmission method for joint sending end and relay point selection can be realized. Wherein, the computer program includes computer program code, and the computer program code may be in the form of source code, object code, executable file or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying the computer program code, a recording medium, a USB flash drive, a removable hard disk, a magnetic disk, an optical disk, a computer memory, and a read-only memory (Read-Only Memory, ROM) , random access memory (Random Access Memory, RAM), electric carrier signal, telecommunication signal and software distribution medium, etc. It should be noted that the content contained in the computer-readable medium may be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, computer-readable media Excluding electrical carrier signals and telecommunication signals.

The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it can still implement the foregoing embodiments Modifications to the technical solutions described in the examples, or equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the application, and should be included in the Within the protection scope of this application.

Claims (10)

1. A transmission method for joint sending end and relay point selection, characterized in that it includes:

   Determine the transmission mode used for information transmission according to the information carried when the sending node sends information to the receiving node;

   Calculate the total transmission rate and total power consumption of all nodes during the information transmission process according to the transmission mode and the channel information used for the information transmission;

   Establishing an objective function and constraint conditions aiming at maximizing energy efficiency according to the total transmission rate and the total power consumption;

   optimizing the objective function;

   According to the constraints, the objective function is solved to obtain an optimal power allocation mode, an optimal time allocation factor and an optimal relay selection mode.
2. The transmission method for joint sending end and relay point selection according to claim 1, wherein the sending node is an ordinary node, a relay node or a cluster head node in a wireless sensor network, and the receiving node is the selected The cluster head node, the relay node or the target node in the wireless sensor network;

   When the sending node is the normal node, the receiving node is the cluster head node; when the sending node is the cluster head node, the receiving node is other cluster head nodes, the relay node or the target node; when the sending node is the relay node, the receiving node is the cluster head node or the target node;

   The common node is a node that sends information to the cluster head node of the cluster to which it belongs; the cluster head node is a node that communicates with nodes in other clusters in a cluster; the relay node is located at the edge of two adjacent clusters, and used for forwarding information between cluster head nodes; the target node is the cluster head node in the cluster closest to the sink node.
3. According to the transmission method for joint sending end and relay point selection according to claim 1 or 2, it is characterized in that, according to the information carried when the sending node sends information to the receiving node, determining the transmission mode adopted for information transmission includes:

   According to the channel gain information and noise information carried when the sending node sends information to the receiving node, the normalized channel gain w TD between the sending node and the receiving node, the normalized channel gain w _TD between the relay node and the receiving node, and The normalized channel gain w _RD of and the normalized channel gain w _TR between the sending node and the relay node;

   When the minimum value between w _TR and w _RD is greater than or equal to w _TD , it is determined that the information transmission of the second stage adopts the relay transmission mode;

   When the minimum value between w _TR and w _RD is less than w _TD , it is determined that the second stage information transmission adopts the direct transmission mode;

   Determine the corresponding transmission rate according to the transmission mode and the channel information and transmission power information carried by the sending node.
4. The transmission method for joint transmission terminal and relay point selection according to claim 3, wherein the determination of the corresponding transmission rate according to the transmission mode and the channel information and transmission power information carried by the transmission node includes:

   Determine the transmission rate of the direct transmission mode according to R _TD1 =B log(1+w _{TD PT} );

   according to

   

   Determine the transmission rate of the relay transmission mode;

   Among them, R _TD1 represents the transmission rate of the direct transmission mode, B represents the baseband transmission bandwidth, _PT represents the transmission power of the sending node, T represents the length of the transmission cycle, R _TD2 represents the transmission rate of the relay transmission mode, and _PR represents the relay node the sending power.
5. According to the transmission method for joint sending end and relay point selection according to claim 3, it is characterized in that, according to the information of the channel used in the transmission mode and information transmission, the total transmission of all nodes in the information transmission process is calculated rate and total power consumption, including:

   When the clustering has been determined and the transmission mode is determined, according to

   

   Calculate the total transmission rate of all nodes in the process of information transmission;

   according to

   

   Calculate the total power consumption of all nodes during information transmission;

   in,

   

   Indicates the total transmission rate of all nodes in the process of information transmission,

   

   represents the time allocation factor,

   

   Indicates the information transmission time allocation factor corresponding to the tth sending node,

   

   Indicates the energy time allocation factor corresponding to the tth sending node,

   

   Indicates the power allocation strategy,

   

   P _t represents the transmission power of the tth sending node, K represents the number of clusters that need to send information to another cluster head node,

   

   Indicates the relay selection condition,

   

   χ _t represents the t-th relay node, R _td represents the information transmission rate from the t-th sending node to the d-th target node, in the direct transmission mode, w _t =w _td , means that the t-th sending node and the The normalized channel gain between d target nodes, in forwarding mode, w _t =w _tr , represents the normalized channel gain between the t-th sending node and the r-th relay node;

   

   Indicates the total power consumption of all nodes in the process of information transmission, _PCT indicates the circuit power consumption of cluster-head nodes, _PCR indicates the circuit consumption of relay nodes, and P _sum indicates the power consumed by nodes in the process of sending and receiving information.
6. The transmission method for joint sending end and relay point selection according to claim 5, wherein the objective function is

   

   The constraints are

   

   Among them, η ^* represents the maximum energy efficiency of the system, ε represents the amplification factor of energy consumption in the whole transmission process, w _rd represents the normalized channel gain between the rth relay node and the dth destination node,

   

   Indicates the energy time allocation factor corresponding to the r-th relay node, E(P _t h _tr ) represents the amount of nonlinear energy received, h _tr represents the channel gain between the t-th sending node and the r-th relay node, h _td represents the channel gain between the t-th sending node and the d-th target node; E _r,0 represents the initial power of the receiving node,

   

   Represents the minimum energy consumption of the receiving node, P _t ^max represents the maximum information rate sent by the sending node, M _t represents the maximum energy accommodated by the node,

   

   Indicates the minimum information rate sent by the sending node.
7. The transmission method for joint sending end and relay point selection according to claim 6, wherein said optimizing said objective function comprises:

   according to

   

   Transform the objective function into an equation; where,

   

   Respectively represent the optimal time allocation factor, the optimal power allocation method and the optimal relay selection method;

   Based on the preset η and the objective function, the calculation makes

   

   established

   

   based on obtained

   

   detection

   

   Whether it holds true, where, η represents the energy efficiency of the system,

   

   Indicates the error threshold at convergence;

   when

   

   established, confirmed

   

   for

   

   and

   

   when

   

   established according to

   

   Determine the new η, and jump to the calculation based on the preset η and the objective function using

   

   established

   

   The steps continue until it is determined

   

   and η ^* end, or the number of iterations reaches the maximum number of iterations.
8. According to the transmission method for joint transmission end and relay point selection according to claim 6, it is characterized in that, according to the constraint conditions, the objective function is solved to obtain the optimal power allocation mode, the optimal Time allocation factors and optimal relay selection methods, including:

   According to the constraints, the energy efficiency optimization problem corresponding to the objective function is set as a convex optimization problem, and Lagrangian dual processing is used to obtain closed-form solutions for each power allocation mode, time allocation factor, and relay selection mode;

   The Lagrangian operator is substituted into each closed-form solution, and the optimal power allocation mode, the optimal time allocation factor and the optimal relay selection mode are calculated.
9. A transmission device for joint sending end and relay point selection, characterized in that it includes:

   A calculation module, configured to determine the transmission mode adopted for information transmission according to the information carried when the sending node sends information to the receiving node;

   The calculation module is also used to calculate the total transmission rate and total power consumption of all nodes during the information transmission process according to the transmission mode and the channel information used for information transmission;

   A model establishment module, configured to establish an objective function and constraint conditions aiming at maximizing energy efficiency according to the total transmission rate and the total power consumption;

   An optimization module, configured to optimize the objective function;

   The calculation module is further configured to solve the objective function according to the constraints to obtain an optimal power allocation mode, an optimal time allocation factor and an optimal relay selection mode.
10. A terminal, comprising a memory, a processor, and a computer program stored in the memory and operable on the processor, characterized in that, when the processor executes the computer program, the above claims 1 to 1 are implemented. The steps of any one of the methods in 8.

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