A method and system for evaluating performance of an outdoor wireless energy harvesting driving network

Abstract

A method and system for evaluating the performance of an outdoor wireless energy collection driven network, comprising: calculating the network's interruption probability and throughput through a pre-constructed outdoor wireless energy collection network model; analyzing the influence of various factors on the network's interruption probability and throughput based on the calculation results; wherein the wireless fading channel in the outdoor wireless energy collection network model is modeled as a Ricean fading channel; the present invention analyzes the relationship between various factors and the network's interruption probability and throughput through the network performance evaluation method; the present invention is a network performance evaluation method under Ricean fading channel conditions that can adapt to the development requirements of the outdoor Internet of Things situation and overcome the disadvantage of limited energy of Internet of Things nodes, and can be used for theoretical analysis and numerical experiments of network design, and is of great significance to network design.

Description

Technical Field

[0001] The present invention relates to the field of network optimization design, and in particular to a method and system for evaluating the performance of an outdoor wireless energy collection driven network. Background Art

[0002] Relay technology can expand network coverage and effectively improve system capacity and user service quality. Wireless RF energy harvesting technology can provide stable energy for energy-constrained nodes in the network and is easy to manage. It can solve the problems of limited battery resources of wireless devices, difficulty in replacement in extreme environments, and high manual maintenance costs. Therefore, relay networks based on wireless energy harvesting have been widely studied.

[0003] Since wireless energy harvesting networks can be widely used in outdoor Internet of Things (such as railway Internet of Things, mining Internet of Things, environmental monitoring Internet of Things, etc.), and the outdoor Internet of Things with open fields of view is mainly in an environment dominated by direct paths, the wireless fading channel in outdoor scenes is usually modeled as a Ricean fading channel. In actual wireless energy transmission, the energy mainly comes from the direct component, so the line-of-sight transmission cannot be ignored. Considering this, the Ricean fading channel model is more practical in wireless energy harvesting networks.

[0004] However, the research works published so far are either for Rayleigh fading channels or Nakagami-m fading channels. Although Nakagami-m can approximately describe Rician fading, it is unable to accurately analyze the impact of the direct component on the performance of the energy harvesting relay network assisted by the energy station. Summary of the invention

[0005] In view of the fact that the outdoor Internet of Things is mainly in an environment dominated by direct paths, in actual wireless energy transmission, energy mainly comes from the direct component, and the Rice fading channel model is used for analysis, the present invention provides an outdoor wireless energy collection driving network performance evaluation method, including:

[0006] The energy and signal-to-noise ratio of each stage of information transmission are calculated based on the relevant parameters of the transmission link between the node and the wireless radio frequency energy station;

[0007] Based on the predetermined calculation formula of the end-to-end interruption probability and throughput of the wireless energy harvesting driven network under the Rice fading channel, combined with the energy and signal-to-noise ratio of each stage of the information transmission, the network interruption probability and throughput are calculated;

[0008] The performance of the outdoor wireless energy harvesting driven network is evaluated based on the network outage probability and throughput.

[0009] Preferably, the calculating of the energy and signal-to-noise ratio of each stage of information transmission includes:

[0010] The energy collected by the source node from the wireless RF energy station and the energy collected by the relay node from the wireless RF energy station in the energy collection phase are calculated based on the channel coefficient and distance of the transmission link between the source node and the destination node and the wireless RF energy station respectively;

[0011] In the information transmission stage, based on the channel coefficient and distance of the transmission link between the source node and the destination node and the wireless radio frequency energy station respectively, the decoding signal-to-noise ratio of the signal received by the relay node from the source node and the decoding signal-to-noise ratio of the signal received by the destination node from the relay node are calculated in sequence;

[0012] The information transmission stage includes: an energy collection stage and an information transmission stage.

[0013] Preferably, the calculation formula for the energy collected by the source node from the wireless radio frequency energy station is as follows:

[0014]

[0015] Among them, E S is the energy collected by the source node from the wireless RF energy station, T is the time to complete the end-to-end information transmission task from the source node to the destination node, α is the time division factor, and h PS represents the channel coefficient of the link between the wireless RF energy station and the source node, d PS represents the distance between the wireless RF energy station and the source node, η is the energy conversion efficiency, P B is the configured transmission power of the wireless RF energy station, and m represents the path loss coefficient;

[0016] The calculation formula of the energy collected by the relay node from the wireless radio frequency energy station is as follows:

[0017]

[0018] Among them, E R is the energy collected by the relay node from the wireless RF energy station, h PR represents the channel coefficient of the link between the wireless RF energy station and the relay node, d PR Indicates the distance between the wireless RF energy station and the relay node.

[0019] Preferably, the calculation formula of the decoding signal-to-noise ratio of the signal received by the relay node from the source node is as follows:

[0020]

[0021]

[0022]

[0023]

[0024] Among them, P S is the transmission power of the source node used to transmit information, y R The relay node receives the signal from the source node, γ R is the decoding signal-to-noise ratio of the relay node, h SR represents the channel coefficient of the link between the source node and the relay node, d SR represents the distance between the source node and the relay node, x S represents the transmitted signal of the source node, n R represents the Gaussian white noise at the relay node, N0 is the variance of the Gaussian white noise, is the square of the channel coefficient of the link between the wireless RF energy station and the relay node, is the square of the channel coefficient of the link between the source node and the relay node, and γ0 is the ratio of the configured transmission power of the wireless RF energy station to the noise power.

[0025] Preferably, the calculation formula of the decoding signal-to-noise ratio of the signal received by the destination node from the relay node is as follows:

[0026]

[0027]

[0028]

[0029]

[0030] Among them, P R is the transmission power of the relay node for information transmission, y D The destination node receives the signal from the relay node, γ D is the receiving signal-to-noise ratio of the destination node, h RD represents the channel coefficient of the link between the relay node and the destination node, d RD represents the distance between the relay node and the destination node, x R represents the transmitted signal of the source node, n D represents the Gaussian white noise at the destination node, is the square of the channel coefficient of the link between the wireless RF energy station and the relay node, is the square of the channel coefficient of the link between the relay node and the destination node.

[0031] Preferably, the calculation formula of the end-to-end interruption probability and throughput of the wireless energy harvesting-driven network under the predetermined Rice fading channel, combined with the energy and signal-to-noise ratio of each stage of the information transmission, calculates the network interruption probability and throughput, including:

[0032] Based on the Rice link model, the end-to-end outage probability of the wireless energy harvesting driven network under the Rice fading channel is calculated;

[0033] The throughput is calculated based on the end-to-end outage probability of the wireless energy harvesting driven network under the Rician fading channel.

[0034] Preferably, the calculation formula for the end-to-end interruption probability of the wireless energy harvesting driven network under the Rice fading channel is as follows:

[0035]

[0036]

[0037] Among them, Y ij represents the product of the square of the channel coefficient of channel i and the square of the channel coefficient of channel j; Represents Y ij The cumulative probability function of OUT is the network outage probability; K ν (·) represents the second-order modified Bessel function of v; K1, K2, K3, K4 represent the Rice factor corresponding to each link from the wireless RF energy station to the source node, the wireless RF energy station to the relay node, the source node to the relay node, and the relay node to the destination node; λ i Represents a random variable The mean value of; k, q, l, p, n, t are the labels in the calculation process; N is a positive integer; γ th is the signal-to-noise ratio threshold of the half-duplex relay system, R th is the transmission rate required by the system, A i express B i express

[0038] Preferably, the throughput is calculated as follows:

[0039]

[0040] Among them, TH represents the throughput of the network.

[0041] Preferably, the performance evaluation of the outdoor wireless energy harvesting driving network based on the network interruption probability and throughput includes:

[0042] When the transmission rate threshold required by the user is determined, the network reliability and data transmission volume are evaluated based on the interruption probability and throughput;

[0043] The performance of outdoor wireless energy harvesting drive networks is evaluated based on network reliability and network data transmission volume.

[0044] Based on the same inventive concept, the present invention also provides an outdoor wireless energy collection network performance evaluation system, characterized in that it includes: a basic data calculation module, a performance data calculation module and a performance evaluation module;

[0045] The basic data calculation module is used to calculate the energy and signal-to-noise ratio of each stage of information transmission based on the relevant parameters of the transmission link between the node and the wireless radio frequency energy station;

[0046] The performance data calculation module is used to calculate the network interruption probability and throughput based on a predetermined calculation formula for the end-to-end interruption probability and throughput of the wireless energy collection-driven network under the Rice fading channel, combined with the energy and signal values ​​at each stage of the information transmission;

[0047] The performance evaluation module is used to perform performance evaluation on the outdoor wireless energy collection drive network based on the network interruption probability and throughput.

[0048] Compared with the prior art, the present invention has the following beneficial effects:

[0049] 1. A method and system for evaluating the performance of an outdoor wireless energy collection network provided by the present invention include: calculating the energy and signal-to-noise ratio of each stage of information transmission based on the transmission link related parameters between the node and the wireless radio frequency energy station; calculating the network interruption probability and throughput based on the predetermined end-to-end interruption probability and throughput calculation formula of the wireless energy collection driving network under the Rice fading channel, combined with the energy and signal-to-noise ratio of each stage of the information transmission; evaluating the performance of the outdoor wireless energy collection driving network based on the network interruption probability and throughput; the present invention provides a network performance evaluation calculation method under Rice fading channel conditions that can adapt to the development requirements of the outdoor Internet of Things situation and overcome the disadvantage of limited energy of Internet of Things nodes, and more accurately analyze the performance of the outdoor wireless energy collection network;

[0050] 2. The outdoor wireless energy collection network performance evaluation method and system provided by the present invention can also analyze the following network performance: energy station transmission power, Ricean factor under Ricean fading channel, time division factor under wireless energy collection mode, system required transmission rate, and the relationship between the relative position of the energy station and the source node and relay node and the network interruption probability and throughput. It can be used for theoretical analysis and numerical experiments of network design, and is of great significance to network design. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 A flowchart of a method for evaluating performance of an outdoor wireless energy collection and driving network according to the present invention;

[0052] Figure 2It is a schematic diagram of an outdoor wireless energy harvesting network model of the present invention;

[0053] Figure 3 Schematic diagram of energy collection and information transmission process of outdoor wireless energy collection network model;

[0054] Figure 4 The relationship between the energy station transmission power and Rice factor and the system outage probability and throughput is shown in the figure;

[0055] Figure 5 is the relationship diagram between the time splitting factor and the system outage probability and throughput;

[0056] Figure 6 This is a graph showing the relationship between the system required rate and the system outage probability and throughput. DETAILED DESCRIPTION

[0057] Embodiment 1:

[0058] The present invention discloses a method for evaluating the performance of an outdoor wireless energy collection network. Figure 1 The schematic diagram is introduced, including:

[0059] Step 1: Calculate the energy and signal-to-noise ratio of each stage of information transmission based on the relevant parameters of the transmission link between the node and the wireless RF energy station;

[0060] Step 2: Based on the predetermined calculation formula of the end-to-end interruption probability and throughput of the wireless energy harvesting driven network under the Rice fading channel, combined with the energy and signal values ​​at each stage of the information transmission, the network interruption probability and throughput are calculated;

[0061] Step 3: Perform performance evaluation on the outdoor wireless energy harvesting driven network based on the network outage probability and throughput.

[0062] Among them, step 1: based on the transmission link related parameters between the node and the wireless radio frequency energy station, the energy and signal-to-noise ratio of each stage of information transmission are calculated, specifically including:

[0063] 1. Construction of outdoor wireless energy harvesting network, such as Figure 2 As shown, specifically including:

[0064] (1) A wireless RF energy station PB deployed on a car / train / drone, a source node S, a relay node R, and a destination node D;

[0065] Among them, S and R are both energy-constrained nodes (they have no energy themselves) and need to collect energy from PB before transmitting information. PB uses radio signal broadcasting to charge S and R. There is no direct link between S and D. S needs to complete the information transmission to D with the help of R. R uses the relay method of decoding and forwarding. PB, S, R and D are all single-antenna devices and work in half-duplex mode.

[0066] (2) In the first stage of αT, PB transmits energy to S and R. In the second stage of (1-α)T / 2, S sends information to R. In the third stage of (1-α)T / 2, R forwards information to D.

[0067] Among them, T is the time to complete the end-to-end information transmission task from S to D, α (0≤α≤1) is the time division factor, that is, the proportion of time occupied by energy collection. Because R adopts half-duplex mode in information transmission, the second and third stages are both (1-α)T / 2. Figure 3 shown.

[0068] 2. Calculate the energy collected by S and R from PB, including:

[0069] The energy collected by S from PB is recorded as E S , the specific calculation method is as follows:

[0070]

[0071] The energy collected by R from PB is recorded as E R , the specific calculation method is as follows:

[0072]

[0073] Among them, h PS and h PR They represent the channel coefficients of the links from PB to S and from PB to R, respectively, and obey the Rice distribution characteristics. PS and d PR represent the distances from PB to S and from PB to R, respectively, η is the energy conversion efficiency (0≤η≤1), P B is the configured transmit power of PB, m represents the path loss coefficient;

[0074] 3. Calculate the received signal-to-noise ratio of the signal received by R from S and the signal received by D from R, including:

[0075] ① The received signal-to-noise ratio of the signal received by R from S;

[0076] The transmission power used by S for information transmission is denoted as P S , the specific calculation method is as follows:

[0077]

[0078] The signal received by R from S is denoted as y R , the specific calculation method is as follows:

[0079]

[0080] Among them, h SR represents the channel coefficient of the link from S to R, which obeys the Rice distribution characteristics, d SR represents the distance between S and R, x S represents the transmitted signal of S, satisfying E[|x S | 2 ]=P S , n R represents Gaussian white noise at R, with a mean of 0 and a variance of N0;

[0081] The received signal-to-noise ratio of R is denoted by γ R , the specific calculation method is as follows:

[0082]

[0083] in,

[0084] γ0 is the transmission signal-to-noise ratio of PB;

[0085] is the square value of the channel coefficient of the link from PB to S;

[0086] is the square value of the channel coefficient of the link from S to R.

[0087] ②The received signal-to-noise ratio of the signal received by D from R;

[0088] The transmission power used by R for information transmission is denoted as P R , the specific calculation method is as follows:

[0089]

[0090] The signal received by D from R is denoted as y D , the specific calculation method is as follows:

[0091]

[0092] Among them, h RD represents the channel coefficient of the link from R to D, which obeys the Rice distribution characteristics, d RD represents the distance between R and D, x R represents the transmitted signal of S, satisfying E[|x R | 2]=P R , n D represents Gaussian white noise at R, with a mean of 0 and a variance of N0;

[0093] The received signal-to-noise ratio of D is denoted by γ D , the specific calculation method is as follows:

[0094]

[0095] in,

[0096] Step 2: Based on the predetermined calculation formula of the end-to-end interruption probability and throughput of the wireless energy harvesting driven network under the Rice fading channel, combined with the energy and signal values ​​at each stage of the information transmission, the network interruption probability and throughput are calculated, specifically including:

[0097] 1. Order According to the Rice link model, calculate Y ij The cumulative probability function (CDF) of is calculated as follows:

[0098]

[0099] Among them, Y ij K represents the product of the square of the channel coefficient of channel i and the square of the channel coefficient of channel j, where i and j are numbers; ν (·) represents the second kind of ν-order modified Bessel function; K i (i=1,2,3,4) are the Ricean factors corresponding to each link from PB to S, PB to R, S to R and R to D, which are used to characterize the ratio of the direct component to the scattered component; λ i (i=1,2,3,4) is a random variable The average value of; k, q, l are the labels in the calculation process, which are only used for counting. The value range has been set in the formula, such as q = 0, 1, 2, ..., l, l = 0, 1, 2, ..., N, k = 0, 1, 2, ..., N; N is a positive integer, and the theoretical value is infinite. The size determines the calculation accuracy of the formula. The larger the value, the more accurate the calculation result; To simplify the expression, define two parameters A about channel i i and B i , whose value can be obtained by and Calculate separately.

[0100] 2. According to the Rice link model, calculate the network interruption probability P OUT , the specific calculation method is as follows:

[0101]

[0102] Among them, suppose the required transmission rate of the system is R th , then the corresponding signal-to-noise ratio threshold of the half-duplex relay system is p, n, t are labels in the calculation process and are only used for counting. Their value ranges have been set in the formula, such as n=0,1,2,…,p, p=0,1,2,…,N, t=0,1,2,…,N; the larger N is, the better. According to the inventor's experiments, in actual applications, high calculation accuracy can be obtained when N is greater than 50.

[0103] 3. Based on the network outage probability, calculate the network throughput, specifically including:

[0104] The network throughput TH is calculated as follows:

[0105]

[0106] Step 3: Based on the network outage probability and throughput, a performance evaluation is performed on the outdoor wireless energy harvesting driving network, specifically including:

[0107] The interruption probability corresponds to the network reliability performance index. A small interruption probability indicates high network reliability, and a large interruption probability indicates low network reliability.

[0108] Throughput corresponds to the performance index of network data transmission volume. A large throughput indicates a large network data transmission volume, and a small throughput indicates a small network data transmission volume.

[0109] When the transmission rate threshold required by the user is determined, the smaller the interruption probability, the greater the throughput, the higher the network reliability, and the larger the network data transmission volume; the greater the interruption probability, the smaller the throughput, the lower the network reliability, and the smaller the network data transmission volume.

[0110] Embodiment 2:

[0111] The present invention discloses a method for evaluating the performance of an outdoor wireless energy harvesting network, which solves the relationship between various network configuration parameters and network interruption probability and throughput, specifically including:

[0112] 1. The relationship between the energy station PB transmission power and the network interruption probability and throughput, such as Figure 4 As shown, specifically including:

[0113] When the Rice factor, time division factor, required transmission rate of the system, relative position of the energy station to the source node and the relay node are fixed, the greater the ratio of the energy station PB transmission power to the noise power, that is, the greater the energy station transmission power, the smaller the system interruption probability and the greater the throughput;

[0114] 2. The relationship between the Rice factor and network outage probability and throughput under the Rice fading channel, such as Figure 4 As shown, specifically including:

[0115] When factors such as the energy station transmission power, time division factor, system required rate, relative position of the energy station to the source node and relay node are fixed, the larger the Rice factor is, the more direct components of the link are, the smaller the system interruption probability is, and the greater the throughput is;

[0116] Figure 4 In this case, K is the Rice factor and Ana is the closed-form solution derived from (P OUT ) calculated, the Sim line is the result obtained from the Monte Carlo simulation experiment; the horizontal axis is the ratio of PB transmission power to noise power P B / N0, the vertical axis is the system outage probability.

[0117] 3. Relationship between time division factor, network interruption probability and throughput in wireless energy harvesting mode, e.g. Figure 5 As shown, specifically including:

[0118] When the energy station transmission power, Rice factor, system required rate, relative position of energy station to source node and relay node and other factors are fixed, the time division factor changes from 0 to 1, the system interruption probability first decreases and then increases, and the throughput first increases and then decreases;

[0119] Figure 5 In the figure, the horizontal axis is the time division factor and the vertical axis is the system outage probability.

[0120] 4. The relationship between the required transmission rate of the system and the interruption probability, such as Figure 6 As shown, specifically including:

[0121] When factors such as the energy station transmission power, Rice factor, time division factor, and relative position of the energy station to the source node and relay node are fixed, the smaller the required rate of the system, the smaller the probability of system interruption;

[0122] Figure 6 In the figure, the horizontal axis is the ratio of PB transmission power to noise power, and the vertical axis is the system outage probability.

[0123] Embodiment 3:

[0124] Based on the same inventive concept, the present invention provides an outdoor wireless energy collection network performance evaluation system, which specifically includes: a basic data calculation module, a performance data calculation module and a performance evaluation module;

[0125] The basic data calculation module is used to calculate the energy and signal-to-noise ratio of each stage of information transmission based on the relevant parameters of the transmission link between the node and the wireless radio frequency energy station;

[0126] The performance data calculation module is used to calculate the network interruption probability and throughput based on a predetermined calculation formula for the end-to-end interruption probability and throughput of the wireless energy collection-driven network under the Rice fading channel, combined with the energy and signal values ​​at each stage of the information transmission;

[0127] The performance evaluation module is used to perform performance evaluation on the outdoor wireless energy collection drive network based on the network interruption probability and throughput.

[0128] The basic data calculation module includes an energy calculation submodule and a signal-to-noise ratio calculation submodule;

[0129] The energy calculation submodule is used to calculate the energy collected by the source node from the wireless radio frequency energy station and the energy collected by the relay node from the wireless radio frequency energy station during the energy collection phase;

[0130] The signal-to-noise ratio calculation submodule is used to sequentially calculate the decoding signal-to-noise ratio of the signal received by the relay node from the source node and the decoding signal-to-noise ratio of the signal received by the destination node from the relay node during the information transmission stage.

[0131] The performance data calculation module includes an interruption probability calculation submodule and a throughput calculation submodule;

[0132] The interruption probability calculation submodule is used to calculate the end-to-end interruption probability of the wireless energy harvesting driven network under the Ricean fading channel based on the Ricean link model;

[0133] The throughput calculation submodule is used to calculate the throughput based on the end-to-end interruption probability of the wireless energy harvesting driven network under the Ricean fading channel.

[0134] The calculation formula for the energy collected by the source node from the wireless RF energy station is as follows:

[0135]

[0136] Among them, E S is the energy collected by the source node from the wireless RF energy station, T is the time to complete the end-to-end information transmission task from the source node to the destination node, α is the time division factor, and h PS represents the channel coefficient of the link between the wireless RF energy station and the source node, d PS represents the distance between the wireless RF energy station and the source node, η is the energy conversion efficiency, P B is the configured transmission power of the wireless RF energy station, and m represents the path loss coefficient;

[0137] The calculation formula of the energy collected by the relay node from the wireless radio frequency energy station is as follows:

[0138]

[0139] Among them, E R is the energy collected by the relay node from the wireless RF energy station, h PR represents the channel coefficient of the link between the wireless RF energy station and the relay node, d PR Indicates the distance between the wireless RF energy station and the relay node.

[0140] The calculation formula of the decoding signal-to-noise ratio of the signal received by the relay node from the source node is as follows:

[0141]

[0142]

[0143]

[0144]

[0145] Among them, P S is the transmission power of the source node used to transmit information, y R The relay node receives the signal from the source node, γ R is the decoding signal-to-noise ratio of the relay node, h SR represents the channel coefficient of the link between the source node and the relay node, d SR represents the distance between the source node and the relay node, x S represents the transmitted signal of the source node, n R represents the Gaussian white noise at the relay node, N0 is the variance of the Gaussian white noise, is the square of the channel coefficient of the link between the wireless RF energy station and the relay node, is the square of the channel coefficient of the link between the source node and the relay node, and γ0 is the ratio of the configured transmission power of the wireless RF energy station to the noise power.

[0146] The calculation formula of the decoding signal-to-noise ratio of the signal received by the destination node from the relay node is as follows:

[0147]

[0148]

[0149]

[0150]

[0151] Among them, P R is the transmission power of the relay node for information transmission, y D The destination node receives the signal from the relay node, γ Dis the receiving signal-to-noise ratio of the destination node, h RD represents the channel coefficient of the link between the relay node and the destination node, d RD represents the distance between the relay node and the destination node, x R represents the transmitted signal of the source node, n D represents the Gaussian white noise at the destination node, is the square of the channel coefficient of the link between the wireless RF energy station and the relay node, is the square of the channel coefficient of the link between the relay node and the destination node.

[0152] The calculation formula for the end-to-end interruption probability of the wireless energy harvesting driven network under the Rice fading channel is as follows:

[0153]

[0154]

[0155] Among them, Y ij represents the product of the square of the channel coefficient of channel i and the square of the channel coefficient of channel j; Represents Y ij The cumulative probability function of OUT is the network outage probability; K ν (·) represents the second-order modified Bessel function of v; K1, K2, K3, K4 represent the Rice factor corresponding to each link from the wireless RF energy station to the source node, the wireless RF energy station to the relay node, the source node to the relay node, and the relay node to the destination node; λ i Represents a random variable The mean value of; k, q, l, p, n, t are the labels in the calculation process; N is a positive integer; γ th is the signal-to-noise ratio threshold of the half-duplex relay system, R th is the transmission rate required by the system, A i express B i express

[0156] The throughput is calculated as follows:

[0157]

[0158] Among them, TH represents the throughput of the network.

[0159] The performance evaluation module includes:

[0160] A reliability and transmission evaluation unit, used to evaluate the network reliability and data transmission volume based on the interruption probability and throughput when the transmission rate threshold required by the user is determined;

[0161] The driving network performance evaluation unit is used to evaluate the performance of the outdoor wireless energy harvesting driving network according to the network reliability and the data transmission volume of the network.

[0162] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0163] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0164] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0165] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0166] The above are merely embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention are included in the scope of the claims of the present invention to be approved.

Claims

1. A method for evaluating the performance of an outdoor wireless energy harvesting driven network, characterized in that: include: The energy and signal-to-noise ratio of each stage of information transmission are calculated based on the relevant parameters of the transmission link between the node and the wireless radio frequency energy station; Based on the predetermined calculation formula of the end-to-end interruption probability and throughput of the wireless energy harvesting driven network under the Rice fading channel, combined with the energy and signal-to-noise ratio of each stage of the information transmission, the network interruption probability and throughput are calculated; Performing performance evaluation on an outdoor wireless energy harvesting driven network based on the network outage probability and throughput; The calculation formula of the end-to-end interruption probability and throughput of the wireless energy harvesting driven network under the predetermined Rice fading channel, combined with the energy and signal-to-noise ratio of each stage of the information transmission, calculates the network interruption probability and throughput, including: Based on the Rice link model, the end-to-end outage probability of the wireless energy harvesting driven network under the Rice fading channel is calculated; Calculating throughput based on the end-to-end interruption probability of the wireless energy harvesting driven network under the Ricean fading channel; The calculation formula for the end-to-end interruption probability of the wireless energy harvesting driven network under the Rice fading channel is as follows: Among them, Y ij represents the product of the square of the channel coefficient of channel i and the square of the channel coefficient of channel j; Represents Y ij The cumulative probability function of OUT is the network outage probability; K ν (·) represents the second-order modified Bessel function of v, where v is k-q+1 or t-n+1; K1, K2, K3, and K4 represent the Ricean factors corresponding to each link from the wireless RF energy station to the source node, the wireless RF energy station to the relay node, the source node to the relay node, and the relay node to the destination node, respectively; λ i Represents a random variable The mean value of; k, q, l, p, n, t are the labels in the calculation process; N is a positive integer; γ th is the signal-to-noise ratio threshold of the half-duplex relay system, R th is the transmission rate required by the system; m represents the path loss coefficient; d PS Indicates the distance between the wireless RF energy station and the source node; d SR represents the distance between S and R; η is the energy conversion efficiency; B1, B2, B3 and B4 represent the parameters of channels 1, 2, 3 and 4 respectively; d PR Indicates the distance between the wireless RF energy station and the relay node; d RD represents the distance between R and D; α is the time division factor; γ0 is the transmission signal-to-noise ratio of the wireless RF energy station; The throughput is calculated as follows: Among them, TH represents the throughput of the network.

2. The method according to claim 1, characterized in that The calculating of the energy and signal-to-noise ratio at each stage of information transmission includes: The energy collected by the source node from the wireless RF energy station and the energy collected by the relay node from the wireless RF energy station in the energy collection phase are calculated based on the channel coefficient and distance of the transmission link between the source node and the destination node and the wireless RF energy station respectively; In the information transmission stage, based on the channel coefficient and distance of the transmission link between the source node and the destination node and the wireless radio frequency energy station respectively, the decoding signal-to-noise ratio of the signal received by the relay node from the source node and the decoding signal-to-noise ratio of the signal received by the destination node from the relay node are calculated in sequence; The information transmission stage includes: an energy collection stage and an information transmission stage.

3. The method according to claim 2, characterized in that The calculation formula for the energy collected by the source node from the wireless RF energy station is as follows: Among them, E S is the energy collected by the source node from the wireless RF energy station, T is the time to complete the end-to-end information transmission task from the source node to the destination node, α is the time division factor, and h PS represents the channel coefficient of the link between the wireless RF energy station and the source node, d PS represents the distance between the wireless RF energy station and the source node, η is the energy conversion efficiency, P B is the configured transmission power of the wireless RF energy station, and m represents the path loss coefficient; The calculation formula of the energy collected by the relay node from the wireless radio frequency energy station is as follows: Among them, E R is the energy collected by the relay node from the wireless RF energy station, h PR represents the channel coefficient of the link between the wireless RF energy station and the relay node, d PR Indicates the distance between the wireless RF energy station and the relay node.

4. The method according to claim 3, characterized in that The calculation formula of the decoding signal-to-noise ratio of the signal received by the relay node from the source node is as follows: Among them, P S is the transmission power of the source node used to transmit information, y R The relay node receives the signal from the source node, γ R is the decoding signal-to-noise ratio of the relay node, h SR represents the channel coefficient of the link between the source node and the relay node, d SR represents the distance between the source node and the relay node, x S represents the transmitted signal of the source node, n R represents the Gaussian white noise at the relay node, N0 is the variance of the Gaussian white noise, is the square of the channel coefficient of the link between the wireless RF energy station and the relay node, is the square of the channel coefficient of the link between the source node and the relay node, and γ0 is the ratio of the configured transmission power of the wireless RF energy station to the noise power.

5. The method according to claim 4, characterized in that The calculation formula of the decoding signal-to-noise ratio of the signal received by the destination node from the relay node is as follows: Among them, P R is the transmission power of the relay node for information transmission, y D The destination node receives the signal from the relay node, γ D is the receiving signal-to-noise ratio of the destination node, h RD represents the channel coefficient of the link between the relay node and the destination node, d RD represents the distance between the relay node and the destination node, x R represents the transmitted signal of the source node, n D represents the Gaussian white noise at the destination node, is the square of the channel coefficient of the link between the wireless RF energy station and the relay node, is the square of the channel coefficient of the link between the relay node and the destination node.

6. The method according to claim 1, characterized in that The performance evaluation of the outdoor wireless energy harvesting driving network based on the network interruption probability and throughput includes: When the transmission rate threshold required by the user is determined, the network reliability and data transmission volume are evaluated based on the interruption probability and throughput; The performance of outdoor wireless energy harvesting drive networks is evaluated based on network reliability and network data transmission volume.

7. A system using the outdoor wireless energy harvesting network performance evaluation method according to any one of claims 1 to 6, characterized in that: include: Basic data calculation module, performance data calculation module and performance evaluation module; The basic data calculation module is used to calculate the energy and signal-to-noise ratio of each stage of information transmission based on the relevant parameters of the transmission link between the node and the wireless radio frequency energy station; The performance data calculation module is used to calculate the network interruption probability and throughput based on a predetermined calculation formula for the end-to-end interruption probability and throughput of the wireless energy collection-driven network under the Rice fading channel, combined with the energy and signal values ​​at each stage of the information transmission; The performance evaluation module is used to perform performance evaluation on the outdoor wireless energy collection drive network based on the network interruption probability and throughput.

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