CN111988804A - Throughput optimization method in direct link-containing SWIPT relay system based on PS strategy - Google Patents
Throughput optimization method in direct link-containing SWIPT relay system based on PS strategy Download PDFInfo
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Abstract
The invention discloses a throughput optimization method in a direct link-containing SWIPT relay system based on a PS strategy. A simultaneous transfer of information and energy (SWIPT) relay system comprising a direct link comprises a source node, a relay node and a destination node. The source node and the destination node are active; the relay nodes are passive but have radio frequency energy harvesting capability and employ a Power Splitting (PS) strategy. All channels are quasi-static block fading channels. The destination node combines the signals respectively from the direct link (the link between the source node and the destination node) and the relay forwarding link by using a maximum ratio combining method as final signals of the destination node. The whole communication system adopts a transmission mode with limited delay. And obtaining a functional relation between throughput and a power division coefficient through theoretical derivation. And establishing an optimization problem by taking the optimal throughput as a target, and obtaining an optimal power division coefficient and optimal throughput by adopting an optimization algorithm.
Description
Technical Field
The invention belongs to the technical field of wireless communication, and particularly relates to a throughput optimization method in a direct link-containing SWIPT relay system based on a PS strategy.
Background
With the rapid development of the information age, the scale of the wireless network is continuously enlarged, and the number of nodes in the network is increased sharply. In a traditional network, the energy of the nodes is provided by a battery with limited capacity, and the energy supply mode determines the limitation of the service life of the nodes. Meanwhile, in the face of more and more nodes, frequent battery replacement consumes a large amount of manpower and material resources. However, the emergence and development of the simultaneity Information and Power Transfer (SWIPT) technology provides a new idea for solving the problem. The SWIPT technology can collect energy for passive nodes in a communication network through radio frequency signals, and meanwhile, information can be transmitted through the radio frequency signals. The technology avoids the defects of the traditional energy supply mode, and greatly prolongs the service life of the network node. Therefore, the application of the SWIPT technique in a wireless communication network is of great interest.
The key of the simultaneous transmission of information and energy lies in the design of a receiver, the receiving strategy of the existing receiver mainly adopts several modes of time division (TS), power division (PS), TS and PS combination and the like.
The SWIPT technology can effectively improve the frequency spectrum utilization rate of the network, reduce delay and reduce power consumption, so that a lot of students consider applying the SWIPT technology to a relay communication system.
With the rapid development of the SWIPT technology, many researchers consider using the SWIPT technology in a relay system. For a single-input single-output relay system, the operation strategy of the relay is the focus of the current research. After the relay is added into the communication system, the path attenuation can be effectively weakened, and the transmission distance and the system performance of the system are improved. In the current research, most scholars neglect the direct link transmission and only consider the transmission of the relay link, which may cause the waste of resources, affect the communication efficiency of the system and limit the improvement of the system performance. Therefore, the invention discloses a throughput optimization method in a direct link-containing SWIPT relay system based on a PS strategy.
Disclosure of Invention
Aiming at the defects of the prior art, the invention discloses a throughput optimization method in a direct link SWIPT relay system based on a PS strategy. As shown in fig. 1, the relay system model including the direct link SWIPT includes a source node S, a relay node R and a destination node D. The link through which the source node S transmits information to the destination node D is called a Direct Link (DL). A link in which the source node S transmits information to the destination node D through the relay node R is called a relay forwarding link (RL). The source node S and the destination node D are active, i.e. both nodes have no energy limitation, they both have a fixed energy supply; the relay node R, however, has no powered device and needs to extract power from the rf signal of the source node S. The relay node forwards the information from the source node S to the destination node D using the collected energy. The relay node adopts a PS receiving strategy. The relay node works in a Decoding Forwarding (DF) mode, the relay node can decode without error only when the signal-to-noise ratio of a signal received by the relay node is greater than or equal to a threshold value, otherwise, the relay node is interrupted, the relay node can not forward information to a target node, and the relay node stores the collected energy for maintaining the basic operation of the relay system, including the energy consumed by the circuit and the energy required by decoding. And after successful decoding, the energy collected by the relay node is completely used for relaying and forwarding information. The destination node combines the signals from the Direct Link (DL) and the relay-forward link (RL) respectively as the final signal of the destination node by means of Maximum Ratio Combining (MRC).
All nodes adopt a half-duplex working mode. h denotes a channel gain between the source node and the relay node, g denotes a channel gain between the relay node and the destination node, and f denotes a channel gain between the source node and the destination node. d1Denotes the distance between the source node and the relay node, d2Denotes a distance between the relay node and the destination node, and d denotes a distance between the source node and the destination node.
All channels are quasi-static block fading channels and are frequency non-selective fading. The channel gain remains constant during a communication time block T, and varies from time block to time block, with these random channel gains being independent and subject to rayleigh distribution. Pi f non-woven dust2、|h|2And | g |)2Are all random variables, are subject to exponential distribution, and their expectation is E [ | f &2]＝E[|h|2]＝E[|g|2]1, wherein E [ ·]Expressing the expectation, |, expressing the modulus value. Random variable | f |2Has a probability density function of ff(z)＝e-zThe probability distribution function is Ff(z)＝P(|f|2＜z)＝1-e-z(ii) a Random variable | h |2Has a probability density function of fh(x)＝e-xThe probability distribution function is Fh(x)＝P(|h|2＜x)＝1-e-x(ii) a Random variable | g |2Has a probability density function of fg(y)＝e-yThe probability distribution function is Fg(y)＝P(|g|2＜y)＝1-e-y. In the communication process, the most important energy loss is path loss, and a loss coefficient is set to be m.
FIG. 2 shows a model of a SWIPT relay system based on a PS strategy, xsIs a normalized signal emitted by the source node, i.e. E [ | x [ ]s(t)|2]1, average transmission power Ps。nrRepresenting the noise generated by the antenna when the relay node receives the signal, nrIs a circularly symmetric complex Gaussian random variable, i.e.
Represents nr(t) obeys a complex Gaussian distribution with a mean of 0 and a variance of
yr(t) represents a signal received by the relay node; beta represents a power division coefficient for collecting energy at the relay node, and beta belongs to [0, 1]](ii) a The passive relay node receives the electromagnetic wave signal y in a power ratio beta: 1-betar(t) for Energy Harvesting (EH) and receiving information, respectively. x is the number ofr(t) represents the signal forwarded by the relay node and has power Pr。ndRepresenting the noise generated by the antenna when the destination node receives the signal, and having
yd(t) represents a signal received by the destination node. In addition, the energy collection efficiency factor is denoted as η.
The time allocation relationship between the relay node collecting energy and transmitting information based on the PS policy is shown in fig. 3, where T represents a complete time block, and in the first part of T/2 time of the transmission block, the source node simultaneously transmits signals to the relay node and the destination node, and the relay node simultaneously performs energy collection and information reception under the PS policy. And in the second part T/2 time of the transmission block, the relay node forwards the received information to the destination node, thereby completing the communication.
The whole communication system adopts a transmission mode of limiting time delay, in which a receiver decodes received information in units of one time block, and throughput performance of the system is measured by interruption probability. Fixing the information transmission rate of the source node as R0Thus, a signal-to-noise ratio threshold is set
By theoretical derivation, the probability of interruption of the direct link
Is composed of
In the formula (I), the compound is shown in the specification,
probability of outage between source node and relay node
Is composed of
In the formula (I), the compound is shown in the specification,
the destination node combines the signals from the direct link and the relay forwarding link respectively by using a maximum ratio combining method to be used as the final signal of the destination nodeProbability of still not being correctly decoded, i.e. probability of interruption in this case
Is composed of
In the formula (I), the compound is shown in the specification,
finally, the probability of interruption P of the communication, seen by the destination nodeoutI.e. the probability that the destination node cannot decode correctly is
The throughput of the relay system comprising the direct link SWIPT based on the PS strategy is
An optimization problem P is established with the optimization of throughput as a target:
at Rs、R0、η、d1、d2、d、m、
And
under the condition of given parameters, an optimization algorithm, such as a golden section method, is adopted to obtain the optimal power division coefficient and the optimal throughput. Recording the optimal throughput as tau; will optimize throughputThe power division coefficient corresponding to the quantity is defined as the optimal power division coefficient and is denoted as beta.
Description of the drawings:
in order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.
Fig. 1 is a relay system model including a direct link SWIPT provided by the present invention;
fig. 2 is a model of a SWIPT relay system based on a PS strategy provided by the present invention;
fig. 3 is a time allocation relationship of collecting energy and transmitting information by a relay node based on a PS policy provided by the present invention;
FIG. 4 is a graph of throughput τ versus power division coefficient β;
the specific implementation mode is as follows:
the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The invention aims to provide a throughput optimization method in a direct link SWIPT relay system based on a PS strategy, so that the system obtains the optimal throughput. The source node and the destination node are active, the relay node is passive, and the structural block diagram is given in fig. 1. Wherein, the passive relay adopts a PS receiving strategy.
Fig. 1 is a diagram containing a direct link SWIPT relay system model including a source node S, a relay node R and a destination node D. The link through which the source node S transmits information to the destination node D is called a Direct Link (DL). A link in which the source node S transmits information to the destination node D through the relay node R is called a relay forwarding link (RL). The source node S and the destination node D are active, i.e. both nodes have no energy limitation, they both have a fixed energy supply; the relay node R, however, has no powered device and needs to extract power from the rf signal of the source node S. The relay node forwards the information from the source node S to the destination node D using the collected energy. The relay node adopts a PS receiving strategy. The relay node works in a Decoding Forwarding (DF) mode, the relay node can decode without error only when the signal-to-noise ratio of a signal received by the relay node is greater than or equal to a threshold value, otherwise, the relay node is interrupted, the relay node can not forward information to a target node, and the relay node stores the collected energy for maintaining the basic operation of the relay system, including the energy consumed by the circuit and the energy required by decoding. And after successful decoding, the energy collected by the relay node is completely used for relaying and forwarding information.
In the actual communication process, when the channel condition is good, the path loss is very small, and the direct link can accurately send information; when the channel condition is poor, the path loss is large, and the energy of the relay node is sufficient, the relay node can accurately forward information to the target node; when the channel condition is poor, the direct link transmission and the relay forwarding link transmission cannot accurately transmit information to the destination node, but the destination node may perform Maximum Ratio Combining (MRC) on the signals on the two links and be able to correctly decode.
In this patent, the source node sends information to the destination node through the relay forwarding link and also sends information to the destination node through the direct link, and the destination node combines signals from the direct link and the relay forwarding link respectively as final signals of the destination node by using a Maximum Ratio Combining (MRC) method, so that the system achieves higher throughput and improves the communication performance of the system.
All nodes adopt a half-duplex working mode. h denotes a channel gain between the source node and the relay node, g denotes a channel gain between the relay node and the destination node, and f denotes a channel gain between the source node and the destination nodeChannel gain between nodes. d1Denotes the distance between the source node and the relay node, d2Denotes a distance between the relay node and the destination node, and d denotes a distance between the source node and the destination node.
All channels are quasi-static block fading channels and are frequency non-selective fading. The channel gain remains constant during a communication time block T, and varies from time block to time block, and these random channel gains are independent of each other and all obey rayleigh distribution. Pi f non-woven dust2、|h|2And | g |)2Are all random variables, are subject to exponential distribution, and their expectation is E [ | f &2]＝E[|h|2]＝E[|g|2]1, wherein E [ ·]Expressing the expectation, |, expressing the modulus value. Random variable | f |2Has a probability density function of
ff(z)＝e-z (1)
Random variable | f |2Has a probability distribution function of
Ff(z)＝P(|f|2＜z)＝1-e-z (2)
Random variable | h |2Has a probability density function of
fh(x)＝e-x (3)
Random variable | h |2Has a probability distribution function of
Fh(x)＝P(|h|2＜x)＝1-e-x (4)
Random variable | g |2Has a probability density function of
fg(y)＝e-y (5)
Random variable | g |2Has a probability distribution function of
Fg(y)＝P(|g|2＜y)＝1-e-y (6)
In the communication process, the most important energy loss is path loss, and a loss coefficient is set to be m.
FIG. 2 shows a model of a SWIPT relay system based on a PS strategy, xsIs a normalized signal transmitted by the source node,i.e. E [ | x [ ]s(t)|2]1, average transmission power Ps。nrRepresenting the noise generated by the antenna when the relay node receives the signal, nrIs a circularly symmetric complex Gaussian random variable, i.e.
Represents nr(t) obeys a complex Gaussian distribution with a mean of 0 and a variance of
yr(t) represents a signal received by the relay node; beta represents a power division coefficient for collecting energy at the relay node, and beta belongs to [0, 1]](ii) a The passive relay node receives the electromagnetic wave signal y in a power ratio beta: 1-betar(t) for Energy Harvesting (EH) and receiving information, respectively. x is the number ofr(t) represents the signal forwarded by the relay node and has power Pr。ndRepresenting the noise generated by the antenna when the destination node receives the signal, and having
yd(t) represents a signal received by the destination node.
The time allocation relationship between the relay node collecting energy and transmitting information based on the PS policy is shown in fig. 3, where T represents a complete time block, and in the first part of T/2 time of the transmission block, the source node simultaneously transmits signals to the relay node and the destination node, and the relay node simultaneously performs energy collection and information reception under the PS policy. And in the second part T/2 time of the transmission block, the relay node forwards the received information to the destination node, thereby completing the communication.
The whole communication system adopts a transmission mode of limiting time delay, in which a receiver decodes received information in units of one time block, and throughput performance of the system is measured by interruption probability. Fixing the information transmission rate of the source node as R0Thus, a signal-to-noise ratio threshold is set
In order to explore the relationship between the throughput and the power division coefficient beta, the link characteristics are respectively introduced.
(1) Direct Link (DL)
In DL transmission links, there is no energy harvesting problem involved, since there is no forwarding by relay nodes. The signal received by the destination node may be represented as
Signal to noise ratio of destination node
Is composed of
Probability of interruption of direct link
Is composed of
By substituting formula (8) for formula (9) and using formula (2), the probability of interruption of the direct link is obtained
Is composed of
In the formula (I), the compound is shown in the specification,
(2) relay forwarding link (RL)
Signal y received by a relay noderCan be expressed as
Signal yrHas a power of
The relay node receives the electromagnetic wave signal y with the power ratio beta: 1-betar(t) for acquiring the required energy and receiving information, respectively. Therefore, during the first part T/2 of the transmission block, the energy collected by the relay node is
Wherein eta is an energy collection efficiency factor, and eta is belonged to [0, 1 ].
Signal to noise ratio at a relay node for a received information portion
Is composed of
And carrying out interruption judgment at the relay node according to the signal-to-noise ratio. If it is not
The relay node cannot accurately decode the information from the source node, which may cause interruption, and the relay node may not forward the information, so that the energy collected by the relay node is stored in the relay node for maintaining the basic operation of the relay node, and satisfying the energy required for decoding, the energy consumed by the circuit, and the like.
Probability of outage between source node and relay node
Is composed of
By substituting the formula (13) for the formula (14) and using the formula (4), the probability of interruption can be obtained
Is composed of
In the formula (I), the compound is shown in the specification,
if it is not
The relay node will successfully decode the information from the source node and then the relay node uses all the collected energy ErAnd forwards the decoded information to the destination node. The transmit power of the relay node may be expressed as
As can be seen from equation (16), the transmission power of the relay node is affected by the power division coefficient β. During the second T/2 time, the relay node forwards the decoded information. Signal y received by destination nodedCan be expressed as
Signal to noise ratio of destination node
Is composed of
Probability of outage between relay node and destination node
Is composed of
In the formula (I), the compound is shown in the specification,
by using the formulae (3) to (6), the compounds
In the relay forwarding link (RL), whether interruption occurs or not is judged at the relay node and the destination node respectively, and when interruption occurs at any place, the whole transmission is interrupted and the transmission fails, so the interruption probability of the relay forwarding link (RL)
Is composed of
According to the definition of the throughput, when the direct link is not considered and only the relay forwarding link is relied on for communication, the throughput of the system is
(3) Relay forwarding link merge direct link (RL-DL)
And the destination node combines the signals from the direct link and the relay forwarding link respectively by using a maximum ratio combining method to serve as the final signal of the destination node. The signal-to-noise ratio of the destination node is the sum of the signal-to-noise ratios of the RL and DL transmission links, and the expression is
Corresponding probability of interruption
Is composed of
In the formula (I), the compound is shown in the specification,
by using the formulae (1) to (6), the compounds
Finally, the probability of interruption P of the communication, seen by the destination nodeoutI.e. the probability that the destination node cannot decode correctly is
By substituting formula (10), formula (15) and formula (25) for formula (26), the compound is obtained
According to the definition of the throughput, the throughput tau of the system is obtained
An optimization problem P is established with the optimization of throughput as a target:
at Ps、R0、η、d1、d2、d、m、
To know
Under the condition of given parameters, an optimization algorithm, such as a golden section method, is adopted to obtain the optimal power division coefficient and the optimal throughput. Recording the optimal throughput as tau; and defining the power division coefficient corresponding to the optimal throughput as the optimal power division coefficient, and marking the optimal power division coefficient as beta.
When the optimization problem P of the formula (29) is solved by adopting a golden section method, the optimal power division coefficient beta and the optimal throughput tau are obtained, and the steps are as follows:
step 1: setting a value interval [ a, b ] and precision e of initialization beta;
step 2: solving section golden section point a1 ═ a + (1-0.618) (b-a), a2 ═ a +0.618 × (b-a);
and 3, step 3: solving the throughputs tau (a1) and tau (a2) corresponding to a1 and a2 respectively; jumping to the 4 th step if the throughput is tau (a1) < tau (a2), otherwise jumping to the 5 th step;
and 4, step 4: if a2-a1 < e, stopping iteration, outputting an optimal solution beta-a 2 and an optimal throughput tau (a 2); otherwise, let a be 1, a1 be a2, a2 be a +0.618 × (b-a), and jump to step 3;
and 5, step 5: if a2-a1 < e, stopping iteration, outputting an optimal solution beta-a 2 and an optimal throughput tau (a 2); otherwise, let b be a2, a2 be a1, a1 be a + (1-0.618) (b-a), and jump to step 3.
The technical scheme provided by the invention is further explained by combining specific experimental simulation.
The invention carries out simulation verification on the throughput optimization method in the direct link-containing SWIPT relay system based on the PS strategy, and the use parameters are set as follows: ps＝1，R0＝2，η＝1，d1＝0.45，d2＝2.55，d＝d2+d2＝3，m＝2.7，
Referring to fig. 4, since both relay link transmissions are included, the throughputs of the relay forwarding link (RL) and the relay forwarding link combined direct link (RL-DL) are increased first and then decreased as β increases, both have an optimal power division coefficient β, and at this point, the throughputs of both have an optimal value, and through numerical calculation, the optimal point of the RL-DL link is (0.78, 0.6291), and the optimal point of the RL link is (0.80, 0.5355). As β increases from 0 to β, the throughput increases. As β continues to increase greater than β, the throughput decreases. As can be seen from fig. 4, as β approaches 0: (1) for the RL link, the throughput is almost 0, because the signal power used by the relay node to collect energy is almost 0 at this time, the relay node cannot acquire the energy required to forward the information, and thus an interruption occurs at the relay node, resulting in the throughput dropping to almost 0; (2) for an RL-DL link, its throughput is a finite value greater than 0 due to the presence of the DL link. When β approaches 1: the intermediate node assigns the signal power received by the information to be almost 0, resulting in the throughput of the destination node to be almost 0. It can be seen from fig. 4 that the throughput of the RL-DL link is always greater than that of the RL link, regardless of the power division factor, and the optimal throughput is improved by 17.5%.
In summary, the invention discloses a throughput optimization method in a relay system including a direct link SWIPT based on a PS strategy, so that the system obtains the optimal throughput.
While the invention has been described in further detail with reference to specific preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.
Claims (1)
1. A throughput optimization method in a direct link-containing SWIPT relay system based on a PS strategy is characterized by comprising the following steps:
the information and energy simultaneous transmission (SWIPT) relay system comprising a direct link comprises a source node S, a relay node R and a destination node D; a link for transmitting information from a source node S to a destination node D is called a Direct Link (DL); a link for transmitting information to a destination node D by a source node S through a relay node R is called a relay forwarding link (RL); the source node S and the destination node D are active, i.e. both nodes have no energy limitation, they both have a fixed energy supply; the relay node R does not have equipment for providing energy, and energy needs to be acquired from the radio frequency signal of the source node S; the relay node transmits the information from the source node S to the destination node D by using the collected energy; the relay node adopts a power division (PS) receiving strategy; the relay node works in a Decoding Forwarding (DF) mode, the relay node can decode without error only when the signal-to-noise ratio of a signal received by the relay node is greater than or equal to a threshold value, otherwise, the relay node is interrupted, the relay node can not forward information to a target node, and the relay node stores the collected energy for maintaining the basic operation of a relay system, including the energy consumed by the circuit and the energy required by decoding; after the decoding is successful, the energy collected by the relay node is completely used for relaying and forwarding information; the destination node combines signals from a Direct Link (DL) and a relay forwarding link (RL) respectively by using a Maximum Ratio Combining (MRC) method to serve as a final signal of the destination node;
all nodes adopt a half-duplex working mode; h represents the channel gain between the source node and the relay node, g represents the channel gain between the relay node and the destination node, and f represents the channel gain between the source node and the destination node; d1Representing a source nodeAnd distance between relay nodes, d2D represents the distance between the source node and the destination node;
all channels are quasi-static block fading channels and are frequency non-selective fading; in a communication time block T, the channel gain is kept constant, the channel gain is changed among different time blocks, and the random channel gains are independent and all obey Rayleigh distribution; pi f non-woven dust2、|h|2And | g |)2Are all random variables, are subject to exponential distribution, and their expectation is E [ | f &2]＝E[|h|2]＝E[|g|2]1, wherein E [ ·]Expressing expectation, | represents modulus value; random variable | f |2Has a probability density function of ff(z)＝e-zThe probability distribution function is Ff(z)＝P(|f|2＜z)＝1-e-z(ii) a Random variable | h |2Has a probability density function of fh(x)＝e-xThe probability distribution function is Fh(x)＝P(|h|2＜x)＝1-e-x(ii) a Random variable | g |2Has a probability density function of fg(y)＝e-yThe probability distribution function is Fg(y)＝P(|g|2＜y)＝1-e-y(ii) a In the communication process, the most important energy loss is path loss, and a loss coefficient is set to be m;
the average power of the normalized signal transmitted by the source node is Ps；nrRepresenting the noise generated by the antenna when the relay node receives the signal, nrIs a circularly symmetric complex Gaussian random variable, i.e.
Represents nr(t) obeys a complex Gaussian distribution with a mean of 0 and a variance of
ndRepresenting the noise generated by the antenna when the destination node receives the signal, and having
Beta represents a power division coefficient for collecting energy at the relay node, and beta belongs to [0, 1]](ii) a The passive relay node uses the received electromagnetic wave signals for energy collection and information reception respectively according to the power ratio beta: 1-beta; recording the energy collection efficiency factor as eta;
t represents a period of complete time block, in the first part T/2 time of the transmission block, the source node simultaneously sends signals to the relay node and the destination node, and the relay node simultaneously performs energy collection and information reception under the PS strategy; in the second part T/2 time of the transmission block, the relay node forwards the received information to the destination node, thereby completing communication;
the whole communication system adopts a transmission mode of limiting time delay, in the mode, a receiver decodes received information by taking a time block as a unit, and the throughput performance of the system is measured by interrupt probability; fixing the information transmission rate of the source node as R0Thus, a signal-to-noise ratio threshold is set
The probability of interruption of the direct link is noted
The probability of interruption between the source node and the relay node is noted
The destination node combines the signals from the direct link and the relay link by using a maximum ratio combining method, and the probability that the signals can not be decoded correctly as the final signal of the destination node is obtained, namely the interruption probability in the case is recorded as
From the destination node, the probability of interruption P of the communicationoutI.e. the probability that the destination node cannot decode correctly is
The throughput of the relay system comprising the direct link SWIPT based on the PS strategy is
In the formula (I), the compound is shown in the specification,
an optimization problem P is established with the optimization of throughput as a target:
s.t. 0≤β≤1
at Ps、R0、η、d1、d2、d、m、
And
and under the condition of given parameters, obtaining the optimal power division coefficient and the optimal throughput by adopting an optimization algorithm.
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| CN114884550B (en) * | 2022-04-06 | 2023-07-25 | 南京邮电大学 | Relay cooperative transmission method for bidirectional transmission FD multi-relay cooperative SWIPT network |
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