CN110602666A - Communication method and device for narrow-band Internet of things terminal equipment - Google Patents
Communication method and device for narrow-band Internet of things terminal equipment Download PDFInfo
- Publication number
- CN110602666A CN110602666A CN201910744209.1A CN201910744209A CN110602666A CN 110602666 A CN110602666 A CN 110602666A CN 201910744209 A CN201910744209 A CN 201910744209A CN 110602666 A CN110602666 A CN 110602666A
- Authority
- CN
- China
- Prior art keywords
- terminal device
- things
- target terminal
- terminal equipment
- narrowband internet
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/14—Relay systems
- H04B7/15—Active relay systems
- H04B7/155—Ground-based stations
- H04B7/15507—Relay station based processing for cell extension or control of coverage area
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W4/00—Services specially adapted for wireless communication networks; Facilities therefor
- H04W4/70—Services for machine-to-machine communication [M2M] or machine type communication [MTC]
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W72/00—Local resource management
- H04W72/04—Wireless resource allocation
- H04W72/044—Wireless resource allocation based on the type of the allocated resource
- H04W72/0453—Resources in frequency domain, e.g. a carrier in FDMA
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W72/00—Local resource management
- H04W72/50—Allocation or scheduling criteria for wireless resources
- H04W72/54—Allocation or scheduling criteria for wireless resources based on quality criteria
- H04W72/542—Allocation or scheduling criteria for wireless resources based on quality criteria using measured or perceived quality
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W76/00—Connection management
- H04W76/10—Connection setup
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W76/00—Connection management
- H04W76/10—Connection setup
- H04W76/14—Direct-mode setup
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
- Y02D30/00—Reducing energy consumption in communication networks
- Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Quality & Reliability (AREA)
- Mobile Radio Communication Systems (AREA)
Abstract
The invention provides a communication method and a device of narrow-band Internet of things terminal equipment, wherein the communication method of the narrow-band Internet of things terminal equipment comprises the following steps: selecting D2D link object equipment for the target terminal equipment according to the signal-to-noise ratio when the target terminal equipment is communicated with the terminal equipment in the narrowband Internet of things, wherein the target terminal equipment is positioned outside the coverage range of the narrowband Internet of things; selecting a channel of a terminal device in the narrowband Internet of things according to a target terminal device and D2D link object devices to allocate a multiplexing channel for the target terminal device; the D2D link between the target terminal device and the D2D link object device is established using a multiplexed channel. The communication method and the communication device of the narrow-band Internet of things terminal equipment fully utilize limited wireless resources in the narrow-band Internet of things system, expand the coverage range of the narrow-band Internet of things, and improve the spectrum utilization rate by multiplexing channels of the terminal equipment in the narrow-band Internet of things through the D2D link.
Description
Technical Field
The invention relates to the field of narrowband Internet of things, in particular to a communication method and device of narrowband Internet of things terminal equipment.
Background
The narrowband internet of things is widely applied in various industry fields, but due to the limited coverage range and the complex application environment of the narrowband internet of things, the poor channel condition and insufficient coverage of the narrowband internet of things can obviously improve the probability of interruption when terminal equipment at the coverage edge communicates with a base station, and greatly influence the success rate of information interaction of a system and the service experience of a user. Taking an electric automobile charging pile as an example, the electric automobile is developed at a high speed, the increase of the load of a power grid is very obvious, and the large-scale random unordered charging process has negative influence on the safety and economic operation of a power grid system in the future, so that the charging pile is required to be used as a terminal carrier of the internet of things, the information of a vehicle-mounted battery of the electric automobile is collected and uploaded to a cellular base station, the full deep interaction with the power grid is realized, and the ordered charging and discharging is realized. However, with the increase of the number of electric vehicles, the deployment number of charging piles is also sharply increased, but the coverage area of the narrowband internet of things base station is limited, and the probability of interruption when the charging piles outside the coverage area of the base station communicate with the base station is high, so that the success rate of information interaction of a power system and the service experience of a user are greatly influenced. Therefore, the problem that the coverage of the narrow-band internet of things needs to be enlarged is urgently solved.
Disclosure of Invention
Therefore, the technical problem to be solved by the present invention is to overcome the defect in the prior art that the probability of interruption is high when the terminal device covering the edge communicates with the base station, so as to provide a communication method and device for the narrowband internet of things terminal device.
The first aspect of the invention provides a communication method for narrowband internet of things terminal equipment, which comprises the following steps: selecting D2D link object equipment for a target terminal device according to the signal-to-noise ratio of the target terminal device when the target terminal device is communicated with the terminal device in the narrowband Internet of things, wherein the target terminal device is positioned outside the coverage range of the narrowband Internet of things; selecting a channel of a terminal device in the narrowband Internet of things according to the target terminal device and the D2D link object device to allocate a multiplexing channel for the target terminal device; establishing a D2D link between the target terminal device and the D2D link object device using the multiplexed channel.
Optionally, the step of selecting a D2D link object device for a target terminal device according to a signal-to-noise ratio when the target terminal device communicates with a terminal device in the narrowband internet of things includes: calculating a first interruption probability according to the signal-to-noise ratio of the communication between the target terminal equipment and the base station of the narrowband Internet of things; respectively calculating second interruption probability of establishing a D2D link between the target terminal device and each terminal device according to the signal-to-noise ratio of the target terminal device when communicating with the terminal device in the narrowband Internet of things; respectively calculating the difference value between the first interruption probability and each second interruption probability; and selecting the terminal device corresponding to the maximum difference value as the D2D link object device of the target terminal device.
Optionally, the step of calculating a first outage probability according to a signal-to-noise ratio of the target terminal device in communication with the base station of the narrowband internet of things includes: calculating the signal-to-noise ratio of the target terminal device when the target terminal device is communicated with the base station of the narrowband Internet of things according to the channel gain, the uplink transmission power, the unilateral power spectrum density and the channel bandwidth between the target terminal device and the base station of the narrowband Internet of things; calculating the probability that the signal-to-noise ratio is smaller than a first preset threshold value when the target terminal device communicates with the base station of the narrowband Internet of things according to the signal-to-noise ratio, signal fading and the first preset threshold value when the target terminal device communicates with the base station of the narrowband Internet of things; and taking the probability that the signal-to-noise ratio of the target terminal equipment is smaller than the first preset threshold value when the target terminal equipment is communicated with the base station of the narrowband Internet of things as the first interruption probability.
Optionally, the step of respectively calculating a second outage probability of establishing a D2D link between the target terminal device and each terminal device according to a signal-to-noise ratio when the target terminal device communicates with the terminal device in the narrowband internet of things includes: calculating the signal-to-noise ratio of uplink transmission after the D2D link is established according to the channel gain, the uplink transmission power, the single-side power spectrum density and the channel bandwidth between the terminal equipment and the target terminal equipment after the D2D link is established; calculating the probability that the signal-to-noise ratio is smaller than a first preset threshold value when the target terminal equipment communicates with the terminal equipment in the narrowband Internet of things according to the signal-to-noise ratio of uplink transmission after the D2D link is established, signal fading and the first preset threshold value; and taking the probability that the signal-to-noise ratio of the target terminal equipment is smaller than the first preset threshold value when the target terminal equipment is communicated with the terminal equipment in the narrowband Internet of things as the second interruption probability.
Optionally, the step of selecting the terminal device corresponding to the maximum difference value as the D2D link object device of the target terminal device includes: judging whether the difference value is larger than a second preset threshold value or not; if the difference is greater than the second preset threshold, bringing the terminal device corresponding to the difference into a potential D2D link object device set of the target terminal device; comparing the difference values corresponding to the terminal devices in the potential D2D link object device set; and selecting the terminal device corresponding to the maximum difference value as the D2D link object device of the target terminal device.
Optionally, the step of selecting a channel of a terminal device in the narrowband internet of things according to the target terminal device and the D2D link object device to allocate a multiplexing channel to the target terminal device includes: respectively calculating power which enables the throughput of the target terminal equipment and the terminal equipment in each narrow-band Internet of things to be maximum according to the transmitting power capability of the target terminal equipment and the terminal equipment in each narrow-band Internet of things and the signal-to-interference-and-noise ratio; calculating the sum of the transmission rates of the target terminal equipment and the terminal equipment in each narrowband Internet of things according to each power; and allocating a multiplexing channel to the target terminal equipment according to the transmission rate sum.
Optionally, the step of allocating a multiplexing channel to the target terminal device according to each of the transmission rates includes: establishing a bipartite graph by taking each target terminal device as a first subset, taking terminal devices in each narrowband Internet of things as a second subset and taking each transmission rate as an edge weight value for connecting the first subset and the second subset; calculating a perfect match for the bipartite graph; and taking the perfectly matched matching scheme as a scheme for allocating multiplexing channels for the target terminal equipment.
A second aspect of the present invention provides a communication device for a narrowband internet of things terminal device, including: a D2D link object device selection module, configured to select a D2D link object device for a target terminal device according to a signal-to-noise ratio when the target terminal device communicates with a terminal device in the narrowband internet of things, where the target terminal device is located outside a coverage area of the narrowband internet of things; the multiplexing channel allocation module is used for selecting a channel of the terminal equipment in the narrowband internet of things according to the target terminal equipment and the D2D link object equipment to allocate a multiplexing channel to the target terminal equipment; a D2D link establishment module to establish a D2D link between the target terminal device and the D2D link object device using the multiplexed channel.
A third aspect of the present invention provides a computer apparatus comprising: at least one processor; and a memory communicatively coupled to the at least one processor; the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor, so as to execute the communication method of the narrowband internet of things terminal device provided by the first aspect of the invention.
A fourth aspect of the present invention provides a computer-readable storage medium, which stores computer instructions for causing a computer to execute the communication method of the narrowband internet of things terminal device provided in the first aspect of the present invention.
The technical scheme of the invention has the following advantages:
1. according to the communication method of the narrow-band Internet of things terminal equipment, the D2D link is established between the target terminal equipment outside the coverage range of the narrow-band Internet of things and the terminal equipment in the narrow-band Internet of things, so that the interruption probability when the terminal equipment outside the coverage range of the narrow-band Internet of things communicates with the narrow-band Internet of things base station is reduced, the coverage range of the narrow-band Internet of things is expanded by fully utilizing limited wireless resources in a narrow-band Internet of things system, the D2D link multiplexes channels of the terminal equipment in the narrow-band Internet of things, and the spectrum utilization rate is improved.
2. According to the communication method of the terminal equipment of the narrowband Internet of things, the interruption probability of establishing a D2D link between the target terminal equipment and the terminal equipment in each narrowband Internet of things is respectively calculated, the interruption probability is compared with the interruption probability of directly communicating the target terminal equipment with the base station, the terminal equipment in the Internet of things with the largest difference value is selected as the D2D link object equipment of the target terminal equipment, the interruption probability after the D2D link is established is reduced to the maximum extent, and the communication quality of the target terminal equipment and the base station is guaranteed.
3. According to the communication method of the terminal equipment of the narrow-band Internet of things, the interruption probability of establishing a D2D link between the target terminal equipment and the terminal equipment in each narrow-band Internet of things is respectively calculated, the interruption probability is compared with the interruption probability of directly communicating the target terminal equipment with the base station, the terminal equipment in the narrow-band Internet of things corresponding to the difference value larger than the preset threshold value is classified into the potential D2D link object equipment set, the terminal equipment with the largest difference value is selected from the set to serve as the D2D link object equipment of the target terminal equipment, only the comparison between the difference values needs to be carried out in the potential D2D link object equipment set, the comparison is not needed to be carried out every time of calculating the difference value, the operation amount is reduced, and the operation process is simplified.
4. According to the communication method of the narrow-band Internet of things terminal equipment, the power enabling the maximum throughput of the target terminal equipment and the terminal equipment in each narrow-band Internet of things is calculated firstly according to the principle that the maximum sum of the transmission rates of the target terminal equipment and the terminal equipment of a multiplexed channel is the maximum when the channel is allocated for the D2D link, then the sum of the transmission rates of the target terminal equipment and the terminal equipment in each narrow-band Internet of things is calculated according to the power, channel allocation is carried out on the D2D link according to the sum of the transmission rates, and interference caused by channel multiplexing during channel transmission is greatly reduced.
5. According to the communication device of the narrow-band Internet of things terminal equipment, the D2D link is established between the target terminal equipment outside the coverage range of the narrow-band Internet of things and the terminal equipment in the narrow-band Internet of things, so that the interruption probability when the terminal equipment outside the coverage range of the narrow-band Internet of things communicates with the narrow-band Internet of things base station is reduced, the coverage range of the narrow-band Internet of things is expanded by fully utilizing limited wireless resources in a narrow-band Internet of things system, the D2D link multiplexes channels of the terminal equipment in the narrow-band Internet of things, and the spectrum utilization rate is improved.
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, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.
Fig. 1 is a flowchart (i) of a specific example of a communication method of a narrowband internet of things terminal device in an embodiment of the present invention;
FIG. 2 is a diagram of a narrowband Internet of things system model in an embodiment of the invention;
fig. 3 is a flowchart (ii) of a specific example of a communication method of a narrowband internet of things terminal device in the embodiment of the present invention;
fig. 4 is a flowchart (iii) of a specific example of a communication method of a narrowband internet of things terminal device in the embodiment of the present invention;
fig. 5 is a flowchart (iv) of a specific example of a communication method of a narrowband internet of things terminal device in the embodiment of the present invention;
fig. 6 is a flowchart (v) of a specific example of a communication method of a narrowband internet of things terminal device in the embodiment of the present invention;
fig. 7 is a flowchart (vi) of a specific example of a communication method of a narrowband internet of things terminal device in the embodiment of the present invention;
fig. 8 is a geometric diagram of optimal power calculation of a communication method of a narrowband internet of things terminal device in the embodiment of the present invention;
fig. 9 is a flowchart (seventh) of a specific example of a communication method of a narrowband internet of things terminal device in the embodiment of the present invention;
fig. 10 is a bipartite graph matching model of a communication method of a narrowband internet of things terminal device in an embodiment of the present invention;
fig. 11 is a simulation diagram (one) of a communication method of a narrowband internet of things terminal device in the embodiment of the present invention;
fig. 12 is a simulation diagram (two) of a communication method of a narrowband internet of things terminal device in the embodiment of the present invention;
fig. 13 is a block diagram of a communication device of a narrowband internet of things terminal device in the embodiment of the present invention;
fig. 14 is a block diagram of a computer device according to an embodiment of the present invention.
Detailed Description
The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. 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.
In the description of the present invention, it should be noted that the terms "first", "second", and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
In addition, the technical features involved in the different embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.
Example 1
The narrow-band Internet of things comprises a base station and terminal equipment, the terminal equipment can be an electric automobile charging pile and can also be other Internet of things carriers, the coverage range of the narrow-band Internet of things base station is limited, and when the terminal equipment is communicated with the base station, a signal attenuation phenomenon exists, so that the interruption condition is increased when the terminal equipment outside the coverage range of the narrow-band Internet of things is communicated with the base station, and therefore a method needs to be provided for increasing the coverage range of the narrow-band Internet of things.
The invention provides a communication method of narrowband Internet of things terminal equipment, which comprises the following steps as shown in figure 1:
s10: according to the signal-to-noise ratio when a target terminal device communicates with a terminal device in a narrowband internet of things, a D2D link object device is selected for the target terminal device, the target terminal device is located outside the coverage of the narrowband internet of things, and a D2D link object device of the target terminal device can be any device in the narrowband internet of things.
S20: the channel of the terminal device in the narrowband internet of things is selected according to the target terminal device and the D2D link object device to allocate a multiplexing channel to the target terminal device, in a specific embodiment, the channel of one terminal device may be multiplexed by one or more D2D links, but for convenience of description, in this embodiment and the following embodiments, a case where the channel of only one terminal device is multiplexed by one D2D link is described, and the terminal device of the multiplexed channel may be any terminal device in the coverage of the narrowband internet of things, including the D2D link object device.
S30: the D2D link between the target terminal device and the D2D link object device is established using a multiplexed channel.
According to the communication method of the narrow-band Internet of things terminal equipment, the D2D link is established between the target terminal equipment outside the coverage range of the narrow-band Internet of things and the terminal equipment in the narrow-band Internet of things, so that the interruption probability when the terminal equipment outside the coverage range of the narrow-band Internet of things communicates with the narrow-band Internet of things base station is reduced, the coverage range of the narrow-band Internet of things is expanded by fully utilizing limited wireless resources in the narrow-band Internet of things system, the D2D link multiplexes channels of the terminal equipment in the narrow-band Internet of things, and the spectrum utilization rate is improved.
In an alternative embodiment, as shown in fig. 3, step S10 specifically includes:
step S11: and calculating the first interruption probability according to the signal-to-noise ratio of the communication between the target terminal equipment and the base station of the narrowband Internet of things.
Step S12: and respectively calculating second interruption probabilities of establishing D2D links between the target terminal device and each terminal device according to signal-to-noise ratios when the target terminal device communicates with the terminal devices in the narrowband Internet of things, and establishing D2D links between the target terminal device and different terminals 3 in the coverage range of the narrowband Internet of things, wherein the interruption probabilities are different due to influences of factors such as distance and the like, so that the second interruption probabilities of establishing D2D links between the target terminal device and each terminal device need to be respectively calculated.
Step S13: and respectively calculating the difference value between the first interruption probability and each second interruption probability.
Step S14: and selecting the terminal device corresponding to the maximum difference value as the D2D link object device of the target terminal device.
According to the communication method of the terminal equipment of the narrowband Internet of things, the interruption probability of establishing a D2D link between the target terminal equipment and the terminal equipment in each narrowband Internet of things is respectively calculated, the interruption probability is compared with the interruption probability of directly communicating the target terminal equipment with the base station, the terminal equipment in the Internet of things with the largest difference value is selected as the D2D link object equipment of the target terminal equipment, the interruption probability after the D2D link is established is reduced to the maximum extent, and the communication quality of the target terminal equipment and the base station is guaranteed.
In an alternative embodiment, as shown in fig. 4, step S11 specifically includes:
step S111: and calculating the signal-to-noise ratio of the target terminal equipment and the base station of the narrowband Internet of things according to the channel gain, the uplink transmission power, the unilateral power spectrum density and the channel bandwidth between the target terminal equipment and the base station of the narrowband Internet of things.
Because the narrow-band internet of things has wide application field and some complex use environments, for example, when the narrow-band internet of things is used in a city, the intensity of a received signal is reduced due to a shadow effect caused by obstacles such as city buildings, and in the embodiment, signal fading is represented as xi-N (mu, sigma)2). According to the experimental measurement result, the signal power change related to the signal fading caused by the shadow effect is represented as a random variable of lognormal distribution and a density probability function thereofComprises the following steps:
where ξ represents the variable, μ represents the mean, and σ represents the variance.
After a D2D link is established between the target terminal device and the terminal device within the coverage range of the narrowband internet of things, the signal-to-noise ratio of uplink transmission is as follows:
wherein G isi,j=di,j -aξ,ξ~N(μ,σ2) Denotes the channel gain, P, between two terminalsi,jRepresents the uplink transmission power, D, of the target terminal device when transmitting signals after establishing a D2D link with the terminal devicei,jDenotes the physical distance between the target terminal device and the terminal device, a denotes the path loss index, σ0 2Representing the noise power, N0Representing single-sided power spectral density, and representing channel bandwidth.
Step S112: calculating the probability that the signal-to-noise ratio is smaller than a first preset threshold value when the target terminal device communicates with the base station of the narrowband Internet of things according to the signal-to-noise ratio, the signal fading and the first preset threshold value when the target terminal device communicates with the base station of the narrowband Internet of things:
step S113: and taking the probability that the signal-to-noise ratio of the target terminal equipment is smaller than a first preset threshold value when the target terminal equipment is communicated with the base station of the narrowband Internet of things as a first interruption probability.
In an alternative embodiment, as shown in fig. 5, step S12 specifically includes:
step S121: the signal-to-noise ratio of the uplink transmission after the D2D link is established is calculated according to the channel gain, the uplink transmission power, the single-side power spectral density and the channel bandwidth between the terminal device after the D2D link is established and the target terminal device, which is described in detail in the above description of step S111.
Step S122: the probability that the signal-to-noise ratio is smaller than the first preset threshold when the target terminal device communicates with the terminal device in the narrowband internet of things is calculated according to the signal-to-noise ratio of uplink transmission after the D2D link is established, the signal fading and the first preset threshold, and the detailed description is described in the above description of step S111.
Step S123: and taking the probability that the signal-to-noise ratio of the target terminal equipment is smaller than a first preset threshold value when the target terminal equipment is communicated with the terminal equipment in the narrowband Internet of things as a second interruption probability.
The calculation method of the second interruption probability is identical to the calculation method of the first interruption probability, and only the values of some parameters are different, so the calculation of the second interruption probability can refer to the above steps S111 to S113.
In an alternative embodiment, as shown in fig. 6, step S14 specifically includes:
step S141: and judging whether the difference value of the first interruption probability and the second interruption probability is greater than a second preset threshold value.
Step S142: and if the difference value is larger than a second preset threshold value, the terminal device corresponding to the difference value is included in the potential D2D link object device set of the target terminal device.
In order to reduce signal attenuation when the terminal device performs signal transmission after the D2D link is established, a terminal device at the edge of the coverage area of the narrowband internet of things close to the target terminal device is generally selected to establish the D2D link, and the interruption probability when the terminal device in the coverage area of the narrowband internet of things communicates with the base station is very small and can be ignored, so the interruption probability after the link is established is obviously lower than the interruption probability when the target terminal device directly communicates with the base station, therefore, in order to select the optimal D2D link object device for the target terminal device, a threshold needs to be set up, only the difference between the first interruption probability and the second interruption probability is greater than the preset threshold, the optimal D2D link can be established between each target terminal device and the terminal device in the coverage area of the narrowband internet of things, a specific preset threshold needs to be set for each target terminal device.
And if the difference is smaller than the second preset threshold, reselecting another terminal device in the narrowband internet of things, and returning to the step S12.
And if all the terminal devices in the narrowband internet of things are traversed, executing the step S143, otherwise, reselecting another terminal device in the narrowband internet of things, and returning to the step S12.
Step S143: comparing the difference values corresponding to the terminal devices in the potential D2D link object device set;
step S144: and selecting the terminal device corresponding to the maximum difference value as the D2D link object device of the target terminal device.
According to the communication method of the narrow-band Internet of things terminal equipment, the interruption probability of establishing a D2D link between the target terminal equipment and the terminal equipment in each narrow-band Internet of things is calculated respectively, the interruption probability is compared with the interruption probability of directly communicating the target terminal equipment with the base station, the terminal equipment in the narrow-band Internet of things corresponding to the difference value larger than the preset threshold value is classified into the potential D2D link object equipment set, the terminal equipment with the largest difference value is selected from the set to serve as the D2D link object equipment of the target terminal equipment, comparison between the difference values in the potential D2D link object equipment set is only needed, comparison is not needed to be conducted every time when one difference value is calculated, the operation amount is reduced, and the operation process is simplified.
In an alternative embodiment, as shown in fig. 7, step S20 specifically includes:
step S21: and respectively calculating the power which enables the maximum throughput of the target terminal equipment and the terminal equipment in each narrow-band Internet of things according to the transmitting power capability of the target terminal equipment and the terminal equipment in each narrow-band Internet of things and the signal-to-interference-and-noise ratio.
For channel multiplexing, their power strategy is not only constrained by the terminal transmit power capability, but also by the signal-to-interference-and-noise ratio, so the following inequality can be obtained:
wherein the content of the first and second substances,representing a target terminal device DiLink object device C with D2DiThe uplink transmission power at the time of communication,representing a target terminal device DiThe maximum transmit power capability of the antenna,terminal equipment C for indicating multiplexed channelkThe uplink transmission power when communicating with the base station,terminal equipment C for indicating multiplexed channelkThe maximum transmit power capability of the antenna,representing a target terminal device DiAnd D2D Link object device CjSignal to interference and noise ratio, gamma, in communicationthIndicating a signal-to-interference-and-noise ratio threshold,c representing multiplexed terminal deviceskSignal to interference plus noise ratio when communicating with a base station.
Therefore, in order to ensure the reliability of transmission, a method of geometric linear programming can be used to obtain the optimal power strategy of the channel multiplexing pair. As shown in fig. 8, by representing the two inequalities by a geometric diagram, the best power set can be found in the feasible region, which is shown by the shaded region, and the relative positions of the shaded regions can include 4 positions as shown in the figure. The region is based on the calculation of the above inequality and varies according to different transmit powers and different channel conditionsAnd (4) transforming. Thread lcLeft area and line ldThe intersection of the right regions of (a) represents the signal to interference and noise ratio requirements of the cellular terminal and its paired D2D terminal. Meanwhile, the calculation of the channel multiplexing optimal power strategy needs to be discussed under different conditions. The boundary point in the graph is a power solution, for a certain channel multiplexing pair, the optimal power strategy which meets the service quality requirement and reduces the interference can be quickly obtained by calculating and comparing the sum of the rates of the corresponding boundary points, the transmission rate and the maximum power strategy of the target terminal equipment and the terminal equipment of the multiplexed channel are selected as the optimal power strategy, and the target terminal equipment D is obtained according to a Shannon capacity formulaiAnd terminal equipment C of multiplexed channelkThe uplink transmission rates of (a) are respectively expressed as follows:
wherein the content of the first and second substances,terminal equipment C for indicating multiplexed channelkLink object device C with D2DjThe gain of the channel in between is increased,terminal equipment C for indicating multiplexed channelkThe channel gain with the base station is,representing the channel gain between the target terminal device and the base station,representing a target terminal device DiLink object terminal equipment C with D2DjThe channel gain in between.
Step S22: and calculating the sum of the transmission rates of the target terminal equipment and the terminal equipment in each narrowband Internet of things according to each power.
Step S23: the purpose of this embodiment is to maximize throughput, i.e. maximize the sum of the transmission rates of all terminals in the system, according to the transmission rates and to allocate the multiplexed channel to the target terminal device, so the principle of allocating the multiplexed channel is as follows:
subchannel resource allocation indexThe sub-channel multiplexing condition is represented, the value is 0 or 1, and when the value is 1, the terminal equipment C in the coverage range of the narrow-band Internet of things is representedkHas been targeted by the target terminal device DiMultiplexing, otherwise 0.
According to the communication method of the narrow-band Internet of things terminal equipment, provided by the embodiment of the invention, when the channel is allocated for the D2D link, the power which enables the maximum throughput of the target terminal equipment and the terminal equipment in each narrow-band Internet of things is calculated firstly according to the principle that the sum of the transmission rates of the target terminal equipment and the terminal equipment of the multiplexed channel is the maximum, then the sum of the transmission rates of the target terminal equipment and the terminal equipment in each narrow-band Internet of things is calculated according to the power, and the channel allocation is carried out on the D2D link according to the sum of the transmission rates, so that the interference caused by channel multiplexing during channel transmission is greatly reduced.
In an alternative embodiment, as shown in fig. 9, step S23 specifically includes:
step S231: as shown in fig. 10, a bipartite graph is established with each target terminal device as a first subset and terminal devices in each narrowband internet of things as a second subset, and each transmission rate is used as an edge weight value connecting the first subset and the second subset, and when a D2D terminal cannot multiplex a corresponding terminal device subchannel, the weight is 0.
Step S232: a perfect match for the bipartite graph is calculated.
In a specific embodiment, a solution of the optimal channel multiplexing matching problem is effectively obtained by using a Hungarian algorithm (Kuhn-Munkres, KM), and the specific steps are as follows:
step S2321: mapping the target terminal device and the terminal device of the multiplexed channel to vertex sets X and Y, where X is the first subset in step S231, Y is the second subset in step S231,edge set of bipartite graphWhereinThe weight values of the edges are initialized according to the sum of the rates of the channel multiplex pairs obtained in the power control scheme.
Step S2322: set the vertex label to L in sets X and Y1,i(t) and L2,i(t), equation L1,i(t)+L2,j(t)=Wi,j(t) always true, initialize vertex label L1,i(t)=max(Wi,j(t)), and L2,j(t)=0。
Step S2323: and adding alternate paths between the matched edges and the non-matched edges, obtaining the best matching set by using a KM algorithm, and otherwise, jumping to the step S2324.
Step S2324: the tag is refined until an extended path is found in the equation graph. Defining a relaxed array reduces temporal complexity: sleep (y) min { l (x) + l (y) -w (x, y) | x ∈ S }. Δ is used to calculate the tag increment, Δ min { slack (Y) | Y ∈ Y \ T }. And the label of vertex r is changed to:
if r∈S,then l′(r)=l(r)-Δ;
if r∈T,then l′(r)=l(r)+Δ;
where S represents the set of candidate augmented alternate paths in the middle of the matching edge, T represents the set of candidate augmented alternate paths in the middle of the non-matching edge, and l (r) represents the label of the vertex r.
Step S2325: step S2323 and step S2324 are repeated until a perfect matching scheme is found.
Step S233: and taking the perfectly matched matching scheme as a scheme for allocating the multiplexing channel for the target terminal equipment.
In a specific embodiment, the inventor performs a simulation test on the communication method of the narrowband internet of things terminal device provided in this embodiment.
The simulation parameter settings are shown in table 1:
TABLE 1
The parameters in table 1 are respectively substituted into the communication method of the narrowband internet of things terminal device provided in this embodiment and the conventional technology for calculation, the comparison results are shown in fig. 11 and 12,
as can be seen from fig. 11, for a target terminal device outside the cell coverage, the probability of interruption is very high due to the too far distance from the base station. When the target terminal device communicates with the base station, a D2D link is established with the terminal device within the coverage range of the narrowband Internet of things as a relay, and the interruption probability is obviously reduced due to the shortened communication distance.
Fig. 12 shows the variation of system throughput for different amounts of channel resources in the system at different terminal scales. As can be seen from the figure, as the amount of resources allocated to the system increases, the throughput of the system gradually increases as more terminals are available to access the system. Compared with the common cellular system, the system throughput is obviously improved by the mechanism provided by the invention.
Example 2
The invention provides a communication device of a narrowband internet of things terminal device, as shown in fig. 13, comprising:
the D2D link object device selecting module 1 is configured to select a D2D link object device for a target terminal device according to a signal-to-noise ratio when the target terminal device communicates with a terminal device in a narrowband internet of things, where the target terminal device is located outside a coverage area of the narrowband internet of things, and specific description is described in the foregoing embodiment 1 with reference to step S10.
The multiplexing channel allocating module 2 is configured to select a channel of a terminal device in the narrowband internet of things according to the target terminal device and the D2D link object device, and allocate a multiplexing channel to the target terminal device, which is described in step S20 in embodiment 1.
The D2D link establishing module 3 is configured to establish a D2D link between the target terminal device and the D2D link object device using the multiplexing channel, and the specific description is given in the above embodiment 1 for the description of the step S30.
According to the communication device of the narrow-band Internet of things terminal equipment, the D2D link is established between the target terminal equipment outside the coverage range of the narrow-band Internet of things and the terminal equipment in the narrow-band Internet of things, so that the interruption probability when the terminal equipment outside the coverage range of the narrow-band Internet of things communicates with the narrow-band Internet of things base station is reduced, the coverage range of the narrow-band Internet of things is expanded by fully utilizing limited wireless resources in the narrow-band Internet of things system, the D2D link multiplexes channels of the terminal equipment in the narrow-band Internet of things, and the spectrum utilization rate is improved.
Example 3
The present invention also provides a computer device, as shown in fig. 14, the computer device mainly includes one or more processors 51 and a memory 52, and fig. 14 takes one processor 51 as an example.
The computer device may further include: an input device 55 and an output device 54.
The processor 51, the memory 52, the input device 55 and the output device 54 may be connected by a bus or other means, and the bus connection is exemplified in fig. 14.
The processor 51 may be a Central Processing Unit (CPU). The Processor 51 may also be other general purpose processors, Digital Signal Processors (DSPs), Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs) or other Programmable logic devices, discrete Gate or transistor logic devices, discrete hardware components, or combinations thereof. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like. The memory 52 may include a storage program area and a storage data area, wherein the storage program area may store an operating system, an application program required for at least one function; the storage data area may store data created from use of the communication device of the narrowband internet of things terminal apparatus, and the like. Further, the memory 52 may include high speed random access memory, and may also include non-transitory memory, such as at least one magnetic disk storage device, flash memory device, or other non-transitory solid state storage device. In some embodiments, the memory 52 optionally comprises a memory remotely located from the processor 51, and these remote memories may be connected to the communication means of the narrowband internet of things terminal device through a network. The input device 55 may receive a calculation request (or other numerical or character information) input by a user and generate a key signal input related to a communication device of the narrowband internet of things terminal device. The output device 54 may include a display device such as a display screen for outputting the calculation result.
Example 4
The invention provides a computer-readable storage medium, which stores computer instructions, and the computer-readable storage medium stores computer-executable instructions, and the computer-executable instructions can execute the communication method of the narrowband internet of things terminal equipment in any method embodiment. The storage medium may be a magnetic Disk, an optical Disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a Flash Memory (Flash Memory), a Hard Disk (Hard Disk Drive, abbreviated as HDD), a Solid State Drive (SSD), or the like; the storage medium may also comprise a combination of memories of the kind described above.
It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications therefrom are within the scope of the invention.
Claims (10)
1. A communication method of narrow-band Internet of things terminal equipment is characterized by comprising the following steps:
selecting D2D link object equipment for a target terminal device according to the signal-to-noise ratio of the target terminal device when the target terminal device is communicated with the terminal device in the narrowband Internet of things, wherein the target terminal device is positioned outside the coverage range of the narrowband Internet of things;
selecting a channel of a terminal device in the narrowband Internet of things according to the target terminal device and the D2D link object device to allocate a multiplexing channel for the target terminal device;
establishing a D2D link between the target terminal device and the D2D link object device using the multiplexed channel.
2. The communication method of the narrowband internet of things terminal device according to claim 1, wherein the step of selecting the D2D link object device for the target terminal device according to a signal-to-noise ratio when the target terminal device communicates with the terminal device in the narrowband internet of things comprises:
calculating a first interruption probability according to the signal-to-noise ratio of the communication between the target terminal equipment and the base station of the narrowband Internet of things;
respectively calculating second interruption probability of establishing a D2D link between the target terminal device and each terminal device according to the signal-to-noise ratio of the target terminal device when communicating with the terminal device in the narrowband Internet of things;
respectively calculating the difference value between the first interruption probability and each second interruption probability;
and selecting the terminal device corresponding to the maximum difference value as the D2D link object device of the target terminal device.
3. The communication method of the narrowband internet of things terminal device according to claim 2, wherein the step of calculating the first outage probability according to the signal-to-noise ratio of the target terminal device in communication with the base station of the narrowband internet of things comprises:
calculating the signal-to-noise ratio of the target terminal device when the target terminal device is communicated with the base station of the narrowband Internet of things according to the channel gain, the uplink transmission power, the unilateral power spectrum density and the channel bandwidth between the target terminal device and the base station of the narrowband Internet of things;
calculating the probability that the signal-to-noise ratio is smaller than a first preset threshold value when the target terminal device communicates with the base station of the narrowband Internet of things according to the signal-to-noise ratio, signal fading and the first preset threshold value when the target terminal device communicates with the base station of the narrowband Internet of things;
and taking the probability that the signal-to-noise ratio of the target terminal equipment is smaller than the first preset threshold value when the target terminal equipment is communicated with the base station of the narrowband Internet of things as the first interruption probability.
4. The communication method of the narrowband internet of things terminal device according to claim 2, wherein the step of calculating the second outage probability for the target terminal device to establish the D2D link with each terminal device according to the signal-to-noise ratio of the target terminal device in communication with the terminal device in the narrowband internet of things includes:
calculating the signal-to-noise ratio of uplink transmission after the D2D link is established according to the channel gain, the uplink transmission power, the single-side power spectrum density and the channel bandwidth between the terminal equipment and the target terminal equipment after the D2D link is established;
calculating the probability that the signal-to-noise ratio is smaller than a first preset threshold value when the target terminal equipment communicates with the terminal equipment in the narrowband Internet of things according to the signal-to-noise ratio of uplink transmission after the D2D link is established, signal fading and the first preset threshold value;
and taking the probability that the signal-to-noise ratio of the target terminal equipment is smaller than the first preset threshold value when the target terminal equipment is communicated with the terminal equipment in the narrowband Internet of things as the second interruption probability.
5. The communication method of the narrowband internet of things terminal device according to claim 2, wherein the step of selecting the terminal device corresponding to the maximum difference value as the D2D link object device of the target terminal device includes:
judging whether the difference value is larger than a second preset threshold value or not;
if the difference is greater than the second preset threshold, bringing the terminal device corresponding to the difference into a potential D2D link object device set of the target terminal device;
comparing the difference values corresponding to the terminal devices in the potential D2D link object device set;
and selecting the terminal device corresponding to the maximum difference value as the D2D link object device of the target terminal device.
6. The communication method of the narrowband internet of things terminal device according to claim 1, wherein the step of selecting the channel of the terminal device in the narrowband internet of things to allocate the multiplexing channel to the target terminal device according to the target terminal device and the D2D link object device includes:
respectively calculating power which enables the throughput of the target terminal equipment and the terminal equipment in each narrow-band Internet of things to be maximum according to the transmitting power capability of the target terminal equipment and the terminal equipment in each narrow-band Internet of things and the signal-to-interference-and-noise ratio;
calculating the sum of the transmission rates of the target terminal equipment and the terminal equipment in each narrowband Internet of things according to each power;
and allocating a multiplexing channel to the target terminal equipment according to the transmission rate sum.
7. The communication method of the narrowband internet of things terminal device according to claim 6, wherein the step of allocating a multiplexing channel to the target terminal device according to each of the transmission rates comprises:
establishing a bipartite graph by taking each target terminal device as a first subset, taking terminal devices in each narrowband Internet of things as a second subset and taking each transmission rate as an edge weight value for connecting the first subset and the second subset;
calculating a perfect match for the bipartite graph;
and taking the perfectly matched matching scheme as a scheme for allocating multiplexing channels for the target terminal equipment.
8. The utility model provides a communication device of narrowband thing networking terminal equipment which characterized in that includes:
a D2D link object device selection module, configured to select a D2D link object device for a target terminal device according to a signal-to-noise ratio when the target terminal device communicates with a terminal device in the narrowband internet of things, where the target terminal device is located outside a coverage area of the narrowband internet of things;
the multiplexing channel allocation module is used for selecting a channel of the terminal equipment in the narrowband internet of things according to the target terminal equipment and the D2D link object equipment to allocate a multiplexing channel to the target terminal equipment;
a D2D link establishment module to establish a D2D link between the target terminal device and the D2D link object device using the multiplexed channel.
9. A computer device, comprising:
at least one processor; and a memory communicatively coupled to the at least one processor; wherein the memory stores instructions executable by the at least one processor to perform the method of communication of a narrowband internet of things terminal device of any of claims 1-7.
10. A computer-readable storage medium, characterized in that the computer-readable storage medium stores computer instructions for causing the computer to execute the communication method of the narrowband internet of things terminal device according to any one of claims 1 to 7.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN2019106085699 | 2019-07-08 | ||
CN201910608569 | 2019-07-08 |
Publications (2)
Publication Number | Publication Date |
---|---|
CN110602666A true CN110602666A (en) | 2019-12-20 |
CN110602666B CN110602666B (en) | 2022-09-23 |
Family
ID=68854098
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN201910744209.1A Active CN110602666B (en) | 2019-07-08 | 2019-08-13 | Communication method and device for narrow-band Internet of things terminal equipment |
Country Status (1)
Country | Link |
---|---|
CN (1) | CN110602666B (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN111050417A (en) * | 2019-12-27 | 2020-04-21 | 咻享智能(深圳)有限公司 | Wireless Internet of things equipment control method and related device |
CN111432396A (en) * | 2020-03-09 | 2020-07-17 | 安徽继远软件有限公司 | Configuration method, system and storage medium of eSIM card network for guaranteeing NB-IoT reliability |
CN112600729A (en) * | 2020-12-08 | 2021-04-02 | 广州技象科技有限公司 | Narrowband Internet of things data transmission method, device, equipment and storage medium |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20150103731A1 (en) * | 2012-07-15 | 2015-04-16 | Lg Electronics Inc. | Method and apparatus for subset network coding with multiple antennas by relay node in wireless communication system |
CN105636235A (en) * | 2014-11-07 | 2016-06-01 | 联想(北京)有限公司 | Information processing method and base station |
CN107172672A (en) * | 2017-05-10 | 2017-09-15 | 中国互联网络信息中心 | A kind of method that use D2D mechanism realizes internet of things equipment routing optimality |
CN108462950A (en) * | 2018-03-26 | 2018-08-28 | 南京邮电大学 | D2D based on NOMA communicates joint sub-channel and power allocation method |
CN109451471A (en) * | 2018-09-28 | 2019-03-08 | 广东电网有限责任公司 | A kind of shared channel D2D relay communication method and system, computer equipment, medium |
CN109743713A (en) * | 2018-12-30 | 2019-05-10 | 全球能源互联网研究院有限公司 | A kind of resource allocation methods and device of electric power Internet of things system |
-
2019
- 2019-08-13 CN CN201910744209.1A patent/CN110602666B/en active Active
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20150103731A1 (en) * | 2012-07-15 | 2015-04-16 | Lg Electronics Inc. | Method and apparatus for subset network coding with multiple antennas by relay node in wireless communication system |
CN105636235A (en) * | 2014-11-07 | 2016-06-01 | 联想(北京)有限公司 | Information processing method and base station |
CN107172672A (en) * | 2017-05-10 | 2017-09-15 | 中国互联网络信息中心 | A kind of method that use D2D mechanism realizes internet of things equipment routing optimality |
CN108462950A (en) * | 2018-03-26 | 2018-08-28 | 南京邮电大学 | D2D based on NOMA communicates joint sub-channel and power allocation method |
CN109451471A (en) * | 2018-09-28 | 2019-03-08 | 广东电网有限责任公司 | A kind of shared channel D2D relay communication method and system, computer equipment, medium |
CN109743713A (en) * | 2018-12-30 | 2019-05-10 | 全球能源互联网研究院有限公司 | A kind of resource allocation methods and device of electric power Internet of things system |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN111050417A (en) * | 2019-12-27 | 2020-04-21 | 咻享智能(深圳)有限公司 | Wireless Internet of things equipment control method and related device |
CN111050417B (en) * | 2019-12-27 | 2021-09-03 | 咻享智能(深圳)有限公司 | Wireless Internet of things equipment control method and related device |
CN111432396A (en) * | 2020-03-09 | 2020-07-17 | 安徽继远软件有限公司 | Configuration method, system and storage medium of eSIM card network for guaranteeing NB-IoT reliability |
CN111432396B (en) * | 2020-03-09 | 2023-02-21 | 安徽继远软件有限公司 | Configuration method, system and storage medium of eSIM card network for guaranteeing NB-IoT reliability |
CN112600729A (en) * | 2020-12-08 | 2021-04-02 | 广州技象科技有限公司 | Narrowband Internet of things data transmission method, device, equipment and storage medium |
CN112600729B (en) * | 2020-12-08 | 2023-03-17 | 广州技象科技有限公司 | Narrowband Internet of things data transmission method, device, equipment and storage medium |
Also Published As
Publication number | Publication date |
---|---|
CN110602666B (en) | 2022-09-23 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CN110602666B (en) | Communication method and device for narrow-band Internet of things terminal equipment | |
US11388644B2 (en) | Apparatus and method for load balancing in wireless communication system | |
CN109391972B (en) | Resource selection method and device for terminal-to-terminal communication supporting carrier aggregation | |
Luo et al. | Dynamic resource allocations based on Q-learning for D2D communication in cellular networks | |
US9788333B2 (en) | D2D communication system that use the non-licensed band to the auxiliary band and method of D2D system thereof | |
US8843070B2 (en) | Method for transmitting and receiving interference control signaling in wireless communication system | |
CN111328133B (en) | V2X resource allocation method based on deep neural network | |
CN106303908B (en) | Communication device between communication between devices method and apparatus | |
US20180098332A1 (en) | Resource allocation method, apparatus, and system, and base station | |
US9131514B2 (en) | Method of allocating radio resources and apparatus of allocating radio resources in cognitive radio small-cell networks | |
CN115134779A (en) | Internet of vehicles resource allocation method based on information age perception | |
CN107484180B (en) | Resource allocation method based on D2D communication in very high frequency band | |
Falkenberg et al. | Rushing full speed with LTE-Advanced is economical-a power consumption analysis | |
CN115866787A (en) | Network resource allocation method integrating terminal direct transmission communication and multi-access edge calculation | |
CN110139282B (en) | Energy acquisition D2D communication resource allocation method based on neural network | |
CN111741450A (en) | Network flow prediction method and device and electronic equipment | |
ElGarhy et al. | Increasing efficiency of resource allocation for D2D communication in NB-IoT context | |
CN107333301B (en) | Cognitive-based joint resource reallocation method in multi-generic heterogeneous network | |
CN113747396A (en) | Social perception V2X network joint resource optimization method based on RIS | |
Zhang et al. | D2D communication underlay uplink cellular network with fractional frequency reuse | |
RU2651577C1 (en) | Wireless communication device, wireless communication method and wireless communication system | |
Gnanaselvam et al. | Signal coverage analysis with link adaptation in Narrowband-IoT | |
US11395115B2 (en) | Resource allocation in presence of in-band emission for NR V2X mobile communications | |
Kim et al. | Spectrum allocation with power control in LBS based D2d cellular mobile networks | |
Zheng et al. | Dynamic resource allocation based on service time prediction for device‐to‐device communication underlaying cellular networks |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PB01 | Publication | ||
PB01 | Publication | ||
SE01 | Entry into force of request for substantive examination | ||
SE01 | Entry into force of request for substantive examination | ||
GR01 | Patent grant | ||
GR01 | Patent grant |