Method and system for building multi-cell Internet of Things system

Abstract

The invention provides a multi-cell Internet of Things system building method and system, and the method comprises the steps: randomly distributing each wireless resource in a wireless resource subset to a cell in a corresponding target cell subset for multiplexing, and obtaining a plurality of wireless resource distribution schemes, calculating the corresponding total inter-cell interference and total interference in each wireless resource allocation scheme to obtain the reachable rate of the Internet of Things equipment of the corresponding target cell on the wireless resources allocated by the corresponding target cell, and obtaining the average total reachable rate corresponding to each wireless resource allocation scheme; and finally, the establishment of the multi-cell Internet of Things system is executed by acquiring a corresponding wireless resource allocation scheme when the average total reachable rate is maximum. Therefore, the cost and limitation of the multi-cell Internet of Things system established by applying the method disclosed by the invention are lower, and the multi-cell Internet of Things system has higher transmission performance and anti-interference capability.

Description

Technical Field

[0001] The present invention relates to the field of Internet of Things communications, and in particular to a method and system for building a multi-cell Internet of Things system. Background Art

[0002] At present, the research focus in this field is mainly on the technology of realizing frequency reuse in multi-cell cellular systems under authorized wireless resources with complex access mechanisms. At the same time, with the widespread popularization of IoT applications and the surge in the number of devices, this technology has gradually been explored and applied to the construction of multi-cell IoT systems. It has been verified that the technology of building multi-cell IoT systems using authorized wireless resources has achieved initial results. It can effectively support the interconnection of large-scale IoT devices and has been widely adopted in practical applications.

[0003] However, in the process of building a multi-cell IoT system using authorized wireless resources, some significant problems have also been exposed. Due to the limited frequency resources in authorized wireless resources and the lack of flexibility in use, the system built using authorized wireless resources faces many limitations and unresolved technical problems in actual applications, such as high implementation costs and difficulty in meeting the average total achievable rate requirements in some scenarios. Summary of the invention

[0004] Based on this, the purpose of the present invention is to provide a method and system for building a multi-cell Internet of Things system, which can reduce the limitations of building a multi-cell Internet of Things system using authorized wireless resources, reduce the corresponding cost of building a multi-cell Internet of Things system, and have higher transmission performance and anti-interference ability.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] A method for building a multi-cell Internet of Things system comprises the following steps: allocating a number of available wireless resource subsets to a number of target cell subsets in a one-to-one correspondence, and randomly allocating each wireless resource contained in the wireless resource subset to a target cell in the corresponding target cell subset for reuse, so as to obtain a number of wireless resource allocation schemes, wherein the number of the wireless resource subsets is equal to the number of the target cell subsets, each of the target cell subsets includes at least one target cell, and each of the wireless resource subsets includes at least one available wireless resource; calculating the total inter-cell interference generated by the Internet of Things devices of each target cell in each of the wireless resource allocation schemes on the allocated wireless resources by the Internet of Things devices of other target cells in the same target cell subset; calculating the total interference generated by the interfering devices of the target cells in each of the wireless resource allocation schemes on the allocated wireless resources by the Internet of Things devices of the target cells; determining the optimal wireless resource allocation scheme for each of the target cell subsets according to the total inter-cell interference and the total interference, and building a multi-cell Internet of Things system according to the optimal wireless resource allocation scheme.

[0007] A multi-cell Internet of Things system construction system, comprising: a wireless resource allocation scheme generating unit, used to allocate a number of available wireless resource subsets to a number of target cell subsets one by one, and randomly allocate each wireless resource contained in the wireless resource subset to the target cell in the corresponding target cell subset for reuse, to obtain a number of wireless resource allocation schemes, wherein the number of the wireless resource subsets is equal to the number of the target cell subsets, each of the target cell subsets includes at least one target cell, and each of the wireless resource subsets includes at least one available wireless resource; a total inter-cell interference calculating unit, used to calculate the total interference between each of the wireless resource subsets. The invention discloses a method for calculating the total inter-cell interference caused by the Internet of Things devices of other target cells in the same target cell subset on the allocated wireless resources to the Internet of Things devices of each target cell in the wireless resource allocation scheme; a total interference calculation unit is used to calculate the total interference caused by the interference devices of the target cells in each target cell subset in each of the wireless resource allocation schemes on the allocated wireless resources to the Internet of Things devices of the target cells; an optimal wireless resource allocation scheme determination unit is used to determine the optimal wireless resource allocation scheme of each of the target cell subsets according to the total inter-cell interference and the total interference, and build a multi-cell Internet of Things system according to the optimal wireless resource allocation scheme.

[0008] Compared with the prior art, the method described in the present invention first divides the target cell set and the wireless resource set into the same number of target cell subsets and wireless resource subsets, and allocates them one by one. Secondly, each wireless resource in the wireless resource subset is randomly allocated to all target cells in the corresponding target cell subset for reuse, and several wireless resource allocation schemes are obtained. Furthermore, the corresponding total inter-cell interference and total interference in each wireless resource allocation scheme are calculated to obtain the reachable rate of the Internet of Things device of the corresponding target cell on the wireless resources allocated to the target cell, and the average total reachable rate corresponding to each wireless resource allocation scheme is obtained. Finally, the wireless resource allocation scheme corresponding to the maximum average total reachable rate is obtained to execute the construction of a multi-cell Internet of Things system. Therefore, the method described in the present invention can avoid the defects of limited resources and insufficient flexibility caused by the use of authorized wireless resources, reduce the construction cost, and have a higher information transmission rate.

[0009] For better understanding and implementation, the present invention is described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 A flowchart of the steps of the method for building a multi-cell Internet of Things system provided by the present invention;

[0011] Figure 2 A flowchart of the steps of obtaining the wireless resource allocation scheme corresponding to the maximum average total achievable rate in the method for building a multi-cell Internet of Things system provided by the present invention;

[0012] Figure 3 A flowchart of the steps of solving the first equivalence problem of the method for building a multi-cell Internet of Things system provided by the present invention;

[0013] Figure 4 A flowchart of the steps of constructing a feasible solution for a wireless resource allocation scheme that is an infeasible solution in the method for building a multi-cell Internet of Things system provided by the present invention;

[0014] Figure 5 A schematic diagram of a multi-cell Internet of Things system provided by the present invention;

[0015] Figure 6 A schematic diagram showing the relationship between the number of IoT devices provided by the present invention and the average total achievable rate;

[0016] Figure 7 A schematic diagram showing the relationship between the active probability of the IoT device provided by the present invention and the average total reachable rate;

[0017] Figure 8 A schematic diagram showing the relationship between the number of interfering devices provided by the present invention and the influence of the average total achievable rate;

[0018] Fig. 9 A schematic diagram of the relationship between the influence of the activity probability of the interfering device provided by the present invention on the average total achievable rate. DETAILED DESCRIPTION

[0019] The present invention provides a method and system for building a multi-cell Internet of Things system. In order to make the purpose, technical solution and effect of the present invention clearer and more specific, the present invention is further described in detail with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0020] It will be understood by those skilled in the art that, unless expressly stated, the singular forms "one", "said", and "the" used herein may also include plural forms. It should be further understood that the term "comprising" used in the specification of the present invention refers to the presence of the features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof. It should be understood that when we refer to an element as being "connected" or "coupled" to another element, it may be directly connected or coupled to the other element, or there may be intermediate elements. In addition, the "connection" or "coupling" used herein may include wireless connection or wireless coupling. The term "and / or" used herein includes all or any unit and all combinations of one or more associated listed items.

[0021] It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as generally understood by those skilled in the art in the art to which the present invention belongs. It should also be understood that terms such as those defined in general dictionaries should be understood to have meanings consistent with the meanings in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless specifically defined as herein.

[0022] The invention is further described below by describing embodiments in conjunction with the accompanying drawings.

[0023] Example 1

[0024] Please refer to Figure 1 , Figure 1 A flowchart of a method for building a multi-cell Internet of Things system provided by the present invention. The method comprises the following steps:

[0025] S10, allocating several available wireless resource subsets to several target cell subsets one by one, and randomly allocating each wireless resource contained in the wireless resource subset to the target cell in the corresponding target cell subset for reuse, to obtain several wireless resource allocation schemes, wherein the number of the wireless resource subsets is equal to the number of the target cell subsets, each of the target cell subsets includes at least one target cell, and each of the wireless resource subsets includes at least one available wireless resource;

[0026] S20, calculating the total inter-cell interference caused by the Internet of Things devices of each target cell in each of the wireless resource allocation schemes and the Internet of Things devices of other target cells in the same target cell subset on the allocated wireless resources;

[0027] S30, calculating the total interference caused by the interfering devices of the target cells in each target cell subset in each of the wireless resource allocation schemes to the IoT devices of the target cells on the allocated wireless resources;

[0028] S40. Determine an optimal wireless resource allocation scheme for each of the target cell subsets according to the total inter-cell interference and the total interference, and build a multi-cell Internet of Things system according to the optimal wireless resource allocation scheme.

[0029] In this embodiment, multiple wireless resource allocation schemes are formed by randomly allocating wireless resources to target cells for multiplexing, and the total inter-cell interference and total interference in each wireless resource allocation scheme are calculated at the same time, so as to obtain the optimal wireless resource allocation scheme to build a multi-cell Internet of Things system, thereby avoiding the defects of limited resources and insufficient flexibility caused by the use of authorized wireless resources, reducing the construction cost and having a higher information transmission rate.

[0030] For step S10, several available wireless resource subsets are allocated to several target cell subsets one by one, and each wireless resource contained in the wireless resource subset is randomly allocated to the corresponding target cell in the target cell subset for reuse, so as to obtain several wireless resource allocation schemes.

[0031] Among them, the available wireless resources include commonly used communication resources such as frequency band resources, time slot resources, and code domain resources; for the frequency band resources, wireless communication systems usually use electromagnetic waves for communication, and the propagation frequency of electromagnetic waves is limited, so frequency band resources are one of the most important resources in wireless communication systems. Wireless communication systems use frequency reuse technology to divide the frequency band into multiple sub-bands, so that multiple users can use the same frequency band for communication at the same time, thereby improving spectrum utilization. At the same time, frequency band resources determine the communication capability and capacity of the system; for the time slot resources, in wireless communication systems, time resources are divided into multiple time slots, each time slot can be used One user communicates, and through time multiplexing technology, multiple users can communicate on the same frequency band, thereby making better use of time resources, and the time slot resources determine the user's access capability and communication capability in the system; for the code domain resources, the system allocates different spread spectrum codes to different users, so that multiple users can communicate in the same frequency band and at the same time without interfering with each other. These spread spectrum codes constitute the basis of code domain resources, and the code domain resources play a key role in wireless communication systems, which allow communication systems to support more users to communicate in the same frequency band and time, thereby improving the capacity and flexibility of communication systems.

[0032] The wireless resource subset refers to a wireless resource set constructed by acquiring a number of available wireless resources, and then obtained by dividing the wireless resource set. In various embodiments of wireless communication of the Internet of Things (IoT), the allocation and division of wireless resources adopt flexible and diverse strategies to adapt to different application scenarios. Among them, the division of frequency band resources is particularly important, which can be optimized according to the communication characteristics of IoT devices. For example, in the Internet of Things, narrower frequency band resource division is usually adopted, which is not only suitable for the low data rate requirements of the device, but also helps to reduce the power consumption of the device and extend the battery life. The division of time resources can also be adjusted according to the specific needs of IoT applications, such as by setting different communication time windows to reduce conflicts and delays and ensure effective data transmission.

[0033] In this embodiment, a general wireless resource set division method for available wireless resources is provided, and the specific steps include:

[0034] S101. Acquire a number of available wireless resources to construct a wireless resource set, and divide the wireless resource set into a number of wireless resource subsets:

[0035]

[0036] , where C is the set of indices of all wireless resource subsets, and is also the number of divisions of the wireless resource subsets, c and c' are indexes used to identify wireless resource subsets, is a wireless resource set, For the A subset of wireless resources, For the A subset of wireless resources, is the union of all the wireless resource subsets, and c,c′∈C,c≠c′.

[0037] The wireless resource set is divided into at least one wireless resource subset, the number of the wireless resource subsets is equal to the number of the target cell subsets, and each of the wireless resource subsets includes at least one wireless resource.

[0038] In one embodiment, in the step of dividing the wireless resource set to obtain a plurality of wireless resource subsets, the divided wireless resource subsets do not intersect with each other, and the sum of the wireless resource subsets is equal to the wireless resource set.

[0039] The target cell refers to the geographical area covered by a base station or a cell site. The target cell is the smallest service area unit in a wireless network, which is used to provide wireless signal coverage and communication services. In one embodiment, the base station is located at or near the center of the target cell, responsible for sending and receiving wireless signals, and communicating with mobile devices (such as mobile phones, tablet computers, etc.). The cell site includes base stations, antennas, feeders and other infrastructure to provide wireless signal coverage. The target cell subset refers to a target cell set constructed by acquiring several target cells, and then obtained by dividing the target cell set. In some embodiments, there are many ways to divide the target cell set, which can be divided according to common knowledge in the field, or divided by obtaining geographical data through field research.

[0040] In this embodiment, a general target cell set division method for target cells is provided, and the specific steps include: S102, acquiring a plurality of target cells to construct a target cell set, and dividing the target cell set into a plurality of target cell subsets:

[0041]

[0042] , where C is the set of indices of all target cell subsets, that is, the number of divisions of the target cell subsets, c and c' are indices used to identify the target cell subsets, is the target cell set, For the A subset of target cells, For the A subset of target cells, is the union of all the target cell subsets, and c,c′∈C,c≠c′.

[0043] The target cell set is divided into at least one target cell subset; the number of the target cell subsets is equal to the number of the wireless resource subsets, and each target cell subset includes at least one target cell.

[0044] In one embodiment, in the step of dividing the cell set to obtain a plurality of cell subsets, the divided cell subsets are mutually disjoint, and the sum of the cell subsets is equal to the cell set.

[0045] The allocation refers to assigning wireless resources to the corresponding target cell to achieve communication, and there are multiple specific allocation methods; the wireless resource allocation scheme refers to an allocation scheme formed by allocating a number of wireless resources in the corresponding allocated wireless resource subset to all target cells in the target cell subset. This embodiment provides a random allocation scheme to form a corresponding wireless resource allocation scheme, and the specific steps are as follows:

[0046] S103: Allocate each of the wireless resource subsets to each of the target cell subsets one by one, and randomly allocate each wireless resource in the wireless resource subset to all target cells in the corresponding target cell subset for reuse, to obtain a plurality of wireless resource allocation schemes.

[0047] Wherein, in the step of randomly allocating each wireless resource in the wireless resource subset to all target cells in the corresponding target cell subset for reuse, the random allocation is allocation or non-allocation;

[0048] In one embodiment, after each of the wireless resource subsets is allocated one-to-one to each of the target cell subsets, multiple wireless resource allocation schemes are obtained by randomly allocating or not allocating the wireless resources in the wireless resource subsets to the corresponding target cell subsets, wherein there are at least two wireless resource allocation schemes for the same wireless resource (including allocating the wireless resource to the corresponding target cell subset for use and not allocating the wireless resource to the corresponding target cell subset for use).

[0049] In this embodiment, the frequency reuse factor of the wireless resource allocation scheme is set to the number of divisions of the target cell subset. Examples of commonly used frequency reuse factors are: the frequency reuse factor of the first generation mobile communication AMPS is 9-11 and the frequency reuse factor of the second generation mobile communication GSM is 4-7.

[0050] In one embodiment, the wireless resource allocation scheme in step S103 is:

[0051]

[0052] , where X is a two-dimensional wireless resource allocation matrix representing the allocation relationship between the target cell and the wireless resources, x c,f is a binary variable, x c,f =1 means that the wireless resource f in the corresponding wireless resource subset is allocated to all target cells in the target cell subset for reuse, x c,f =0 means that the wireless resource f in the corresponding wireless resource subset is not allocated to all target cells in the target cell subset for reuse, c is an index for identifying the target cell subset, and C is a set of indexes of all target cell subsets. is a set of wireless resources and meets the wireless resource allocation constraints:

[0053]

[0054] ,in, is the number of wireless resources in the wireless resource subset, is the wireless resource subset.

[0055] For step S20, calculate the total inter-cell interference caused by the Internet of Things devices in other target cells in the same target cell subset on the allocated wireless resources for the Internet of Things devices in each target cell in each of the wireless resource allocation schemes.

[0056] Among them, the total inter-cell interference describes the phenomenon that in a wireless communication network, signals between adjacent cells interfere with each other due to the use of the same frequency resources between different cells. The wireless resources include frequency band resources of unlicensed frequency bands; the unlicensed frequency band refers to a frequency band in the radio spectrum that is not authorized to any specific user or service. In this embodiment, the unlicensed frequency band does not need to obtain a specific spectrum license, but may be interfered with by other wireless signals or technologies. Commonly used unlicensed frequency bands include unlicensed frequency bands at 902MHz-928MHz and 2.4GHz-2.5GHz for industrial, scientific and medical purposes; the wireless resource refers to the frequency range occupied by the signal or the maximum frequency width of the channel that can effectively transmit the signal. The wireless resource is an important parameter in the communication field that describes the signal frequency width and channel transmission capacity, and is associated with the transmission quality and rate of the signal. In one embodiment, the wireless resource refers to each available frequency band in the available unlicensed frequency band.

[0057] In one embodiment, since different cells use the same frequency band resources, when users in these cells send or receive signals at the same time, co-channel interference will occur. This interference will cause signal quality to degrade and affect the reliability and stability of communications.

[0058] Please refer to Figure 7 and Fig. 9When implementing the method of the present invention, it is necessary to consider the active states of the IoT devices and the interfering devices. Thus, in one embodiment, the active state of the IoT device k (interfering device n) in a coherent block is represented as a k ∈{0,1} Among them, if active, a k =1 Otherwise a k =0 And define it as:

[0059]

[0060] Among them, a and is a Bernoulli random vector following an arbitrary multivariate Bernoulli distribution.

[0061] In one embodiment, the indicator variable for the IoT device k to select the wireless resource f is represented as s k,f ∈{0,1}, where s k,f =1 means that the IoT device k selects the wireless resource f, otherwise s k,f =0, and is defined as:

[0062]

[0063] Please refer to Figure 6 and Figure 8 When implementing the method of the present invention, it is necessary to consider the number of IoT devices and interfering devices. Therefore, in one embodiment, the large-scale fading power between the target cell b and the IoT device k and (interfering device n) on the wireless resource f is expressed as g b,k,f The small-scale fading power between the target cell b and the IoT device k (interference device n) on the wireless resource f within a coherent block is expressed as h b,k,f And define it as:

[0064]

[0065]

[0066] Among them, (h b,k,f )and is a random variable following an arbitrary distribution.

[0067] In one embodiment, when the wireless resource is a frequency band resource of an unlicensed frequency band, step S20 provides a specific calculation scheme for the value of inter-cell interference, and the specific steps are as follows:

[0068] S201. According to the inter-cell interference calculation formula, calculate the total inter-cell interference caused by the Internet of Things devices of each target cell in each of the wireless resource allocation schemes and the Internet of Things devices of other target cells in the same target cell subset on the allocated wireless resources:

[0069]

[0070] , where I b,k,f (a c ,h c,f ,s c,f ) is the total inter-cell interference, a c is the active state of the IoT device in the target cell in a coherent block and ∈ {0,1}, h c,f is the small-scale fading power of the IoT device in the target cell on the wireless resource f in a coherent block, s c,f The indicator variable for selecting the wireless resource f for the IoT device in the target cell is ∈{0,1}, b is the bth target cell, b′ is the b′th other target cell, For the target cell subsets, k′ is the IoT device of the k′th other target cell, is the set of IoT devices in the b′th other target cell, a k′ is the active state of the IoT device in the k′th other target cell, P k′ g b,k′,f h b,k′,f is the signal power of the IoT device of the k′th other target cell received on the wireless resource f of the target cell b, P k′ is the theoretical signal power of the IoT device in the k′th other target cell, g b,k′,f is its large-scale fading power, h b,k′,f Its small-scale fading power, s k′,f The indicator variable for selecting the wireless resource f for the IoT device in the k′th other target cell.

[0071] In which, the coherent block refers to a preset time-frequency resource block. In one embodiment, the coherent block is a resource block defined in time and frequency, in which the channel response is statistically considered to be correlated or "coherent". At the same time, it is defined by a coherent time interval and a coherent bandwidth, indicating that within this time and bandwidth, the channel characteristics can be considered to be constant or slowly changing, that is, approximately unchanged; the large-scale fading refers to the average signal power change of the signal over a long distance (hundreds of meters to tens of kilometers), and the small-scale fading refers to the rapid change of the signal over a short distance (several meters to tens of meters). In one embodiment, large-scale fading and small-scale fading need to be considered and compensated when modeling wireless channels to ensure the reliability and effectiveness of communications.

[0072] For step S30, the total interference caused by the interfering devices of the target cells in each target cell subset in each of the wireless resource allocation schemes to the Internet of Things devices of the target cells on the allocated wireless resources is calculated.

[0073] Among them, the interference device refers to a device that will send out signals to interfere with other devices. In this embodiment, the interference device is a device that generates signal interference to the Internet of Things devices in the target cell. Common interference devices include radio, television, high-frequency welding machine, and servo motor.

[0074] In one embodiment, when transmitting signals, equipment such as radio and television may generate functional interference of fundamental wave signals, as well as non-functional useless signal interference composed of harmonics and spurious emissions; the powerful output power of equipment such as high-frequency welding machines may interfere with IoT devices through space radiation or industrial frequency power grids; the sudden change in current and the accompanying electric sparks generated by equipment such as servo motors during the on and off process become a signal interference source, causing interference to IoT devices.

[0075] In one embodiment, when the wireless resource is a frequency band resource of an unlicensed frequency band, step S30 provides a specific calculation scheme for the total interference value, and the specific steps are as follows:

[0076] S301. Calculate the total interference caused by the interference devices in the target cells in each target cell subset of each wireless resource allocation scheme to the IoT devices in the target cells on the allocated wireless resources according to the interference calculation formula of the interference devices:

[0077]

[0078] ,in, is the total interference, is the active state of the interfering device in the target cell and ∈{0,1}, is the small-scale fading power of the interference device of the target cell on the wireless resource f in a coherent block, n is the nth interference device, is the number of interfering devices, b is the bth target cell, is the active state of the interfering device in the nth target cell, is the signal power of the interference device of the nth target cell received on the wireless resource f of the target cell b, is the theoretical signal power of the interfering device in the nth target cell, is its large-scale fading power, is its large-scale fading power, is the target cell set, and when When , the interfering device n does not use the wireless resource f.

[0079] For step S40, based on the total inter-cell interference and the total interference, the optimal wireless resource allocation scheme for each of the target cell subsets is determined, and a multi-cell Internet of Things system is built based on the optimal wireless resource allocation scheme.

[0080] In the method described in the present invention, the step S40 can determine the corresponding optimal wireless resource allocation scheme by calculating the average total achievable rate corresponding to each of the wireless resource allocation schemes, or the average signal-to-noise ratio corresponding to each of the wireless resource allocation schemes, and specifically includes the following steps:

[0081] S4001. Calculate, according to the total inter-cell interference and the total interference, the achievable rate of the Internet of Things device of each target cell in each of the wireless resource allocation schemes on the wireless resources allocated to the corresponding target cell, and obtain the average total achievable rate corresponding to each of the wireless resource allocation schemes;

[0082] S4002, obtaining a wireless resource allocation scheme corresponding to the maximum average total achievable rate as an optimal wireless resource allocation scheme;

[0083] or,

[0084] S4011. According to the total inter-cell interference and the total interference, combined with the signal power of the Internet of Things device of the target cell in each of the wireless resource allocation schemes, obtain the average signal-to-noise ratio of each target cell corresponding to each of the wireless resource allocation schemes;

[0085] S4012: Acquire a wireless resource allocation scheme corresponding to the highest average signal-to-noise ratio as an optimal wireless resource allocation scheme.

[0086] In one embodiment, in step S40, the optimal wireless resource allocation scheme can be obtained by applying steps S4011-S4012, and its working principle is: by measuring the signal-to-noise ratio of the signal received by the signal receiving end of the Internet of Things device of the target cell in each of the wireless resource allocation schemes, the corresponding signal-to-noise ratio value is obtained; according to a preset signal-to-noise ratio threshold and resource allocation strategy (such as commonly used weight allocation and proportional allocation, etc.), the amount of resources to be allocated to each corresponding channel is determined to form a number of allocation schemes; finally, the performance of the allocation scheme is evaluated and verified, and the wireless resource allocation scheme corresponding to the highest average signal-to-noise ratio is obtained as the optimal wireless resource allocation scheme.

[0087] In one embodiment, in step S40, the achievable rate of the Internet of Things devices in the target cell of each of the wireless resource allocation schemes on the wireless resources allocated in the target cell can be calculated by steps S4001-S4002, and the average total achievable rate corresponding to each of the wireless resource allocation schemes can be obtained to determine the most appropriate wireless resource allocation scheme to execute.

[0088] In one embodiment, when the wireless resource is a frequency band resource of an unlicensed frequency band, the step S4001 specifically includes the following steps:

[0089] S401. Calculate the achievable rate of the IoT device in each target cell in each of the wireless resource allocation schemes on the wireless resources allocated to the corresponding target cell according to the achievable rate calculation formula of the IoT device:

[0090]

[0091] ,in, is the achievable rate of the IoT devices in each target cell of the wireless resource allocation scheme on each wireless resource, is the achievable rate of the IoT devices in each target cell of the wireless resource allocation scheme on the wireless resources allocated to the corresponding target cell, σ 2 is the preset noise power,

[0092] is a random variable following an arbitrary distribution.

[0093] Among them, the achievable rate refers to when multiple independent information are transmitted at a certain rate through encoding in a communication network, if the bit error rate can be kept arbitrarily small, then these rates are called achievable rates, and the closed set of the achievable rates constitutes the capacity of the channel; the achievable rate describes the rate at which information can be reliably transmitted in a communication system.

[0094] In one embodiment, the achievable rate can be expressed by the following formula:

[0095] C=B*log2(1+S / N)

[0096] , where C is the theoretical upper limit of the transmission rate (in bits per second), B is the bandwidth (in Hertz), S is the signal power, and N is the noise power.

[0097] S402: Perform equivalent conversion of expressions for the reachable rates of the Internet of Things devices of each target cell of the wireless resource allocation scheme on the wireless resources allocated by the corresponding target cell, and obtain a first expression for the reachable rates of the Internet of Things devices of each target cell of the wireless resource allocation scheme on the wireless resources allocated by the corresponding target cell:

[0098]

[0099] S403. Calculate the average total achievable rate corresponding to each of the wireless resource allocation schemes according to the total average achievable rate calculation formula and in combination with the first expression:

[0100]

[0101] , where r(X) is the total average achievable rate, w c,f To allocate the wireless resource f to the target cell that reuses the same frequency The value of, and

[0102]

[0103] Among them, the average total achievable rate refers to the average transmission rate that all users or data flows in the network can simultaneously achieve in a specific network environment, taking into account all possible interference, noise and channel conditions; the average total achievable rate describes the average transmission rate that all users or data flows in the network can achieve under given conditions.

[0104] In one embodiment, after the achievable rate is known, the calculation formula of the average total achievable rate can be obtained through theoretical deduction and simulation experiments.

[0105] In one embodiment, w c,f It can be interpreted as allocating wireless resources f to cells that reuse the same frequency The profit if a c , h c,f , s c,f The distribution of is unknown, and we can collect samples of multi-cell IoT systems and use the stepwise approximation method to calculate wc,f .

[0106] For step 4002, the wireless resource allocation scheme corresponding to when the average total achievable rate is the maximum is obtained as the optimal wireless resource allocation scheme.

[0107] In one embodiment, since maximizing the average total achievable rate and then directly obtaining the corresponding wireless resource allocation scheme belongs to an integer linear programming problem, which belongs to the category of generalized allocation problems in NP-hard problems and is difficult to solve directly, it is equivalently converted into a linear programming problem. According to its strong duality, by constructing a Lagrangian dual function and performing partial dual decomposition, the complexity of the solution is reduced and a more efficient solution is performed.

[0108] In other alternative implementations, the simplex method or the interior point method can also be used, with the computational complexity of each iteration being Under the premise of , solving the problem in polynomial time to obtain the wireless resource allocation scheme corresponding to the maximum average total achievable rate, and at the same time, continue to implement the remaining steps of the method described in the present invention.

[0109] Please refer to Figure 2 , Figure 2 A flowchart of the steps of obtaining the wireless resource allocation scheme corresponding to the maximum average total achievable rate of the multi-cell Internet of Things system construction method provided by the present invention. In one embodiment, when the wireless resource is a frequency band resource of an unlicensed frequency band, the step S4002 specifically includes the following steps:

[0110] S40021. According to the wireless resource allocation constraint condition and the value w c,f , the wireless resource allocation constraint condition is set to the form of weighted sum, and the corresponding Lagrangian function is constructed:

[0111]

[0112] , where the weight For The associated Lagrange multipliers, weights For The associated Lagrange multiplier, and

[0113] S40022. According to the Lagrangian function, obtain a dual function:

[0114]

[0115] , where inf is the infimum in mathematical operations;

[0116] S40023. Decompose the dual function into a main problem and sub-problems coordinated with the main problem, wherein the sub-problems are:

[0117] For all λ 1,f ,λ 2,c ≥0,

[0118]

[0119] x c,f ∈[0,1];

[0120] The main problem is:

[0121]

[0122] λ 2,c ≥0,c∈C;

[0123] S40024. Solve the sub-problem and obtain the corresponding optimal solution for:

[0124] If -w c,f +λ 1,f +λ 2,c ≠0,

[0125]

[0126] If -w c,f +λ 1,f +λ 2,c =0,

[0127] Can be any value in the interval [0,1];

[0128] In one embodiment, since if -w c,f +λ 1,f +λ 2,c >0, then the objective function of the subproblem is about x c,f is monotonically increasing, so is the optimal solution to the subproblem; similarly, if -w c,f +λ 1,f +λ 2,c <0, then is the optimal solution; if -w c,f +λ 1,f +λ 2,c =0, then the objective function of the subproblem is a constant, therefore, It can be any point in [0,1].

[0129] S40025. Combine the optimal solutions of the sub-problems and transform the main problem into a first equivalent problem:

[0130]

[0131] λ 2,c ≥0,c∈C;

[0132] S40026. Solve the first equivalent problem, and obtain the wireless resource allocation scheme corresponding to the maximum average total achievable rate as the optimal wireless resource allocation scheme.

[0133] Also, please refer to Figure 3 , Figure 3 The present invention provides a flowchart of the steps of solving the first equivalent problem of the method for building a multi-cell Internet of Things system. The method of the present invention also provides some other steps to solve the first equivalent problem by example to obtain the wireless resource allocation scheme corresponding to the maximum average total achievable rate. However, it should be stated that this cannot be used as one of the limiting parts of the method. In other alternative implementations, other method steps can also be used to solve the first equivalent problem to continue to implement the remaining steps of the method of the present invention. The steps specifically include the following steps:

[0134] S40026a. Perform a secondary equivalent transformation on the first equivalent problem to obtain a second equivalent problem:

[0135]

[0136] λ 2,c ≥0,c∈C;

[0137] S40026b, obtaining the dual function about and λ 2,c , the subgradient of c∈C:

[0138]

[0139] in, is g(λ1,λ2) with respect to The sub-gradient of is g(λ1,λ2) with respect to λ 2,c , the subgradient of c∈C;

[0140] S40026c, according to the second equivalent problem, and the second equivalent problem is a convex problem with a non-smooth objective function, using the projected subgradient method, in i iterations, parallelly calculate the optimal solutions of all the subproblems Among them, i is the number;

[0141] S40026d. Update the Lagrange multipliers λ1 and λ2 according to the multiplier update formula:

[0142]

[0143] ,in, And the step length α (i) satisfy:

[0144] and

[0145] S40026e, judging whether the changes of the Lagrange multipliers λ1 and λ2 in two consecutive iterations are less than a preset threshold ∈:

[0146]

[0147] If yes, end the iteration;

[0148] S40026f, output the final Lagrange multiplier and And the corresponding wireless resource allocation scheme when the average total achievable rate is the maximum For the optimal wireless resource allocation solution:

[0149]

[0150] ,in, is the optimal solution to all the sub-problems.

[0151] Please refer to Figure 5 , Figure 5 A schematic diagram of a multi-cell Internet of Things system provided by the present invention. In one embodiment, by implementing the wireless resource allocation scheme corresponding to the maximum average total achievable rate Complete the construction of a multi-cell Internet of Things system, where B=7, K=27, N=28, C=3, and F=12.

[0152] In one embodiment, by executing steps S40021-S40026f, the wireless resource allocation scheme corresponding to the maximum average total achievable rate is obtained. The computational complexity of each iteration is The complexity of solving the linear programming problem is effectively reduced.

[0153] Also, please refer to Figure 4 , Figure 4The method for building a multi-cell Internet of Things system provided by the present invention is a flowchart of the steps of constructing a feasible solution for a wireless resource allocation scheme that is an infeasible solution. The method provided by the present invention also provides some other steps for constructing a feasible solution for a wireless resource allocation scheme that is an infeasible solution. In this embodiment, due to some cases, w c,f May be equal to You can arbitrarily choose whether to allocate wireless resource f to the target cell subset All target cells in the multiplexing are reused, so the corresponding wireless resource allocation scheme is determined It is an infeasible solution, and the steps specifically include the following steps:

[0154] S50, judge w c,f Is it equal to If yes, determine the wireless resource allocation scheme As an infeasible solution, a greedy method is used to allocate the wireless resources Construct a feasible solution, including:

[0155] S501: Extract the wireless resource allocation scheme All the ones that do not meet the wireless resource allocation constraints The index (c,f) of

[0156]

[0157] ,in, The target cell b is allocated with radio resource f. For no allocation, f ′ To collect wireless resources A temporary variable for iterating over all wireless resources in the calculation of the total allocation, c ′ is a temporary variable for iterating all target cells in the target cell set, used to check whether the wireless resource f is allocated multiple times;

[0158] S502: traverse the index set Select a minimum w c,f (c,f), set to

[0159] S503, according to Cancel the corresponding wireless resource allocation and modify it. The corresponding Set to 0;

[0160] S504, the From the index collection Removed;

[0161] S505: Check whether the wireless resource allocation scheme meets the capacity constraint preset in the wireless resource allocation constraint condition, and update the iteration index set.

[0162]

[0163] S506: Check whether the wireless resource allocation scheme meets the allocation constraints preset in the wireless resource allocation constraint condition, and update the iteration index set.

[0164]

[0165] S507: Determine index set Is it an empty set? If so, output the corrected As a feasible solution, if not, loop to execute the construction of feasible solutions.

[0166] In one embodiment, a feasible solution is constructed for a wireless resource allocation scheme that is an infeasible solution by executing steps S501-S507, wherein the computational complexity involved is Consistent with the above steps, it does not affect the computational complexity of the method described in the present invention, and maintains efficient solution performance.

[0167] In one embodiment, the construction of feasible solutions may also be performed by applying random radio resource allocation.

[0168] Example 2

[0169] The present invention also provides a multi-cell Internet of Things system construction system to implement the steps of the multi-cell Internet of Things system construction method described in the above embodiment. The multi-cell Internet of Things system construction system includes: a wireless resource allocation scheme generation unit, a total inter-cell interference calculation unit, a total interference calculation unit, and an optimal wireless resource allocation scheme determination unit;

[0170] The wireless resource allocation scheme generating unit is used to allocate several available wireless resource subsets to several target cell subsets in a one-to-one correspondence, and randomly allocate each wireless resource contained in the wireless resource subset to the target cell in the corresponding target cell subset for reuse, so as to obtain several wireless resource allocation schemes, wherein the number of the wireless resource subsets is equal to the number of the target cell subsets, each of the target cell subsets includes at least one target cell, and each of the wireless resource subsets includes at least one available wireless resource;

[0171] The total inter-cell interference calculation unit is used to calculate the total inter-cell interference caused by the Internet of Things devices of each target cell in each of the wireless resource allocation schemes on the allocated wireless resources by the Internet of Things devices of other target cells in the same target cell subset;

[0172] The total interference calculation unit is used to calculate the total interference caused by the interference devices of the target cells in each target cell subset in each of the wireless resource allocation schemes to the Internet of Things devices of the target cells on the allocated wireless resources;

[0173] The optimal wireless resource allocation scheme determination unit is used to determine the optimal wireless resource allocation scheme for each of the target cell subsets according to the total inter-cell interference and the total interference, and to build a multi-cell Internet of Things system according to the optimal wireless resource allocation scheme.

[0174] It should be noted that the multi-cell Internet of Things system construction system provided in the above embodiment only uses the division of the above-mentioned functional modules as an example when implementing a multi-cell Internet of Things system construction method. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the device is divided into different functional modules to complete all or part of the functions described above.

[0175] In addition, the multi-cell Internet of Things system construction system provided in the above embodiment and the multi-cell Internet of Things system construction method of Example 1 belong to the same concept, and the implementation process thereof is detailed in the method embodiment, i.e., Example 1, and will not be repeated here.

[0176] Compared with the prior art, the method described in the present invention proposes a more efficient and low-cost construction method for a broadband multi-cell Internet of Things system operating on an unlicensed frequency band under frequency reuse conditions, while also reducing interference between cells within the Internet of Things system and interference from other systems, having superior performance and significant practical value.

[0177] The above-mentioned embodiments only express several implementation methods of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, and the present invention is also intended to include these modifications and modifications.

Claims

1. A method for building a multi-cell Internet of Things system, comprising the following steps: Allocating a number of available wireless resource subsets to a number of target cell subsets in a one-to-one correspondence, and randomly allocating each wireless resource contained in the wireless resource subset to a target cell in the corresponding target cell subset for reuse, to obtain a number of wireless resource allocation schemes, wherein the number of the wireless resource subsets is equal to the number of the target cell subsets, each of the target cell subsets includes at least one target cell, and each of the wireless resource subsets includes at least one available wireless resource; Calculate the total inter-cell interference caused by the Internet of Things devices of each target cell in each of the wireless resource allocation schemes and the Internet of Things devices of other target cells in the same target cell subset on the allocated wireless resources; Calculate the total interference caused by the interfering devices of the target cells in each target cell subset in each of the wireless resource allocation schemes to the Internet of Things devices of the target cells on the allocated wireless resources; According to the total inter-cell interference and the total interference, the optimal wireless resource allocation scheme for each of the target cell subsets is determined, and a multi-cell Internet of Things system is built according to the optimal wireless resource allocation scheme.

2. The method for building a multi-cell Internet of Things system according to claim 1, characterized in that: The step of determining the optimal radio resource allocation scheme for each of the target cell subsets according to the total inter-cell interference and the total interference comprises: According to the total inter-cell interference and the total interference, calculate the achievable rate of the Internet of Things device of each target cell in each of the wireless resource allocation schemes on the wireless resources allocated by the corresponding target cell, and obtain the average total achievable rate corresponding to each of the wireless resource allocation schemes; Acquire the wireless resource allocation scheme corresponding to the maximum average total achievable rate as the optimal wireless resource allocation scheme; or, According to the total inter-cell interference and the total interference, combined with the signal power of the Internet of Things device of the target cell in each of the wireless resource allocation schemes, an average signal-to-noise ratio of each target cell corresponding to each of the wireless resource allocation schemes is obtained; The wireless resource allocation scheme corresponding to the time when the average signal-to-noise ratio is the highest is obtained as the optimal wireless resource allocation scheme.

3. The method for building a multi-cell Internet of Things system according to claim 2, characterized in that: The steps of allocating a plurality of available wireless resource subsets to a plurality of target cell subsets in a one-to-one correspondence, and randomly allocating each wireless resource contained in the wireless resource subset to a corresponding target cell in the target cell subset for reuse, to obtain a plurality of wireless resource allocation schemes include: Acquire a plurality of target cells to construct a target cell set, and divide the target cell set into a plurality of target cell subsets, wherein each of the target cell subsets includes at least one target cell, the divided target cell subsets are mutually disjoint, and the sum of the target cell subsets is equal to the target cell set; Acquire a number of available wireless resources to construct a wireless resource set, and divide the wireless resource set into a number of wireless resource subsets, wherein each of the wireless resource subsets includes at least one of the wireless resources, the divided wireless resource subsets do not intersect with each other, and the sum of the wireless resource subsets is equal to the wireless resource set; Allocate each of the wireless resource subsets to each of the target cell subsets one by one, and randomly allocate each wireless resource in the wireless resource subset to all target cells in the corresponding target cell subset for reuse, thereby obtaining a plurality of wireless resource allocation schemes.

4. The method for building a multi-cell Internet of Things system according to claim 3, characterized in that: The wireless resource allocation scheme is: ， Where X is a two-dimensional wireless resource allocation matrix representing the allocation relationship between the target cell and the wireless resources, x c，f is a binary variable, x c，f =1 means that the wireless resource f in the corresponding wireless resource subset is allocated to all target cells in the target cell subset for reuse, x c，f =0 means that the wireless resource f in the corresponding wireless resource subset is not allocated to all target cells in the target cell subset for reuse, c is an index for identifying the target cell subset, and C is a set of indexes of all target cell subsets. is a set of wireless resources and meets the wireless resource allocation constraints: ， in, is the number of radio resources in the radio resource subset, is the wireless resource subset.

5. The method for building a multi-cell Internet of Things system according to any one of claims 1 to 4, characterized in that: The wireless resources include frequency band resources or code domain resources in an unlicensed frequency band.

6. The method for building a multi-cell Internet of Things system according to any one of claims 1 to 4, characterized in that: The wireless resource is a frequency band resource of an unlicensed frequency band, The step of calculating the total inter-cell interference caused by the IoT devices of each target cell in each of the wireless resource allocation schemes and the IoT devices of other target cells in the same target cell subset on the allocated wireless resources comprises: According to the inter-cell interference calculation formula, the total inter-cell interference caused by the IoT devices of each target cell in each of the wireless resource allocation schemes on the allocated wireless resources by the IoT devices of other target cells in the same target cell subset is calculated: ， Among them, I b，k，f (a c ,h c，f ,s c，f ) is the total inter-cell interference, a c is the active state of the IoT device in the target cell in a coherent block and ∈ {0, 1}, h c，f is the small-scale fading power of the IoT device in the target cell on the wireless resource f in a coherent block, s c，f The indicator variable for selecting the wireless resource f for the IoT device of the target cell is ∈{0,1}, b is the bth target cell, b′ is the b′th other target cell, For the target cell subsets, k′ is the IoT device of the k′th other target cell, is the set of IoT devices in the b′th other target cell, a k′ is the active state of the IoT device in the k′th other target cell, P k′ g b，k′ , f hb，k′，f is the signal power of the IoT device of the k′th other target cell received on the wireless resource f of the target cell b, P k′ is the theoretical signal power of the IoT device in the k′th other target cell, g b，k′，f is its large-scale fading power, h b，k′，f Its small-scale fading power, s k′，f The indicator variable for selecting the wireless resource f for the IoT device in the k′th other target cell.

7. The method for building a multi-cell Internet of Things system according to claim 6, characterized in that: The step of calculating the total interference caused by the interfering devices of the target cells in each target cell subset in each of the wireless resource allocation schemes to the Internet of Things devices of the target cells on the allocated wireless resources comprises: According to the interference calculation formula of the interference device, the total interference caused by the interference device of the target cell in each target cell subset in each of the wireless resource allocation schemes to the IoT device of the target cell on the allocated wireless resources is calculated: ， in, is the total interference, is the active state of the interfering device in the target cell and is ∈{0, 1}, is the small-scale fading power of the interfering device of the target cell on the wireless resource f in a coherent block, n is the nth interfering device, N is the number of interfering devices, b is the bth target cell, is the active state of the interfering device in the nth target cell, is the signal power of the interference device of the nth target cell received on the wireless resource f of the target cell b, is the theoretical signal power of the interfering device in the nth target cell, is its large-scale fading power, is its large-scale fading power, is the target cell set, and when When , the interfering device n does not use the wireless resource f.

8. The method for building a multi-cell Internet of Things system according to claim 7, characterized in that: According to the total inter-cell interference and the total interference, calculating the achievable rate of the Internet of Things device of each target cell in each of the wireless resource allocation schemes on the wireless resources allocated to the corresponding target cell, and obtaining the average total achievable rate corresponding to each of the wireless resource allocation schemes includes: According to the calculation formula of the reachable rate of the IoT device, the reachable rate of the IoT device of each target cell in each of the wireless resource allocation schemes on the wireless resources allocated by the corresponding target cell is calculated: ， in, is the achievable rate of the IoT devices in each target cell of the wireless resource allocation scheme on each wireless resource, is the achievable rate of the IoT devices in each target cell of the wireless resource allocation scheme on the wireless resources allocated to the corresponding target cell, σ 2 is the preset noise power; Perform equivalent conversion of expressions for the reachable rates of the Internet of Things devices of each target cell of the wireless resource allocation scheme on the wireless resources allocated by the corresponding target cell, and obtain a first expression for the reachable rates of the Internet of Things devices of each target cell of the wireless resource allocation scheme on the wireless resources allocated by the corresponding target cell: According to the total average achievable rate calculation formula, combined with the first expression, the average total achievable rate corresponding to each of the wireless resource allocation schemes is calculated: ， Where r(X) is the total average achievable rate, w c，f To allocate the wireless resource f to the target cell that reuses the same frequency The value of, and 9. The method for building a multi-cell Internet of Things system according to claim 8, characterized in that: The step of obtaining the wireless resource allocation scheme corresponding to the maximum average total achievable rate as the optimal wireless resource allocation scheme comprises: According to the wireless resource allocation constraint and the value, the wireless resource allocation constraint is set to a weighted sum form, and a corresponding Lagrangian function is constructed: ， Among them, the weight For The associated Lagrange multipliers, weights For The associated Lagrange multiplier, and According to the Lagrangian function, the dual function is obtained: ， Among them, inf is the infimum in mathematical operations; Decompose the dual function into a main problem and sub-problems coordinated with the main problem, wherein the sub-problems are: For all λ 1，f ,λ 2，c ≥0, x c，f ∈[0，1]； The main problem is: λ2, c ≥ 0, c ∈ C; Solve the subproblem and obtain the corresponding optimal solution for: If -w c，f +λ 1，f +λ 2，c ≠0, If -w c，f +λ 1，f +λ 2，c =0, Can be any value in the interval [0, 1]; Combined with the optimal solution of the sub-problem, the main problem is transformed into the first equivalent problem: l 2，c ≥0, c∈C; Solving the first equivalent problem and obtaining the wireless resource allocation scheme corresponding to the maximum average total achievable rate is the optimal wireless resource allocation scheme.

10. The method for building a multi-cell Internet of Things system according to claim 9, characterized in that: The step of solving the first equivalent problem and obtaining the wireless resource allocation scheme corresponding to the maximum average total achievable rate as the optimal wireless resource allocation scheme includes: Get the dual function about and λ 2，c , the subgradient of c∈C: ， in, is g(λ1,λ2) with respect to The sub-gradient of is g(λ1,λ2) with respect to λ 2，c , the subgradient of c∈C; Using the projected subgradient method, the optimal solutions of all the subproblems are calculated in parallel in i iterations. Among them, i is the number; According to the multiplier update formula, the Lagrange multipliers λ1 and λ2 are updated: ， in, And the step size α(i) satisfies: and Determine whether the changes of the Lagrange multipliers λ1 and λ2 in two consecutive iterations are less than a preset threshold ∈: If yes, end the iteration; Output the final Lagrange multiplier and And the corresponding wireless resource allocation scheme when the average total achievable rate is the maximum For the optimal wireless resource allocation solution: ， in, is the optimal solution to all the sub-problems.

11. The method for building a multi-cell Internet of Things system based on frequency reuse in an unlicensed frequency band according to claim 10, characterized in that: After the step of obtaining that the wireless resource allocation scheme corresponding to the maximum average total achievable rate is the optimal wireless resource allocation scheme, the following steps are also included: Judge w c，f Is it equal to If yes, determine the wireless resource allocation scheme As an infeasible solution, a greedy method is used to allocate the wireless resources Construct a feasible solution, including: Extract the wireless resource allocation scheme All the ones that do not meet the wireless resource allocation constraints The index (c, f) of ， in, The target cell b is allocated with radio resource f. is not allocated, f′ is the wireless resource set is a temporary variable for iterating all wireless resources in the target cell set, used to calculate the total allocation, and c′ is a temporary variable for iterating all target cells in the target cell set, used to check whether the wireless resource f is allocated multiple times; Traverse the index collection Select a minimum w c，f (c, f), set to According to the Cancel the corresponding wireless resource allocation and modify it. The corresponding Set to 0; The From the index collection Removed; Check whether the wireless resource allocation scheme meets the capacity constraint in the wireless resource allocation constraint condition, and update the iteration index set Check whether the wireless resource allocation scheme satisfies the allocation constraints in the wireless resource allocation constraint condition, and update the iteration index set Determine the index collection Is it an empty set? If so, output the corrected As a feasible solution, if not, loop to execute the construction of feasible solutions.

12. A multi-cell Internet of Things system construction system, characterized in that: include: A wireless resource allocation scheme generating unit is used to allocate a number of available wireless resource subsets to a number of target cell subsets in a one-to-one correspondence, and randomly allocate each wireless resource contained in the wireless resource subset to a target cell in the corresponding target cell subset for reuse, so as to obtain a number of wireless resource allocation schemes, wherein the number of the wireless resource subsets is equal to the number of the target cell subsets, each of the target cell subsets includes at least one target cell, and each of the wireless resource subsets includes at least one available wireless resource; A total inter-cell interference calculation unit, used to calculate the total inter-cell interference caused by the Internet of Things devices of each target cell in each of the wireless resource allocation schemes to the Internet of Things devices of other target cells in the same target cell subset on the allocated wireless resources; A total interference calculation unit, used to calculate the total interference caused by the interference devices of the target cells in each target cell subset in each of the wireless resource allocation schemes to the Internet of Things devices of the target cells on the allocated wireless resources; The optimal wireless resource allocation scheme determining unit is used to determine the optimal wireless resource allocation scheme for each of the target cell subsets according to the total inter-cell interference and the total interference, and to build a multi-cell Internet of Things system according to the optimal wireless resource allocation scheme.

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