CN108777857B - Access control method and system under coexistence scene of URLLC and mMTC - Google Patents

Abstract

The embodiment of the invention provides an access control method and system under a URLLC and mMTC coexistence scene, wherein the method comprises the following steps: and for each subcarrier on the bandwidth of the Internet of things system, simultaneously accessing a plurality of URLLC devices and a plurality of mMTC devices according to a preset power distribution algorithm based on an uplink non-orthogonal multiple access (NOMA) mechanism. According to the access control method under the coexistence scene of URLLC and mMTC, the NOMA technology is used, and the multiple URLLC devices and the multiple mMTC devices share the same subcarrier according to the preset power distribution rule, so that the Internet of things system can support higher connection density, and the spectrum efficiency is improved.

Description

A method and system for access control in the coexistence scenario of URLLC and mMTC

technical field

Embodiments of the present invention relate to the field of communication technologies, and in particular, to an access control method and system in a scenario where URLLC and mMTC coexist.

Background technique

Machine Communication (MTC) is an important part of the Internet of Things (IoT), enabling communication from MTC devices to a central MTC server or a group of MTC servers. MTC devices (MTCDs) have extremely broad application prospects, such as wireless detection and sensing equipment, wireless control systems for factory equipment, and intelligent transportation systems. The International Telecommunication Union (ITU) divides MTC into two categories: Massive MTC (mMTC) and Ultra-Reliable and Low-Latency Communications (URLLC). Among them, mMTC devices have high connection density, and each cell will coexist with a large number of low-cost and low-power MTCD devices, such as wireless sensor systems. These devices transmit small packets with lower latency requirements in sequences of seconds or less. mMTC devices need to communicate with high energy efficiency and have low requirements for latency and other aspects. While URLLC requires reliable data transmission with strict latency constraints of 10ms or less, as it is used in mission-critical applications such as medical IoT systems as well as transportation system IoT systems.

In NB-IoT, when the frequency division multiple access (FDMA) of the orthogonal multiple access (OMA) method is used to access a physical resource block (PRB), that is, a narrow bandwidth of 180 kHz, the system bandwidth can be divided into 48 or 12 subcarriers. In the case of 48 subcarriers, each MTCD may be allocated a single subcarrier. In the case of 12 subcarriers, each MTCD can be allocated a single subcarrier or 3, 6, 12 consecutive subcarriers. In the case of OFDMA, only one MTCD device is allowed to use each sub-carrier, so it may not be able to cope well with the scenario of a large number of MTCD devices requesting a link in the LTE-A Pro network. When the number of devices is large, many devices cannot upload data to the base station in time because subcarriers cannot be allocated, especially for devices such as URLLC, which require high rate and delay, this greatly affects the user experience.

Therefore, an access control method in the coexistence scenario of URLLC and mMTC is urgently needed to solve the above problems.

SUMMARY OF THE INVENTION

In order to solve the above problem, the embodiments of the present invention provide a configuration method and a terminal device for an uplink scheduling request that overcome the above problem or at least partially solve the above problem.

The first aspect of the present invention provides an access control method in a scenario where URLLC and mMTC coexist, including:

For each sub-carrier on the bandwidth of the IoT system, based on the uplink non-orthogonal multiple access NOMA mechanism, several URLLC devices and several mMTC devices are simultaneously connected according to the preset power allocation algorithm.

In the second aspect, the embodiment of the present invention also provides an access control system in a scenario where URLLC and mMTC coexist, including:

The access control module is used to simultaneously access several URLLC devices and several mMTC devices according to the preset power allocation algorithm based on the uplink non-orthogonal multiple access NOMA mechanism for each subcarrier on the bandwidth of the Internet of Things system.

A third aspect of the present invention provides an access control device in a scenario where URLLC and mMTC coexist, including:

a processor, a memory, a communication interface, and a bus; wherein, the processor, memory, and communication interface communicate with each other through the bus; the memory stores program instructions that can be executed by the processor, and the processing The access control method in the coexistence scenario of the URLLC and the mMTC can be executed by the device calling the program instruction.

Fourth aspect An embodiment of the present invention provides a non-transitory computer-readable storage medium, where the non-transitory computer-readable storage medium stores computer instructions, and the computer instructions cause the computer to execute the above method.

The access control method in the coexistence scenario of URLLC and mMTC provided by the embodiment of the present invention realizes that multiple URLLC devices and multiple mMTC devices share the same sub-carrier by using the NOMA technology and according to the preset power allocation rule, so that This enables IoT systems to support higher connection densities and improve spectral efficiency.

Description of drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description These are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained according to these drawings without creative efforts.

1 is a schematic flowchart of an access control method in a coexistence scenario of URLLC and mMTC provided by an embodiment of the present invention;

2 is a structural diagram of an access control system in a coexistence scenario of URLLC and mMTC provided by an embodiment of the present invention;

FIG. 3 is a structural block diagram of an access control device in a scenario where URLLC and mMTC coexist according to an embodiment of the present invention.

Detailed ways

In order to make the purposes, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly described below with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are the Some, but not all, embodiments are disclosed. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

At present, NB-IoT, the narrowband Internet of Things, can achieve energy-efficient communication in the narrow bandwidth of low-cost MTC devices (MTCDs) with a narrow bandwidth of 180kHz, but cannot provide connections for a large number of MTCDs, including URLLCs with high QOS requirements. mMTC devices with lower equipment and QOS requirements.

In order to realize the problem that users cannot access or wait for a long time in the case of a large number of users in the narrowband Internet of Things, FIG. 1 is a schematic flowchart of an access control method in a scenario where URLLC and mMTC coexist according to an embodiment of the present invention, As shown in Figure 1, it includes:

110. For each subcarrier on the bandwidth of the Internet of Things system, based on the uplink non-orthogonal multiple access NOMA mechanism, simultaneously access several URLLC devices and several mMTC devices according to a preset power allocation algorithm.

In step 110, it can be understood that the NOMA mechanism described in the embodiment of the present invention is the NOMA technology, and by using the NOMA technology in the NB-IoT system, the sharing of multiple MTCD devices can be realized for each subcarrier in each time slot, This is very helpful for scenarios with a large number of devices in IoT.

Further, if only a single URLLC device is allowed to share subcarriers with one mMTC device at most, the utilization of frequency band resources is extremely wasteful. In view of this problem, the embodiment of the present invention can allow multiple mMTC devices according to a preset power allocation algorithm. Share the same sub-carrier with multiple URLLC devices in the NB-IoT system, thereby supporting higher connection density and improving spectral efficiency.

The preset power allocation algorithm is determined in real time according to the information of the URLLC device to be accessed and the information of the mMTC device to be accessed in the embodiment of the present invention.

For ease of description, the embodiments of the present invention take the following scenarios as examples to describe the embodiments of the present invention.

其中，s_u,k和_sm,k分别代表使用第k个子载波发送信息的URLLC设备的集合和mMTC设备的集合，第k个子载波上URLLC设备和mMTC设备数量分别为_Nu,k和_Nm,k。X_u和X_m分别代表了URLLC设备和mMTC设备发送的消息，h_u,k和h_m,k分别代表URLLC设备和mMTC设备发射信号到基站过程中由于衰落和损耗造成的信道增益，σ为高斯白噪声，此时每个设备只能使用一个子载波，因此可以得出：The embodiment of the present invention assumes that the NB-IoT system includes n subcarriers, the subcarrier set is C, U={u ₁ , u ₂ , u ₃ , ... u _U } represents the URLLC device set under the current base station that requests to upload information, M ={m ₁ ,m ₂ ,m ₃ ,...m _M } represents the set of mMTC devices under the current base station that request to upload information. Further, it is assumed that the access priority of each URLLC device is the same, and the access priority of each mMTC device is the same, and the priority of the URLLC device is higher than that of the mMTC device. At the same time, assuming that the QOS requirements of each URLLC device are the same, and the QOS requirements of each mMTC device are also the same, and the channel state information CSI of each device is known, then on the kth subcarrier, multiple URLLC devices and multiple mMTC The scenario where devices upload information together can be expressed as:

Among them, s _u,k and _sm,k represent the set of URLLC devices and the set of mMTC devices that use the kth subcarrier to send information, respectively, and the number of URLLC devices and mMTC devices on the kth subcarrier are _Nu,k and _Nm,k respectively. . X _u and X _m represent the messages sent by the URLLC device and the mMTC device, respectively, hu _{, k} and h _{m, k} represent the channel gain due to fading and loss in the process of transmitting the signal from the URLLC device and the mMTC device to the base station, respectively, σ is Gaussian white noise, each device can only use one subcarrier at this time, so we can get:

Then for uplink NOMA, the SIC receiver needs different arrival powers to differentiate multiplexing UEs. In an ideal situation, the base station can distinguish each device according to the arrival power of the information sent by each device. Since URLLC has high requirements for SINR rate and other aspects, it is assumed that the arrival power of URLLC device sending information is greater than that of mMTC device, that is |h _{u, k} | ² p _u,k >|h _m,k | ² p _m,k . In the case of two URLLC devices, the arrival power of the signals transmitted by the URLLC devices is different. It is assumed that the signal strength of URLLC device 1 is greater than that of URLLC device 2, that is, |h _u1,k | ² p _u1,k >|h _{u2 ,k} | ² p _u2,k , since Device 1 suffers the most interference, let Device 1 transmit at maximum power to guarantee its SINR requirement. Then the SINRs of the signals of URLLC device 1 and device 2 received by the base station are:

表示后面解调的mMTC设备和后面解调的URLLC设备对URLLC设备的干扰。mMTC设备信号的SINR为：

其中，

表示后面解调的mMTC设备对前面第m个设备造成的干扰。where N ₀ is the noise power spectral density,

Indicates the interference of the later demodulated mMTC device and the later demodulated URLLC device to the URLLC device. The SINR of the mMTC device signal is:

in,

Indicates the interference caused by the later demodulated mMTC device to the mth device in front.

并且，各个设备也都有最大发射功率的约束限制，即

The rates required by the URLLC device and the mMTC device to meet the QOS conditions are R _U and R _m respectively, that is to say, the SINR requirements of the signals received by the base station from each device are:

Moreover, each device also has a constraint on the maximum transmit power, that is,

Based on the above description, the embodiment of the present invention can substantially access as many MTCD devices as possible while satisfying the respective QOS requirements, which can be expressed as:

Wherein, Wu and W _m are weighting factors set according to their access priorities. Since the access priority of the URLLC device _{is the highest, Wu u =} W _m +1.

The access control method in the coexistence scenario of URLLC and mMTC provided by the embodiment of the present invention realizes that multiple URLLC devices and multiple mMTC devices share the same sub-carrier by using the NOMA technology and according to the preset power allocation rule, so that This enables IoT systems to support higher connection densities and improve spectral efficiency.

On the basis of the above embodiment, for each subcarrier in the bandwidth of the Internet of Things system, based on the uplink non-orthogonal multiple access NOMA mechanism, according to the preset power allocation algorithm, several URLLC devices and several URLLC devices are simultaneously connected. Before the mMTC device, the method further includes:

Determine the maximum number of URLLC devices that can be accessed by each subcarrier on the IoT bandwidth.

It can be seen from the content of the above embodiment that the embodiment of the present invention needs to access as many MTCD devices as possible under the condition that the respective QOS requirements are met, and the priority of the URLLC device is higher than that of the mMTC device, so the embodiment of the present invention needs to be prioritized. Meet the maximum number of URLLC devices that can be accessed on the subcarrier.

It is understandable that the greater the degree of interference that URLLC devices can tolerate, the more opportunities for mMTC devices to access. Then the embodiment of the present invention essentially selects a device pair from the URLLC device set under each subcarrier to maximize I, which can be represented by the following formula:

The above formula takes whether one subcarrier can be connected to two URLLC devices as an example. It is assumed that the channel gains of device a and device b satisfy Ga>Gb, and the NOMA receiver can receive information from both devices at the same time. When the signal strength of the two devices is different, the demodulation sequence of the receiver is also different, and the maximum value of tolerable interference is also different, which can be expressed by the following formula:

成立，则上式中I有解，那么设备a和设备b可以共享同一个子载波。反之，若

不成立，则上式I无解，则该子载波只能让一个URLLC设备使用。Then, by solving the above equation, it can be calculated

If established, there is a solution for I in the above formula, then device a and device b can share the same subcarrier. Conversely, if

If it does not hold, the above formula I has no solution, and the subcarrier can only be used by one URLLC device.

On the basis of the above-mentioned embodiment, for each sub-carrier on the bandwidth of the Internet of Things system, based on the NOMA mechanism, according to the preset power allocation algorithm, several URLLC devices and several mMTC devices are simultaneously connected, including:

For each sub-carrier on the bandwidth of the Internet of Things system, based on the NOMA mechanism, select several target URLLC devices that meet the requirements of the first channel in the URLLC device set, and the number of the target URLLC devices is less than or equal to the current sub-carrier can access. Maximum number of URLLC devices;

Select several target mMTC devices that meet the requirements of the second channel in the mMTC device set;

According to the preset power allocation algorithm, the several target URLLC devices and the several target mMTC devices are simultaneously connected.

It can be understood that in this embodiment of the present invention, it is first necessary to determine the number of URLLC devices that access the subcarrier, and then determine the mMTC device that accesses the same subcarrier, and in the determination process, the URLLC device needs to meet the first channel requirement, and the mMTC device needs to Satisfy the second channel requirement. It should be noted that the first channel requirement is the determination rule for URLLC device access in the embodiment of the present invention, and similarly, the second channel requirement is the determination rule for mMTC device access in the embodiment of the present invention, which is not practical Requirements for the existence of a transport channel.

Further, when the target URLLC device to be accessed is determined, the embodiment of the present invention determines the transmit power of the target URLLC device, so as to perform data transmission according to the determined transmit power. Similarly, when the target mMTC device to be accessed is determined, the embodiment of the present invention determines the transmit power of the target mMTC device, so as to perform data transmission according to the determined transmit power.

On the basis of the foregoing embodiment, the selection of several target URLLC devices that meet the requirements of the first channel in the URLLC device set includes:

Sort the URLLC devices that have not yet been connected in the URLLC device set according to the channel gain from large to small to obtain the first sequence;

The first two URLLC devices included in the first sequence are divided into a group, and the URLLC device in the group that meets the requirements of the first channel is used as the target URLLC device.

It can be known from the content of the foregoing embodiment that in the embodiment of the present invention, for each subcarrier, it is calculated that the subcarrier can access two URLLC devices. It should be noted that it is a preferred way to access two URLLC devices. For a way to access more number of URLLC devices, refer to the way to access two devices. The embodiment of the present invention does not specifically limit the number of accesses.

Then there are actually two cases, one is that two URLLC devices can be connected, and the other is that only one URLLC device can be connected.

As far as only one URLLC device can be accessed, it can be understood that in order to allow the connected device to tolerate as much interference caused by mMTC as possible, it is necessary to select a device with good channel conditions to use this subcarrier.

Then, the URLLC device selection method provided by the embodiment of the present invention is specifically: sorting the URLLC devices that have not yet been connected in the URLLC device set according to the channel gain from large to small to obtain a first sequence, so that the most front-arranged URLLC devices in the first sequence are obtained. That is, the URLLC device with the best channel condition is the target URLLC device described in this embodiment of the present invention.

At the same time, the transmit power of the uniquely determined target URLLC device is P _max , correspondingly,

其中，P_max为设备的最大发射功率，h_a为所述小组内信道增益较大的URLLC设备的信道增益，h_b为所述小组内信道增益较小的URLLC设备的信道增益，γ_u为URLLC设备信号的信号与干扰加噪声比。In another situation, if both URLLC devices in the group meet the first channel requirement, the transmission power of the URLLC device with the larger channel gain in the group is P max , and the URLLC device with the smaller channel gain in the group has the transmit power of P _max . The transmit power of the device is:

Wherein, _Pmax is the maximum transmit power of the device, h _a is the channel gain of the URLLC device with a larger channel gain in the group, h _b is the channel gain of the URLLC device with a smaller channel gain in the group, γ _u is Signal-to-interference-plus-noise ratio of URLLC device signals.

On the basis of the above embodiment, the selection of several target mMTC devices that meet the requirements of the second channel in the mMTC device set includes:

Sort the unconnected mMTC devices in the mMTC device set according to the channel gain from small to large to obtain the second sequence;

Determine the top Q mMTC devices corresponding to the second sequence when the second channel requirement is met, and use the top Q mMTC devices corresponding to the second sequence as the target mMTC device.

It can be seen from the content of the above embodiment that after the target URLLC device to be accessed by the subcarrier is determined, it is necessary to access as many mMTC devices as possible. Then the access process can be described by the formula as:

与此同时，还需要满足各个接入的mMTC设备的SINR需求：

And when allocating mMTC devices on each subcarrier, all connected devices cannot be greater than the maximum interference tolerated by the URLLC devices on the subcarriers where they are located, that is:

At the same time, it is also necessary to meet the SINR requirements of each connected mMTC device:

Assuming that there are m mMTC devices and URLLC devices with the maximum interference tolerance I _k share subcarriers, and the signal strengths from device 1 to m increase in turn, they need to meet the following conditions:

尽可能小。考虑到每个设备的最大发射功率的限制，可以让信道条件好的设备用较大的发射功率提升接入信号强度来忍受其他设备对其造成的干扰。这样上述公式就可以改写为：p_m|h_m|²≥γ_mMTC(γ_mMTC+1)^m-1N₀B。则每个mMTC设备可以忍受对其造成干扰的设备数量为：

则第k个子载波下mMTC设备的信号强度之和URLLC设备可以忍受的最大干扰值之间的关系可以为：I_k≥((γ_mMTC+1)ⁿ-1)N₀B，则每个子载波下可以和URLLC共享资源的mMTC设备的数量最多为：

It can be seen from the above formula that if the signal of each mMTC device from 1 to n just meets its SINR requirement, it can be

as small as possible. Considering the limitation of the maximum transmit power of each device, a device with good channel conditions can use a larger transmit power to increase the access signal strength to endure the interference caused by other devices. In this way, the above formula can be rewritten as: p _m |h _m | ² ≥γ _mMTC (γ _mMTC +1) ^m-1 N ₀ B. Then the number of devices that each mMTC device can tolerate is:

Then the relationship between the signal strength of the mMTC device under the kth subcarrier and the maximum interference value that the URLLC device can tolerate can be: I _k ≥((γ _mMTC +1) ⁿ -1)N ₀ B, then each subcarrier The maximum number of mMTC devices that can share resources with URLLC is:

The specific steps for determining the target mMTC device can be expressed as:

进行换算。M中信道增益值可以取到w种数值，取到数值的集合T为，T中元素从大到小排列为{t₁,t₂,t₃,...t_w}。Step 1. Initialize the set of unconnected mMTC devices, and set the channel gain value G of the elements in M according to

Do the conversion. The channel gain value in M can take w kinds of values, the set T of the obtained values is, and the elements in T are arranged from large to small as {t ₁ , t ₂ , t ₃ ,...t _w }.

Step 2. Initialize k=0.

Step 3, k=k+1, select the kth subcarrier from the set R, and initialize i=0.

Step 4. Select the first element from the set M, assign its channel gain value to x, i=i+1, and let Y be equal to the number of elements in M whose channel gain value is equal to x.

Step 5. When i<w is established, let Q=min{x, t(i)-t(i+1), Y}, and merge the first Q elements in the set M into the mMTC equipment group under the kth subcarrier Set Mk, Mk=Mk∪{M ₁ , M ₂ ,...M _Q }, and remove it from the set M, M=M/{M ₁ , M ₂ ,... M _Q }, update the set T.

Step 6. When i<w does not hold, let Q=min{x, t(i), Y}, and merge the first Q elements in the set M into the mMTC device group set Mk under the kth subcarrier, Mk=Mk∪ {M ₁ , M ₂ ,...M _Q }, and remove it from the set M, M=M/{M ₁ , M ₂ ,...M _Q }, update the set T.

Step 7. When X>0 and i<w are established at the same time, return to Step 3.

Step 8. The elements in Mk are sorted from low to high according to the size of the channel gain value as Mk={M ₁ , M ₂ ,...M _Q }, where the transmit power of the i-th device is:

Step 9. Determine whether k<card(R) is established, if so, return to step 2, otherwise the mMTC device grouping process ends.

It can be understood that, through the above-mentioned mMTC device grouping process, the target mMTC device to be accessed and the transmit power of each target mMTC device can be determined.

其中，γ_m为mMTC设备信号的信号与干扰加噪声比，N₀为噪声功率谱密度，h_i为第i个mMTC设备的信道增益。Wherein, in the first Q mMTC devices corresponding to the second sequence, the transmit power of the i-th mMTC device is:

Among them, γ _m is the signal-to-interference plus noise ratio of the mMTC device signal, N ₀ is the noise power spectral density, and hi is the channel gain of the _ith mMTC device.

FIG. 2 is a structural diagram of an access control system in a coexistence scenario of URLLC and mMTC provided by an embodiment of the present invention. As shown in FIG. 2, the system includes: an access control module 210, wherein:

The access control module 210 is configured to simultaneously access several URLLC devices and several mMTC devices according to the preset power allocation algorithm based on the uplink non-orthogonal multiple access NOMA mechanism for each subcarrier on the bandwidth of the IoT system.

Specifically, how to perform access control in the coexistence scenario of URLLC and mMTC by the access control module 210 can be used to implement the technical solution of the embodiment of the access control method in the coexistence scenario of URLLC and mMTC shown in FIG. 1 , and its implementation principle and technology The effect is similar and will not be repeated here.

The access control system in the coexistence scenario of URLLC and mMTC provided by the embodiment of the present invention realizes that multiple URLLC devices and multiple mMTC devices share the same sub-carrier by using NOMA technology and according to preset power allocation rules, thereby This enables IoT systems to support higher connection densities and improve spectral efficiency.

An embodiment of the present invention provides an access control device in a scenario where URLLC and mMTC coexist, including: at least one processor; and at least one memory communicatively connected to the processor, wherein:

3 is a structural block diagram of an access control device in a scenario where URLLC and mMTC coexist according to an embodiment of the present invention. Referring to FIG. 3, the access control device in the coexistence scenario of URLLC and mMTC includes: a processor ) 310 , a communications interface (Communications Interface) 320 , a memory (memory) 330 and a bus 340 , wherein the processor 310 , the communication interface 320 , and the memory 330 communicate with each other through the bus 340 . The processor 310 can call the logic instructions in the memory 330 to execute the following method: for each sub-carrier on the bandwidth of the Internet of Things system, based on the uplink non-orthogonal multiple access NOMA mechanism, simultaneously access several sub-carriers according to the preset power allocation algorithm. URLLC devices and several mMTC devices.

An embodiment of the present invention discloses a computer program product, where the computer program product includes a computer program stored on a non-transitory computer-readable storage medium, the computer program includes program instructions, and when the program instructions are executed by a computer, The computer can execute the methods provided by the above method embodiments, for example, including: for each sub-carrier on the bandwidth of the Internet of Things system, based on the uplink non-orthogonal multiple access NOMA mechanism, according to the preset power allocation algorithm to simultaneously access several sub-carriers. URLLC device and several mMTC devices.

Embodiments of the present invention provide a non-transitory computer-readable storage medium, where the non-transitory computer-readable storage medium stores computer instructions, and the computer instructions cause the computer to execute the methods provided by the foregoing method embodiments, for example Including: for each sub-carrier on the bandwidth of the Internet of Things system, based on the uplink non-orthogonal multiple access NOMA mechanism, according to the preset power allocation algorithm, simultaneously access several URLLC devices and several mMTC devices.

Those of ordinary skill in the art can understand that all or part of the steps of implementing the above method embodiments can be completed by program instructions related to hardware, the aforementioned program can be stored in a computer-readable storage medium, and when the program is executed, execute It includes the steps of the above method embodiments; and the aforementioned storage medium includes: ROM, RAM, magnetic disk or optical disk and other media that can store program codes.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that it can still be The technical solutions described in the foregoing embodiments are modified, or some technical features thereof are equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims (9)

1. An access control method under a URLLC and mMTC coexistence scene is characterized by comprising the following steps:

for each subcarrier on the bandwidth of the Internet of things system, simultaneously accessing a plurality of URLLC devices and a plurality of mMTC devices according to a preset power distribution algorithm based on an uplink non-orthogonal multiple access (NOMA) mechanism;

the method for simultaneously accessing a plurality of URLLC devices and a plurality of mMTC devices according to a preset power allocation algorithm on the basis of an uplink non-orthogonal multiple access (NOMA) mechanism for each subcarrier on the bandwidth of the Internet of things system comprises the following steps:

for each subcarrier on the bandwidth of the Internet of things system, selecting a plurality of target URLLC devices meeting the requirement of a first channel from a URLLC device set based on a NOMA mechanism, wherein the number of the target URLLC devices is less than or equal to the maximum number of the URLLC devices which can be accessed by the current subcarrier;

selecting a plurality of target mMTC devices which meet the requirements of a second channel from the mMTC device set;

and simultaneously accessing the target URLLC devices and the target mMTC devices according to a preset power distribution algorithm.

2. The method according to claim 1, wherein before the simultaneously accessing a plurality of URLLC devices and a plurality of mtc devices according to a preset power allocation algorithm based on an uplink non-orthogonal multiple access (NOMA) mechanism for each subcarrier on the internet of things system bandwidth, the method further comprises:

and determining the maximum number of URLLC devices which can be accessed by each subcarrier on the bandwidth of the Internet of things.

3. The method of claim 1, wherein selecting a number of target URLLC devices in a set of URLLC devices that meet a first channel requirement comprises:

sorting the URLLC devices which are not accessed in the URLLC device set from large to small according to the channel gain to obtain a first sequence;

and dividing the first two URLLC devices included in the first sequence into a small group, and taking the URLLC device meeting the first channel requirement in the small group as the target URLLC device.

4. The method of claim 3, wherein if both URLLC devices in the group meet the first channel requirement, the transmit power of the URLLC device with larger channel gain in the group is P_maxThe transmission power of the URLLC device with smaller channel gain in the group is:

wherein, P_maxIs the maximum transmit power, h, of the device_aThe channel gain h of the URLLC device with larger channel gain in the group_bFor the channel gain, γ, of the URLLC device with the smaller channel gain within the subgroup_uThe signal to interference plus noise ratio of the URLLC device signal.

5. The method of claim 1, wherein selecting a number of target mMTC devices in a set of mMTC devices that meet a second channel requirement comprises:

according to the channel gain, the mMTC devices which are not accessed in the mMTC device set are sequenced from small to large to obtain a second sequence;

determining the first Q mMTC devices corresponding to the second sequence when the requirement of a second channel is met, and taking the first Q mMTC devices corresponding to the second sequence as the target mMTC devices.

6. The method according to claim 5, wherein the transmission power of the ith mMTC device in the first Q mMTC devices corresponding to the second sequence is:

wherein, γ_mSignal to interference plus noise ratio, N, for mMTC device signals₀To noise power spectral density, h_iIs the channel gain of the ith mtc device.

7. An access control system in a coexistence scenario of URLLC and mtc, comprising:

the access control module is used for simultaneously accessing a plurality of URLLC devices and a plurality of mMTC devices according to a preset power distribution algorithm on the basis of an uplink non-orthogonal multiple access (NOMA) mechanism for each subcarrier on the bandwidth of the Internet of things system;

the method for simultaneously accessing a plurality of URLLC devices and a plurality of mMTC devices according to a preset power allocation algorithm on the basis of an uplink non-orthogonal multiple access (NOMA) mechanism for each subcarrier on the bandwidth of the Internet of things system comprises the following steps:

for each subcarrier on the bandwidth of the Internet of things system, selecting a plurality of target URLLC devices meeting the requirement of a first channel from a URLLC device set based on a NOMA mechanism, wherein the number of the target URLLC devices is less than or equal to the maximum number of the URLLC devices which can be accessed by the current subcarrier;

selecting a plurality of target mMTC devices which meet the requirements of a second channel from the mMTC device set;

and simultaneously accessing the target URLLC devices and the target mMTC devices according to a preset power distribution algorithm.

8. An access control device under the coexistence scene of URLLC and mMTC is characterized by comprising a memory and a processor, wherein the processor and the memory complete mutual communication through a bus; the memory stores program instructions executable by the processor, the processor invoking the program instructions to perform the method of any of claims 1 to 6.

9. A non-transitory computer-readable storage medium storing computer instructions that cause a computer to perform the method of any one of claims 1 to 6.

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