eMBB URLLC multiplexing resource allocation method based on queuing preemption mechanism

Abstract

The present invention provides an eMBB-URLLC multiplexing resource allocation method based on a queuing preemption mechanism under the consideration of URLLC bursts. Under the premise that the total computing resources of the base station are fixed, the computing resources are divided into two parts: the URLLC-eMBB shared part, where a queuing mechanism with forced priority is proposed, and the eMBB exclusive part, and the average computing delays of eMBB and URLLC are calculated respectively; and under the premise that the total spectrum resources of the base station are fixed, a URLLC queuing mechanism with active packet loss is proposed to calculate the average transmission delays of eMBB and URLLC; an optimization problem and constraints are constructed based on the computing delay and transmission delay, and two resource allocation schemes are solved. The present invention combines the optimization of the computing resources and spectrum resource allocation problems of URLLC and eMBB, ensuring the transmission requirements of eMBB while achieving the requirements of ultra-reliability and low latency of URLLC.

Description

Technical Field

[0001] The present invention belongs to the field of communication technology, and in particular relates to an eMBB URLLC multiplexing resource allocation method based on a queuing preemption mechanism. Background Art

[0002] The next-generation mobile communications technology, 5G, will be widely used in scenarios such as enhanced mobile broadband (eMBB), ultra-reliable low-latency communication (URLLC), and massive machine type communication (mMTC). According to the 5G development strategy, the coexistence of eMBB and URLLC services will be a typical application scenario in the initial deployment phase. eMBB services are an upgrade of traditional mobile networks, characterized by high data transmission rates and resource utilization. URLLC services are a new application scenario introduced with the development of 5G. Compared to previous mobile communications, they have more stringent latency and reliability requirements and are widely applicable in vertical industries such as the Internet of Vehicles, smart grids, and industrial automation.

[0003] Because both eMBB and URLLC services require wireless transmission and computation, the limited spectrum and computing resources in communication systems face intense competition. Therefore, properly allocating resources for both services while meeting their varying quality of service requirements is a pressing technical challenge. Summary of the Invention

[0004] In order to solve the above problems existing in the prior art, the present invention provides an eMBB URLLC multiplexing resource allocation method based on a queuing preemption mechanism. The technical problem to be solved by the present invention is achieved through the following technical solutions:

[0005] like Figure 1 As shown, the present invention provides an eMBB URLLC multiplexing resource allocation method based on a queuing preemption mechanism, including:

[0006] Step 1: Under the premise that the total computing resources of the base station are fixed, the total computing resources are allocated into the first part and the second part;

[0007] The computing resources in the first part are shared by eMBB users and URLLC users, while the computing resources in the second part are exclusively used by eMBB users.

[0008] Step 2: Calculate the average computing delay of eMBB using the first and second computing resources, and the average computing delay of URLLC using the first computing resources.

[0009] Step 3: Calculate the average transmission delay of eMBB packets and the average transmission delay of URLLC packets, assuming the total spectrum resources of the base station are fixed.

[0010] The eMBB data packet determines the number of packets to be transmitted at the beginning of each transmission gap and allocates all spectrum resources for transmission. The URLLC data packet uses a queuing mechanism to determine the number of packets to be transmitted and queued. At the beginning of each URLLC transmission gap, matching spectrum resources are preempted from the spectrum resources occupied by the eMBB data packets for transmission.

[0011] Step 4: Sum the average transmission delay of the URLLC data packet with the average delay of the first part, use the summation result as the optimization problem, and set the constraints of the optimization problem;

[0012] Step 5: Solve the optimization problem under the constraints to obtain an allocation scheme for eMBB and URLLC under total computing resources and total spectrum resources.

[0013] Beneficial effects of the present invention:

[0014] The present invention provides an eMBB-URLLC multiplexing resource allocation method based on a queuing preemption mechanism in consideration of URLLC bursts. Under the premise that the total computing resources of the base station are fixed, the computing resources are divided into two parts: the URLLC-eMBB shared part, and a queuing mechanism with forced insertion priority is proposed, and the exclusive part of eMBB is used to calculate the average computing delays of eMBB and URLLC respectively; and under the premise that the total spectrum resources of the base station are fixed, a URLLC queuing mechanism with active packet loss is proposed to calculate the average transmission delays of eMBB and URLLC; based on the computing delay and transmission delay, an optimization problem and constraints are constructed to solve and obtain two resource allocation schemes. The present invention combines the optimization of the computing resources and spectrum resource allocation problems of URLLC and eMBB, ensuring the transmission requirements of eMBB while achieving the requirements of ultra-reliability and low latency of URLLC.

[0015] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a flow chart of an eMBB URLLC multiplexing resource allocation method based on a queuing preemption mechanism provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0017] The present invention will be further described in detail below with reference to specific examples, but the embodiments of the present invention are not limited thereto.

[0018] like Figure 1 As shown, the present invention provides an eMBB URLLC multiplexing resource allocation method based on a queuing preemption mechanism, including:

[0019] Step 1: Under the premise that the total computing resources of the base station are fixed, the total computing resources are allocated into the first part and the second part;

[0020] The first portion of computing resources is shared by eMBB and URLLC users, while the second portion is exclusively reserved for eMBB users. When eMBB and URLLC share the first portion of computing resources, a priority queuing mechanism exists, with URLLC user requests taking precedence over eMBB user requests. In step 1, the computing resources allocated to the first portion account for a times the total computing resources of the base station; the computing resources allocated to the second portion account for c times the total computing resources of the base station. The total computing resources of the base station are F cycles / s.

[0021] This invention divides the base station's computing resources into two parts, A and C. Part A (the first part) is shared by URLLC and eMBB, processing both URLLC and eMBB computing requests. The computing resources allocated to Part A account for a times the total computing resources of the base station. Part C (the second part) is exclusively used by eMBB users and only processes eMBB computing requests. The computing resources allocated to Part C account for c times the total computing resources of the base station. The total computing resources of the base station are F cycles / s.

[0022] The arrival process of URLLC is modeled as a compound Poisson process. The arrivals are in bursts or batches. The arrival processes between batches are independent and the time intervals between arrivals are exponentially distributed. The average arrival rate of a batch is λ. u The number of packets arriving in each batch is independent of each other and conforms to the Poisson distribution with strength λ.

[0023] The arrival process of eMBB is modeled as a Poisson process, and the total average arrival rate of eMBB is λ e ; The first part of the eMBB arrival process is the average rate The second part of the eMBB arrival process is the average rate Poisson process; It is positively correlated with a. And there is

[0024] In part A, a priority queuing mechanism is designed. The priority of URLLC users is higher than that of eMBB users. When a sudden URLLC calculation request arrives, the service to the eMBB user is immediately suspended. After processing the incoming URLLC calculation request, the eMBB request can be processed again.

[0025] The time it takes for a base station to process a URLLC data packet follows the average value The exponential distribution, η u Cycles is the average task computing intensity of URLLC, assuming that the time for the base station to process a batch of data packets is s u , then the average time to process a batch of data packets is And there is Part A: The time it takes to process one eMBB data packet obeys the exponential distribution, η e cycles is the average computing intensity of eMBB tasks, and

[0026] Step 2: Calculate the average computing delay of eMBB using the first and second computing resources, and the average computing delay of URLLC using the first computing resources.

[0027] Part A is a queueing system with M / G / 1 forced priority. According to queueing theory, the sum of the URLLC average queuing delay and the average computational processing delay is:

[0028]

[0029] The sum of the average queuing delay and the average computing processing delay of eMBB is:

[0030]

[0031] Among them, to ensure the stability of the calculation queue in this part:

[0032]

[0033] In part C, the base station processes eMBB computing requests in the order of arrival, which is an M / M / 1 queuing system. The time it takes to process an eMBB data packet in part C is obeys an exponential distribution, and

[0034] According to queuing theory, the sum of the average queuing delay and the average computing processing delay of eMBB is:

[0035]

[0036] To ensure the stability of the calculation queue in this part, the following are implemented:

[0037]

[0038] Therefore, the average computational delay of the two parts of the eMBB computation process is:

[0039]

[0040] Step 3: Under the premise that the total spectrum resources of the base station are fixed, calculate the average transmission delay of eMBB data packets during the transmission gaps of eMBB data packets and the average transmission delay of URLLC data packets during the transmission gaps of URLLC data packets.

[0041] eMBB determines the number of packets to be transmitted at the beginning of each transmission gap and allocates all spectrum resources for transmission. URLLC packets use a queuing mechanism to determine the number of packets to be transmitted and queued. At the beginning of each URLLC transmission gap, matching spectrum resources are preempted from the spectrum resources occupied by eMBB packets for transmission.

[0042] Specifically, step 3 includes:

[0043] Step 31: Under the premise that the total spectrum resources of the base station are fixed, during the transmission gap of the URLLC data packets, the number of transmitted URLLC data packets, the number of discarded URLLC data packets, and the number of queued URLLC data packets are calculated respectively;

[0044] Step 32: performing a Markov stationary distribution conversion on the number of queued URLLC packets to obtain the number of queued URLLC packets after conversion, and combining the number of transmitted URLLC packets and the number of discarded URLLC packets to calculate the average number of transmitted URLLC packets;

[0045] Step 33: Calculate the average transmission delay of the URLLC data packets according to the average number of transmitted URLLC data packets;

[0046] Step 34: Calculate the average transmission delay of the eMBB data packets based on the number of eMBB data packets.

[0047] Considering the URLLC-eMBB shared downlink transmission link, the eMBB packet transmission scheduling duration is slot, the URLLC scheduling duration is minislot, the duration of a minislot is τ, and a slot contains D minislots. Since the speed of processing computing requests is much faster than the speed of user arrival, the arrival process of URLLC in the transmission queue is similar to the process of computing requests arriving at the base station. Let the set of base station subcarriers be The set of eMBB users is Matrix L = [L n,b ] represents the subcarrier allocation scheme for eMBB users, L n,b is a binary variable, L n,b=1 means that subcarrier b is allocated to eMBB user n, L n,b =0 means that subcarrier b is not allocated to eMBB user n. Assume that each subcarrier is allocated to an eMBB user, that is, Each subcarrier is assigned f b bandwidth.

[0048] Consider a queuing system with active packet loss. In step 3, the transmission time slot of the eMBB data packet is slot, and the transmission time slot of the URLLC data packet is minislot. The duration of a minislot is τ, and a slot contains D minislots.

[0049] The set of eMBB users is Matrix L = [L n,b ] represents the subcarrier allocation scheme for eMBB users, L n,b is a binary variable, L n,b =1 means that subcarrier b is allocated to eMBB user n, L n,b = 0 means that subcarrier b is not allocated to eMBB user n; initially, each subcarrier is allocated to an eMBB user; each subcarrier is allocated f b bandwidth;

[0050] The queuing mechanism for URLLC packets is:

[0051] The maximum number of URLLC packets transmitted by the system in each minislot is M. Packets exceeding M enter the queue and wait for transmission in the next minislot.

[0052] Each URLLC packet waits for a maximum of two minislots. If a URLLC packet in the queue is still not transmitted in the next minislot, the URLLC packet is actively discarded and the URLLC packet in the queue is transmitted first;

[0053] The number of URLLC packets arriving in minislot (d-1) and minislot (d) is m d The number of URLLC packets in the queue waiting to be transmitted in minislot d is Q d . m d =z’s probability function is:

[0054]

[0055] Among them B n (x) is an exponential complete Bell polynomial, and its probability distribution function is:

[0056]

[0057] The number of URLLC packets transmitted in minislot(d) is:

[0058] x d =min(M,m d +Q d )

[0059] The number of URLLC packets dropped in minislot(d) is:

[0060] y d =max(0,Q d -M)

[0061] The number of URLLC packets queued in minislot(d) is:

[0062]

[0063] Obviously, by Q d-1 →Q d The process is a Markov process, Q d When ≥M, the states are equivalent. The states are merged. The merged Markov chain is an irreducible ergodic chain with a unique stationary distribution. The stationary distribution is converted into a vector form:

[0064]

[0065] make

[0066] The probability of actively discarding URLLC packets is P(Q>M). To ensure the ultra-reliability of URLLC, P(Q>M)<ξ;

[0067] The average number of URLLC packets transmitted in minislot(d) is:

[0068]

[0069] Assume that the probability matrix of URLLC data packets preempting eMBB user subcarriers is I = [I n,b ], the URLLC data packet preempts the eMBB user n subcarrier subcarrier ratio is 1 n,b , then the average transmission delay of URLLC data packets is:

[0070]

[0071] where k uis the size of the URLLC data packet, P is the base station downlink transmission power, h is the channel gain, V is the channel dispersion, b l is the block length, Q(x) -1 is the inverse of the Gaussian function, ξ represents the probability of transmission error, σ 2 For noise.

[0072] The average approximate transmission delay of eMBB data packets is:

[0073]

[0074] k e is the eMBB data packet size.

[0075] Step 4: Sum the average transmission delay of the URLLC data packet and the sum of the delays in the first part, use the sum result as the optimization problem, and set the constraints of the optimization problem;

[0076] The optimization problem in step 4 is:

[0077]

[0078]

[0079]

[0080] a+c=1 (4)

[0081] T e,o +T e,w <τ e (5)

[0082]

[0083] L n,b ={0,1} (7)

[0084] I n,b ,a,c∈[0,1](8)

[0085] Among them, formulas (1) to (8) represent constraints. Formula (1) minimizes the average calculation processing and downlink transmission delay of URLLC users, and (5) ensures that the average eMBB delay is within a certain range.

[0086] Step 5: Solve the optimization problem under the constraints to obtain an allocation scheme for eMBB data packets and URLLC under total computing resources and total spectrum resources.

[0087] This optimization problem can be solved using the block coordinate descent method. The first step of the block coordinate descent method is to fix the allocation schemes L and I of the wireless spectrum resources of eMBB and URLLC and set an initial value that satisfies the constraints. Then, the average URLLC delay T is solved under the constraints. u,o +T u,w (Optimization formula 1) minimizes the allocation of computing resources a, c; in the second step, the updated computing resource allocation a, c and the initial URLLC spectrum resource allocation I are fixed, and the URLLC average delay T is solved under the constraints. u,o +T u,w The minimum eMBB spectrum allocation L; the third step is to fix the updated computing resources a, c and the eMBB spectrum allocation L, and solve the URLLC average delay T that is minimized under the constraints. u,o +T u,w URLLC spectrum allocation I.

[0088] Repeat the three steps of the cyclic block coordinate descent method. When the kth cycle is completed, the T u,o +T u,w At the end of the k-1th cycle, we get T u,o +T u,w The loop stops when the difference between them is less than θ, and the optimal URLLC and eMBB computing resource and spectrum resource allocation is obtained through continuous iteration when the constraints are met.

[0089] The present invention provides an eMBB URLLC multiplexing resource allocation method based on a queuing preemption mechanism. Under the premise that the total computing resources of a base station are fixed, the total computing resources are allocated into a first part and a second part. The average delays of eMBB packets and URLLC packets in the two parts are calculated respectively. Under the premise that the total spectrum resources of the base station are fixed, the average transmission delay of eMBB packets is calculated within the transmission gaps of eMBB packets, and the average transmission delay of URLLC packets is calculated within the transmission gaps of URLLC packets. The average transmission delay of URLLC packets is summed with the average computing delay of the first part, and the summation result is used as an optimization problem. Constraints for the optimization problem are set. The optimization problem is solved under the constraints to obtain the allocation ratio of eMBB packets and URLLC packets within the total computing resources, as well as the share of spectrum resources. The present invention combines the optimization of URLLC and eMBB computing resources with the spectrum resource allocation problem. A queuing mechanism is established during the arrival of URLLC bursts. A priority-based queuing mechanism is proposed to allocate computing resources. In addition, an active packet loss queuing mechanism is proposed to allocate spectrum resources. This ensures eMBB transmission requirements while achieving the ultra-reliability and low latency requirements of URLLC.

[0090] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0091] Although the present application is described herein with reference to various embodiments, those skilled in the art will be able to understand and implement other variations of the disclosed embodiments in practicing the claimed application by reviewing the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude a plurality.

[0092] The above is a further detailed description of the present invention in conjunction with specific preferred embodiments, and the specific implementation of the present invention should not be considered to be limited to these descriptions. For those skilled in the art of the present invention, without departing from the concept of the present invention, several simple deductions or substitutions can be made, which should be considered to fall within the scope of protection of the present invention.

Claims

1. A method for allocating eMBB URLLC multiplexing resources based on a queuing preemption mechanism, characterized in that: include: Step 1: Under the premise that the total computing resources of the base station are fixed, the total computing resources are allocated into the first part and the second part; The computing resources in the first part are shared by eMBB users and URLLC users, while the computing resources in the second part are exclusively used by eMBB users. Step 2: Calculate the average computing delay of eMBB using the first and second computing resources, and the average computing delay of URLLC using the first computing resources. Step 3: Calculate the average transmission delay of eMBB packets and the average transmission delay of URLLC packets, assuming the total spectrum resources of the base station are fixed. The eMBB data packet determines the number of packets to be transmitted at the beginning of each transmission gap and allocates all spectrum resources for transmission. The URLLC data packet uses a queuing mechanism to determine the number of packets to be transmitted and queued. At the beginning of each URLLC transmission gap, matching spectrum resources are preempted from the spectrum resources occupied by the eMBB data packets for transmission. Step 4: Sum the average transmission delay of the URLLC data packet with the average delay of the first part, use the summation result as the optimization problem, and set the constraints of the optimization problem; Step 5: Solve the optimization problem under the constraints to obtain an allocation scheme for eMBB and URLLC based on total computing resources and total spectrum resources. The optimization problem in step 4 is: a+c=1 (4) T e,o +T e,w <τ e (5) L n,b ＝{0,1} (7) I n,b ,a,c∈[0,1] (8) Among them, formulas (2) to (8) represent constraints. Formula (1) minimizes the average calculation processing and downlink transmission delay of URLLC users. Formulas (2) and (3) ensure the stability of the calculation part queue. Formula (5) ensures that the average eMBB delay is within the predetermined range. Formulas (4) (6) (7) (8) are restrictions on the allocated resources. T u,o represents the average computational delay of URLLC under the first part of computing resources, T u,w represents the average transmission delay of URLLC data packets, λ u 、 and represents the average rate of the Poisson process, represents the average time to process a batch of data packets, a and c represent the multiples of computing resources allocated to the first and second parts of the total base station resources, respectively. The set of eMBB users is Matrix L = [L n,b ] represents the subcarrier allocation scheme for eMBB users, L n,b is a binary variable, L n,b =1 means that subcarrier b is allocated to eMBB user n, L n,b =0 means that subcarrier b is not allocated to eMBB user n; the probability matrix of URLLC data packets occupying eMBB user subcarriers is I = [I n,b ], the URLLC data packet preempts the eMBB user n subcarrier subcarrier ratio is 1 n,b .

2. The eMBB URLLC multiplexing resource allocation method based on a queuing preemption mechanism according to claim 1, characterized in that: When the eMBB and URLLC share the computing resources of the first part, there is a priority queuing mechanism, and the priority of the URLLC user request is higher than the priority of the eMBB user request.

3. The eMBB URLLC multiplexing resource allocation method based on a queuing preemption mechanism according to claim 1, characterized in that: The computing resources allocated to the first part in step 1 account for a times the total computing resources of the base station; the computing resources allocated to the second part account for c times the total computing resources of the base station; the total computing resources of the base station are Fcycles / s; The arrival process of URLLC is modeled as a compound Poisson process. The arrivals are in bursts or batches. The arrival processes between batches are independent and the time intervals between arrivals are exponentially distributed. The arrival process of a batch is at an average rate of λ. u The number of packets arriving in each batch is independent of each other and conforms to the Poisson distribution with strength λ. The arrival process of eMBB is modeled as a Poisson process, and the total average arrival rate of eMBB is λ e ; The first part of the eMBB arrival process is the average rate The second part of the eMBB arrival process is the average rate Poisson process; It is positively correlated with a. And there is 4. The eMBB URLLC multiplexing resource allocation method based on a queuing preemption mechanism according to claim 3, characterized in that: Under the priority queuing mechanism, the average computational delay of URLLC in step 2 under the first part of computing resources is: The average computing latency of eMBB under the first part of computing resources is: The average computing latency of eMBB under the second part of computing resources is: The average computational latency of eMBB in the two parts is: Among them, the time for the base station to process a URLLC data packet follows the average value The exponential distribution, η u Cycles is the average task computing intensity of URLLC, and the time it takes for the base station to process a batch of data packets is s u , the average time to process a batch of data packets is And there is The first part calculates the time it takes for a resource to process an eMBB data packet. obeys the exponential distribution, η e cycles is the average computing intensity of eMBB tasks, and 5. The eMBB URLLC multiplexing resource allocation method based on a queuing preemption mechanism according to claim 4, characterized in that: In step 3, the transmission time slot of the eMBB data packet is slot, and the transmission time slot of the URLLC data packet is minislot. The duration of a minislot is τ, and a slot contains D minislots. Initially, each subcarrier is assigned to an eMBB user. Each subcarrier is assigned f b bandwidth; The queuing mechanism for URLLC packets is: The maximum number of URLLC packets transmitted by the system in each minislot is M. Packets exceeding M enter the queue and wait for transmission in the next minislot. Each URLLC packet waits for a maximum of two minislots. If a URLLC packet in the queue is still not transmitted in the next minislot, the URLLC packet is actively discarded and the URLLC packet in the queue is transmitted first; Among them, the number of URLLC packets arriving in minislot (d-1) and minislot (d) is m d The number of URLLC packets in the queue waiting to be transmitted in minislot (d) is Q d ;m d =z’s probability function is: B n (x) is an exponential complete Bell polynomial, and its probability distribution function is:

6. The eMBB URLLC multiplexing resource allocation method based on a queuing preemption mechanism according to claim 5, characterized in that: Step 3 includes: Step 31: Under the premise that the total spectrum resources of the base station are fixed, in the transmission minislot of the URLLC data packets, the number of transmitted URLLC data packets, the number of discarded URLLC data packets, and the number of queued URLLC data packets are calculated respectively; The number of URLLC packets transmitted in minislot(d) is: x d =min(M,m d +Q d ) The number of URLLC packets dropped in minislot(d) is: y d =max(0,Q d -M) The number of URLLC packets queued in minislot(d) is: Among them, Q d-1 →Q d The process is a Markov process, Q d When ≥M, the states are equivalent, and the stationary distribution is converted into vector form: make The probability of actively discarding URLLC packets is P(Q>M). To ensure the ultra-reliability of URLLC, P(Q>M)<ξ; Step 32: performing a Markov stationary distribution conversion on the number of queued URLLC packets to obtain the probability of the number of queued URLLC packets after the conversion, and combining the number of transmitted URLLC packets and the number of discarded URLLC packets to calculate the average number of transmitted URLLC packets; The average number of URLLC packets transmitted in minislot(d) is: Step 33: Calculate the average transmission delay of the URLLC data packets according to the average number of transmitted URLLC data packets; The average transmission delay of URLLC data packets is: Among them, k u is the size of the URLLC data packet, P is the base station downlink transmission power, h is the channel gain, V is the channel dispersion, b l is the block length, Q(x) -1 is the inverse of the Gaussian function, ξ represents the probability of transmission error, σ 2 For noise; Step 34: Calculate the average transmission delay of the eMBB data packets based on the number of eMBB data packets. The average transmission delay of eMBB data packets is: Among them, k e is the eMBB data packet size.

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