CN106954232B - Time delay optimized resource allocation method - Google Patents

Abstract

The invention discloses a resource allocation method for time delay optimization, which relates to the technical field of wireless communication. First, the wireless resource manager determines the users to be scheduled in the current time slot, according to the current time slot and the previous time slot of all the users to be scheduled. On the QSI, calculate the priority factor of each service of the user to be scheduled, and generate a priority sequence table of user services, which is used to guide the radio resource manager to transmit the data of the user to be scheduled with the highest priority. and the decision on radio resource block allocation, then, the resource allocation result is sent to the corresponding user to be scheduled; finally, the QSI of each service corresponding to the cache queue of each user is updated; the present invention ensures that all cache queues in the network are bounded In order to reduce the average transmission delay of services, and on the premise of achieving network stability, the network energy efficiency performance can approach the optimal value.

Description

A Delay-Optimized Resource Allocation Method

technical field

The invention relates to the technical field of wireless communication, in particular to a resource allocation method for time delay optimization in a wireless access network.

Background technique

According to Cisco's public research report in 2016, more than 55% of the current data traffic comes from video streaming media and voice conversation services, and such delay-sensitive real-time services will continue to grow exponentially in the next five years. In 2020, the data traffic generated by real-time services will account for more than 75% of the total data traffic. Therefore, in order to ensure that real-time services run by smart terminals such as smart phones, tablet computers, and wearable devices can bring better user experience to customers, mobile Internet applications put forward higher requirements on the latency performance of wireless networks.

The requirement of real-time services for low-latency wireless networks makes traditional resource allocation methods no longer able to effectively guarantee the overall performance of wireless networks. The basic starting point of the traditional resource allocation method is to flexibly and dynamically adjust the available resources of the wireless network for the served users and optimize the network according to the obtained physical layer information, such as Channel State Information (CSI, Channel State Information) and inter-cell interference. spectral efficiency or energy efficiency.

However, this resource allocation method cannot perform resource allocation that effectively reduces the service transmission delay according to the actual delay of the service requested by the user, and cannot make a resource allocation strategy that optimizes the delay according to the delay characteristics of the service requested by the user. . The resource allocation method that only uses the physical layer information to optimize the physical layer performance index cannot provide users with high-level service quality assurance, nor can it further improve the delay performance of the wireless network. Therefore, it is necessary to propose a resource allocation method that can optimize the delay according to the delay characteristics of the service requested by the user and the queue state information (QSI, Queue State Information) of the corresponding cache queue, so as to reduce the transmission delay of the service requested by the user. , to achieve network stability and provide users with better quality of service (QoS, Quality of Service).

At present, most of the resource allocation methods that optimize the delay for real-time services usually consider the user's delay, the priority of the service and the user's current CSI, which can meet the user's QoS requirements for real-time services and achieve a better network. Overall performance, but the complexity of related algorithms is usually high, and it is impossible to take into account the differentiated QoS requirements of real-time services and non-real-time services at the same time, or there may be a high rate of network packet discarding, which cannot guarantee the stability of the network, or There is a lack of consideration for achieving energy-efficient performance in building green communication networks.

As an indicator that is currently widely studied in academia and industry, energy efficiency is used to estimate how energy is efficiently utilized, which needs to consider not only the total rate sum of the optimized network, but also the overall energy consumption of the optimized network. Therefore, there is an urgent need to propose a new resource allocation method for delay optimization, which can ensure that the average transmission delay of each user service is within the set threshold range, and at the same time maximize the energy efficiency performance of the network.

SUMMARY OF THE INVENTION

In view of this, the present invention proposes a resource allocation method for delay optimization, which is a resource allocation method for realizing network energy efficiency and average transmission delay balance. The allocation of resources is aimed at maximizing the energy efficiency of the network, and at the same time, according to the different service delay characteristics, the average transmission delay of the service is optimized on demand to ensure that the average transmission delay of the service does not exceed the set threshold.

Specific steps are as follows:

Step 1: The wireless resource manager counts service types with different delay characteristics that the network can perceive;

There are N types of service types; expressed as {1,2,…,n,…,N}; n is the service serial number; there are K total attached users; expressed as {1,2,…,k,…,K}; k is the user ID.

Step 2, assigning a time slot for each resource, the radio resource manager configures service control parameters for each service at the starting moment, and determines the set of all available radio resource blocks in the current time slot;

(1) The radio resource manager sequentially configures service control parameters for N services that the network can perceive;

V _n is the service control parameter of service n;

(2) The radio resource manager determines the set of all available radio resource blocks in the current time slot;

All available radio resource blocks are serially numbered and counted; the set of all available radio resource blocks is defined as {1,2,...,R}, and the available radio resource blocks refer to the idle state that is not allocated to any user , the natural number R is the total number of all available radio resource blocks in the current time slot;

Step 3, for each resource allocation time slot, the radio resource manager obtains the QSI of the buffer queue corresponding to each service of each user, determines all the users that need to be scheduled, and obtains the CSI of all the users to be scheduled in the current time slot;

The QSI of the buffer queue refers to the backlog of service data to be transmitted in the buffer queue; the CSI is the channel gain of the user on the available radio resource blocks;

According to whether the buffer queue corresponding to each service of each user is empty, the radio resource manager determines all users that need to be scheduled in the current time slot, and obtains the CSI reported by all users to be scheduled in the current time slot;

Step 4: For each service of each user to be scheduled, the radio resource manager obtains the QSI of the corresponding buffer queue in the current time slot t and the previous time slot t-1 respectively;

Step 5, the radio resource manager calculates the priority of each service of each user to be scheduled and determines the service with the highest priority of each user to be scheduled according to the QSI of time slot t and time slot t-1;

The formula for calculating the priority of each service of each user k' to be scheduled is as follows:

PRI _k',n (t)=(Q _k',n (t)) ² -(Q _k',n (t-1)) ²

PRI _k',n (t) is the priority factor of user k' to be scheduled on service n on time slot t, Q _k',n (t) is the buffer corresponding to service n of user k' to be scheduled on time slot t QSI of the queue;

For each user to be scheduled, the service corresponding to the maximum priority factor has the highest priority;

Step 6: The radio resource manager selects the radio resource block with the smallest number value from the set of available radio resource blocks, and calculates the optimal transmit power and utility factor;

Specific steps are as follows:

First, the radio resource manager selects the radio resource block with the smallest number value from the set of available radio resource blocks determined in step 2, and the sequence number is r;

Then, calculate the optimal transmit power required when transmitting the data of the service with the highest priority of each user to be scheduled on the radio resource block r;

For the to-be-scheduled user k', when calculating the data of the highest priority service n to be transmitted on the radio resource block r, the required optimal transmit power formula is as follows:

为在时隙t上待调度用户k′的能量效率值；σ²为无线资源块r上对应的高斯白噪声功率；g_k′,r(t)为在时隙t上待调度用户k′在无线资源块r上的信道增益；P^max为无线接入点的最大发射功率；P _k',n,r (t) is the optimal transmit power required when using the radio resource block r to transmit the data of the highest priority service n of the user k' to be scheduled on the time slot t; W is the value of the radio resource block r Bandwidth; ε is an energy efficiency factor with a value between 0 and 1. The closer the value of ε is to the natural number 1, the higher the power conversion rate of the system;

is the energy efficiency value of user k' to be scheduled on time slot t; σ ² is the corresponding white Gaussian noise power on radio resource block r; g _k',r (t) is user k' to be scheduled on time slot t The channel gain on the wireless resource block r; ^Pmax is the maximum transmit power of the wireless access point;

取最大值的函数定义为

The value of P _k′,n,r (t) follows the following formula: The function of taking the minimum value is defined as

The function to take the maximum value is defined as

Finally, according to the optimal transmit power required to serve each to-be-scheduled user, calculate the utility factor of using the radio resource block r to transmit the highest-priority service data of each to-be-scheduled user;

For the to-be-scheduled user k', calculate the utility factor when transmitting the data of the service with the highest priority on the radio resource block r. The formula is as follows:

为在时隙t上使用无线资源块r传输待调度用户k′优先级最高业务n的数据时的效用因子；

is the utility factor when the radio resource block r is used to transmit the data of the service n with the highest priority of the user k' to be scheduled on the time slot t;

Step 7: Determine the allocation decision and power control result of the radio resource block r according to the utility factor when transmitting the service data with the highest priority of each user to be scheduled according to the radio resource block r with the smallest number value, and the radio resource manager updates the radio resource block r. A collection of resource blocks;

First, sort the utility factors calculated by all the users to be scheduled, and select the minimum value; at the same time, obtain the value of the user serial number and the service serial number corresponding to the minimum utility factor;

When the utility factor reaches the minimum value, the value function of the corresponding user serial number and its service serial number is:

如果是，无线资源管理器将无线资源块r分配给用户k^*用以传输其优先级最高业务n^*的数据，并且设置在时隙t上无线接入点通过无线资源块r服务用户k^*传输其优先级最高业务n^*的数据的最优发射功率为

否则，无线资源管理器不会将无线资源块r分配给任何待调度用户；Then, on the basis of selecting the user k ^* corresponding to the minimum utility factor and the service n ^* with the highest priority, it is judged whether it satisfies the

If so, the radio resource manager allocates radio resource block r to user k ^* to transmit data of its highest priority service n ^* , and sets the wireless access point to serve user k ^* through radio resource block r on time slot t The optimal transmit power for transmitting data with the highest priority service n ^* is

Otherwise, the radio resource manager will not allocate the radio resource block r to any user to be scheduled;

Step 8, the radio resource manager judges whether all available radio resource blocks have been traversed; if so, execute step 9; otherwise, return to step 6;

Step 9, the radio resource manager sends the allocation decision and power control result of each radio resource block to the corresponding user to be scheduled;

Step 10, count the data transmission rate of each user in the current time slot t, the total transmit power consumed and calculate the energy efficiency value of the next time slot t+1;

First, for the user k ^o to be scheduled allocated to the radio resource block, the calculation method of the energy efficiency value is as follows:

是在时隙t上采集到用户k^o的数据传输速率；

是在时隙t上用户k^o所需的总发射功率，其定义为

is the data transmission rate of user k ^o collected on time slot t;

is the total transmit power required by user k ^o on time slot t, which is defined as

For other users i ^o that are not allocated to radio resource blocks, the calculation method of the energy efficiency value is as follows:

Step 11, the radio resource manager updates the QSI of the cache queue corresponding to each service of each user;

For the to-be-scheduled user k ^o allocated to the radio resource block on the time slot t, the QSI update method of the cache queue corresponding to the service n with the highest priority is as follows:

为当前时隙t上用户k^o优先级最高业务n的新数据到达速率；

is the new data arrival rate of the highest priority service n of user k ^o on the current time slot t;

For the to-be-scheduled user k ^o allocated to the radio resource block on the time slot t, the QSI update method of the buffer queue corresponding to the non-highest-priority service n ^o is as follows:

For other users i ^o that are not allocated to radio resource blocks on time slot t, the QSI update method for each service corresponding to the buffer queue is as follows:

Step 12: The radio resource manager ends the radio resource allocation process in the current time slot t, and judges whether all resource allocation time slots are completed, if so, end; otherwise, enter the next radio resource allocation time slot start time. If so, go back to step 2.

The advantages of the present invention are:

Compared with the existing method, the present invention not only fully considers the CSI of the user, but also fully utilizes the QSI of the buffer queue, and the proposed resource allocation method for delay optimization prioritizes resource allocation to the user to be scheduled that most urgently needs to transmit service data. Allocated to ensure the boundedness of all buffer queues in the network, so that the average transmission delay of users requesting various services is kept within the set threshold. At the same time, when performing power control and radio resource block allocation, the goal is to reduce the average transmission delay of various services and to achieve high network energy efficiency. Under the premise of achieving network stability, the energy efficiency performance of the network is close to the maximum. The value of merit can effectively improve the user's service experience.

Description of drawings

FIG. 1 is a schematic diagram of an embodiment of a resource allocation method for delay optimization according to the present invention;

FIG. 2 is a schematic flowchart of the resource allocation method for delay optimization according to the present invention.

specific embodiment

In order to make the objectives, design solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

A schematic diagram of an embodiment of the resource allocation method for delay optimization according to the present invention, as shown in FIG. 1 , when the radio resource manager executes the process of user scheduling and service priority determination, the radio resource manager first obtains from the buffer area of the baseband processor Each service of each user corresponds to the QSI of the buffer queue, determines all the users that need to be scheduled in the current time slot, and then obtains the CSI reported by all the users to be scheduled in the current time slot through the uplink control channel;

The radio resource manager obtains the QSI of the buffer queue corresponding to each service of each user to be scheduled from the buffer area of the baseband processor, calculates the priority factor of each service of all users to be scheduled, and arranges the priority factors from large to small. Generate a user service priority sequence table to guide the radio resource manager to control the transmit power required by the users to be scheduled and allocate radio resource blocks, and then send the decision results to all the corresponding users to be scheduled through the downlink control channel ; Finally, update the QSI of the buffer queue corresponding to each service of each user in the baseband processor buffer area.

The wireless resource manager executes the resource allocation process with a time slot as the smallest granularity in time, and monitors the service requests of each user at all times. The wireless resource allocation algorithm runs periodically, that is, the resource allocation of the wireless access point is updated once per time slot. strategy, each radio resource block occupies a time slot in the time domain, and the bandwidth in the frequency domain is W, the corresponding white Gaussian noise power is σ ² , and each radio resource block can only be used by one radio resource block in a time slot. Exclusive use by users, each user may be assigned to multiple radio resource blocks in a time slot, or may not be assigned to a radio resource block, and a user assigned to a radio resource block only transmits its highest priority in a time slot business data.

As shown in Figure 2, the specific operation steps are as follows:

Step 1, the wireless resource manager counts the service types with different delay characteristics supported by the network;

The service control function entity in the network can perceive N service types with different delay characteristics, the baseband processor buffer can establish a buffer queue for each service requested by each user, and the set of all users in the network is {1, 2, ...,K}, the set of all service types is {1,2,...,N}, where the natural number K is the number of all attached users in the network, and the natural number N is the number of all service types.

Step 2, for each resource allocation time slot, the radio resource manager configures service control parameters for each service in turn at the starting moment, and determines the set of all available radio resource blocks in the current time slot;

First, the radio resource manager classifies the services according to the different delay characteristics of N services, and configures service control parameters for each service that can be perceived in turn;

Specifically, the first service is defined as a virtual reality service, the second service is defined as a video streaming service, the third service is positioned as an email service, and so on; the wireless resource manager configures control parameters for each service in turn, V _n is the service control parameter of service n, n is the serial number of the requested service and n∈{1,2,…,N};

The service control parameter is a non-negative number used to balance the average transmission delay of the service and the performance of the network energy efficiency. Generally speaking, for a service with high real-time requirements, the service control parameter is set to a small value. For non-real-time services, the service control parameters can be set to a larger value; smaller service control parameters can ensure lower average service transmission delay, and larger service control parameters can achieve higher energy efficiency performance;

During initialization, for services with high real-time requirements such as virtual reality, set the corresponding service control parameters to a small value to ensure a low average service transmission delay. For background-level services such as email, you can Set its corresponding service control parameter to a larger value to ensure that the network achieves high energy efficiency performance;

In addition, the service control parameters can be reconfigured in the next resource allocation time slot according to the current change in network performance requirements. Specifically, if the network operator's requirements for the delay performance of service n increase, V _n can be appropriately set to Reduce to achieve a lower average transmission delay. Similarly, if the energy efficiency performance requirements of users requesting service _n increase, Vn can be appropriately increased to achieve higher energy efficiency performance of the network;

Then, traverse all radio resource blocks to determine the set of all available radio resource blocks in the current time slot;

The radio resource manager traverses all the radio resource blocks that the network operator plans to allocate to the wireless access point, determines the number of all available radio resource blocks in the current time slot and numbers them in sequence, and determines the set of all available radio resource blocks. The available radio resource blocks refer to the radio resource blocks that can be allocated to any user, that is, the radio resource blocks in an idle state;

The set of all available radio resource blocks in the current time slot is defined as {1,2,...,R}, where the natural number R is the total number of all available radio resource blocks in the current time slot.

Step 3: Allocating a time slot for each resource, the radio resource manager obtains the QSI of the buffer queue corresponding to each service of each user in the current time slot, determines all the users that need to be scheduled, and obtains all the users to be scheduled through the uplink control channel. Report its own CSI in the current time slot;

The wireless resource manager monitors the requested services of all attached users, determines whether a cache queue for the requested service needs to be established for the user, and then traverses the cache queues corresponding to all services of all users, determines the users that need to be scheduled in the current time slot, and obtains all pending scheduling. CSI of the user in the current slot.

Specifically, when user k requests service n at the beginning of the current radio resource allocation time slot t, k is the user ID and k∈{1,2,...,K}; the radio resource manager accesses the buffer area of the baseband processor , obtain the QSI value Q _k,n (t) of the cache queue corresponding to the request service n in the time slot t of the user k, if no observation value of Q _k,n (t) is returned, then establish Q _k,n (t) and Assign Q _k,n (t)=0, otherwise, no operation is performed;

If there are users who attach to the network in the current time slot or the service data of the users has been transmitted, the wireless resource manager deletes the buffer queues corresponding to the corresponding services of these users from the buffer area of the baseband processor; Cache queue, if it is observed that a user's corresponding cache queue for each service has not been established, it is confirmed that the user is a non-scheduled user in the current time slot, otherwise, the user is a scheduled user in the current time slot;

The resource manager collects the CSI values of all users to be scheduled in the current radio resource allocation time slot, that is, all users to be scheduled report their CSI values in the current time slot to the radio resource manager through the uplink control channel, and the buffer queue corresponds to For each service of each user, the QSI of the buffer queue refers to the backlog of service data to be transmitted in the buffer queue, and the CSI is the channel gain of the user on the available radio resource blocks.

Step 4: For each service of each user to be scheduled, the radio resource manager accesses the buffer area of the baseband processor, and obtains the cache queue corresponding to each service of all users to be scheduled in the current time slot t and the previous time slot t- 1 QSI;

Step 5, the radio resource manager calculates the priority factor of each service of each user to be scheduled and determines the service with the highest priority of each user to be scheduled according to the QSI of time slot t and time slot t-1;

The method for calculating the priority factor of each service of each user to be scheduled is:

According to PRI _k,n (t)=(Q _k,n (t)) ² -(Q _k,n (t-1)) ² , determine the priority factor PRI _{k of user k with respect to service n on time slot t, n} (t);

For each user to be scheduled, according to its service priority factor, the service priority is generated from large to small to determine the priority order table. The user service corresponding to the largest priority factor has the highest priority, and PRI _k,n (t ) reflects the degree of change in the backlog of service data of user k's service n within a time slot interval. When the value of PRI _k,n (t) is relatively large, it indicates that the backlog of cache queue data of user k corresponding to service n is incremented It is relatively large, so the priority of business n scheduling should be correspondingly higher, which can effectively reduce the large average business transmission delay when the cache queue is in a high-occupancy state, and can also effectively reduce the loss of newly arrived business data. package phenomenon.

函数

为用户k在时隙t上PRI_k,n(t)取最大值时的业务序号的取值。Specifically, for user k, the priority of the service corresponding to the maximum priority factor is the highest, that is, the service that user k needs to be scheduled most urgently on time slot t is the ith service, where,

function

is the value of the service sequence number when user k takes the maximum value of PRI _k,n (t) on time slot t.

Step 6: The radio resource manager selects the radio resource block with the smallest number value from the determined set of available radio resource blocks, and calculates the optimal value required for each user to be scheduled to transmit its service data with the highest priority on the radio resource block. transmit power, and calculate the utility factor of each user to be scheduled using the radio resource block;

Specific steps are as follows:

First, the radio resource manager selects the radio resource block with the smallest number value from the set of available radio resource blocks determined in step 2;

It is assumed that the sequence number of the extracted radio resource block is r.

Then, calculate the optimal transmit power required when each user to be scheduled transmits the data of the service with the highest priority on the smallest radio resource block r;

The radio resource manager obtains the service control parameters of the service with the highest priority of each user to be scheduled, as well as the QSI, energy efficiency value and CSI of the corresponding buffer queue in the current time slot, and calculates the priority of each user to be scheduled on the radio resource block The optimal transmit power required for the highest service data;

The optimal transmit power formula is as follows:

为在时隙t上用户k的能量效率值，该无线资源块上对应的高斯白噪声功率为σ²，P_k,n,r(t)取值遵循以下公式：取最小值的函数定义为

取最大值的函数定义为

Among them, P _k,n,r (t) is the optimal transmit power required when using the radio resource block r to transmit the data of the highest priority service n of the user k on the time slot t, and W is the bandwidth of the radio resource block r ; g _k,r (t) is the CSI of user k on radio resource block r in time slot t, P ^max is the maximum transmit power of the wireless access point,

is the energy efficiency value of user k on time slot t, the corresponding white Gaussian noise power on the radio resource block is σ ² , and the value of P _k,n,r (t) follows the following formula: the function of taking the minimum value is defined as

The function to take the maximum value is defined as

Specifically, the optimal transmit power P _k,r,n (t) required when using the radio resource block r to transmit the data of the highest priority service n of user k on time slot t is not only related to the CSI of the current time slot t, Also related to QSI, if the channel gain of user k on the radio resource block r is larger, the transmit power is also larger to achieve higher data transmission rate and spectrum utilization. In addition, if user k is concerned about the highest priority service The greater the QSI of n, the greater the transmit power, because by increasing the transmit power to improve the data transmission rate, the average transmission delay of service n can be controlled within a certain range, thereby achieving network stability.

According to the optimal transmit power required by each user to be scheduled, the utility factor of using the radio resource block to transmit the service data with the highest priority of each user to be scheduled is calculated, and the specific method is as follows:

为在时隙t上，使用无线资源块r传输用户k优先级最高业务n的数据时的效用因子。in

is the utility factor when the radio resource block r is used to transmit the data of the highest priority service n of user k on time slot t.

是使用无线资源块r服务用户k所需的发射功率与实现的数据传输速率的加权减式，如果效用因子

数值越小，则反映用户k使用无线资源块r传输优先级最高业务n可以消耗越少的发射功率来得到越大的数据传输速率，即能实现更低的业务平均传输时延和更高的网络能量效率，用户k越应该分配到无线资源块r。Specifically, the utility factor

is the weighted subtraction of the transmit power required to serve user k using radio resource block r and the achieved data transmission rate, if the utility factor

The smaller the value is, it reflects that user k can use the radio resource block r to transmit the highest priority service n, which can consume less transmit power to obtain a larger data transmission rate, that is, it can achieve a lower average service transmission delay and a higher transmission rate. Network energy efficiency, the more user k should be allocated to the radio resource block r.

Step 7: Determine the allocation decision and power control result of the radio resource block r according to the utility factor when transmitting the service data with the highest priority of each user to be scheduled according to the radio resource block r of the minimum number value, and update the radio resource block set;

The described radio resource block allocation strategy method is:

且

时，无线资源管理器将无线资源块r分配给用户k用以传输其优先级最高业务n，并且设置在时隙t上无线接入点通过无线资源块r服务用户k传输其优先级最高业务n时的最优发射功率为P_k,n,r(t)，否则，无线资源管理器不会将无线资源块r分配给任何待调度用户，其中，函数

为

取最小值时的用户序号和业务序号的取值。If the conditions are met

and

When , the radio resource manager allocates radio resource block r to user k to transmit its highest priority service n, and the wireless access point is set on time slot t to serve user k to transmit its highest priority service through radio resource block r The optimal transmit power at n is P _k,n,r (t), otherwise, the radio resource manager will not assign the radio resource block r to any user to be scheduled, where the function

for

The value of the user serial number and service serial number when taking the minimum value.

Step 8, the radio resource manager deletes the radio resource block r from the radio resource block set, updates the available radio resource block set, and judges whether all available radio resource blocks have been traversed; if so, perform step nine; otherwise , return to step 6;

Step 9, the radio resource manager sends the allocation decision and power control result of each radio resource block to the corresponding user to be scheduled;

The radio resource manager sends the determined power control result and radio resource block allocation decision to the corresponding user to be scheduled through the downlink control channel;

Step ten, the radio resource manager counts the data transmission rate of each user in the current time slot t transmitting the highest priority service, the total transmit power required to consume and calculates the energy efficiency value of the next time slot t+1;

According to the data transmission rate of all users in the current time slot and the arrival rate of new data of the requested service, update the QSIs of the cache queues corresponding to all services of all users, and end the resource allocation process of the current time slot;

The specific process is as follows:

First, for the user k ^o to be scheduled allocated to the radio resource block, the calculation method of the energy efficiency value is as follows:

是在时隙t上采集到用户k^o的数据传输速率，

是在时隙t上用户k^o所需的总发射功率，其定义为

ε是介于0到1之间的能量效率因子，ε数值越接近自然数1则表示系统的电能转化率越高。in

is the data transmission rate of user k ^o collected on time slot t,

is the total transmit power required by user k ^o on time slot t, which is defined as

ε is an energy efficiency factor between 0 and 1. The closer the value of ε is to the natural number 1, the higher the power conversion rate of the system.

For other users i ^o that are not allocated to radio resource blocks, the calculation method of the energy efficiency value is as follows:

Step 11, the wireless resource manager updates the QSI of the cache queue corresponding to each service of each user;

If a user is allocated a radio resource block on time slot t, the radio resource manager updates the cache queue corresponding to the service with the highest priority of all users allocated to the radio resource block according to the following formula:

Q _k,n (t+1)=max[Q _k,n (t)-R _k (t),0]+A _k,n (t);

Among them, k is the user ID allocated to the radio resource block, n is the sequence number of the highest priority service of user k, R _k (t) is the data transmission rate of user k on the current time slot t, and A _k,n (t) is User k requests the new data arrival rate of service n with the highest priority on the current time slot t,

For the to-be-scheduled users allocated to the radio resource block on the time slot t, the radio resource manager updates the buffer queue corresponding to the service with the highest non-priority according to the following formula:

Among them, n ^o is the sequence number of the non-highest priority service of user k,

For other users who are not allocated to radio resource blocks on time slot t, the radio resource manager updates all the corresponding buffer queues for each service according to the following formula:

Step 12: The radio resource manager ends the radio resource allocation process in the current time slot t, and judges whether all resource allocation time slots are completed, if so, end; otherwise, enter the next radio resource allocation time slot start time. If so, go back to step 2.

The core idea of the present invention is that when each service of each user to be scheduled is prioritized, priority is given to the service with a large change rate of the cache queue, and the service with the largest change rate of the cache queue of each user to be scheduled is regarded as an absolute high priority. This can reduce the backlog of service data to be transmitted in the buffer queue to a minimum state, thereby reducing the average service transmission delay and ensuring the stability of the network; for each user to be scheduled, determine the highest priority service data for During transmission, with the goal of reducing the average transmission delay of services and improving network energy efficiency, combined with different delay characteristics of services, buffer queue QSI, and user CSI, power control and radio resource block allocation are performed for users to be scheduled, which can ensure high performance. The backlog of real-time services (such as augmented reality services, video streaming services) is transmitted in a relatively short period of time, so that latency-insensitive services (such as e-mail services) sacrifice a certain latency performance in exchange for more time. High energy efficiency performance, under the premise of realizing network stability, makes the energy efficiency performance of the network approach the optimal value, effectively promoting the construction of a green energy network.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the present invention. within the scope of protection.

Claims (3)

1. a resource allocation method of time delay optimization, is characterized in that, concrete steps are as follows: Step 1: The wireless resource manager counts service types with different delay characteristics that the network can perceive; There are N types of service types; expressed as {1,2,…,n,…,N}; n is the service serial number; there are K total attached users; expressed as {1,2,…,k,…,K}; k is the user ID; Step 2, assigning a time slot for each resource, the radio resource manager configures service control parameters for each service at the starting moment, and determines the set of all available radio resource blocks in the current time slot; Step 3, for each resource allocation time slot, the radio resource manager obtains the QSI of the buffer queue corresponding to each service of each user, determines all the users that need to be scheduled, and obtains the CSI of all the users to be scheduled in the current time slot; The QSI of the buffer queue refers to the backlog of service data to be transmitted in the buffer queue; the CSI is the channel gain of the user on the available radio resource blocks; According to whether the buffer queue corresponding to each service of each user is empty, the radio resource manager determines all users that need to be scheduled in the current time slot, and obtains the CSI reported by all users to be scheduled in the current time slot; Step 4: For each service of each user to be scheduled, the radio resource manager obtains the QSI of the corresponding buffer queue in the current time slot t and the previous time slot t-1 respectively; Step 5, the radio resource manager calculates the priority of each service of each user to be scheduled and determines the service with the highest priority of each user to be scheduled according to the QSI of time slot t and time slot t-1; The formula for calculating the priority of each service of each user k' to be scheduled is as follows: PRI _k',n (t)=(Q _k',n (t)) ² -(Q _k',n (t-1)) ² PRI _k',n (t) is the priority factor of user k' to be scheduled on service n on time slot t, Q _k',n (t) is the buffer corresponding to service n of user k' to be scheduled on time slot t QSI of the queue; For each user to be scheduled, the service corresponding to the maximum priority factor has the highest priority; Step 6: The radio resource manager selects the radio resource block with the smallest number value from the set of available radio resource blocks, and calculates the optimal transmit power and utility factor; Specific steps are as follows: First, the radio resource manager selects the radio resource block with the smallest number value from the set of available radio resource blocks determined in step 2, and the sequence number is r; Then, calculate the optimal transmit power required when transmitting the data of the service with the highest priority of each user to be scheduled on the radio resource block r; For the to-be-scheduled user k', when calculating the data of the highest priority service n to be transmitted on the radio resource block r, the required optimal transmit power formula is as follows:

P _k',n,r (t) is the optimal transmit power required when using radio resource block r to transmit the data of the highest priority service n of user k' to be scheduled on time slot t; W is the value of radio resource block r Bandwidth; ε is an energy efficiency factor with a value between 0 and 1. The closer the value of ε is to the natural number 1, the higher the power conversion rate of the system;

is the energy efficiency value of user k' to be scheduled on time slot t; σ ² is the corresponding white Gaussian noise power on radio resource block r; g _k',r (t) is user k' to be scheduled on time slot t The channel gain on the wireless resource block r; ^Pmax is the maximum transmit power of the wireless access point; _Vn is the service control parameter of service n; Finally, according to the optimal transmit power required to serve each to-be-scheduled user, calculate the utility factor of using the radio resource block r to transmit the highest-priority service data of each to-be-scheduled user; For the to-be-scheduled user k', calculate the utility factor when transmitting the data of the service with the highest priority on the radio resource block r. The formula is as follows:

is the utility factor when using the radio resource block r to transmit the data of the highest priority service n of the user k' to be scheduled on the time slot t; Step 7: Determine the allocation decision and power control result of the radio resource block r according to the utility factor when transmitting the highest priority service data of each user to be scheduled using the radio resource block r with the minimum number value, and the radio resource manager updates the radio resource A collection of resource blocks; Step 8, the radio resource manager judges whether all available radio resource blocks have been traversed; if so, execute step 9; otherwise, return to step 6; Step 9, the radio resource manager sends the allocation decision and power control result of each radio resource block to the corresponding user to be scheduled; Step 10, count the data transmission rate of each user in the current time slot t, the total transmit power consumed and calculate the energy efficiency value of the next time slot t+1; First, for the user k ^o to be scheduled allocated to the radio resource block, the calculation method of the energy efficiency value is as follows:

is the data transmission rate of user k ^o collected on time slot t;

is the total transmit power required by user k ^o on time slot t, which is defined as

For other users i ^o that are not allocated to radio resource blocks, the calculation method of the energy efficiency value is as follows:

Step 11, the radio resource manager updates the QSI of the cache queue corresponding to each service of each user; For the to-be-scheduled user k ^o allocated to the radio resource block in the time slot t, the QSI update method of the buffer queue corresponding to the highest priority service n is as follows:

is the new data arrival rate of the highest priority service n of user k ^o on the current time slot t; For the to-be-scheduled user k ^o allocated to the radio resource block on the time slot t, the QSI update method of the buffer queue corresponding to the non-highest priority service n ^o is as follows:

For other users i ^o that are not allocated to radio resource blocks on time slot t, the QSI update method for each service corresponding to the buffer queue is as follows:

Step 12: The radio resource manager ends the radio resource allocation process in the current time slot t, and judges whether all resource allocation time slots are completed, if so, end; otherwise, enter the next radio resource allocation time slot start time. If so, go back to step 2. 2. The resource allocation method for time delay optimization according to claim 1, wherein in the step 2, the radio resource manager sequentially configures service control parameters for N kinds of services that the network can perceive; let V _n is the business control parameter of business n; The radio resource manager determines the set of all available radio resource blocks in the current time slot; by serially numbering all available radio resource blocks and counting the number; defining the set as {1,2,...,R}, the available radio resources A block refers to an idle radio resource block that is not allocated to any user, and the natural number R is the total number of all available radio resource blocks in the current time slot. 3. the resource allocation method of a kind of time delay optimization as claimed in claim 1, is characterized in that, described step 7 is specifically: First, sort the utility factors calculated by all the users to be scheduled, and select the minimum value; at the same time, obtain the value of the user serial number and the service serial number corresponding to the minimum utility factor; When the utility factor reaches the minimum value, the value function of the corresponding user serial number and its service serial number is:

Then, on the basis of selecting the user k ^* corresponding to the minimum utility factor and its highest priority service n ^* , determine whether it satisfies the

If so, the radio resource manager assigns radio resource block r to user k ^* to transmit data for its highest priority service n ^* , and sets the wireless access point to serve user k ^* through radio resource block r on time slot t The optimal transmit power to transmit data of its highest priority service n ^* is

Otherwise, the radio resource manager will not allocate radio resource block r to any user to be scheduled.

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