CN105407488A - Optimization method for resource pool size adjustment based on D2D terminal feedback value - Google Patents

Abstract

The present invention claims to protect an optimization method for adjusting the size of a resource pool based on D2D terminal feedback values, which belongs to the technical field of resource pool adjustment, and includes the steps: the base station first presets the upper and lower thresholds of resource usage for the allocated resource pool, and through Notify the terminals supporting the D2D function in the form of broadcasting or the like. While selecting resources in the resource pool, the D2D terminal acquires the status information of the current resource pool periodically or passively triggered by events, and compares the obtained resource pool "status value" with the threshold value preset by the base station. The base station adjusts the size of the resource pool according to the feedback information from the terminal. The method can avoid resource waste and flexibly adjust the size of the resource pool.

Description

An optimization method for adjusting resource pool size based on D2D terminal feedback value

technical field

The invention belongs to the technical field of resource pool adjustment in 5G communications, and specifically relates to an optimization method for adjusting the size of a resource pool based on a D2D terminal feedback value.

Background technique

D2D communication means that the communication between two users can directly perform end-to-end direct communication without passing through the base station. Due to the limited communication distance, information can be sent with low power consumption to reduce the energy consumption of the terminal. D2D communication is expected to become one of the effective supplementary technologies for future communication. At the same time, for the resource acquisition method of D2D communication, whether it is signaling transmission or data transmission, the agreement obtained by the current R-12 version is: support two ways of resource acquisition, that is, the traditional base station scheduling resource allocation method and resource pool random selection method. For data transmission in D2D communication, two modes are respectively defined: mode1 and mode2. Mode2 is a manner in which the base station randomly divides resource pools. That is, in this manner, the D2D terminal communicates by randomly obtaining resources from the resource pool.

However, regarding the size of the resource pool, the opinions reached by various companies are to allow the conversion of the resource acquisition mode (that is, the resource acquisition mode can be changed from mode2 to mode1); Feedback information to increase the resource pool. However, the case of reducing the resource pool is not considered. This will cause problems such as waste of resources and even degradation of user experience. Based on this, the present invention proposes a solution for flexibly and dynamically adjusting the resource pool, which can better adjust the size of the resource pool according to the feedback information of the D2D terminal, so as to avoid resource waste.

Contents of the invention

Aiming at the following existing deficiencies, an optimization method for adjusting the size of the resource pool based on D2D terminal feedback values to avoid resource waste and flexibly adjust the size of the resource pool is proposed. . The technical solution of the present invention is as follows: an optimization method for adjusting the size of a resource pool based on a D2D terminal feedback value, which includes the following steps:

101. The base station provides a resource pool for D2D terminals to use, and at the same time, notifies the D2D terminals in the cell of the upper and lower thresholds N _{up_threshold} and N _{down_threshold} of the preset resource usage;

102. While acquiring resource pool resources, the D2D terminal acquires the state value of the current resource pool in a periodic or event-triggered passive manner;

103. The D2D terminal respectively compares the state value with the threshold value preset by the base station, and feeds back the indication information I _up and I _down of the resource pool situation used for feedback; where I _up : indicates that when the D2D terminal of the receiving party detects When the state value is greater than or equal to N _{up_threshold} , that is, I _up is fed back. ; I _down , when the D2D terminal of the receiving party detects that the status value is less than N _{down_threshold} , it will feedback I _down ;

104. After the base station sets a measurement time period for the D2D terminal, the base station collects I _up and I _down fed back from multiple D2D terminals within the coverage area, and then compares the times of I _up and I _down . When the fed back I _up When the number of times is greater than the number of I _down times, increase the size of the resource pool; otherwise, reduce or keep the resource pool.

Further, after the resource pool is adjusted in step 104, when the adjustment result of the resource pool is: reduce or maintain the size of the resource pool, and for D2D terminals whose feedback I _up times are greater than I _down feedback times, the The base station separately divides a resource pool for the D2D terminal to communicate, that is, mode1 is changed to mode2.

Further, after the resource pool is adjusted in step 104, when the resource pool is sufficient, the base station can choose to reclaim part of the resources in the resource pool or not reclaim the resources in the resource pool, and broadcast the adjusted The adjusted resource pool information is broadcast to all terminals under its coverage. Other non-D2D communication terminals can use the resource pool. For the "sleeping" terminals within the coverage area, the base station notifies the terminals through paging.

Further, the manner in which the base station provides the resource pool for the D2D terminal in step 101 is to randomly provide a resource pool, and inform the terminal in the cell of the base station of the upper and lower thresholds of the preset resource usage. Including: A. broadcasting the threshold value to the terminal users within the coverage of the base station; B. the terminal obtaining the threshold value information by establishing an RRC connection with the base station.

Further, the preset thresholds N _{up_threshold} and N _{down_threshold} are selected from one or a combination of the following: (1), the upper and lower thresholds of the number of activated D2D terminals; (2), the use of resource pools Efficiency upper and lower thresholds.

Further, the status value in step 102 includes: (1), the number of activated D2D users; (2), the resource usage rate.

Advantage of the present invention and beneficial effect are as follows:

In the present invention, in the case of randomly allocating resource pools, the base station feeds back information to the base station according to the D2D terminals within its coverage, and dynamically adjusts the size of the resource pool according to a preset threshold value. The adjustment method includes reducing the size of the resource pool in addition to increasing the resource pool. At the same time, for special D2D terminals, a resource allocation conversion method is adopted. Taking into account the reduction of resource pools. In this way, there will be no waste of resources or even a decline in user experience.

Description of drawings

FIG. 1 is a flowchart of an optimization method for adjusting the size of a resource pool based on a D2D terminal feedback value according to a preferred embodiment of the present invention;

Fig. 2 is a schematic diagram of reducing or maintaining a resource pool.

detailed description

Below in conjunction with accompanying drawing, the present invention will be further described:

As shown in FIG. 1 , the present invention mainly considers scenarios of in-coverage and random allocation of resource pools. For D2D communication, 3GPP currently proposes a new resource allocation method based on the traditional LTE base station scheduling resources for terminals, that is, randomly divides a resource pool, that is, an RB resource block. It will be seen in LTE after the R12 version. in,

N _{up_threshold} : the pre-configured upper limit threshold of the base station.

N _{down_threshold} : The pre-configured lower threshold of the base station.

I _up : when the receiving D2D terminal detects that the "status value" is greater than or equal to N _{up_threshold} , it will feed back I _up .

I _down : When the D2D terminal of the receiver detects that the "status value" is less than or equal to N _{down_threshold} , it will feed back I _down . N _{D2D terminals} : the number of D2D terminals in the cell. N _RU : The usage efficiency of the actual resource pool.

The specific steps of this program are as follows:

1. The base station randomly divides a resource pool for the D2D terminal to use. At the same time, the upper and lower thresholds N _{up_threshold} and N _{down_threshold} of the preset resource usage are notified to the terminals in the cell in the following two ways.

(1) The threshold value is notified to the terminal user through broadcasting.

(2) The terminal obtains the threshold value information by establishing an RRC connection with the base station.

2. The threshold values N _{up_threshold} and N _{down_threshold} preset by the base station may be but not limited to one or more combinations of the following types.

(1) The upper and lower thresholds of the number of activated D2D terminals.

(2) The upper and lower thresholds of the utilization efficiency of the resource pool.

3. The D2D terminal acquires the "status value" of the current resource pool in a passive manner periodically or triggered by an event while acquiring resource pool resources. Specifically, the "status value" is:

(1) Number of activated D2D users;

(2) Resource utilization rate.

4. The D2D terminal compares the "status value" with the preset threshold value of the base station, and feeds back the indication information I _up and I _down of the resource pool used for feedback.

5. In a certain period, after the base station collects I _up and I _down fed back from multiple D2D terminals within the coverage area, it compares the times of I _up and I _down . When the times of I _up fed back are greater than the times of I _down , Increase the size of the resource pool; conversely, decrease the resource pool.

6. (1) In particular, when the result of the final resource pool adjustment is "reduce or maintain the resource pool size", and for the D2D terminal pair whose feedback I _up times are greater than I _down feedback times, the base station allocates resources for them separately The pool communicates, that is, mode1 becomes mode2.

(2) In particular, when the resource pool is sufficient, the base station can choose to take back part of the resource pool, or not take back the resource pool resources, and broadcast the adjusted resource pool information to all terminals under its coverage through broadcasting, and other Users of non-D2D communication can use this resource pool. For "sleeping" terminals within the coverage area, the base station can also notify the terminals through paging.

Among them, the specific embodiments for the three "status values" in process 3 and the adjustment scheme of the resource pool are:

Embodiment one:

When the number of activated D2D users is used as the judgment condition, N _{up_threshold} and N _{down_threshold} are the upper and lower thresholds of the D2D terminals using the resource pool, and the unit is the number. The base station adjusts the size of the resource pool according to the comparison between the "status value" fed back by the D2D terminal and the preset thresholds N _{up_threshold} and N _{down_threshold} .

●When N _{D2D terminals} >N _{up_threshold} or N _{D2D terminals} >=N _{up_threshold} , increase the number of resource pools;

● When N _{D2D terminals} < N _{down_threshold} or N _{D2D terminals} <= N _{down_threshold} , reduce or maintain the resource pool size.

1) When N _{D2D terminals} >N _{up_threshold} or N _{D2D terminals} >=N _{up_threshold} , that is, in the case of increasing resource pool resources, D2D terminals establish an RRC connection with the base station, and send the actual "status value" to the base station, and the base station according to The absolute value of the difference between the number of users and the threshold |N _{D2D terminal-} N _{up_threshold} |, to find the specific number of users, and estimate the frequency domain resources occupied by the average D2D terminal for communication according to the communication quality with different users The situation (or the number of RBs), that is, the base station adds frequency domain resources (or the number of RBs) of a corresponding size.

2) When N _{D2D terminals} < N _{down_threshold} or N _{D2D terminals} <= N _{down_threshold} , that is, in the case of reducing resource pool resources, D2D terminals establish an RRC connection with the base station, and send the actual "status value" to the base station, and the base station According to the absolute value of the difference between the number of users and the threshold |N _{down_threshold} -N _{D2D terminals} |, the specific number of users is calculated, and at the same time, the frequency domain occupied by the average D2D terminal for communication is estimated according to the communication quality with different users Resource conditions (or number of RBs), that is, the base station further reduces frequency domain resources (or number of RBs) of a corresponding size.

Embodiment two:

When the use of the resource pool is used as the judgment condition, at this time, N _{up_threshold} and N _{down_threshold} are the upper and lower thresholds of the D2D terminals using the resource pool, and the unit is HZ. The base station adjusts the size of the resource pool according to the comparison between the "status value" fed back by the D2D terminal and the preset thresholds N _{up_threshold} and N _{down_threshold} .

● When N _RU >N _{up_threshold} or N _RU >=N _{up_threshold} , increase the number of resource pools.

● When N _RU < N _{down_threshold} or N _RU <= N _{down_threshold} , reduce or maintain the resource pool size.

(1) When N _RU >N _{up_threshold} or N _RU >=N _{up_threshold} , that is, in the case of increasing resource pool resources, the D2D terminal establishes an RRC connection with the base station, and sends the actual "status value" to the base station, and the base station according to the user The absolute value of the difference between the number and the threshold |N _{D2D terminal-} N _{up_threshold} |, to find out the specific number of users, and estimate the frequency domain resources (or RB number), that is, the base station increases frequency domain resources (or number of RBs) of a corresponding size.

(2) When N _RU < N _{down_threshold} or N _RU <= N _{down_threshold} , that is, in the case of reducing resource pool resources, the D2D terminal establishes an RRC connection with the base station, and sends the actual "status value" to the base station, and the base station according to The absolute value of the difference between the number of users and the threshold |N _{down_threshold} -N _{D2D terminals} |, to find out the specific number of users, and at the same time estimate the frequency domain resources occupied by the average D2D terminal for communication according to the communication quality with different users situation (or the number of RBs), that is, the base station further reduces the frequency domain resources (or the number of RBs) of a corresponding size.

The above embodiments should be understood as only for illustrating the present invention but not for limiting the protection scope of the present invention. After reading the contents of the present invention, skilled persons can make various changes or modifications to the present invention, and these equivalent changes and modifications also fall within the scope defined by the claims of the present invention.

Claims (6)

1. An optimization method for adjusting the size of a resource pool based on a D2D terminal feedback value is characterized by comprising the following steps:

101. the base station provides a resource pool for the D2D terminal to use, and simultaneously, the upper and lower threshold values N for the preset resource use_{up_threshold}And N_{down_threshold}Informing D2D terminals in the cell;

102. the D2D terminal acquires the resource of the resource pool and acquires the state value of the current resource pool in a passive mode of periodic or event triggering;

103. D2D terminalRespectively comparing the state value with a threshold value preset by the base station, and feeding back indication information I of the resource pool condition for feedback_upAnd I_down(ii) a Wherein I_upIndicating that the D2D terminal of the receiving party detects that the state value is greater than or equal to N_{up_threshold}I.e. feedback I_up。；I_downWhen the D2D terminal of the receiving party detects that the state value is less than N_{down_threshold}I.e. feedback I_down；

104. In the period that the base station sets a measurement time period for the D2D terminal, the base station collects I fed back from a plurality of D2D terminals in the coverage area_upAnd I_downThen, I is mixed_upAnd I_downWhen the number of times of feedback is compared, when I is fed back_upNumber of times is greater than I_downIncreasing the size of the resource pool when times are required; otherwise, the resource pool is reduced or maintained.

2. The optimizing method of claim 1, wherein after the resource pool is adjusted in step 104, when the result of the adjustment of the resource pool is: i for feedback while reducing or maintaining the resource pool size_upNumber of times is greater than I_downAnd the base station independently divides a resource pool for the D2D terminal to communicate with the D2D terminal feeding back the number of times, namely, changing the mode1 into the mode 2.

3. The optimizing method for adjusting the size of the resource pool according to the D2D terminal feedback value according to claim 1, wherein after the resource pool is adjusted in step 104, when the resource pool is sufficient, the base station selectively reclaims part of the resources in the resource pool or does not reclaim the resources in the resource pool, and broadcasts the adjusted resource pool information to all terminals under its coverage through a broadcast mode, and other terminals not in D2D communication can use the resource pool, and the base station informs the terminals through a paging mode for the terminals "sleeping" in the coverage area.

4. The method as claimed in claim 1, 2 or 3, wherein the step 101 of providing the resource pool for the D2D terminal by the base station is to randomly provide a block resource pool, and the manner of presetting the upper and lower threshold values for resource usage to inform the terminals in the lower cell of the base station comprises: A. the threshold value is told to the terminal user in the coverage area of the base station in a broadcasting mode; B. and the terminal acquires the threshold value information by establishing RRC connection with the base station.

5. The optimizing method for adjusting the size of the resource pool according to the D2D terminal feedback value of claim 1, wherein the preset threshold value N is_{up_threshold}And N_{down_threshold}Selected from one or a combination of: (1) activating upper and lower limit threshold values of the D2D terminal number; (2) and the upper and lower threshold values of the utilization efficiency of the resource pool.

6. The optimizing method for adjusting the size of the resource pool according to the D2D terminal feedback value of claim 1, wherein the status values in step 102 include: (1) the number of activated D2D users; (2) and resource utilization rate.