阅读说明：本技术 一种基于下行链路干扰抑制区的通信模式选择实现方法 (Communication mode selection realization method based on downlink interference suppression zone ) 是由 张晶 刘金鑫 马维鑫 姜鸿强 于 2020-02-19 设计创作，主要内容包括：本发明提供一种基于下行链路干扰抑制区的通信模式选择实现方法,考虑在单小区场景中,D2D用户复用蜂窝用户的下行链路。首先根据预设的阈值,推导出下行链路干扰抑制区(DILA)的范围,然后基于下行链路干扰抑制区和D2D通信范围制定模式选择的标准,最后依据标准来进行模式选择,解决了目前D2D用户性能不足的问题。在通信模型中定义了下行干扰抑制区。这在保证蜂窝通信性能的前提下,有效抑制了因用户复用蜂窝通信而产生的基站对D2D接收机的干扰。基于下行干扰抑制区和D2D通信范围,制定了一种新的通信模式选择策略。该过程实现了用户的无缝通信模式切换,保证通信的质量要求。(The invention provides a method for realizing communication mode selection based on a downlink interference suppression area, which considers that D2D users reuse the downlink of cellular users in a single-cell scene. Firstly, deducing the range of a downlink interference suppression area (DILA) according to a preset threshold value, then formulating a mode selection standard based on the downlink interference suppression area and a D2D communication range, and finally selecting the mode according to the standard, thereby solving the problem of insufficient performance of the current D2D user. A downlink interference suppression zone is defined in the communication model. On the premise of ensuring the cellular communication performance, the interference of the base station to the D2D receiver, which is generated by multiplexing cellular communication by users, is effectively inhibited. Based on the downlink interference suppression area and the D2D communication range, a new communication mode selection strategy is established. The process realizes the seamless communication mode switching of the user and ensures the quality requirement of communication.)

1. A method for realizing communication mode selection based on a downlink interference suppression zone is characterized in that: the implementation method comprises the following steps:

the method comprises the following steps: defining a downlink interference suppression area, wherein in a single-cell scene, the cell radius is R, R > R, and a path loss model is defined as P_a＝c·(d_a)^-α·P₀In which P is₀Representing the initial transmit power, P_aRepresenting the receiving signal power of a receiving end, wherein c and alpha respectively represent a path fading constant and a fading index;

step two: adopting a management strategy of a downlink interference suppression zone to manage harmful interference caused by cellular communication to D2D communication;

step three: the criteria for mode selection are defined as: (1) the users in the intersection of the communication range of the D2D and the interference suppression area perform a D2D special mode, namely, the users use independent frequency bands to perform D2D communication; (2) users in the communication range of D2D outside the interference suppression zone carry out D2D multiplexing mode, namely, the users carry out D2D communication by multiplexing the time-frequency resources of cellular users; (3) the user carries out traditional cellular communication in the range of the cellular area outside the communication range of D2D;

step four: and the user selects the mode according to the mode selection standard and switches the mode in the mobile scene to realize continuous and efficient communication.

2. The method of claim 1, wherein the method further comprises: in the first step, the cellular user receives the received signal power from the base station as

3. The method of claim 1, wherein the method further comprises selecting a communication mode based on a downlink interference suppression zoneThe method is characterized in that: in the first step, the power of the D2D transmitter DT is strictly controlled to avoid harmful interference to the cellular user, i.e. the minimum signal-to-noise ratio that the cellular user CU should meet is recorded as_cI.e. byThe interference power formula of DT is substituted into the minimum signal-to-noise ratio formula to obtain

4. The method of claim 1, wherein the method further comprises: in the second step, the position of the D2D receiver DR is derived from the range of the downlink interference suppression zone, i.e. the range of the limited activity of the D2D receiver DR, while ensuring the cellular communication performance.

Technical Field

The invention relates to the field of interference management in D2D communication, in particular to a method for realizing communication mode selection based on a downlink interference suppression zone.

Background

The D2D (device to device) technology refers to a technology for directly exchanging information between neighboring devices in a communication network. The D2D communication multiplexes the cellular user uplink or downlink resources in an overlay or underlay mode, so that the data pressure of the core network of the communication system can be reduced, the frequency spectrum utilization rate and the throughput are greatly improved, the network capacity is enlarged, the communication network can be ensured to operate more flexibly, intelligently and efficiently, and a new way is opened up for zero-delay communication of a large-scale network, mass access of a mobile terminal and large data transmission. With the attendant problems of communication mode selection and interference. Therefore, how to efficiently select a communication mode and coordinate interference becomes a key for improving network performance. The D2D discovery technique involved enables devices to discover potential candidates in the vicinity and establish direct connections with them. To accomplish this task, devices share beacon signals among themselves to gather information such as device location/distance, channel status and device ID. The devices use this information to evaluate the feasibility of grouping into pairs with each other.

For D2D communication underlying the cellular network, the first problem is to find an effective interference coordination, which improves the throughput of D2D system or ensures the reliability of D2D communication on the premise of preventing D2D communication from generating harmful interference to cellular communication. Takshi, G.

Arslan et al propose a method for joint optimization of power allocation and resource allocation based on a genetic algorithm to maximize the spectral efficiency of the network. G.yu, l.xu, d.feng, r.yin, g.y.li, y.jiang et al propose three interaction modes for D2D communication: cellular mode, dedicated mode, reuse mode. Therefore, a joint optimization of mode selection, channel allocation and power control is provided to maximize the spectrum efficiency. M.zulhasnine, c.huang, a.srinivasan et al propose a greedy heuristic algorithm to reduce the interference of D2D communication to the host cellular network. By using game theory, f.wang, c.xu, l.song, q.zhao, x.wang, z.han and the like, a resource auction algorithm is proposed to optimize power and allocate channel resources in an iterative manner, so thatMaximizing the service life of the battery. X.xu, y.zhang, z.sun, y.hong, x.tao et al consider that D2D multiplexes cellular network downlink resources, D2D mode switching in D2D mobile scenarios, and deduce that D2D communication range can be represented by offset circles of different radii. H.min, j.lee, s.park, d.hong et al propose an interference suppression area (ILA) to mitigate the cellular network's interference with D2D communications, thereby enhancing system capacity. Within the ILA, the D2D receiver signal-to-noise ratio (ISR) is greater than a preset threshold, and if the cellular subscriber CU is within the ILA, the D2D subscriber cannot reuse the resources of the cellular subscriber. C.wang, f.fu, m.tsai et al propose a position recommendation and power adjustment algorithm (LP)&PA) to adjust the location and extent of the interference suppression area (ILA) to thereby improve spectral efficiency. Most of the current studies have the following disadvantages: only the performance of the cellular link is considered, ignoring the performance of the D2D user.

Disclosure of Invention

The invention aims to provide a method for realizing communication mode selection based on a downlink interference suppression zone, which considers that in a single-cell scene, a D2D user multiplexes a downlink of a cellular user. Firstly, deducing the range of a downlink interference suppression area (DILA) according to a preset threshold value, then formulating a mode selection standard based on the downlink interference suppression area and a D2D communication range, and finally selecting the mode according to the standard, thereby solving the problem of insufficient performance of the current D2D user.

The invention provides a method for realizing communication mode selection based on a downlink interference suppression zone, which comprises the following steps:

the method comprises the following steps: defining a downlink interference suppression area, wherein in a single-cell scene, the cell radius is R, R > R, and a path loss model is defined as P_a＝c·(d_a)^-α·P₀In which P is₀Representing the initial transmit power, P_aRepresenting the receiving signal power of a receiving end, wherein c and alpha respectively represent a path fading constant and a fading index;

step two: adopting a management strategy of a downlink interference suppression zone to manage harmful interference caused by cellular communication to D2D communication;

step three: the criteria for mode selection are defined as: (1) the users in the intersection of the communication range of the D2D and the interference suppression area perform a D2D special mode, namely, the users use independent frequency bands to perform D2D communication; (2) users in the communication range of D2D outside the interference suppression zone carry out D2D multiplexing mode, namely, the users carry out D2D communication by multiplexing the time-frequency resources of cellular users;

(3) the user carries out traditional cellular communication in the range of the cellular area outside the communication range of D2D;

step four: and the user selects the mode according to the mode selection standard and switches the mode in the mobile scene to realize continuous and efficient communication.

The further improvement lies in that: in the first step, the cellular user receives the received signal power from the base station as

Interference power from the base station received by the D2D receiver DR is

WhereinRepresents the received signal power of the BS-CU link,

representing the interference power of the DT-CU link, the interference power received by the cellular user from the D2D transmitter DT

The further improvement lies in that: in the first step, the power of the D2D transmitter DT is strictly controlled to avoid harmful interference to the cellular user, i.e. the minimum signal-to-noise ratio that the cellular user CU should meet is recorded as_cI.e. byThe interference power formula of DT is substituted into the minimum signal-to-noise ratio formula to obtainThe D2D receiver DR receives the received signal power from the D2D transmitter DT

Wherein

Representing the interference power of the DT-CU link,

representing the received signal power of the DT-DR link, the signal-to-noise ratio (SIR) of the receiver DR, deduced as D2D, is expressed as

The DR signal-to-noise ratio of the D2D receiver should be less than a preset threshold_DI.e. by

Get SIR_DRIs less than the maximum value of_DWherein

The above formula is modified intoLet M be a²+b²，Where M ≠ 0 and N ≠ 0, the above-described variation is M [ (x-d)²+y²]＞N(x²+y²) When M > N, the above formula is modified toIn this case, the DILA range isIs used as the center of a circle,

a honeycomb area outside a circle of a radius; when M < N, M [ (x-d)²+y²]＞N(x²+y²) Is deformed into

In this case, the DILA range isIs used as the center of a circle,is the radius within a circle, when M ═ N, M [ (x-d)²+y²]＞N(x²+y²) Deformation to d²-2dx > 0, when DILA is in the rangeI.e. the abscissa is smaller thanWithin the cellular region of (a).

The further improvement lies in that: in the second step, the position of the D2D receiver DR is derived from the range of the downlink interference suppression zone, i.e. the range of the limited activity of the D2D receiver DR, while ensuring the cellular communication performance.

And (3) deducing the range of a downlink interference suppression area (DILA) on the premise of ensuring the performance of the cellular link by considering the downlink channel resource of the D2D link multiplexing cellular link. In the downlink interference suppression zone, the users cannot reuse the time-frequency resources of the cellular users for D2D communication. It is assumed that the cellular users and the D2D users only know to receive CSI, while the base station BS knows all CSI of all the links connected to the base station. Here we assume that the D2D communication range is a circular area centered at the D2D transmitter and having a radius r. Since the maximum power of the D2D transmitter DT has been tightly controlled to avoid any harmful interference to the cellular user, the interference to the cellular user by DT can be disregarded. However, in downlink transmission, the base station may cause interference to the D2D receiver DR.

When M > N, the interference suppression zone is shaded in the figure, and since the range of motion of the D2D receiver should be an area centered on the D2D transmitter DT, it is more reasonable than the other two cases. At the same time because_CAnd_Dis much less than 1, and d_BS,CUFar greater than d_DT,CUTherefore, M > N holds. When the D2D receiver DR is located within the interference suppression zone and will be subject to harmful interference due to cellular communications, the signal-to-noise ratio (SIR) of the D2D receiver DR is less than a preset threshold_DAnd the performance of D2D communication is not ideal. Currently, M > N is mainly discussed as a problem of user communication mode selection.

The invention has the beneficial effects that: a downlink interference suppression zone is defined in the communication model. On the premise of ensuring the cellular communication performance, the interference of the base station to the D2D receiver, which is generated by multiplexing cellular communication by users, is effectively inhibited. Based on the downlink interference suppression area and the D2D communication range, a new communication mode selection strategy is established. The process realizes the seamless communication mode switching of the user and ensures the quality requirement of communication.

Drawings

Fig. 1 is a system model to which the present invention is applicable.

FIG. 2 is a schematic diagram of a downlink interference suppression zone when M > N in the present invention.

FIG. 3 is a diagram of the downlink interference suppression zone when M < N in the present invention.

Fig. 4 is a schematic diagram of the downlink interference suppression zone when M is equal to N in the present invention.

Detailed Description

For the purpose of enhancing understanding of the present invention, the present invention will be further described in detail with reference to the following examples, which are provided for illustration only and are not to be construed as limiting the scope of the present invention. As shown in fig. 1-4, the present embodiment provides a method for implementing communication mode selection based on a downlink interference suppression zone, where the method includes the following steps:

the method comprises the following steps: defining downlink interference suppression zones in single cell scenariosThe radius of the honeycomb is R, R > R, and the path loss model is defined as P_a＝c·(d_a)^-α·P₀In which P is₀Representing the initial transmit power, P_aRepresenting the receiving signal power of a receiving end, wherein c and alpha respectively represent a path fading constant and a fading index;

step two: adopting a management strategy of a downlink interference suppression zone to manage harmful interference caused by cellular communication to D2D communication;

step three: the criteria for mode selection are defined as: (1) the users in the intersection of the communication range of the D2D and the interference suppression area perform a D2D special mode, namely, the users use independent frequency bands to perform D2D communication; (2) users in the communication range of D2D outside the interference suppression zone carry out D2D multiplexing mode, namely, the users carry out D2D communication by multiplexing the time-frequency resources of cellular users;

(3) the user carries out traditional cellular communication in the range of the cellular area outside the communication range of D2D;

step four: and the user selects the mode according to the mode selection standard and switches the mode in the mobile scene to realize continuous and efficient communication.

In the first step, the cellular user receives the received signal power from the base station as

Interference power from the base station received by the D2D receiver DR is

WhereinRepresents the received signal power of the BS-CU link,

representing the interference power of the DT-CU link, the interference power received by the cellular user from the D2D transmitter DT

In the first step, D2 is strictly controlledD power of transmitter DT to avoid harmful interference to cellular user, i.e. minimum SNR that cellular user CU should satisfy is recorded as_cI.e. byThe interference power formula of DT is substituted into the minimum signal-to-noise ratio formula to obtainThe D2D receiver DR receives the received signal power from the D2D transmitter DT

WhereinRepresenting the interference power of the DT-CU link,representing the received signal power of the DT-DR link, the signal-to-noise ratio (SIR) of the receiver DR, deduced as D2D, is expressed asThe DR signal-to-noise ratio of the D2D receiver should be less than a preset threshold_DI.e. byGet SIR_DRIs less than the maximum value of_DWherein

The above formula is modified into

Let M be a²+b²，

Where M ≠ 0 and N ≠ 0, variants of the above formulaForm M [ (x-d)²+y²]＞N(x²+y²) When M > N, the above formula is modified toIn this case, the DILA range is

Is used as the center of a circle,

a honeycomb area outside a circle of a radius; when M < N, M [ (x-d)²+y²]＞N(x²+y²) Is deformed intoIn this case, the DILA range is

Is used as the center of a circle,is the radius within a circle, when M ═ N, M [ (x-d)²+y²]＞N(x²+y²) Deformation to d²-2dx > 0, when DILA is in the range

I.e. the abscissa is smaller thanWithin the cellular region of (a).

In the second step, the position of the D2D receiver DR is derived from the range of the downlink interference suppression zone, i.e. the range of the limited activity of the D2D receiver DR, while ensuring the cellular communication performance.

And (3) deducing the range of a downlink interference suppression area (DILA) on the premise of ensuring the performance of the cellular link by considering the downlink channel resource of the D2D link multiplexing cellular link. In the downlink interference suppression zone, the users cannot reuse the time-frequency resources of the cellular users for D2D communication. It is assumed that the cellular users and the D2D users only know to receive CSI, while the base station BS knows all CSI of all the links connected to the base station. Here we assume that the D2D communication range is a circular area centered at the D2D transmitter and having a radius r. Since the maximum power of the D2D transmitter DT has been tightly controlled to avoid any harmful interference to the cellular user, the interference to the cellular user by DT can be disregarded. However, in downlink transmission, the base station may cause interference to the D2D receiver DR.

When M > N, the interference suppression zone is shaded in the figure, and since the range of motion of the D2D receiver should be an area centered on the D2D transmitter DT, it is more reasonable than the other two cases. At the same time because_CAnd_Dis much less than 1, and d_BS,CUFar greater than d_DT,CUTherefore, M > N holds. When the D2D receiver DR is located within the interference suppression zone and will be subject to harmful interference due to cellular communications, the signal-to-noise ratio (SIR) of the D2D receiver DR is less than a preset threshold_DAnd the performance of D2D communication is not ideal. A downlink interference suppression zone is defined in the communication model. On the premise of ensuring the cellular communication performance, the interference of the base station to the D2D receiver, which is generated by multiplexing cellular communication by users, is effectively inhibited. Based on the downlink interference suppression area and the D2D communication range, a new communication mode selection strategy is established. The process realizes the seamless communication mode switching of the user and ensures the quality requirement of communication.