KR20180106131A - Base station and operation method of the base station - Google Patents

Abstract

Disclosed are a base station capable of mitigating interference at boundaries of beams and providing a good communication environment, and an operation method thereof. The operation method comprises the steps of: obtaining, for each terminal, a scheduling metric for each of radio resources of each of a plurality of beams; correcting the scheduling metric by using a correction metric that is dependent on a beam index and a radio resource index of each of the plurality of beams; and determining a radio resource to be allocated to each of terminals in a beam coverage of each of the plurality of beams based on the corrected scheduling metric.

Description

Technical Field [0001] The present invention relates to a base station and a base station,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a base station and a base station operating method, and more particularly, to a technique in which a base station operating a plurality of beams mitigates interference at the boundaries of beams and provides a high-quality communication environment.

As the spread of mobile communication devices spreads, the number of Internet accesses of mobile devices surpasses the number of Internet accesses of PCs, and most of the total number of Internet accesses now occur in mobile devices. As the wireless communication environment is activated, the traffic volume of smart phones is steadily increasing.

The millimeter-wave band covers a wide frequency band from 30GHz to 300GHz, and has recently attracted worldwide attention as a 5G candidate frequency band. The millimeter wave based mobile communication system can use a wide frequency band, however, the path loss in the process of transmitting data due to the frequency characteristic having a very strong directivity tends to be large and the propagation attenuation tends to be large. In order to minimize the path loss due to the use of the millimeter-wave band, a beam forming technique of dividing each region in the cell by a beam is regarded as a very important technical factor. Beamforming not only increases signal strength in a specific direction, but also reduces signal transmission to undesired directions.

When the base station operates a plurality of beams, the data transmission capacity can be increased in proportion to the number of beams. However, performance degradation may occur due to adjacent beam interference. Also, terminals located at the center of beam coverage are easy to receive beams, while terminals located at the edge of beam coverage are difficult to receive beams, which may result in uneven communication quality.

The present invention provides a method by which a base station operating a plurality of beams can mitigate interference at the boundaries of beams and provide a high quality communication environment.

According to an aspect of the present invention, there is provided an operation method of a base station operating a plurality of beams according to an embodiment of the present invention,

Obtaining, for each terminal, a scheduling metric for each of the radio resources of each of the plurality of beams; Correcting the scheduling metric using a correction metric that is dependent on a beam index and a radio resource index of each of the plurality of beams; And determining a radio resource to be allocated to each of the terminals in the beam coverage of each of the plurality of beams based on the corrected scheduling metric.

Here, the radio resource index may be an index of a frequency component of a radio resource.

If the beam coverage of the first beam and the beam coverage of the second beam are adjacent to each other,

The correction metric for the first beam may be determined by a first function for the radio resource index and the correction metric for the second beam may be determined by a second function different from the first function.

The output value of the first function increases as the radio resource index increases, and the output value of the second function decreases as the radio resource index increases.

Wherein the obtaining the scheduling metric comprises:

The base station transmits a reference signal, acquires information on the reference signal strength of each of the in-base-station beams received by each of the terminals from the terminals, and calculates the scheduling metric from information on the reference signal strength.

Wherein the correcting the scheduling metric comprises:

A correction metric that depends on the beam index of each of the plurality of beams may be added to the scheduling metric of each of the plurality of beams to correct the scheduling metric.

The step of determining a radio resource to be allocated to each of the UEs comprises:

A terminal that is preferentially allocated to each of the wireless resources of each of the plurality of beams is determined and a wireless resource having a good scheduling metric among the wireless resources of the beam that can be allocated to the terminal is preferentially allocated to the terminal .

Wherein if the beam coverage of the first beam and the beam coverage of the second beam are adjacent to each other, allocating at least some of the idle resources of the second beam to cooperative communications with the first beam have.

Here, if the second beam does not use the kth radio resource allocated to the UE having a weak reception intensity of the first beam among the UEs in the beam coverage of the first beam, the kth radio resource To the k th wireless resource of the first beam through the first beam.

The method of operating the base station may further include transmitting information on radio resources allocated to the terminals within the coverage of each of the plurality of beams to the terminals.

According to another aspect of the present invention,

Receiving a reference signal from the base station; Transmitting information on the reception strength of the reference signal to the base station; Receiving radio resource allocation information set based on a scheduling metric corrected by a correction metric that is dependent on a beam index and a radio resource index of each of the plurality of beams; And demodulating a signal received through the radio resource allocated to the UE according to the radio resource allocation information to identify downlink data.

Here, the radio resource index may be an index of a frequency component of a radio resource.

Here, when the beam coverage of the first beam and the beam coverage of the second beam are adjacent to each other,

The correction metric for the first beam may be determined by a first function for the radio resource index and the correction metric for the second beam may be determined by a second function different from the first function.

Here, the output value of the first function increases as the radio resource index increases, and the output value of the second function decreases as the radio resource index increases.

A base station operating a plurality of beams according to an embodiment of the present invention includes:

A processor; And a memory in which at least one instruction executed via the processor is stored,

Wherein the at least one instruction comprises:

For each terminal, a scheduling metric is obtained for each of the plurality of beams of radio resources, and the calibration metric is corrected using a correction metric that depends on the beam index and radio resource index of each of the plurality of beams And to determine a radio resource to be allocated to each of the terminals in the beam coverage of each of the plurality of beams based on the corrected scheduling metric.

Here, when the beam coverage of the first beam and the beam coverage of the second beam are adjacent to each other,

The correction metric for the first beam may be determined by a first function for the radio resource index and the correction metric for the second beam may be determined by a second function different from the first function.

Here, the output value of the first function increases as the radio resource index increases, and the output value of the second function decreases as the radio resource index increases.

Wherein the at least one command comprises:

The base station may transmit a reference signal, obtain information on the reference signal strength of each of the beams from the respective terminals from the terminals, and calculate the scheduling metric from information on the reference signal strength have.

Wherein the at least one command comprises:

And to allocate at least some of the idle resources of the second beam to the collaborative communications with the first beam if the beam coverage of the first beam and the beam coverage of the second beam are adjacent to each other.

Wherein the at least one command comprises:

If the second beam does not use the kth radio resource allocated to the terminal having a weak reception intensity of the first beam among the terminals in the beam coverage of the first beam, The same information as the information to be transmitted to the kth radio resource of the first beam can be transmitted.

According to the present invention, when a plurality of beams of a base station are operated, degradation of communication quality due to interference between beams can be reduced. Also, frequency resource distribution of each of the beams can be efficiently performed. And, by performing cooperative communication with adjacent beams, the communication quality can be improved.

1 is a block diagram illustrating a communication node performing a method of operating a communication node in a communication network according to an embodiment of the present invention.
2 is a conceptual diagram illustrating a base station according to an exemplary embodiment of the present invention.
FIG. 3 is a plan view showing the base station shown in FIG. 2 viewed from above in the z-axis direction.
4 is a flowchart illustrating a method of operating a base station according to an exemplary embodiment of the present invention.
FIG. 5 is a flowchart illustrating a process of performing step S110 shown in FIG.
FIG. 6 is a flowchart illustrating a process of performing step S120 of FIG.
7 is a graph showing a change in the correction metric according to the radio resource index k.
8 is a conceptual diagram illustrating a first embodiment in which resources of beams are allocated to terminals.
9 is a conceptual diagram illustrating a second embodiment in which resources of beams are allocated to terminals.
10 is a flowchart illustrating a method of operating a base station according to another exemplary embodiment of the present invention.
11 is a flowchart illustrating steps S140 and steps performed in FIG.
12 is a conceptual diagram illustrating a third embodiment in which resources of beams are allocated to terminals.
13 is a conceptual diagram illustrating an example in which radio resources of respective beams are allocated.
FIG. 14 is a flowchart illustrating an operation method of a terminal according to an exemplary embodiment of the present invention.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component. And / or < / RTI > includes any combination of a plurality of related listed items or any of a plurality of related listed items.

It is to be understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, . On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between.

The terminology used in this application is used only to describe a specific embodiment and is not intended to limit the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the terms "comprises" or "having" and the like are used to specify that there is a feature, a number, a step, an operation, an element, a component or a combination thereof described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the relevant art and are to be interpreted in an ideal or overly formal sense unless explicitly defined in the present application Do not.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In order to facilitate the understanding of the present invention, the same reference numerals are used for the same constituent elements in the drawings and redundant explanations for the same constituent elements are omitted.

Throughout the specification, the network can be, for example, a wireless Internet such as WiFi (wireless fidelity), a wireless broadband internet (WiBro) or a portable internet such as world interoperability for microwave access (WiMax) A 3G mobile communication network such as Wideband Code Division Multiple Access (WCDMA) or CDMA2000, a high speed downlink packet access (HSDPA), or a high speed uplink packet access (HSUPA) A 3.5G mobile communication network, a 4G mobile communication network such as an LTE (Long Term Evolution) network or an LTE-Advanced network, a 5G mobile communication network, and a C-RAN (Cloud Radio Access Network).

Throughout the specification, a terminal is referred to as a mobile station, a mobile terminal, a subscriber station, a portable subscriber station, a user equipment, an access terminal, A terminal, a mobile station, a mobile station, a subscriber station, a mobile subscriber station, a user equipment, an access terminal, and the like.

Here, the terminal may include a sensor that is attached to the object and can communicate with the object. Sensors attached to objects can be used to implement Internet Of Things (IOT). The terminal may be a desktop computer, a laptop computer, a tablet PC, a wireless phone, a mobile phone, a smart phone, a smart watch, ), Smart glass, an e-book reader, a portable multimedia player (PMP), a portable game machine, a navigation device, a digital camera, a digital multimedia broadcasting (DMB) player, a digital voice recorder an audio recorder, a digital audio player, a digital picture recorder, a digital picture player, a digital video recorder, a digital video player, Lt; / RTI >

Throughout the specification, a base station is referred to as an access point, a radio access station, a node B, an evolved node B, a base transceiver station, an MMR mobile multihop relay) -BS, and may include all or some of the functions of a base station, an access point, a radio access station, a Node B, an eNodeB, a base transceiver station, and a MMR-BS.

Throughout the specification, a decentralized base station means a base station in which the function of the base station is divided into a digital unit and a wireless unit.

Hereinafter, a method of operating a communication node in a communication network according to an embodiment of the present invention and a communication node performing the same will be described.

1 is a block diagram illustrating a communication node performing a method of operating a communication node in a communication network according to an embodiment of the present invention.

Referring to FIG. 1, a communication node 100 may include at least one processor 110, a memory 120, and a network interface device 130 for communicating with a network. The communication node 100 may further include an input interface device 140, an output interface device 150, a storage device 160, and the like. Each component included in the communication node 100 may be connected by a bus 170 and communicate with each other.

The processor 110 may execute a program command stored in the memory 120 and / or the storage device 160. The processor 110 may refer to a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor on which the methods of the present invention are performed. The memory 120 and the storage device 160 may be composed of a volatile storage medium and / or a non-volatile storage medium. For example, the memory 120 may be comprised of read only memory (ROM) and / or random access memory (RAM). Here, a program instruction executed through the processor 310 may include a plurality of steps for performing a method of operating a communication node in the communication network proposed by the present invention.

2 is a conceptual diagram showing a base station 200 according to an exemplary embodiment of the present invention.

Referring to FIG. 2, the base station 200 may operate a plurality of beams. Illustratively, the base station 200 may include a plurality of antennas 210, 220, and 230 disposed on each of the three sides. Each of the plurality of antennas 210, 220, 230 may individually form and emit a beam. For example, antennas in the same horizontal row may be tuned to the same down-tilt angle. For example, the antennas 210 in the uppermost row may emit a beam toward the far side from the base station 200 with a small angle. The middle row antennas 220 may emit beams at a larger angle than the antennas 210 in the upper row. The antennas 230 in the bottom row may emit beams toward the base station 200 toward the near side with a larger angle than the antennas 220 in the middle row.

FIG. 3 is a plan view showing the base station 200 shown in FIG. 2 viewed from above in the z-axis direction.

Only the antennas in the upper row are shown in FIG. Referring to FIG. 3, antennas may be provided on three sides of the base station 200, respectively. Each of the three sides of the base station 100 may cover a 120 degree angular range. For example, the antennas 210 may cover the C1 to C6 region. However, the beam emission range of the antennas 210 is not limited to the above-described area.

The terminals can receive the signals transmitted by the antennas. Depending on which beam coverage the terminals are located in, which antenna signal to use first can be determined. For example, the terminal in the C1 region can receive the beam of the first antenna 211 most strongly. Therefore, the C1 region can be the beam coverage of the first antenna 211. [ Similarly, the beam coverage of the second antenna 212 becomes the C2 region, the beam coverage of the third antenna 213 becomes the C3 region, the beam coverage of the fourth antenna 214 becomes the C4 region, The beam coverage of the second antenna 212 may be the C5 region, and the beam coverage of the sixth antenna 216 may be the C6 region.

The beam coverage may refer to an area where the receiving intensity of the beam is stronger than the receiving intensity of the other beam. However, this does not mean that the radiation range of the beam is limited within the corresponding beam coverage.

In the above example, the beam coverage of the base station 200 and beams operating a plurality of beams has been described. However, the embodiment is not limited thereto. For example, the number and arrangement of antennas provided in the base station 200 may be changed differently. Further, the sizes of the beam coverage of each of the antennas may be different or the same.

The reception intensity of the beam can be changed depending on the position of the terminals in each beam coverage. For example, terminals located close to the antenna or located in the center of the beam coverage can receive the beam with strong intensity. On the other hand, terminals located far from the antenna or located at the edge of the beam coverage can receive the beam with weak intensity.

Also, the influence of interference between beams may vary depending on the location of the terminals within each beam coverage. For example, terminals located at the center of the beam coverage may receive little interference from the beams. On the other hand, terminals located close to the boundary between two adjacent beams may be affected by interference of two adjacent beams. Therefore, there is a need for a method that can reduce the influence of interference between beams and compensate for the change in communication quality according to the position of the terminal.

4 is a flowchart illustrating a method of operating the base station 200 according to an exemplary embodiment of the present invention.

로 나타낼 수 있다. 여기서, 빔 인덱스를 고정하고 스케쥴링 메트릭을 고려할 경우, 스케쥴링 메트릭은

로 나타낼 수 있다.In step S110, the base station 200 may obtain, for each terminal, a scheduling metric for each of the radio resources of each of the plurality of beams. The scheduling metric may be determined based on the strength with which the terminal receives a signal carried over the radio resource of the beam. For example, for terminal i, the scheduling metric for radio resource k of beam b is

. Here, when fixing the beam index and considering the scheduling metric, the scheduling metric is

.

The scheduling metric may provide information that is the basis for resource allocation. For example, the higher the value of the scheduling metric, the better the reception of the corresponding radio resource signal by the corresponding terminal. However, the above description is merely illustrative. When the scheduling metric value is small, the value of the scheduling metric may be set so that the signal reception state is good.

FIG. 5 is a flowchart illustrating a process of performing step S110 shown in FIG.

Referring to FIG. 5, in step S112, the base station 200 may transmit a reference signal. For example, the base station 200 may insert a reference signal into each radio resource for each subframe and transmit the same. A reference signal may be inserted for each radio resource of the beams operated by the base station 200. The terminals in the cell of the base station 200 can receive the reference signal from the base station 200. [ The UEs can measure the reception strength of the reference signal transmitted through each radio resource. The base station 200 may set the reference signal differently according to the beam index and the radio resource index. The UEs can measure the reception strength of the reference signal according to the type of the reference signal.

In step S114, the base station 200 may acquire information related to the reception strength of the reference signal from the terminals. For example, the UEs can receive the reference signal transmitted through each of the radio resources of each of the beams, and measure the reception intensity for each reference signal. That is, the UEs can measure the reception strength of a reference signal transmitted through each radio resource of each beam. The UEs can convert information on the reception strength of the reference signal into a channel quality indicator (CQI) format. The channel quality indicator may have a value of 0 to 15 depending on the signal reception strength. The above numerical values are merely illustrative, and the embodiments are not limited thereto. When the UE transmits information on the reception strength for each reference signal in the form of a channel quality indicator, the base station 200 can receive information on the reception strength for each reference signal.

In step S116, the base station 200 may calculate a scheduling metric based on information on the reception strength of the reference signal received from the UEs. For each terminal, the base station 200 may calculate a scheduling metric for each radio resource of each beam. The base station 200 may calculate the scheduling metrics in various manners. For example, the base station 200 may calculate a scheduling metric based on information (e.g., a channel quality indicator) about the strength of a reference signal received from a terminal. In another example, the base station 200 may calculate the scheduling metric by dividing the channel quality indicator by the data throughput of the corresponding terminal per unit time, taking into account the uniformity of communication quality between the terminals.

Referring back to FIG. 4, in step S120, the base station 200 may correct the scheduling metric. By correcting the scheduling metric, the base station 200 can prevent communication quality degradation due to interference between beams. For example, the base station 200 may reduce the interference effects of adjacent beams by correcting the scheduling metric using different correction metrics for each of the beams that are adjacent to each other. The correction metric may depend on the beam index and the radio resource index of the beams. In addition, the radio resource index may be an index of a frequency component of a radio resource. The radio resource index can be set differently according to the frequency component of the resource block. As another example, the radio resource index may be set differently according to the OFDM symbol.

FIG. 6 is a flowchart illustrating a process of performing step S120 of FIG.

Referring to FIG. 6, in step S122, the base station 200 may calculate a correction metric that is dependent on the beam index and the radio resource index. The correction metric may depend on the beam index and the supported block index regardless of the channel state. In addition, the radio resource index can be determined according to the frequency component of the radio resource. For example, the base station 200 may reduce the influence of interference between the first beam and the second beam by making the correction metric for the adjacent first beam different from the correction metric for the second beam.

For example, base station 200 may calculate a correction metric according to equation (1).

In Equation (1), b denotes an index of a beam, n denotes an arbitrary natural number, K denotes a maximum value of a radio resource index, and k denotes a radio resource index. Further, L _b (k) means a correction metric for the radio resource k of the beam b.

In Equation (1), it is assumed that the beam index is determined according to the beam coverage. If the beam index values are adjacent to each other, the beam coverage may be adjacent to each other. Referring to Equation (1), if the beam coverage of the first beam and the second beam are adjacent to each other, the correction metric for the first beam is determined by the first function and the correction metric for the second beam is determined by the second function Lt; / RTI > For example, a correction metric for a beam with an even beam index is determined by a first function, and a correction metric for a beam index with an odd beam index may be determined by a second function.

The first function may increase as the radio resource index k increases. On the other hand, the second function may decrease as the radio resource index k increases. The correction metric for the even-numbered beam may increase as the radio resource index k increases. The correction metric for the odd-numbered beams may decrease as the radio resource index k increases.

7 is a graph showing a change in the correction metric according to the radio resource index k.

Referring to FIG. 7, if the beam index b is an even number, the correction metric may increase as the radio resource index k increases. On the other hand, if the beam index b is odd, the correction metric may decrease as the radio resource index k increases. By determining the correction metric as shown in Figure 7, one of the correction metrics of the two beams with beam coverage is increased as the radio resource index k is increased, and the other is decreasing as the radio resource index k decreases can do.

The example shown in Fig. 7 is merely an example and the embodiment is not limited thereto. For example, if the beam index b is an even number, the correction metric decreases as the radio resource index k increases, and if the beam index b is odd, the correction metric may decrease as the radio resource index k increases. In Equation (6), both the first function and the second function are linear functions for the radio resource index k, but the embodiment is not limited thereto. For example, the first function and the second function may be non-linear functions for the radio resource index k.

Referring back to FIG. 6, in step S124, the base station 200 may correct the scheduling metric obtained in step S110 of FIG. The base station 200 may correct the scheduling metric by adding a correction metric to the scheduling metric. For example, the base station 200 may correct the scheduling metric according to Equation (2).

In Equation (2), b denotes a beam index, i denotes a terminal index, and k denotes a radio resource index. M _{b, i, k} means a corrected scheduling metric for radio resource k of beam b for terminal i. m _{b, i , k} denotes a scheduling metric for the radio resource k of the beam b for the terminal i acquired in step S110. L _b (k) means a correction metric for radio resource k of beam b. In addition, W denotes a weight of the correction metric. The base station 200 may determine the weight W in consideration of the size of the scheduling metric m _{b, i , k} . For example, if the size of the scheduling metric m _{b, i , k} is large, the base station 200 may set the weight W to be large, and if the size of the scheduling metric m _{b, i , k} is small, . The base station 200 may determine the weight W considering the required quality for interference mitigation. For example, when the required quality for interference mitigation is high, the base station 200 sets the weight W to a large value, and when the required quality for interference mitigation is low, the base station 200 can set the weight W to be small.

Referring to Equation (2), by adding the correction metric L _b (k) to the scheduling metric m _{b, i, k} , the scheduling metric can be corrected. The scheduling metric M _{b, i, k} is the correction of the beam adjacent to the resource allocation by the correction metric L _b (k) can be deflected to different radio resources.

Referring back to FIG. 4, in step S130, the base station 200 may determine a radio resource to be allocated to the UE based on the corrected scheduling metric. In step S150, the base station 200 can transmit information on the radio resources allocated to each of the terminals. The UEs can receive information on the allocated radio resources from the Node B 200. [

Hereinafter, a process of determining a radio resource to be allocated to a mobile station 200 by the base station 200 will be described.

The base station 200 may determine the radio resource of the beam allocated to each of the terminals based on the corrected scheduling metric. It is assumed that the base station 200 knows the index of certain terminals in the beam coverage of each beam. For example, the base station 200 can determine which beam coverage each terminal is in by determining which of the reference signals of the beams received the strongest reference signal of the beams.

The base station 200 may perform the following procedure for resource allocation of the first beam, for example. The base station 200 can determine a terminal to which each radio resource is preferentially allocated for each radio resource of the first beam. The base station 200 can determine a terminal that is preferentially allocated to each radio resource of the first beam among the terminals in the beam coverage of the first beam. The base station 200 can determine a terminal that is preferentially allocated the kth radio resource of the first beam among the terminals using Equation (3).

가운데, 보정된 스케쥴링 메트릭 M_i,k가 최대가 되도록 하는 무선 자원 인덱스를 의미한다.In Equation (3), i denotes a terminal index, I (1) denotes a set of indices of UEs in the beam coverage of the first beam, and k denotes a radio resource index. Also, M _{i, k} denotes a corrected scheduling metric for the k-th radio resource of the first beam for the i-th UE. Since the beam index is assumed to be fixed at 1, the beam index is omitted in the scheduling metric. J is the terminal index

Means a radio resource index for maximizing the corrected scheduling metric M _{i, k} .

Referring to Equation (3), the base station 200 can determine a j-th UE that can preferentially receive the k-th radio resource of the first beam. The base station 200 can determine the jth UE that maximizes the corrected scheduling metric M _{i, k} among the UEs. The base station 200 can determine the terminal that is preferentially allocated to the kth radio resource of the first beam to be the jth terminal using Equation (3). Similarly, the base station 200 can determine a terminal that can be preferentially allocated to each of the remaining radio resources of the first beam. In addition, the base station 200 may determine a terminal that is preferentially allocated to each of the remaining radio resources of the other beams. When the base station 200 determines a terminal capable of preferentially allocating each of the radio resources of the beams , And one terminal may be matched for each of the radio resources of the beams. One terminal is matched for each wireless resource, but a plurality of wireless resources may be matched for each terminal. Accordingly, the base station 200 can determine which radio resource to allocate to the terminal, among the radio resources that can be allocated to each terminal.

The BS 200 may determine the number of radio resources to be allocated to the MS, considering the amount of data to be transmitted to the MS. The base station 200 may preferentially allocate a radio resource having a good scheduling metric among the radio resources of the beam that can be preferentially allocated to each mobile station to the mobile station. For example, the base station 200 may determine the radio resource of the beam preferentially allocated to the terminal using Equation (4).

가운데, 보정된 스케쥴링 메트릭 M_i,k가 최대가 되도록 하는 무선 자원 인덱스를 의미한다.In Equation (4), i denotes a terminal index and k denotes a radio resource index. K (1, i) denotes an index set of radio resources that can be preferentially allocated to the i-th UE among the radio resources of the first beam. K (1, i) can be determined by Equation (3). Also, M _{i, k} denotes a corrected scheduling metric for the k-th radio resource of the first beam for the i-th UE. Since the beam index is assumed to be fixed at 1, the beam index is omitted in the scheduling metric. Also, l denotes a radio resource index

Means a radio resource index for maximizing the corrected scheduling metric M _{i, k} .

Referring to Equation (4), the Node B 200 can determine which radio resource to assign to the i-th UE preferentially among the radio resources that the i-th UE can preferentially allocate to the other UEs. For example, the base station 200 may determine to allocate the first radio resource to the i-th UE most preferentially. The BS 200 can allocate to the MS a radio resource having a corrected scheduling metric value among the radio resources to which each MS can be preferentially allocated.

8 is a conceptual diagram illustrating a first embodiment in which resources of beams are allocated to terminals.

Referring to FIG. 8, a first terminal UE1 and a second terminal UE2 may be in beam coverage C1 of the first beam. Also, the third terminal UE3, the fourth terminal UE4 and the fifth terminal UE5 may be in the beam coverage C2 of the second beam.

The correction metric for the first beam may decrease as the radio resource index increases. On the other hand, the correction metric for the second beam may increase as the radio resource index increases. The radio resource index can be determined according to the frequency component. In the case of performing the scheduling using the corrected metric, the first beam allocates resources with small radio resource indexes to the UEs due to the influence of the correction metric, and the second beam allocates resources with large radio resource indexes to the UEs .

For example, the radio resource RS1-1 of the first beam may be allocated to the second terminal UE2, and the radio resource RS1-2 of the first beam may be allocated to the first terminal UE1. In addition, the radio resource RS2-5 of the second beam is allocated to the fourth terminal UE4, the radio resource RS2-6 of the second beam is allocated to the fifth terminal UE5, and the radio resource RS2- 7 may be assigned to the third terminal UE3.

Although FIG. 8 shows an example in which the first beam and the second beam use radio resources at both ends, the embodiment is not limited thereto.

9 is a conceptual diagram illustrating a second embodiment in which resources of beams are allocated to terminals.

Referring to FIG. 9, the radio resource RS1-1 of the first beam is allocated to the second terminal UE2, and the radio resource RS1-2 of the first beam is allocated to the first terminal UE1. Referring to Equation (2), the correction metric L _b (k) of the first beam decreases as the radio resource index increases. However, due to the influence of the pre-correction metric m _{b, i, k} , . A radio resource RS1-3 having a relatively large radio resource index may be allocated to the first terminal UE1 without allocating the radio resource RS1-2 to the first terminal UE1.

As shown in FIGS. 8 and 9, if the beam coverage allocates resources in two different ways, the interference effect between the beams received by the terminal can be reduced. In addition, when the terminal receives the beam, the signal-to-noise ratio performance can be improved. For example, when using the pre-correction scheduling metric, the signal-to-noise ratio can be expressed as:

In Equation (5), SINR _ib denotes a signal-to-noise ratio when the i-th terminal receives the beam b. P _ib denotes an intensity at which the i-th terminal receives the beam b. P _ij denotes the intensity at which the i th UE receives the beam j. In addition, N means white noise. Referring to Equation (5), all remaining beams except beam b may act as noise to terminal i.

In case of using the corrected scheduling metric, the signal-to-noise ratio can be expressed as Equation (6).

In Equation (6), SINR _ib denotes a signal-to-noise ratio when the i-th terminal receives the beam b. P _ib denotes an intensity at which the i-th terminal receives the beam b. P _ij denotes the intensity at which the i th UE receives the beam j. N means white noise. K denotes an index set of beams that do not allocate radio resources allocated to the i-th UE to other UEs.

Referring to Equation (6), the correction metrics may be applied differently according to the beam index, and the beams may be deflected to different radio resource indices to allocate radio resources, thereby improving the signal-to-noise ratio performance.

8 and 9, there may be idle resources that are not allocated to the terminals in the first beam and the second beam, respectively. Such idle resources can be utilized for cooperative communication between adjacent beams.

10 is a flowchart illustrating an operation method of the base station 200 according to another exemplary embodiment of the present invention. In the description of the embodiment of FIG. 10, the description overlapping with FIG. 4 is omitted.

Referring to FIG. 10, in step S140, the base station 200 may allocate at least some of the idle resources of each of the plurality of beams for cooperative communication with an adjacent beam. The base station 200 may allocate some of the idle resources of the first beam for cooperative communications with the second beam if the beam coverage of the first beam and the beam coverage of the second beam are adjacent to each other. For example, if the second beam does not use the kth radio resource allocated to the terminal having a weak reception intensity of the first beam among the terminals in the beam coverage of the first beam, To the terminal having the weak reception intensity of the first beam.

11 is a flowchart illustrating steps S140 and steps performed in FIG. In FIG. 11, it is assumed that the beam index is determined according to the beam coverage. If the beam index values are adjacent to each other, the beam coverage may be adjacent to each other.

Referring to FIG. 11, the base station 200 may set the beam index b to 1 in step S141.

In step S142, the base station 200 can search for a terminal within the beam coverage of the b-1 beam and the b + 1 beam adjacent to each other with the b-beam and the beam coverage.

In step S143, the base station 200 may set the radio resource index k to 1. The radio resource index k may be determined according to the frequency component of the radio resource.

In step S145, the base station 200 may determine whether the kth radio resource of the b beam is allocated to the UE within the beam coverage of the b beam. If the kth wireless resource of the b-beam is allocated to the UE, the beam index k may be increased by 1 and the process may proceed to step S145 again. If the kth wireless resource of the b beam is not allocated to the terminal, the base station 200 may proceed to step S146.

In step S146, the base station 200 can determine whether cooperative communication is required for the terminal allocated with the kth radio resource of the b-1 beam and the b + 1 beam. The base station 200 can determine whether cooperative communication is necessary based on information on the strength of the terminal receiving the k th radio resource signal of the b-1 beam or the k th radio resource signal of the b + 1 beam. For example, when the terminal is positioned at the center of the beam coverage, since the signal reception intensity of the terminal is strong, the base station 200 can determine that cooperative communication is unnecessary. On the other hand, when the UE is located close to the beam coverage boundary, since the signal reception intensity of the UE is weak, the base station 200 may determine that cooperative communication is necessary. If it is determined in step S146 that the cooperative communication is unnecessary, the base station 200 increases the radio resource index k by 1 and proceeds to step S145 again. If it is determined in step S146 that the base station 200 requires cooperative communication, the base station 200 may proceed to step S147.

In step S147, the base station 200 may allocate the kth radio resource, which is the idle resource of the beam b, for cooperative communication with the beam b-1 or the beam b + 1. The base station 200 can allocate the kth radio resource of the beam b to the terminal determined to require the cooperative communication in step S146.

In step S148, the base station 200 has a radio resource index k can be determined smaller than the maximum value K _max of the radio resource index. If the radio resource index k is smaller than the maximum value K _max of the radio resource index, the base station 200 increases the radio resource index k by 1 and proceeds to step S145. If the radio resource index k is not smaller than the maximum value K _max of the radio resource index, the base station 200 can proceed to step S149.

In step S149, the base station 200 may determine that the beam index b is smaller than the maximum value B _max of a beam index. If the beam index b is smaller than the maximum value _Bmax of the beam index, the base station 200 may increment the beam index b by one and proceed to step S142. If the beam index b is not less than the maximum value B _max of the beam index, the base station 200 may terminate the resource allocation procedure for cooperative communication.

12 is a conceptual diagram illustrating a third embodiment in which resources of beams are allocated to terminals. In the following description of the embodiment of FIG. 12, the description overlapping with FIG. 8 is omitted.

12, radio resources RS1-5, RS1-6, and RS1-7, which are idle resources of the first beam, may be allocated for cooperative communication with the second beam. In addition, the radio resources RS2-1 and RS2-2, which are idle resources of the second beam, can be allocated for cooperative communication with the first beam.

For example, the resource blocks RS1-5 of the first beam may be allocated for cooperative communication to a fourth terminal UE4 in the beam coverage of the second beam. The resource blocks RS1-6 of the first beam may be allocated for cooperative communication to the fifth terminal UE5 in the beam coverage of the second beam. The resource blocks RS1-5 of the first beam may be allocated for cooperative communication to a third terminal UE3 in the beam coverage of the second beam.

The resource block RS2-1 of the second beam may be allocated for cooperative communication to the second terminal UE2 in the beam coverage of the first beam. The resource block RS2-2 of the second beam may be allocated for cooperative communication to the first terminal UE1 in the beam coverage of the first beam.

13 is a conceptual diagram illustrating an example in which radio resources of respective beams are allocated.

Referring to FIG. 13, the base station 200 may allocate radio resources having small radio resource indexes of b-bands to terminals located within the beam coverage of the b-beam. In addition, the base station 200 may allocate radio resources having a large radio resource index to terminals within the respective beam coverage, for the b-1 beam and the b + 1 beam. The base station 200 may allocate at least some of the idle resources of the b beam to the cooperative communication with the b -1 beam or the b + 1 beam.

According to the operation method of the base station 200 described with reference to FIGS. 10 to 13, cooperative communication between beams is performed for terminals located at a beam coverage boundary, so that communication quality can be improved. In addition, the signal-to-noise ratio performance can be improved. When cooperative communication is performed, the signal-to-noise ratio can be expressed by Equation (7).

In Equation (7), SINR _ib denotes a signal-to-noise ratio when the i-th terminal receives the beam b. P _ib denotes an intensity at which the i-th terminal receives the beam b. P _ij denotes the intensity at which the i th UE receives the beam j. N means white noise. K denotes an index set of beams that do not allocate radio resources allocated to the i-th UE to other UEs. P _im denotes the intensity at which the ith terminal receives a signal provided by the beam adjacent to the beam b in cooperation with the beam b.

Referring to Equation (7), P _im may be added to the denominator of the right side of Equation (6) by cooperative communication, thereby improving the signal-to-noise ratio performance.

The base station 200 according to the exemplary embodiments of the present invention has been described above. Hereinafter, a terminal communicating with the base station 200 will be described.

FIG. 14 is a flowchart illustrating an operation method of a terminal according to an exemplary embodiment of the present invention.

Referring to FIG. 14, in step S210, the terminal can receive a reference signal from the base station 200. FIG. The UE can receive the reference signals embedded in the respective radio resources for each subframe. The reference signal may be inserted for each radio resource of the beams operated by the base station 200. The UE can measure the reception strength of the reference signal transmitted through each radio resource. The reference signal may be set differently according to the beam index and the wireless resource index. The terminal can measure the reception intensity of the reference signal for each type of reference signal.

In step S220, the UE can transmit information related to the reception strength of the reference signal. For example, the UE may receive the reference signal transmitted through each of the radio resources of each of the beams, and measure the reception intensity for each reference signal. The UE can convert information on the reception strength of the reference signal into a channel quality indicator (CQI) format. The UE can generate and transmit information on the reference signal strength in the form of a channel quality indicator.

In step S230, the UE can receive radio resource allocation information from the Node B 200. [ The radio resources to which the UE is allocated may be determined based on the above-described corrected scheduling metric.

In step S240, the UE can receive the downlink signal from the Node B 200. [ The UE can demodulate a signal transmitted through a radio resource allocated to the UE according to the resource allocation information among the received downlink signals. The UE can demodulate the signal transmitted through the radio resource allocated to the UE and confirm the downlink data. In addition, the UE may demodulate not only the beam of the beam coverage to which it belongs but also the signal transmitted through the radio resource of the beam providing cooperative communication.

The operation method of the base station, the terminal, and the base station according to the exemplary embodiments of the present invention and the operation method of the terminal have been described above with reference to FIG. 1 through FIG. According to the embodiments described above, when operating the plurality of beams of the base station, it is possible to reduce communication quality degradation due to interference between beams. Also, frequency resource distribution of each of the beams can be efficiently performed. And, by performing cooperative communication with adjacent beams, the communication quality can be improved.

The methods according to the present invention can be implemented in the form of program instructions that can be executed through various computer means and recorded on a computer readable medium. The computer readable medium may include program instructions, data files, data structures, and the like, alone or in combination. The program instructions recorded on the computer readable medium may be those specially designed and constructed for the present invention or may be available to those skilled in the computer software.

Examples of computer readable media include hardware devices that are specially configured to store and execute program instructions, such as ROM, RAM, flash memory, and the like. Examples of program instructions include machine language code such as those produced by the compiler 1, as well as high-level language code that can be executed by a computer using an interpreter or the like. The hardware devices described above may be configured to operate with at least one software module to perform the operations of the present invention, and vice versa.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined in the appended claims. It will be possible.

Claims (20)

A method of operating a base station operating a plurality of beams,
Obtaining, for each terminal, a scheduling metric for each of the radio resources of each of the plurality of beams;
Correcting the scheduling metric using a correction metric that is dependent on a beam index and a radio resource index of each of the plurality of beams;
And determining a radio resource to be allocated to each of the terminals in the beam coverage of each of the plurality of beams based on the corrected scheduling metric. The method according to claim 1,
Wherein the radio resource index is an index of a frequency component of a radio resource. The method according to claim 1,
If the beam coverage of the first beam and the beam coverage of the second beam are adjacent to each other,
Wherein the correction metric for the first beam is determined by a first function for a radio resource index and the correction metric for the second beam is determined by a second function different from the first function, . The method of claim 3,
Wherein the output value of the first function increases as the radio resource index increases and the output value of the second function decreases as the radio resource index increases. The method according to claim 1,
Wherein obtaining the scheduling metric comprises:
A method of operating a base station that transmits a reference signal, obtains information on a reference signal strength of each of the beams received by the terminals from each of the terminals, and calculates the scheduling metric from information on the reference signal strength. The method according to claim 1,
Wherein the correcting the scheduling metric comprises:
And adding a correction metric that is dependent on a beam index of each of the plurality of beams to a scheduling metric of each of the plurality of beams to correct the scheduling metric. The method according to claim 1,
Wherein the step of determining a radio resource allocated to each of the terminals comprises:
A terminal that is preferentially allocated to each radio resource of each of the plurality of beams is determined and a radio resource having a good scheduling metric among the radio resources of the beam that can be allocated to the terminal is preferentially allocated to the terminal A method of operating a base station. The method according to claim 1,
Further comprising assigning at least some of the idle resources of the second beam to cooperative communications with the first beam if the beam coverage of the first beam and the beam coverage of the second beam are adjacent to each other, Way. The method of claim 8,
If the second beam does not use the kth radio resource allocated to the terminal having a weak reception intensity of the first beam among the terminals in the beam coverage of the first beam, And may transmit the same information as information to be transmitted to the kth radio resource of the first beam. The method according to claim 1,
And transmitting information on radio resources allocated to the UEs in the coverage of each of the plurality of beams to the UEs. A method of operating a terminal connected to a base station operating a plurality of beams,
Receiving a reference signal from the base station;
Transmitting information on the reception strength of the reference signal to the base station;
Receiving radio resource allocation information set based on a scheduling metric corrected by a correction metric that is dependent on a beam index and a radio resource index of each of the plurality of beams; And
And demodulating a signal received through the radio resource allocated to the UE according to the radio resource allocation information to identify downlink data. The method of claim 11,
Wherein the radio resource index is an index of a frequency component of a radio resource. The method of claim 11,
If the beam coverage of the first beam and the beam coverage of the second beam are adjacent to each other,
Wherein the correction metric for the first beam is determined by a first function for a radio resource index and the correction metric for the second beam is determined by a second function different from the first function, . 14. The method of claim 13,
Wherein the output value of the first function increases as the radio resource index increases and the output value of the second function decreases as the radio resource index increases. In a base station operating a plurality of beams,
A processor; And
Wherein at least one instruction executed through the processor includes a memory,
Wherein the at least one instruction comprises:
For each terminal, a scheduling metric is obtained for each of the plurality of beams of radio resources, and the calibration metric is corrected using a correction metric that depends on the beam index and radio resource index of each of the plurality of beams And to determine radio resources allocated to each of the terminals in the beam coverage of each of the plurality of beams based on the corrected scheduling metric. 16. The method of claim 15,
If the beam coverage of the first beam and the beam coverage of the second beam are adjacent to each other,
Wherein the correction metric for the first beam is determined by a first function for a radio resource index and the correction metric for the second beam is determined by a second function different from the first function. 18. The method of claim 16,
Wherein the output value of the first function increases as the radio resource index increases and the output value of the second function decreases as the radio resource index increases. 16. The method of claim 15,
Wherein the at least one instruction comprises:
Wherein the base station is configured to transmit a reference signal, obtain information on a reference signal strength of each of the beams received by the terminals from each of the terminals, and calculate the scheduling metric from information on the reference signal strength. 16. The method of claim 15,
Wherein the at least one instruction comprises:
Wherein at least some of the idle resources of the second beam are assigned to cooperative communications with the first beam when the beam coverage of the first beam and the beam coverage of the second beam are adjacent to each other. The method of claim 19,
Wherein the at least one instruction comprises:
If the second beam does not use the kth radio resource allocated to the terminal having a weak reception intensity of the first beam among the terminals in the beam coverage of the first beam, And may transmit the same information as information to be transmitted to the kth radio resource of the first beam.

Images