KR20150010625A - Transmitting and receiving method of pilot signal in communication system - Google Patents

Abstract

Disclosed is a method for transceiving a pilot signal in a communication system. The method for transceiving a pilot signal includes: receiving a cyclic shift set from the master base station; generating pilot signal based on a first cyclic shift value assigned to the first personal base station, wherein the first cyclic shift value is included in the cyclic shift set; and transmitting the generated pilot signal. Thus, performance of channel estimation can be enhanced.

Description

TECHNICAL FIELD [0001] The present invention relates to a method of transmitting and receiving pilot signals in a communication system,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of transmitting and receiving pilot signals, and more particularly, to a method of transmitting and receiving pilot signals for detecting data or interference in an environment where a plurality of nodes exist.

In a cellular communication environment, a general method by which terminals transmit and receive data is through a base station. That is, when there is data to be transmitted to the second terminal, the first terminal transmits the data to the first base station to which the first terminal belongs. The first base station transmits the data received from the first terminal to the second base station to which the second terminal belongs through the core network. Finally, the second base station transmits the data received from the first base station to the second terminal. Here, the first base station and the second base station may be the same base station or different base stations.

Meanwhile, when device-to-device communication, communication between base stations of a small cell, communication between base stations (pNBs) of a private cell, etc. are performed, Resources (i. E., Co-channels). ≪ / RTI > In this case, the channel must first be estimated for data detection or interference cancellation, but the performance of the channel estimation is degraded when the same pilot signal is used or when the correlation between the pilot signals is high.

In order to solve the above problems, an object of the present invention is to provide a method for transmitting and receiving a pilot signal for improving channel estimation performance in an environment in which communication is performed on the same-channel basis.

Another object of the present invention is to provide an apparatus for transmitting and receiving a pilot signal for improving channel estimation performance in an environment in which communication is performed based on co-channel.

According to another aspect of the present invention, there is provided a method of transmitting and receiving pilot signals, the method comprising: receiving a cyclic shift set from a main base station; Generating a pilot signal based on the shift value, and transmitting the generated pilot signal.

Here, the cyclic shift set may include cyclic shift values assigned to the plurality of personal base stations.

Here, the cyclic shift value may be set differently for each of the plurality of personal base stations.

Here, the cyclic shift set may be transmitted to the plurality of private base stations in a broadcast manner.

The method of transmitting and receiving pilot signals may further comprise the steps of: when data is received from a second personal base station among the plurality of personal base stations, based on a cyclic shift value allocated to the second private base station included in the cyclic shift set And estimating the channel.

According to another aspect of the present invention, there is provided a method of transmitting and receiving a pilot signal, the method comprising: receiving a first cyclic shift set for a first personal base station group from a main base station; And assigning the cyclic-shift values included in the first personal station group to a plurality of personal stations included in the first personal station group.

Here, the cyclic shift set may be set differently for each individual base station group.

Here, the cyclic shift value may be differently allocated to a plurality of individual base stations included in the first personal base station group.

Here, the first cyclic shift set may be transmitted to the first personal station group in a group cast manner.

The transmitting and receiving method of the pilot signal may further include generating a pilot signal based on the cyclic shift value assigned in the first cyclic shift set and transmitting the generated pilot signal.

Here, the method of transmitting / receiving the pilot signal may include: when receiving data from an arbitrary individual base station included in the first personal base station group, And estimating the channel based on the shift value.

The method of transmitting and receiving pilot signals may further include estimating a channel based on a blind search method when data is received from an arbitrary individual base station included in a group of other base stations other than the first base station group .

The transmitting and receiving method of the pilot signal may further include transmitting information on a cyclic shift value allocated to a plurality of private base stations included in the first personal base station group to the primary base station.

The method of transmitting and receiving pilot signals includes receiving information on a cyclic shift value allocated to a personal station included in a personal base station group located within a cell range of the primary base station from the primary base station, And estimating a channel based on the cyclic shift value allocated to the arbitrary individual base station when receiving data from any of the individual base stations included in the other individual base station group other than the base station group.

According to another aspect of the present invention, there is provided a method for transmitting a pilot signal, the method comprising: receiving a cyclic shift set from a main base station; receiving a first set of time- Frequency resource used by a second personal base station of the plurality of personal basestations, the first cyclic-shift value of the first personal station included in the cyclic-shift set is converted into the first time- Frequency resource, and generates a first pilot signal by applying the first cyclic-shift value to an area overlapping the second time-frequency resource among the first time-frequency resources, To generate a second pilot signal, and transmitting the first pilot signal and the second pilot signal.

Here, the cyclic shift set may include cyclic shift values assigned to the plurality of personal base stations.

Here, the cyclic shift value may be set differently for each of the plurality of personal base stations.

Here, the cyclic shift set may be transmitted to the plurality of private base stations in a broadcast manner.

According to the present invention, channel estimation performance can be improved in an environment where communication is performed based on the same-channel.

1 is a block diagram illustrating one embodiment of a base station that performs methods in accordance with the present invention.
2 is a conceptual diagram showing an environment in which the same channel is used.
3 is a conceptual diagram showing a resource allocation of a completely same-channel.
4 is a flowchart illustrating a method of transmitting and receiving a pilot signal according to an embodiment of the present invention.
5 is a flowchart illustrating a method of transmitting and receiving a pilot signal according to another embodiment of the present invention.
6 is a flowchart illustrating a method of transmitting and receiving a pilot signal according to another embodiment of the present invention.
7 is a conceptual diagram showing resource allocation of partial co-channel.
8 is a flowchart illustrating a method of transmitting a pilot signal according to an 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, and a 5G mobile communication 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, And may include all or some of the functions of a terminal, a mobile station, a mobile terminal, a subscriber station, a mobile subscriber station, a user equipment, an access terminal, and the like.

Here, a desktop computer, a laptop computer, a tablet PC, a wireless phone, a mobile phone, a smart phone, a smart watch, smart watch, smart glass, e-book reader, portable multimedia player (PMP), portable game machine, navigation device, digital camera, digital multimedia broadcasting (DMB) A digital audio recorder, a digital audio player, a digital picture recorder, a digital picture player, a digital video recorder, a digital video player ) Can be used.

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.

1 is a block diagram illustrating one embodiment of a base station that performs methods in accordance with the present invention.

Referring to FIG. 1, a base station 10 may include at least one processor 11, a memory 12, and a network interface device 13 connected to and performing communication with a network. The base station 10 may further include an input interface device 14, an output interface device 15, a storage device 16, and the like. Each of the configurations included in the base station 10 may be connected by a bus 17 and communicate with each other.

The processor 11 may execute program instructions stored in the memory 12 and / or the storage 16. The processor 11 may be a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor on which the methods according to the present invention are performed. The memory 12 and the storage device 16 may be composed of a volatile storage medium and / or a non-volatile storage medium. For example, the memory 12 may be comprised of read only memory (ROM) and / or random access memory (RAM).

)가 파일럿 신호로 사용될 수 있다. 매크로셀 내에서 기본 신호가

만큼 사이클릭 시프트(cyclic shift) 된 변경 신호(

)가 사용될 수 있다.In the LTE communication system, a base station (eNB) manages different macrocells (macrocells)

May be used as the pilot signal. The basic signal in the macro cell is

A cyclic-shifted change signal (

) Can be used.

과

)가 사용되기 때문에 통신 개체는 채널을 추정하는 경우 각 계층을 구별할 수 있다.In general, since a basic signal having a low correlation or a basic signal orthogonal to each other is used for each macro cell, a communication entity (i.e., a base station or a terminal) can distinguish each macro cell when estimating a channel. In order to distinguish a plurality of layers (or antenna ports) included in a communication entity, a basic signal having a low correlation or a base signal orthogonal to each other (for example,

and

), The communication entity can distinguish each layer when estimating the channel.

Meanwhile, when device-to-device communication, communication between base stations of a small cell, communication between base stations (pNBs) of a private cell, etc. are performed, Resources (i. E., Co-channels). ≪ / RTI > The co-channels can be assigned to communication entities for capacity enhancement or interference cancellation, and each channel must first be estimated for co-channel data detection or interference cancellation.

2 is a conceptual diagram showing an environment in which the same channel is used.

Referring to FIG. 2, the eNB may denote a macro base station managing a macro cell, and pNB-A to pNB-I may denote a private base station managing a private cell. pNB-A to pNB-F may be within the range of the eNB, and pNB-I may be outside the range of the eNB. pNB-A, pNB-B, pNB-C, and pNB-D may constitute one personal station group (PGR), which may be referred to as PGR-1. That is, any private base station belonging to PGR-1 may be located within the cell range of another private base station belonging to PGR-1. The pNB-E can also constitute another personal station group PGR-2. pNB-F, pNB-G, pNB-H and pNB-I can constitute another personal station group PGR-3. That is, any private base station belonging to PGR-3 may be located within the cell range of another private base station belonging to PGR-3.

A signal transmission from pNB-A to pNB-B may cause interference to pNB-D if all the personal stations belonging to PGR-1 are assigned exactly the same time-frequency resources or are allocated partly the same time-frequency resources , And signal transmission from pNB-C to pNB-D may cause interference to pNB-B. Signal transmission from pNB-H to pNB-G may interfere with pNB-F if all the individual base stations belonging to PGR-3 are assigned exactly the same time-frequency resources or are allocated partly the same time-frequency resources , And signal transmission from pNB-I to pNB-F may cause interference to pNB-G. The signaling from pNB-E to pNB-B to pNB-B to pNB-B to pNB-B to pNB- may cause interference with pNB-F. In such an environment, the channel must first be estimated for detection of data or removal (or suppression) of interference.

3 is a conceptual diagram showing a resource allocation of a full co-channel.

Referring to FIG. 3, the time-frequency resource of a transmission-resource block (T-RB) is exactly the same as the time-frequency resource of an interference-resource block (I-RB). If any private base station receives data through a transmission-resource block (T-RB), the data transmitted via the interfering-resource block (I-RB) can be seen as interference on any individual base station side.

4 is a flowchart illustrating a method of transmitting and receiving a pilot signal according to an embodiment of the present invention.

Referring to FIG. 4, a master base station 20 may be referred to as a macro base station controlling macro cells. The first personal station 31 and the second personal station 32 may denote a base station managing a private cell. The first personal station 31 and the second personal station 32 may be located within the cell range of the main base station 20. [ Communication can be performed over the full co-channel between the primary base station 20, the first personal station 31, and the second private base station 32.

The primary base station 20 may set a first cyclic shift value for the first personal base station 31 and a second cyclic shift value for the second private base station 32. [ At this time, the first cyclic shift value may be set different from the second cyclic shift value. That is, the main base station 20 may set different cyclic-shift values for a plurality of individual base stations located within its cell range.

The main base station 20 may generate a cyclic shift set including a first cyclic shift value and a second cyclic shift value. Alternatively, the main base station 20 may generate a cyclic shift set including an index for a first cyclic shift value and an index for a second cyclic shift value. The main base station 20 can transmit the cyclic shift set (SlOO). At this time, the main base station 20 can transmit a cyclic shift set in a broadcast manner.

Thereafter, the first personal station 31 and the second private base station 32 can transmit and receive messages based on the cyclic-shift value assigned thereto. For example, when the first personal base station 31 receives the cyclic shift set, the first personal base station 31 determines, based on the first cyclic shift value (or index for the first cyclic shift value) included in the cyclic shift set, A pilot signal can be generated (S110). The second personal base station 32 generates a second pilot signal based on a second cyclic shift value included in the cyclic shift set (or an index for the second cyclic shift value) when the cyclic shift set is received (S120).

The first personal base station 31 may transmit a message including the first pilot signal to the second personal base station 32 (S130). The second personal base station 32 transmits a first cyclic shift value included in the cyclic shift set (i.e., a cyclic shift value of the first personal station 31) ). ≪ / RTI > The second personal base station 32 may transmit a message including the second pilot signal to the first personal base station 31 (S140). The first personal base station 31 transmits a second cyclic shift value included in the cyclic shift set (i.e., a cyclic shift value of the second personal base station 32) ). ≪ / RTI >

5 is a flowchart illustrating a method of transmitting and receiving a pilot signal according to another embodiment of the present invention.

Referring to FIG. 5, the main base station 20 may refer to a macro base station that controls a macro cell. The first personal station group may include a plurality of personal stations (i.e., the representative personal station 30, the first personal station 31, and the second personal station 32) Lt; / RTI > Any individual base station belonging to the first individual base station group may be located within the cell range of another individual base station belonging to the first individual base station group. The second group of personal base stations 40 may include at least one personal base station and may be located within the cell range of the primary base station 20. Any personal base station belonging to the second personal base station group 40 may be located within the cell range of another personal base station belonging to the second personal base station group 40. [ Communication can be performed over the full co-channel between the primary base station 20, the individual base stations belonging to the first personal station group, and the individual base stations belonging to the second private base station group 40. [

The primary base station 20 may generate a first cyclic shift set for the first personal base station group. The main base station 20 calculates a cyclic shift value (for example, a ₁ , a ₂ , a ₃ ) or a cyclic shift value for the number of personal base stations belonging to the first personal base station group A first cyclic shift set including an index can be generated. The primary base station 20 may transmit the first cyclic shift set to the first personal base station group (S200). At this time, the primary base station 20 can transmit the first cyclic shift set to the private base stations belonging to the first personal base station group in a groupcast manner. Alternatively, the primary base station 20 may transmit the first cyclic shift set to the representative personal base station 30 of the first personal base station group in a unicast manner.

In addition, the primary base station 20 may generate a second cyclic shift set for the second private base station group 40. The main base station 20 generates a second cyclic shift set including an index for a cyclic shift value or a cyclic shift value as many as the number of individual base stations belonging to the second personal base station group 40 can do. Here, the second cyclic shift set may have a different value from the first cyclic shift set. That is, the main base station 20 can set cyclic shift sets differently for each individual base station group located within its cell range. The primary base station 20 may transmit the second cyclic shift set to the second private base station group (S210). At this time, the primary base station 20 can transmit the second cyclic shift set to the private base stations belonging to the second private base station group 40 in a group casting manner. Alternatively, the primary base station 20 may transmit the second cyclic shift set to the representative personal base station of the second personal base station group 40 in a unicast manner.

When receiving the first cyclic shift set, the representative personal base station 30 of the first personal base station group allocates the cyclic-shift values included in the first cyclic shift set to the personal base stations constituting the first personal base station group (S220). The representative personal base station 30 can assign one cyclic shift value included in the first cyclic shift set to the first private base station 31 and can transmit the other cyclic shift value included in the first cyclic shift set, The shift value can be assigned to the second personal base station 32 and the remaining cyclic shift value included in the first cyclic shift chef can be assigned to the second base station 32 itself. That is, different cyclic shift values may be assigned to the individual base stations constituting the first personal base station group. Here, the representative personal base station 30 may transmit the allocated cyclic-shift information to the personal base stations included in the first personal base station group in a broadcasting scheme or a group cast scheme. The assigned cyclic-shift information may include cyclic-shift values assigned to all personal base stations constituting the first personal station group. In a manner similar to the above, the individual base stations constituting the second personal base station group 40 may be assigned cyclic shift values included in the second cyclic shift set.

Thereafter, the first and second personal base station groups 40 and 40 may transmit and receive messages based on the assigned cyclic-shift value. For example, the representative personal station 30 may generate a pilot signal based on the assigned cyclic-shift value, and may transmit a message including the generated pilot signal to the first personal base station 31 (S230) . Since the first personal base station 31 knows the cyclic shift value assigned to the representative personal base station 30, when the first personal base station 31 receives a message from the representative personal base station 30, The channel can be estimated based on the value.

Similarly, the second personal base station 32 may generate a pilot signal based on the cyclic shift value assigned to itself, and may transmit a message including the generated pilot signal to the representative personal base station 30 (S240 ). The representative personal base station 30 knows the cyclic shift value of the second personal base station 32 allocated by the representative personal base station 30. Therefore, when receiving the message from the second private base station 32, The channel can be estimated based on the click shift value.

Any individual base station belonging to the second personal base station group 40 can generate a pilot signal based on the assigned cyclic shift value and transmit a message including the generated pilot signal to a representative personal base station 30) (S250). In this case, the representative personal base station 30 does not know the cyclic shift value assigned to any personal base station belonging to the second personal base station group 40 (that is, the personal base station included in the first personal base station group 40 (I.e., a cyclic shift value assigned to a group of individual base stations other than the individual base station group is not known), a cyclic shift assigned to an arbitrary individual base station belonging to the second individual base station group 40 based on a blind searching scheme The shift value can be estimated. For example, the representative personal base station 30 may first perform a discrete fourier transform (DFT) interpolation on the message and perform an inverse discrete fourier transform (IDFT) on the result. Thereafter, the representative personal base station 30 can consider that the pilot signal is transmitted through an arbitrary region when the sum of the received signal intensities in a certain region exceeds a predefined threshold, and based on this, Can be estimated.

6 is a flowchart illustrating a method of transmitting and receiving a pilot signal according to another embodiment of the present invention.

Referring to FIG. 6, the main base station 20 may refer to a macro base station managing macro cells. The first personal station group may include a plurality of personal stations (i.e., the representative personal station 30, the first personal station 31, and the second personal station 32) Lt; / RTI > Any individual base station belonging to the first individual base station group may be located within the cell range of another individual base station belonging to the first individual base station group. The second group of personal base stations 40 may include at least one personal base station and may be located within the cell range of the primary base station 20. Any personal base station belonging to the second personal base station group 40 may be located within the cell range of another personal base station belonging to the second personal base station group 40. [ Communication can be performed over the full co-channel between the primary base station 20, the individual base stations belonging to the first personal station group, and the individual base stations belonging to the second private base station group 40. [

The primary base station 20 may generate a first cyclic shift set for the first personal base station group and may transmit the generated first cyclic shift set to the first private base station group S300. Here, a specific method of generating and transmitting the first cyclic shift set may be the same as step S200 described with reference to FIG. The primary base station 20 may also generate a second set of cyclic shifts for the second private base station group 40 and may transmit the generated second set of cyclic shifts to the second private base station group 40 (S310). Here, the specific method of generating and transmitting the second cyclic shift set may be the same as the step S210 described with reference to FIG.

When receiving the first cyclic shift set, the representative personal base station 30 of the first personal base station group allocates the cyclic-shift values included in the first cyclic shift set to the personal base stations constituting the first personal base station group (S320). Here, a specific method of assigning cyclic-shift values to the personal base stations constituting the first personal base station group may be the same as the step S220 described with reference to FIG. The representative personal station 30 may transmit the cyclic-shift values assigned to the private base stations constituting the first personal station group to the main base station 20 (S330). That is, the representative personal station 30 may transmit the cyclic shift value assigned to the first personal base station 31 and the cyclic shift value assigned to the second personal base station 32 to the primary base station 20.

Similarly, a cyclic shift value included in the second cyclic shift set may be assigned to the personal base station constituting the second personal base station group 40. [ The representative personal base station of the second personal base station group 40 may transmit the cyclic shift values assigned to the personal base stations constituting the second personal base station group to the main base station 20 at step S340.

The main base station 20 receives the cyclic shift values allocated from the representative individual base stations of all the individual base station groups (for example, the first personal station group and the second personal station group 40) located within its cell range The cyclic shift information including the received cyclic-shift values can be generated, and the generated cyclic-shift information can be transmitted in a broadcast manner (S350). Any individual base station that has received cyclic shift information from the main base station 20 can know the cyclic shift value assigned to the individual base station belonging to another group of individual base stations.

Thereafter, the first and second personal base station groups 40 and 40 may transmit and receive messages based on the assigned cyclic-shift value. For example, the representative personal station 30 may generate a pilot signal based on the assigned cyclic-shift value, and may transmit a message including the generated pilot signal to the first personal base station 31 (S360) . Since the first personal base station 31 knows the cyclic shift value assigned to the representative personal base station 30, when the first personal base station 31 receives a message from the representative personal base station 30, The channel can be estimated based on the value.

Similarly, the second personal base station 32 may generate a pilot signal based on the assigned cyclic-shift value, and may transmit a message including the generated pilot signal to the representative personal base station 30 (S370). The representative personal base station 30 knows the cyclic shift value of the second personal base station 32 allocated by the representative personal base station 30. Therefore, when receiving the message from the second private base station 32, The channel can be estimated based on the click shift value.

Meanwhile, an individual base station belonging to the second personal station group 40 can generate a pilot signal based on the assigned cyclic-shift value, and transmit a message including the generated pilot signal to a representative individual To the base station 30 (S380). In this case, the representative personal base station 30 can know the cyclic shift value assigned to the personal base station belonging to the other personal base station group through the cyclic-shift information received from the main base station 20. Accordingly, the representative personal station 30 can recognize the cyclic shift value assigned to any personal base station belonging to the second personal base station group 40, It is possible to estimate the channel based on the cyclic shift value of any personal base station belonging to the second personal base station group 40. [

7 is a conceptual diagram showing resource allocation of a partial co-channel.

Referring to FIG. 7, some time-frequency resources of a T-RB may be included in an interference-resource block (I-RB). That is, the transmission-resource block (T-RB) may overlap with the interference-resource block (I-RB) in the frequency domain 'f2 to f1' of the time domain 't0 to t1'. Basically, a pilot signal can be set according to the size of a resource block in an LTE communication system. For example, since the subcarriers of the transmission-resource block (T-RB) are 'f0 to f1', the pilot signal can be set to a size of 'f0 to f1'. Similarly, since the subcarriers of the interference-resource block I-RB are 'f2 to f3', the pilot signal can be set to a size of 'f2 to f3'. If some of the resources used by the communication entities are the same as above, the communication entity may not distinguish the channel because the pilot signal can have a high correlation in the region where the resources overlap. Therefore, in order to solve this problem, the pilot signal can be set for each region where resources do not overlap and resources overlap each other.

8 is a flowchart illustrating a method of transmitting a pilot signal according to an embodiment of the present invention.

Referring to FIG. 8, the main base station 20 may refer to a macro base station that controls macro cells. The first personal station 31 and the second personal station 32 may denote a base station managing a private cell. The first personal station 31 and the second personal station 32 may be located within the cell range of the main base station 20. [ Here, the first personal base station 31 can perform communication with the second personal base station 32 based on the T-RBs shown in FIG. The primary base station 20 can communicate with the second private base station 32 based on the interference-resource block (I-RB) shown in FIG. That is, communication can be performed over the partial co-channel between the primary base station 20, the first personal station 31, and the second private base station 32.

Next, a method of transmitting a pilot signal in an environment where resources are allocated as shown in FIG. 7 will be described. The primary base station 20 may set a first cyclic shift value for the first personal base station 31 and a second cyclic shift value for the second private base station 32. [ At this time, the first cyclic shift value may be set different from the second cyclic shift value. That is, the main base station 20 may set different cyclic-shift values for a plurality of individual base stations located within its cell range.

The main base station 20 may generate a cyclic shift set including a first cyclic shift value and a second cyclic shift value. Alternatively, the primary base station 20 may generate a cyclic shift set including an index for a first cyclic shift value and an index for a second cyclic shift value. The main base station 20 may transmit the cyclic shift set (S400). At this time, the main base station 20 can transmit the cyclic shift set in a broadcast manner.

Thereafter, the first personal station 31 and the second private base station 32 can transmit and receive messages based on the cyclic-shift value assigned thereto. For example, the first personal base station 31, which wishes to transmit a message to the second personal base station 32, transmits the time-frequency resource used for transmitting the message to the second personal base station 32, Frequency resources used for communication between the base station 20 and the main base station 20 overlap each other, a pilot signal for an area in which resources do not overlap with a pilot signal for an area in which resources overlap can be generated.

That is, the first personal base station 31 applies the cyclic shift value allocated to itself to the 'f0 to f2' region (i.e., the region where resources do not overlap) of the T-RBs in the transmission-resource block A signal can be generated (S410). Also, the first personal station 31 applies the cyclic shift value assigned to itself to the 'f2 to f1' region (that is, the region where resources overlap) of the T-RBs, (S420). The first personal station 31 may transmit a message including the first pilot signal and the second pilot signal to the second personal base station 32 (S430). Since the second personal base station 32 knows the cyclic shift value assigned to the first personal base station 31, the second personal base station 32 transmits a transmission-resource block (T-RB) based on the cyclic- It is possible to estimate the channel for the 'f0 ~ f2' region and the 'f2 ~ f1' region.

Meanwhile, in the method of transmitting and receiving a pilot signal described above with reference to FIGS. 5 and 6, when the same resources are partially allocated to communication entities, in an area where resources overlap with the pilot signal for an area in which resources do not overlap Respectively, may be generated.

On the other hand, in an environment where communication entities partially use the same resource, the difficulty of channel estimation can be solved when the cyclic shift value is appropriately distributed to communication entities. Referring again to FIG. 7, in an environment in which 'f2 to f1' regions overlap in the transmission-resource block (T-RB), the pilot of the T-RB to which the cyclic shift value (a _i ) And the pilot signal of the I-RB to which the cyclic shift value a _j is applied to the 'f2 to f3' region are simultaneously received, the correlation between the 'f2 to f1' region and _ai and _aj A pilot signal with a low relation can be generated.

For example, when the LTE uplink DMRS (demodulation reference signal) is used as a pilot signal, even if some time-frequency resources overlap in a case other than the case mentioned in Table 1 below, The pilot signal need not be generated separately. In this case, good channel estimation performance can be obtained by one pilot signal of size 72.

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 generated by a compiler, 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.

20: main base station
30: Representative personal base station
31: first personal station
32: second personal base station
40: second personal base station group

Claims (18)

A method for transmitting and receiving a pilot signal carried out by a first personal station of a plurality of personal stations, the method comprising the steps of:
Receiving a cyclic shift set from the main base station;
Generating a pilot signal based on a cyclic shift value assigned to the first personal base station included in the cyclic shift set; And
And transmitting the generated pilot signal. The method according to claim 1,
Wherein the cyclic shift set includes cyclic shift values assigned to the plurality of personal base stations. The method according to claim 1,
Wherein the cyclic shift value is set differently for each of the plurality of personal base stations. The method according to claim 1,
Wherein the cyclic shift set is transmitted to the plurality of private base stations in a broadcast manner. The method according to claim 1,
A method for transmitting and receiving a pilot signal,
And estimating a channel based on a cyclic shift value assigned to the second personal base station included in the cyclic shift set when receiving data from a second personal base station among the plurality of personal basestations And transmitting the pilot signal. A plurality of personal base station groups including a plurality of individual base stations in a cell range of a master base station and a representative personal base station group included in the first personal base station group of the at least one personal base station group, A method for transmitting and receiving a pilot signal,
Receiving a first cyclic shift set from the primary base station for the first group of personal base stations; And
And assigning the cyclic-shift values included in the first cyclic shift set to a plurality of private base stations included in the first personal base station group. The method of claim 6,
Wherein the cyclic shift set is set differently for individual base station groups. The method of claim 6,
Wherein the cyclic shift value is differently assigned to a plurality of individual base stations included in the first personal base station group. The method of claim 6,
Wherein the first cyclic shift set is transmitted to the first personal station group in a groupcast manner. The method of claim 6,
A method for transmitting and receiving a pilot signal,
Generating a pilot signal based on an assigned cyclic shift value among the first cyclic shift sets; And
And transmitting the generated pilot signal. ≪ Desc / Clms Page number 20 > The method of claim 6,
A method for transmitting and receiving a pilot signal,
Estimating a channel based on a cyclic shift value allocated to the arbitrary individual base station included in the first cyclic shift set when receiving data from any personal base station included in the first personal base station group, And transmitting the pilot signal. The method of claim 6,
A method for transmitting and receiving a pilot signal,
Further comprising the step of estimating a channel based on a blind searching scheme when data is received from any personal base station included in a group of other base stations other than the first base station group, / RTI > The method of claim 6,
A method for transmitting and receiving a pilot signal,
And transmitting information on a cyclic shift value allocated to a plurality of personal base stations included in the first personal station group to the main base station. The method of claim 6,
A method for transmitting and receiving a pilot signal,
Receiving from a main base station information on a cyclic shift value assigned to a personal base station included in a personal base station group located within a cell range of the main base station; And
And estimating a channel based on the cyclic shift value allocated to the arbitrary individual base station when data is received from an arbitrary individual base station included in a group of individual base stations other than the first individual base station group And transmitting the pilot signal. A method for transmitting a pilot signal carried in a first personal station of a plurality of personal basestations, the method comprising the steps of:
Receiving a cyclic shift set from the main base station;
When a part of a first time-frequency resource used by the first personal station equals a second time-frequency resource used by a second personal station of the plurality of personal stations, Frequency resource to a region of the first time-frequency resource that does not overlap the second time-frequency resource to generate a first pilot signal, and the first cyclic- Generating a second pilot signal by applying the first time-frequency resource to an area overlapping the second time-frequency resource; And
And transmitting the first pilot signal and the second pilot signal. 16. The method of claim 15,
Wherein the cyclic shift set includes cyclic shift values assigned to the plurality of private base stations. 16. The method of claim 15,
Wherein the cyclic shift value is set differently for each of the plurality of personal base stations. 16. The method of claim 15,
Wherein the cyclic shift set is transmitted to the plurality of private base stations in a broadcast manner.

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