KR20140081499A

KR20140081499A - Wireless communication system and method for mapping antennal port in the same

Info

Publication number: KR20140081499A
Application number: KR1020120151322A
Authority: KR
Inventors: 강승현; 최우진
Original assignee: 주식회사 케이티
Priority date: 2012-12-21
Filing date: 2012-12-21
Publication date: 2014-07-01

Abstract

A wireless communication system and an AP mapping method in the system are disclosed.
The system comprises a digital signal processing device connected to the core system for processing a wireless digital signal and a digital signal processing device physically separated from the digital signal processing device and converting and amplifying the digital signal received from the digital signal processing device, The base station transmits the amplified signal to the terminal based on the multi-antenna technology using the antenna, receives a signal transmitted from the terminal based on the multi-antenna technology using the two antennas, Processing apparatus. When two radio signal processing apparatuses of the plurality of radio signal processing apparatuses are paired to perform quad antenna transmission, the digital signal processing apparatus includes an RB (Resource Block) used as a measurement bandwidth, And a CRS (Common Reference Signal) AP (Antenna Port) mapped to the two radio signal processing apparatuses based on the index of the radio signal processing apparatus.

Description

TECHNICAL FIELD [0001] The present invention relates to a wireless communication system and a method of mapping an AP in the system,

The present invention relates to a wireless communication system and an AP mapping method in the system.

2. Description of the Related Art Generally, a base station in a wireless communication system includes a digital signal processor (Digital) (hereinafter referred to as "DU") that performs a baseband function and a radio signal processor (hereinafter referred to as "RU Quot;). &Lt; / RTI >

A typical base station is implemented with both DU and RU in the center of cell coverage, but recently, DU and RU have been separated and optical cable has been connected between the two. In this case, the RU is located at the center of the cell coverage, the DU can be installed at a remote location, the DUs forming a plurality of cells can be collected and installed in the same place, and an X2 interface can be secured to enable communication between DUs. Furthermore, by setting a plurality of DUs to be managed by one virtualization server, inter-cell interference control in the cell boundary region and cooperative transmission between the base stations become possible.

The base station implemented by virtualization allocates the same physical cell identifier (hereinafter, referred to as "PCI") to a plurality of RUs. A plurality of cell coverage formed by a plurality of RUs using the same PCI form a single large cell coverage.

In addition, using virtualization technology, two RUs with the same PCI can be paired. Assuming that each RU has two transmit antennas, it is possible to use four transmit antennas if two paired RUs act as if they were one RU. Such RU virtualization technology is called Quad Antenna Transmission.

Meanwhile, in the wireless communication system, a CRS (Common Reference Sign) is used for channel estimation used by a base station, and the CRS is used for RSRP measurement for cell coverage measurement in addition to channel estimation. Antenna Port (hereinafter referred to as "AP") allocated to the CRS uses 0 and 1 when there are 2 transmit antennas and 0, 1 and 2 when 4 transmit antennas Then use number three. Here, the reference signals transmitted by the physical antennas for the four APs 0, 1, 2 and 3 are referred to as R0, R1, R2, and R3, and the two RUs transmit the reference signals according to the AP mapping method do. In this case, the terminal basically measures the RSRP by measuring the reception power of the antenna port # 0 of the base station, and can further use the AP # 1.

However, if the RU is adjacent to one RU while the two RUs are paired for the quad antenna transmission, the AP 0 (or AP 1) transmitted from the remote RU in the case of a UE relatively far from the other RU, Is weakly received, and a relatively low SNR value is reported to the RU in the RSRP measurement.

Accordingly, there is a problem that the RU judges that the UE is out of cell coverage even though it is adjacent to the UE, and thus does not provide a service for the UE.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and it is an object of the present invention to provide a wireless communication system capable of solving the problem that a UE within a paired RU can be determined to be out of cell coverage, AP mapping method.

A wireless communication system according to an aspect of the present invention includes:

A digital signal processing device connected to the core system for processing a wireless digital signal; And converting the digital signal received from the digital signal processor into a digital signal and transmitting the amplified signal to the terminal based on a multi-antenna technique using two antennas, A plurality of radio signal processing apparatuses for receiving a signal transmitted from a terminal and transmitting the signal to the digital signal processing apparatus based on a multi-antenna technique using a plurality of antennas, When performing the quad antenna transmission, the digital signal processing apparatus exchanges the CRS AP mapped to the two radio signal processing apparatuses based on the index of the RB used for the measurement bandwidth .

Here, the digital signal processing apparatus performs mutual exchange of the CRS APs so that reference signals used for RSRP measurement are alternately transmitted from the two radio signal processing apparatuses.

In addition, the digital signal processing apparatus performs a modulo 2 operation on the index of the RB, and performs CRS AP mapping on the two radio signal processing apparatuses according to the result.

In addition, the digital signal processing apparatus boosts transmission power when transmitting a reference signal used for the RSRP measurement.

In addition, the digital signal processing apparatus performs mutual exchange of the CRS APs so that reference signals used for the RSRP measurement are mapped to the two radio signal processing apparatuses the same number of times.

The digital signal processing apparatus may further include: a resource allocation unit allocating resources to the two radio signal processing apparatuses, wherein the resources include RBs used for the RSRP measurement; An RB index determination unit for performing a modulo 2 operation on the index of the RB allocated by the resource allocation unit and calculating the result; And an AP mapping unit for performing CRS AP mapping for the two radio signal processing apparatuses according to a result of a 2-ary operation for each RB index calculated by the RB index determination unit and transmitting the CRS AP mapping information to the two radio signal processing apparatuses.

According to another aspect of the present invention, there is provided an AP mapping method,

A digital signal processing apparatus for processing a wireless digital signal, comprising: a plurality of wireless signal processing apparatuses installed in a service area for processing wireless signals, wherein a plurality of wireless signal processing apparatuses are connected to a terminal A method of mapping a CRS AP to a wireless signal processing apparatus that performs quad antenna transmission by pairing among a plurality of wireless signal processing apparatuses, the method comprising: allocating an RB used as a measurement bandwidth to the two wireless signal processing apparatuses; Performing an operation of modulo 2 for each index of the RB; And performing CRS AP mapping for the two radio signal processing apparatuses different from each other according to the calculation result of the modulo 2.

Herein, as the RB index increases, a CRS AP corresponding to a reference signal used for the RSRP measurement is alternately mapped to the two wireless signal processing devices.

A wireless communication system according to another aspect of the present invention includes:

A digital signal processing device connected to the core system for processing a wireless digital signal; And converting the digital signal received from the digital signal processor into a digital signal and transmitting the amplified signal to the terminal based on a multi-antenna technique using two antennas, A plurality of radio signal processing apparatuses for receiving a signal transmitted from a terminal and transmitting the signal to the digital signal processing apparatus based on a multi-antenna technique using a plurality of antennas, When performing a Quad Antenna Transmission, the digital signal processing apparatus transmits a CRS (Common Reference Sign) AP (Antenna Port) mapping to the two radio signal processing apparatuses, Reference Signal Received Power) A wireless signal that is not mapped to a reference signal used for measurement The reference signal used for the RSRP measurement is further mapped to the RSRP device.

Here, the digital signal processing apparatus does not transmit PDSCH data scheduled in a measurement bandwidth to a reference signal used for the RSRP measurement, the PDSCH data being further mapped with a reference signal used for the RSRP measurement, do.

The digital signal processing apparatus may further include: a resource allocation unit allocating resources to the two radio signal processing apparatuses, wherein the resources include CRS AP information mapped to the two radio signal processing apparatuses; A mapping analyzer for analyzing CRS AP information mapped by the resource allocation unit and determining a wireless signal processing device to which a reference signal used for the RSRP measurement is not mapped; And a mapping adder for further mapping a reference signal used for the RSRP measurement to a radio signal processor to be searched by the mapping analyzer.

A digital signal processing apparatus for processing a wireless digital signal, comprising: a plurality of wireless signal processing apparatuses installed in a service area for processing wireless signals, wherein a plurality of wireless signal processing apparatuses are connected to a terminal A method of mapping a CRS AP to a plurality of wireless signal processing apparatuses, the method comprising: mapping CRS APs to two wireless signal processing apparatuses that are paired among the plurality of wireless signal processing apparatuses and perform quad antenna transmission; Determining a radio signal processing apparatus to which a reference signal used for RSRP measurement as a result of the CRS AP mapping is not mapped; And mapping a reference signal used for the RSRP measurement to a radio signal processing apparatus to which the reference signal used for the RSRP measurement is not mapped.

Here, the scheduling is performed such that a radio signal processor, which is further mapped with a reference signal used for the RSRP measurement, does not transmit PDSCH data scheduled for a measurement bandwidth with respect to a reference signal used for the RSRP measurement.

A digital signal processing device connected to the core system for processing a wireless digital signal; And converting the digital signal received from the digital signal processor into a digital signal and transmitting the amplified signal to the terminal based on a multi-antenna technique using two antennas, A plurality of radio signal processing apparatuses for receiving a signal transmitted from a terminal and transmitting the signal to the digital signal processing apparatus based on a multi-antenna technique using a plurality of antennas, The CRS APs mapped to the two radio signal processing devices are exchanged in accordance with the exchange period.

Here, the switching period is a basic unit that can represent time in the wireless communication system, and is a number of subframes or a number of system frames.

In addition, the exchange period is smaller than the period of the RSRP report reported to the radio signal processing apparatus by the UE.

A time counting unit for counting the time of the switching cycle; A mapping storage unit for storing CRS AP information allocated to the two radio signal processing devices; And mapping the CRS APs to be exchanged to the two radio signal processing devices based on the CRS AP information stored in the mapping storage when the exchange period is counted by the time counting part, To the device.

A digital signal processing apparatus for processing a wireless digital signal, comprising: a plurality of wireless signal processing apparatuses installed in a service area for processing wireless signals, wherein a plurality of wireless signal processing apparatuses are connected to a terminal Receiving a resource allocation request from two radio signal processing apparatuses that are paired among the plurality of radio signal processing apparatuses and perform quad antenna transmission; Determining whether an exchange cycle has been reached; And mapping the CRS APs so that the CRS APs are mutually exchanged and mapped to the two wireless signal processing devices based on the CRS AP information mapped to the two wireless signal processing devices, .

Mapping the CRS APs to the two radio signal processing apparatuses according to the CRS AP information mapped to the two radio signal processing apparatuses when it is determined that the exchange cycle is not performed in the determining step .

A digital signal processing device connected to the core system for processing a wireless digital signal; And converting the digital signal received from the digital signal processor into a digital signal and transmitting the amplified signal to the terminal based on a multi-antenna technique using two antennas, A plurality of radio signal processing apparatuses for receiving a signal transmitted from a terminal and transmitting the signal to the digital signal processing apparatus based on a multi-antenna technique using a plurality of antennas, Performs CRS AP mapping so that the two reference signals are mapped to the two radio signal processing devices one by one when the terminal performs RSRP measurement using two reference signals, .

Here, the terminal information verifying unit confirms whether the terminal uses the two reference signals in the RSRP measurement. And when the UE confirms that the UE performs the RSRP measurement using the two reference signals, when the CRS AP mapping for the two wireless signal processing devices is performed, And a resource allocation unit for mapping the wireless signal processing apparatuses to the wireless signal processing apparatuses one by one.

A digital signal processing apparatus for processing a wireless digital signal, comprising: a plurality of wireless signal processing apparatuses installed in a service area for processing wireless signals, wherein a plurality of wireless signal processing apparatuses are connected to a terminal Receiving a resource allocation request from two radio signal processing apparatuses that are paired among the plurality of radio signal processing apparatuses and perform quad antenna transmission; Confirming whether the terminal performs the RSRP measurement using the two reference signals; And when the UE is confirmed to perform the RSRP measurement using the two reference signals, when the CRS AP mapping for the two radio signal processing apparatuses is performed, the two reference signals are transmitted to the two radio signal processing apparatuses And mapping them one by one.

According to the present invention, an RSRP value measured by a UE within a cell coverage constituted by two paired RUs can be maintained at a certain level or more.

This solves the problem that it is possible to determine that the mobile station is out of cell coverage for a terminal in the paired RU.

1 is a diagram schematically illustrating a general quad antenna transmission method through a paired RU.
2 is a schematic configuration diagram of a network according to an embodiment of the present invention.
3 is a diagram illustrating a concept of RU-to-RU mapping exchange according to an RB index in the reference signal transmission method according to the first embodiment of the present invention.
4 is a detailed block diagram of a DU according to the first embodiment of the present invention.
5 is a flowchart of a reference signal transmission method according to the first embodiment of the present invention.
6 is a diagram illustrating a concept of adding CRS AP # 0 in the reference signal transmission method according to the second embodiment of the present invention.
7 is a detailed block diagram of the DU according to the second embodiment of the present invention.
8 is a flowchart of a reference signal transmission method according to the first embodiment of the present invention.
9 is a diagram illustrating a concept of exchanging a CRS AP mapping every cycle T in a reference signal transmission method according to the third embodiment of the present invention.
10 is a specific configuration block diagram of a DU according to the third embodiment of the present invention.
11 is a flowchart of a reference signal transmission method according to a third embodiment of the present invention.
FIG. 12 is a diagram illustrating a concept of mapping a CRS AP when CRS AP # 0 and # 1 are used for RSRP measurement in the reference signal transmission method according to the fourth embodiment of the present invention.
13 is a specific configuration block diagram of a DU according to the fourth embodiment of the present invention.
14 is a flowchart of a reference signal transmission method according to a fourth embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are denoted by like reference characters throughout the specification.

Throughout the specification, when an element is referred to as "comprising ", it means that it can include other elements as well, without excluding other elements unless specifically stated otherwise. Also, the terms " part, "" module," and " module ", etc. in the specification mean a unit for processing at least one function or operation and may be implemented by hardware or software or a combination of hardware and software have.

In this specification, a terminal includes a mobile station (MS), a mobile terminal (MT), a subscriber station (SS), a portable subscriber station (PSS), a user equipment , An access terminal (UE), an access terminal (AT), and the like, and may include all or some functions of a terminal, a mobile terminal, a subscriber station, a mobile subscriber station, a user equipment,

In this specification, a base station (BS) includes an access point (AP), a radio access station (RAS), a node B, an evolved NodeB (eNodeB) A base station (BTS), a mobile multihop relay (MMR) -BS, or the like, and may perform all or a part of functions of an access point, a radio access station, a Node B, an eNodeB, a base transceiver station, .

First, a general quad antenna transmission method through a paired RU will be described with reference to FIG.

1 is a diagram schematically illustrating a general quad antenna transmission method through a paired RU.

Referring to FIG. 1, RUs 21 and 23 are located at the center of two cells 11 and 13, respectively. These RUs 21 and 23 are paired with each other and located in two cells 11 and 13 And provides a quad antenna transmission service to the terminals 31, 33, and 35.

In this quad antenna transmission method, each RU (21, 23) has two physical antennas, and each physical antenna must be mapped to a CRS AP. For example, AP 0 is mapped to the first antenna 41 of the RU 1 21, AP 1 is mapped to the second antenna 42, AP 2 is mapped to the first antenna 43 of the RU 2 23, AP 3 may be mapped to the second antenna 44.

Therefore, the terminals 31, 33, and 35 within the cell coverage formed by the RU1 21 and the RU2 23 receive the four transmit antennas 41, 42, 43, and 44 from the RU1 21 and the RU2 23, respectively. The downlink signal is received.

However, since the terminal 33 is located in the border area between the RUs 21 and 23, all the AP signal strengths are similarly received. However, in the case of the terminal 31, the terminal 33 is adjacent to the RU 21, , AP 0 and 1 signals are received relatively strongly and AP 2 and 3 signals are received relatively weakly.

On the contrary, in the case of the terminal 35, AP 2 and AP 3 signals are relatively strongly received and AP 0 and AP 1 signals are relatively strong because AP 3 is adjacent to RU 2 23 but relatively far away from RU 1 21 .

Therefore, although the terminal 35 is adjacent to the RU2 23, the terminal 35 relatively far from the RU1 21 always receives the AP 0 (or AP 1) signal weakly, A low SNR value is reported to the RU2 23 and the RU2 23 reports a low SNR value even though the terminal 35 is adjacent to the RU2 23 so that it can be determined that there is a paired cell coverage.

Hereinafter, embodiments of the present invention for solving the above problems will be described.

The network structure to which the embodiment of the present invention is applied will be described with reference to FIG.

2 is a schematic configuration diagram of a network according to an embodiment of the present invention.

Referring to FIG. 2, a network according to an embodiment of the present invention includes an RU 100, a DU 200, and a core system 300.

The RU 100 converts a digital signal received from the DU 200 as a radio signal processing unit into a radio frequency (RF) signal according to a frequency band and amplifies the digital signal. Then, the signal is transmitted to the terminal through the antenna, and the signal is received from the terminal through the antenna, processed and transmitted to the DU 100.

A plurality of RUs 100, 110, 120, and 130 are connected to the DU 200, and each RU 100 is installed in a service area, that is, a cell. The RU 100 and the DU 200 may be connected by an optical cable.

The DU 200 performs processing such as encryption and decryption of a wireless digital signal and is connected to the core system 300. Unlike the RU 100, the DU 200 is not installed in a service area, but is a server that is mainly installed in a central office of a communication company and is a virtualized base station. The DU 200 transmits and receives signals to and from a plurality of RUs 100.

The existing communication base station includes a processing unit corresponding to each of the RU 100 and the DU 200 in one physical system, and one physical system is installed in the service target area. On the contrary, the system according to the embodiment of the present invention physically separates the RU 100 and the DU 200, and only the RU 100 is installed in the service area.

The core system 300 handles the connection between the DU 200 and the external network, and includes an exchange (not shown) and the like.

Hereinafter, a reference signal transmission method according to the first embodiment of the present invention will be described.

First, in all embodiments of the present invention, the RU1 110 and the RU2 120, which are two RUs, are paired with each other to give a terminal located in the cell coverage formed by the RU1 110 and the RU2 120, It is assumed that a transmission service is provided.

In the reference signal transmission method according to the first embodiment of the present invention, a physical antenna and a CRS AP mapping between RUs are swapped via an index of a resource block (hereinafter referred to as "RB") .

In a wireless communication system, the RSRP uses six RBs, i.e., 6 RBs, located at the center among the entire bandwidth of the frequency domain, as a measurement bandwidth. According to the implementation method of the UE, the number and position of the RBs used for the measurement bandwidth can be changed. However, since the UE must perform the RSRP measurement even when the system bandwidth is unknown, 6 RBs corresponding to the smallest system bandwidth are considered. In the embodiment of the present invention, the RB used for the RSRP measurement including the 6 RBs described above is targeted.

In the first embodiment of the present invention, the RBs used for the RSRP measurement bandwidth are set to exchange the CRS AP mapped to the RU1 110 and the RU2 120, respectively, according to the RB index value, The RU1 110 and the RU2 120 alternately transmit the CRS AP # 0 (or both the AP # 0 and the AP # 1).

Since the RSRP measurement uses the average value of the CRS reception power, if CRS is transmitted according to the first embodiment of the present invention, within the cell coverage formed by the two paired RUs 110 and 120, . However, as the distance from each RU 110, 120 to the terminal increases, the RSRP value only decreases. Therefore, in order to solve this problem, it is also possible to boost the transmission power by 3 dB when transmitting the R0 signal.

3 is a diagram illustrating a concept of RU-to-RU mapping exchange according to an RB index in the reference signal transmission method according to the first embodiment of the present invention.

Referring to FIG. 3, it is shown that CRS APs mapped between RUs 110 and 120 are exchanged each time the RB index is incremented by one within the measurement bandwidth.

In order to exchange CRS APs every time the RB index increases, a modulo 2 operation is first performed on the RB index i, and when the result is 0, CRS APs 0 and 1 are mapped to RU1 110, and RU2 120) maps the CRS AP # 2 and # 3.

Conversely, if the result of the modulo 2 operation is 1 in the RB index i, the CRU APs 2 and 3 are allocated to the RU1 110 in order to exchange the mapping between the RU1 110 and the RU2 120 And maps the CRS APs 0 and 1 to the RU2 120. [

Unlike the above, if the result of the modulo 2 operation is 1 on the RB index i, the CRS APs 2 and 3 are mapped to the RU1 110, and the CRS APs 0 and 2 You can also map times. In this case, the modulo 2 operation is performed on the RB index i, and when the result is 0, the RU1 110 is assigned with the CRS APs 0 and 1 in order to exchange the mapping between the RU1 110 and the RU2 120 And mapping the CRS APs 2 and 3 to the RU2 120.

3 is an embodiment according to the first embodiment of the present invention, and the CRS AP mapping can be interchanged according to various conditions via the RB index within the RSRP measurement bandwidth. However, the number of times the CRS AP # 0 (or both the 0 and 1) is mapped to each of the RUs 110 and 120 for the two paired RUs 110 and 120 is set to be equal to the maximum.

4 is a detailed block diagram of a DU according to the first embodiment of the present invention.

4, the DU 200 according to the first embodiment of the present invention includes a transmission / reception unit 210, a resource allocation unit 220, an RB index determination unit 230, and an AP mapping unit 240 .

The transceiver unit 210 receives a resource allocation request from the RUs 110 and 120 and transmits resource information allocated to the RUs 110 and 120 to the RUs 110 and 120.

The resource allocation unit 220 allocates resources for the RUs 110 and 120 that request resource allocation through the transceiver unit 210. [ Among these allocated resources, the RB of the frequency band used for the RSRP measurement is also included.

The RB index determination unit 230 performs a modulo 2 operation on the index of the RB allocated by the resource allocation unit 220 and calculates the result.

The AP mapping unit 240 performs AP mapping with respect to the RU1 110 and the RU2 120 according to the result of the 2 arithmetic operation by the module for each RB index calculated by the RB index determination unit 230, To the RU1 (110) and the RU2 (120). Here, for the sake of convenience of description, when the module 2 operation result of the RB index is 0, the CRS APs 0 and 1 are mapped to the RU1 110 and the CRS APs 2 and 3 are mapped to the RU2 120 And mapping the CRS APs 2 and 3 to the RU1 110 and the CRS APs 0 and 1 to the RU2 120 when the modulo 2 operation result is 1. FIG.

Therefore, the RU1 110 and the RU2 120 request resource allocation through the transmission / reception unit 210 of the DU 200 and transmit the CRS according to the CRS AP mapping information transmitted through the transmission / reception unit 210. [

5 is a flowchart of a reference signal transmission method according to the first embodiment of the present invention.

5, when the resource allocation unit 220 of the DU 200 receives a resource allocation request from the RU1 110 and the RU2 120 through the transmission / reception unit 210 (S100), the RU1 110 and the RU2 And performs resource allocation for the resource 120 (S110). In this case, resource allocation performed by the resource allocation unit 220 to the RU1 110 and the RU2 120 is performed through a generally performed method, and thus a detailed description thereof will be omitted. The RB is included in this allocated resource.

Accordingly, the RB index determination unit 230 performs a modulo 2 operation on the index of the RB allocated by the resource allocation unit 220. When the modulo 2 operation result is 0 (S130), the AP mapping unit 240 updates the RU1 The CRS AP # 0 and # 1 are mapped to the RU # 2 110 and the CRS AP # 2 and # 3 are mapped to the RU # 2 120 at step S140.

However, when the modulo 2 operation result is 1 (S130), the AP mapping unit 240 maps the CRS APs 2 and 3 to the RU1 110, and transmits the CRS APs 0 and 1 to the RU2 120 (S150).

Thereafter, the RB index determination unit 230 determines whether the RB to be subjected to the modulo 2 operation remains (S160), and repeats the steps S120, S130, S140, and S150 until the RB does not remain And performs AP mapping for each RB index.

The AP mapping unit 240 then transmits the AP mapping information to the RU1 110 and the RU2 120 through the transceiver unit 210. The RU1 110 and the RU2 120 transmit the AP mapping information to the DU 200 (CRS) AP mapping information transmitted from the CRS AP mapping information (S180).

As described above, according to the first embodiment of the present invention, the mapping between the physical antennas of the RUs 110 and 120 and the CRS APs is performed mutually between the RUs 110 and 120 via the RB index, And 120 may have a RSRP value of a predetermined level or higher.

Next, a reference signal transmission method according to a second embodiment of the present invention will be described.

In the second embodiment of the present invention, the CRS AP # 0 is assigned to one of the two physical antennas only for the RUs to which the CRS AP # 0 is not allocated. That is, after two CRS APs are respectively mapped to the two paired RUs 110 and 120, CRS AP 0 is assigned to two RUs 110 and 120 that are paired with respect to RBs used as a measurement bandwidth And allocates the CRS AP 0 to one of the two physical antennas of the RU to transmit the R0 signal. In this case, the RU that is further allocated with CRS AP # 0 may not operate with the AP # 0 that is additionally assigned when transmitting the scheduled PDSCH (Physical Downlink Shared CHannel) data to the measurement bandwidth, and only the CRS R0 signal It is possible to operate with AP 0 only when transmitting.

Since the two RUs 110 and 120 that are paired transmit the R0 signal, all the UEs have a certain RSRP value within the cell coverage formed by the two paired RUs 110 and 120 . However, only the RSRP value decreases as the distance from each RU 110, 120 to the terminal increases.

6 is a diagram illustrating a concept of adding CRS AP # 0 in the reference signal transmission method according to the second embodiment of the present invention.

Referring to FIG. 6, AP 0 and 1 are mapped to RU1 110 by AP mapping within a measurement bandwidth, and APs 2 and 3 are mapped to RU2 120. Therefore, since AP 0 is not allocated to RU2 120, CRS AP 0 is further allocated to one of the two physical antennas of RU2 120 so that R0 signal can be transmitted from RU2 120. [

7 is a detailed block diagram of the DU according to the second embodiment of the present invention.

7, the DU 200 according to the second embodiment of the present invention includes a transmitting / receiving unit 410, a resource allocating unit 420, a mapping analyzing unit 430, and a mapping adding unit 440 do.

The transceiver unit 410 receives a resource allocation request from the RUs 110 and 120 and transmits resource information allocated to the RUs 110 and 120 to the RUs 110 and 120.

The resource allocator 420 allocates resources for the RUs 110 and 120 that request resource allocation through the transceiver 210. [ The CRS AP information mapped to the RU1 110 and the RU2 120 is also included among the resources allocated as described above.

The mapping analyzer 430 analyzes the CRS AP information mapped to the RU1 110 and the RU2 120 by the resource allocation unit 420 and determines an RU to which the CRS AP 0 is not mapped. For example, if AP # 0 and AP # 1 are allocated to RU1 110 and AP # 2 and AP # 3 are allocated to RU2 120, mapping analyzer 430 maps CRS AP # 0 And judges the RU2 120 with an unused RU.

The mapping adder 440 receives the RU information to which the CRS AP 0 is not mapped by the mapping analyzer 430 and further allocates the CRS AP 0 to the RU. Since the CRS AP 0 is not assigned to the RU 2 120 in the above example, the mapping adder 440 assigns the CRS AP 0 to the RU 2 120. The allocation information is transmitted to the RUs 110 and 120 through the transmission / reception unit 410.

Therefore, the RU1 110 and the RU2 120 request resource allocation through the transceiver 210 of the DU 200 and transmit the CRS according to the CRS AP mapping information transmitted through the transceiver 210, The RU2 110 as well as the RU2 120 can transmit the R0 signal.

8 is a flowchart of a reference signal transmission method according to the first embodiment of the present invention.

Referring to FIG. 8, when the resource allocation unit 420 of the DU 200 receives a resource allocation request from the RU1 110 and the RU2 120 through the transmission / reception unit 410 (S200), the RU1 110 and the RU2 And performs resource allocation for the resource 120 (S210). In this case, resource allocation performed by the resource allocator 420 to the RU1 110 and the RU2 120 is performed through a generally performed method, and thus a detailed description thereof will be omitted. The CRS AP mapping information for the RU1 110 and the RU2 120 is included in the resource.

Thereafter, the mapping analysis unit 430 analyzes the CRS AP mapping information allocated by the resource allocation unit 420 (S220), and determines whether there is an RU to which the CRS AP 0 is not mapped (S230).

If the RU that is not mapped to the CRS AP # 0 is the RU1 110 (S240), the mapping adder 440 further maps the CRS AP # 0 to the RU1 110 (S250).

However, if the RU that is not mapped to the CSR AP 0 is not the RU1 110 but the RU2 120 (S240), the mapping adder 440 further maps the CRS AP # 0 to the RU2 120 (S260) .

Thereafter, the mapping adding unit 440 transmits the CRS AP mapping information to the RU1 110 and the RU2 120 (S270) through the transmitting / receiving unit 410, and the RU1 110 and the RU2 120 transmit the DU 200 according to the CRS AP mapping information (S280).

In this way, all of the two RUs 110 and 120 that are paired transmit the R0 signal, so that all the UEs can have a certain level of RSRP value within the cell coverage formed by the two paired RUs 110 and 120 have.

Next, a reference signal transmission method according to the third embodiment of the present invention will be described.

The third exemplary embodiment of the present invention is characterized in that the physical antennas and the CRS AP mapping between the RUs 110 and 120 are swapped as the time varies. Here, the time may be a basic unit capable of expressing time in a wireless communication system, such as the number of subframes or the number of system frames, or may be a function of a time unit.

In the third embodiment of the present invention, the expression of time is represented by T, which is a cycle of exchanging a CRS AP for convenience. That is, when the period T is reached, the mapped CRS APs between the RUs 110 and 120 are exchanged.

9 is a diagram illustrating a concept of exchanging a CRS AP mapping every cycle T in a reference signal transmission method according to the third embodiment of the present invention.

Referring to FIG. 9, a CRS AP is mapped to two RUs 110 and 120 for a total RB of a measurement bandwidth at an arbitrary time t. For example, as shown in FIG. 9, it is assumed that CRS APs 0 and 1 are mapped to RU1 110 and CRS APs 2 and 3 are mapped to RU2 120.

Thereafter, the CRS APs mapped to the respective RUs 110 and 120 are exchanged with respect to all the RBs of the measurement bandwidths after the CRS AP exchange period T, that is, at the time t + T. That is, the RU1 110 maps the CRS APs 2 and 3, and the RU2 120 maps the CRS APs 0 and 1.

Thereafter, the CRS APs mapped to the respective RUs 110 and 120 are exchanged again with respect to all the RBs of the measured bandwidths again after the CRS AP exchange period T, that is, at the time t + 2T. That is, the CRU AP 110 maps the CRS APs 0 and 1 to the RU1 110, and maps the CRS APs 2 and 3 to the RU2 120.

As described above, the CRS AP exchange for the RU1 110 and the RU2 120 is repeated every cycle T.

Since the RSRP measurement uses the average value of the CRS reception power, a T value smaller than the RSRP report period is set to adjust the number of CRS exchanges, and the CRS APs 110 and 120 are allocated to the two RUs 110 and 120, Set the number of times to map 0 (or both 0 and 1) as much as possible.

When the R0 signal is transmitted, the transmission power may be boosted by 3 dB.

In this manner, the CRS AP mapping between the RUs 110 and 120 is performed mutually in the CRS AP switching period T, so that all the terminals within the cell coverage formed by the two paired RUs 110 and 120 can obtain the RSRP value Lt; / RTI >

10 is a specific configuration block diagram of a DU according to the third embodiment of the present invention.

10, the DU 200 according to the third embodiment of the present invention includes a transmission / reception unit 510, a time measurement unit 520, a mapping storage unit 530, and a resource allocation unit 540 do.

The transceiver unit 510 receives a resource allocation request from the RUs 110 and 120 and transmits resource information allocated to the RUs 110 and 120 to the RUs 110 and 120.

The time counting unit 520 counts a preset CRS AP cycle T time. For example, the time counting unit 520 counts time from 0 and counts up to the period T time.

The mapping storage unit 530 stores CRS AP information mapped to the RUs 110 and 120, respectively.

The resource allocation unit 540 allocates resources for the RUs 110 and 120 that request resource allocation through the transmission / reception unit 210. [ If the CRS AP period T has not been counted by the time counting unit 520, the resource allocating unit 540 allocates the resource to the RUs 110 and 120 according to the CRS AP information stored in the mapping storage unit 530 The same CRS AP is assigned.

However, if the time T is counted by the time count unit 520, the resource allocation unit 540 maps the resource to the RU1 110 and the RU2 120 according to the CRS AP information stored in the mapping storage unit 530 The CRS APs are mapped to the RU1 110 and the RU2 120, respectively, and the mapped CRS AP information is stored in the mapping storage unit 530 again. Then, the time counting unit 520 operates to count the period T again.

11 is a flowchart of a reference signal transmission method according to a third embodiment of the present invention. It is assumed that CRS AP information previously mapped to the RUs 110 and 120 is stored in the mapping storage unit 530 and the time count unit 520 previously stores the CRS AP information mapped to the RUs 110 and 120 It is assumed that the CRS AP is exchanged and mapped and counted from time 0 to cycle T time.

11, when the resource allocation unit 540 of the DU 200 receives a resource allocation request from the RU1 110 and the RU2 120 through the transmission / reception unit 510 (S300), the time count unit 520 (S310). &Lt; / RTI >

If the time counted by the time count unit 520 is not the period T (S320), the resource allocation unit 540 allocates the RU 110 and the RU 110 according to the CRS AP information stored in the mapping storage unit 530, And maps the CRS AP to the BS 120 (S330). For example, if the CRS APs 0 and 1 are mapped to the RU1 110 and the CRS APs 2 and 3 are mapped to the RU2 120, if they are stored in the mapping storage unit 530, And maps the CRS APs to the RUs 110 and 120, respectively.

However, if the time counted by the time counting unit 520 reaches the period T (S320), the resource allocating unit 540 allocates the resource to the RU1 110 based on the CRS AP information stored in the mapping storage unit 530 The CRS APs are mapped to the RUs 110 and 120 so that the CRS AP mapping is mutually exchanged between the RUs 120 and 120 (S340). Referring to the above example, the CRS APs 2 and 3 are mapped to the RU1 110, and the CRS APs 0 and 1 are mapped to the RU2 120.

Thereafter, the resource allocation unit 540 stores the CRS AP information mapped to the RUs 110 and 120 in the mapping storage unit 530 (S350).

The resource allocation unit 540 transmits the CRS AP mapping information to the RU1 110 and the RU2 120 through the transmission and reception unit 510 and the RU1 110 and the RU2 120 from the DU 200 And transmits the CRS according to the CRS AP mapping information to be transmitted (S370).

In this manner, the physical antennas of the RUs 110 and 120 and the CRS AP mapping are mutually performed between the RUs 110 and 120 based on the CRS AP exchange period T, thereby forming two paired RUs 11 and 120 All the terminals within the cell coverage can have a certain level of RSRP value.

Next, a reference signal transmission method according to a fourth embodiment of the present invention will be described.

In the fourth embodiment of the present invention, the CRS AP mapping method is used in the case where the UE uses both CRS AP # 0 and the CRS AP # 1 for RSRP measurement. In this case, the CRS AP # 0 or the CRS AP # 1 is mapped to each of the two paired RUs 110 and 120. In this case, the terminal can use the average value of the received power of both the R0 signal and the R1 signal as RSRP. Therefore, when transmitting the R0 and R1 signals, each of the RUs 110 and 120 may boost the transmission power by 3 dB.

FIG. 12 is a diagram illustrating a concept of mapping a CRS AP when CRS AP # 0 and # 1 are used for RSRP measurement in the reference signal transmission method according to the fourth embodiment of the present invention.

Referring to FIG. 12, since the UE uses both the CRS AP # 0 and the CRS AP # 1 in the RSRP measurement, the CRS AP mapping needs to be mapped to the RU1 110 and the RU2 120, APs 0 and 2, and CRS APs 1 and 3, respectively, or mapped to CRS APs 0 and 3, and CRS APs 1 and 4, respectively.

In Fig. 12, it is shown that it is allocated as in the previous example. That is, the CRS AP # 0 and # 2 are mapped to the RU1 110 and the CRS AP # 1 and # 3 are mapped to the RU2 120.

In this manner, by mapping the CRS 0 and 1 used in the RSRP measurement to the two RUs 110 and 120, all the terminals within the cell coverage formed by the two paired RUs 110 and 120 can perform RSRP Value. &Lt; / RTI >

13 is a specific configuration block diagram of a DU according to the fourth embodiment of the present invention.

As shown in FIG. 13, the DU 200 according to the fourth embodiment of the present invention includes a transmitter / receiver 610, a terminal information verifier 620, and a resource allocator 630.

The transmitting and receiving unit 610 receives a resource allocation request from the RUs 110 and 120 and transmits the resource information allocated to the RUs 110 and 120 to the RUs 110 and 120.

The terminal information verification unit 620 confirms the information of the terminal requesting the resource allocation. In the fourth embodiment of the present invention, the UE checks whether CRS AP 0 or CRS AP 1 is used in RSRP measurement.

If it is confirmed by the UE information checking unit 620 that the UE performs the RSRP measurement using both the CRS AP # 0 and the CRS AP # 1, the resource allocation unit 630 allocates the CRS AP # 0 and the CRS AP # RU 110 and 120 to the RUs 110 and 120 through the transmitting and receiving unit 610. [

14 is a flowchart of a reference signal transmission method according to a fourth embodiment of the present invention.

14, when the resource allocation unit 630 of the DU 200 receives a resource allocation request from the RU1 110 and the RU2 120 through the transmission / reception unit 610 (S400), the terminal information verification unit 620 ) Confirms whether the UE is also using the CRS AP 1 in the RSRP measurement (S410).

If it is determined that the UE is also using the CRS AP 1 in the RSRP measurement (S420), the resource allocator 630 allocates the CRS 0 and 1 to the two RUs 110 and 120 The CRS AP mapping is performed so that the mapped addresses are mapped one by one (S430). For example, the resource allocation unit 630 maps the CRS APs 0 and 2 to the RU 110 and maps the CRS APs 1 and 3 to the RU 2 120.

However, if it is confirmed that the UE does not use the CRS AP # 1 in the RSRP measurement (S420), the resource allocator 630 performs the CRS AP mapping to the two RUs 110 and 120 using the conventional scheme S440). Or may be mapped using the CRS AP mapping method according to the first embodiment, the second embodiment, or the third embodiment described above.

Thereafter, the resource allocator 630 transmits the CRS AP mapping information to the RU1 110 and the RU2 120 through the transmission / reception unit 610, and the RU1 110 and the RU2 120 transmit the DU (110) 200 according to the CRS AP mapping information (S460).

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, It belongs to the scope of right.

Claims

A digital signal processing device connected to the core system for processing a wireless digital signal; And
And converting the digital signal received from the digital signal processor into a digital signal and transmitting the amplified signal to the terminal based on a multi-antenna technique using two antennas, And a plurality of radio signal processing apparatuses for receiving a signal transmitted from a terminal based on a multi-antenna technique using an antenna and transmitting the received signal to the digital signal processing apparatus,
When two radio signal processing apparatuses of the plurality of radio signal processing apparatuses are paired to perform quad antenna transmission, the digital signal processing apparatus includes an RB (Resource Block) used as a measurement bandwidth, (Common Reference Signl) AP (Antenna Port) mapped to the two radio signal processing apparatuses based on the index of the AP
And the wireless communication system.

The method according to claim 1,
Wherein the digital signal processing apparatus performs mutual exchange of the CRS APs such that reference signals used for RSRP measurement are alternately transmitted from the two radio signal processing apparatuses.

3. The method of claim 2,
Wherein the digital signal processing apparatus performs a modulo 2 operation on the index of the RB and performs a CRS AP mapping on the two wireless signal processing apparatuses according to a result of the calculation.

3. The method of claim 2,
Wherein the digital signal processing device boosts transmission power when transmitting a reference signal used for the RSRP measurement.

3. The method of claim 2,
Wherein the digital signal processing apparatus performs mutual exchange of the CRS APs so that reference signals used for the RSRP measurement are mapped to the two radio signal processing apparatuses the same number of times.

3. The method of claim 2,
The digital signal processing apparatus comprising:
A resource allocation unit for allocating resources to the two radio signal processing apparatuses, wherein the resource includes an RB used for the RSRP measurement;
An RB index determination unit for performing a modulo 2 operation on the index of the RB allocated by the resource allocation unit and calculating the result; And
An AP mapping unit for performing CRS AP mapping for the two radio signal processing apparatuses according to a result of a 2-ary operation for each RB index calculated by the RB index determination unit, and transmitting the CRS AP mapping to the two radio signal processing apparatuses;
&Lt; / RTI >

A digital signal processing apparatus for processing a wireless digital signal, comprising: a plurality of wireless signal processing apparatuses installed in a service area for processing wireless signals, wherein a plurality of wireless signal processing apparatuses are connected to a terminal A method of mapping a Common Reference Sign (AP) Antenna Port (AP) to an AP (Antenna Port)
Allocating an RB (Resource Block) used as a measurement bandwidth to two radio signal processing apparatuses that are paired among the plurality of radio signal processing apparatuses and perform Quad Antenna Transmission;
Performing an operation of modulo 2 for each index of the RB; And
Performing CRS AP mapping different from each other for the two radio signal processing devices according to the calculation result of the modulo 2
/ RTI >

8. The method of claim 7,
And a CRS AP corresponding to a reference signal used for the RSRP measurement is mapped alternately to the two wireless signal processing devices according to the increase of the RB index.

A digital signal processing device connected to the core system for processing a wireless digital signal; And
And converting the digital signal received from the digital signal processor into a digital signal and transmitting the amplified signal to the terminal based on a multi-antenna technique using two antennas, And a plurality of radio signal processing apparatuses for receiving a signal transmitted from a terminal based on a multi-antenna technique using an antenna and transmitting the received signal to the digital signal processing apparatus,
When two radio signal processing apparatuses of the plurality of radio signal processing apparatuses are paired to perform quad antenna transmission, the digital signal processing apparatus performs CRS (Radio Frequency Identification) processing on the two radio signal processing apparatuses, A reference signal used for the RSRP measurement is further mapped to a wireless signal processing apparatus to which a reference signal used for RSRP measurement is mapped in mapping of an AP (Antenna Port)
And the wireless communication system.

10. The method of claim 9,
The digital signal processing apparatus transmits a PDSCH (Physical Downlink Shared CHannel) data scheduled for a measurement bandwidth to a reference signal used for the RSRP measurement by the wireless signal processing apparatus to which the reference signal used for the RSRP measurement is further mapped The wireless communication system comprising:

10. The method of claim 9,
The digital signal processing apparatus comprising:
A resource allocation unit allocating resources to the two radio signal processing apparatuses, wherein the resources include CRS AP information mapped to the two radio signal processing apparatuses;
A mapping analyzer for analyzing CRS AP information mapped by the resource allocation unit and determining a wireless signal processing device to which a reference signal used for the RSRP measurement is not mapped; And
And a mapping adder for additionally mapping a reference signal used for the RSRP measurement to a radio signal processor,
&Lt; / RTI >

A digital signal processing apparatus for processing a wireless digital signal, comprising: a plurality of wireless signal processing apparatuses installed in a service area for processing wireless signals, wherein a plurality of wireless signal processing apparatuses are connected to a terminal A method of mapping a Common Reference Sign (AP) Antenna Port (AP) to an AP (Antenna Port)
Mapping a CRS (Common Reference Sign) AP (Antenna Port) to two radio signal processing apparatuses that are paired among the plurality of radio signal processing apparatuses and perform Quad Antenna Transmission;
Determining a radio signal processor to which a reference signal used for RSRP measurement is not mapped as a result of the CRS AP mapping; And
Further mapping a reference signal used for the RSRP measurement to a radio signal processing device to which a reference signal used for the RSRP measurement is not mapped
/ RTI >

13. The method of claim 12,
Scheduling is performed such that a radio signal processor that has further mapped a reference signal used for the RSRP measurement does not transmit PDSCH (Physical Downlink Shared CHannel) data scheduled for a measurement bandwidth with respect to a reference signal used for the RSRP measurement Wherein the AP mapping method comprises:

A digital signal processing device connected to the core system for processing a wireless digital signal; And
And converting the digital signal received from the digital signal processor into a digital signal and transmitting the amplified signal to the terminal based on a multi-antenna technique using two antennas, And a plurality of radio signal processing apparatuses for receiving a signal transmitted from a terminal based on a multi-antenna technique using an antenna and transmitting the received signal to the digital signal processing apparatus,
When two radio signal processing apparatuses of the plurality of radio signal processing apparatuses are paired to perform quad antenna transmission, the digital signal processing apparatus performs the two radio signal processing (Common Reference Signl) AP (Antenna Port) mapped to each device
And the wireless communication system.

15. The method of claim 14,
Wherein the switching period is a basic unit capable of representing time in the wireless communication system and is a number of subframes or a number of system frames.

16. The method according to claim 14 or 15,
Wherein the exchange period is smaller than a period of a reference signal received power (RSRP) report reported by the UE to the radio signal processing device.

16. The method of claim 15,
Wherein the digital signal processing apparatus performs mutual exchange of the CRS APs so that reference signals used for the RSRP measurement are mapped to the two radio signal processing apparatuses the same number of times.

15. The method of claim 14,
A time counting unit for counting the time of the switching cycle;
A mapping storage unit for storing CRS AP information allocated to the two radio signal processing devices; And
When the switching period is counted by the time counting unit, maps the CRS APs to be exchanged to the two radio signal processing units based on the CRS AP information stored in the mapping storage unit, To the resource allocation unit
&Lt; / RTI >

A digital signal processing apparatus for processing a wireless digital signal, comprising: a plurality of wireless signal processing apparatuses installed in a service area for processing wireless signals, wherein a plurality of wireless signal processing apparatuses are connected to a terminal A method of mapping a Common Reference Sign (AP) Antenna Port (AP) to an AP (Antenna Port)
Receiving a resource allocation request from two radio signal processing apparatuses that are paired among the plurality of radio signal processing apparatuses and perform Quad Antenna Transmission;
Determining whether an exchange cycle has been reached; And
And performing CRS AP mapping so that CRS APs are mutually exchanged and mapped to the two wireless signal processing devices based on the CRS AP information mapped to the two wireless signal processing devices Step
/ RTI >

20. The method of claim 19,
If it is determined that the exchange cycle is not performed, mapping the CRS APs to the two radio signal processing devices as they are, according to the CRS AP information mapped to the two radio signal processing devices Including AP mapping method.

A digital signal processing device connected to the core system for processing a wireless digital signal; And
And converting the digital signal received from the digital signal processor into a digital signal and transmitting the amplified signal to the terminal based on a multi-antenna technique using two antennas, And a plurality of radio signal processing apparatuses for receiving a signal transmitted from a terminal based on a multi-antenna technique using an antenna and transmitting the received signal to the digital signal processing apparatus,
Two radio signal processing apparatuses of the plurality of radio signal processing apparatuses are paired to perform quad antenna transmission and the terminal measures a reference signal received power (RSRP) using two reference signals (Common Reference Sign) AP (Antenna Port) mapping so that the two reference signals are mapped to the two radio signal processing devices one by one
And the wireless communication system.

22. The method of claim 21,
A terminal information verifying unit for verifying whether the terminal uses the two reference signals in the RSRP measurement; And
When it is confirmed by the terminal information verifying unit that the terminal performs RSRP measurement using the two reference signals, when mapping the CRS APs to the two wireless signal processing apparatuses, And a resource allocation unit
&Lt; / RTI >

A digital signal processing apparatus for processing a wireless digital signal, comprising: a plurality of wireless signal processing apparatuses installed in a service area for processing wireless signals, wherein a plurality of wireless signal processing apparatuses are connected to a terminal A method of mapping a Common Reference Sign (AP) Antenna Port (AP) to an AP (Antenna Port)
Receiving a resource allocation request from two radio signal processing apparatuses that are paired among the plurality of radio signal processing apparatuses and perform Quad Antenna Transmission;
Confirming whether the terminal performs a reference signal received power (RSRP) measurement using two reference signals; And
When it is confirmed that the UE performs the RSRP measurement using the two reference signals, when the CRS AP mapping for the two radio signal processing devices is performed, the two reference signals are allocated to the two radio signal processing devices Steps to Map
/ RTI >