KR101537736B1 - Method for Relaying Data in Wireless Network and Personal Relay of Enabling the Method, and Mobile Device for Communicating with the Personal Relay - Google Patents

Abstract

A method of relaying data in a wireless network and a personal repeater performing the method and a terminal communicating with the personal repeater are disclosed. A method of relaying data in a wireless network according to an aspect of the present invention includes receiving and decoding data transmitted from a base station or a legacy repeater to a target terminal and selecting a data retransmission band based on a power of a received signal for all frequency bands And transmitting the decoded data to the target terminal through the data retransmission band.

Multi-cell, wireless network, resource reuse, repeater, data

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of relaying data in a wireless network and a personal repeater for performing the method and a terminal for communicating with the personal repeater,

A method of relaying data in a wireless network and a personal repeater performing the method and a terminal communicating with the personal repeater are disclosed.

Recent wireless applications and services require large transmission bandwidth.

Users of wireless network services demand data rate and quality of service similar to wired network services, but in the case of wireless networks, interference, multi-path fading, it is difficult to provide services with performance similar to that of a wired network due to problems such as shadowing. In addition, wireless network service providers and users are concerned about the cost per bit for services in the wireless service. In order to meet such a demand, a combination of orthogonal frequency division multiple access (OFDMA) and repeater technology is being studied.

The combination of OFDMA and repeater technology has several interesting issues, in particular resource assignment and interference management on a wireless network with multiple nodes involved. In a multi-cellular wireless network environment, a particular network element (e.g., a Remote Network Controller (RNC) or a base station) is connected to a centralized Radio Resource Management (RRM) Has a large complexity due to the network overhead problem due to the increased feedback information. In order to solve the complexity of the centralized radio resource management scheme, various studies such as a radio resource management scheme of a distributed scheme or a reuse of radio resources in a cell have been conducted.

A method of relaying data in a wireless network according to an aspect of the present invention includes receiving and decoding data transmitted from a base station or a legacy repeater to a target terminal and selecting a data retransmission band based on a power of a received signal for all frequency bands And transmitting the decoded data to the target terminal through the data retransmission band.

A personal repeater according to an aspect of the present invention includes a data receiver for decoding data transmitted from a base station or a legacy repeater to a target terminal, a radio resource manager for selecting a data retransmission band based on a power of a received signal for the entire frequency band, And a data retransmission unit for transmitting the decoded data to the target terminal through the data retransmission band.

According to another aspect of the present invention, there is provided a method of receiving data from a wireless terminal, the method comprising: establishing connection establishment with a personal repeater; receiving data transmitted from a base station or a legacy repeater; Transmitting an error report signal corresponding to the data to the personal repeater when there is an error in the data, and retransmitting the data corresponding to the error report signal from the personal repeater.

A distributed radio resource management scheme is provided in a cell-based wireless network.

In a cell-based wireless network, reuse of radio resources in a cell increases data throughput of a wireless terminal.

A personal repeater is provided that communicates with a wireless terminal in a cell-based wireless network to enhance communication performance.

In a cell-based wireless network, a power allocation method is provided in which a private repeater can minimize interference within its coverage.

The legacy repeaters described herein and in the figures are repeaters used in cell-based wireless networks, including: (1) fixed-type relays that are fixed in a specific location to perform data relaying, and (2) Or a mobile relay mounted on a mobile object such as a subway or performing relay of data between a base station and a wireless base station or between base stations and repeaters due to a change in installation position in real time. Generally, a legacy repeater performs a function of relaying target data received from a base station to a wireless terminal or another legacy repeater, and the legacy repeater provides data services to two or more wireless terminals included in its coverage.

The personal repeater according to an exemplary embodiment of the present invention can be defined as a repeater that provides a dedicated data relay service to a specific wireless terminal connected thereto. A data relaying method according to an embodiment of the present invention may be provided to two or more wireless terminals through a single personal repeater physically, but it is considered that two personal repeaters are logically installed in one equipment. The personal repeater may be a device specially designed to perform the functions described herein, and other terminals located near a specific wireless terminal may be operated as a personal repeater according to an embodiment of the present invention.

Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a diagram illustrating an example of a wireless network to which a personal repeater according to an aspect of the present invention is applied.

1, a wireless network according to an exemplary embodiment of the present invention includes a base station 101 and a legacy repeater 102, a base station 101, and a legacy repeater 102 that provide data services to wireless terminals 103 and 105, respectively. 106 for communicating with the wireless terminals 103, 105 and the wireless terminals 103, 105, respectively.

The personal repeaters 104 and 106 shown in FIG. 1 overhearing / receiving data frames transmitted from the base station 101 and the legacy repeater 102 to the wireless terminals 103 and 105, respectively, And stores the decoded data.

The wireless terminals 103 and 105 receive and decode the data frames transmitted from the base station 101 and the legacy repeater 102. If there is an error in the decoded data, the wireless terminals 103 and 105 transmit an error report signal to the personal relays 104 and 106. The wireless terminals 103 and 105 are each retransmitted from the personal relays 104 and 106 according to the manner promised respectively by the personal relays 104 and 106 with erroneous data frames.

Hereinafter, an example of a method of transmitting data between the base station 101 and the legacy repeater 102, the personal repeaters 104 and 106, and the wireless terminals 103 and 105 will be described in detail with reference to FIG.

2 is a diagram illustrating a method of transmitting data according to an aspect of the present invention performed by network components included in a wireless network.

The signal transmission flow shown in FIG. 2 is an example of a data transmission method performed in a wireless network configured by a base station / legacy repeater, a personal repeater, and a target terminal.

When the personal repeater is turned on 201, an initial connection setup is performed between the personal repeater and the target terminal. The personal repeater transmits control information including a preamble and downlink map (DL_MAP) information to the target terminal (202). The target terminal transmits the initial access information including the information on the base station or the legacy repeater currently being served by the target terminal and the connection identifier (CID) of the target terminal to the personal repeater (203).

The personal repeater obtains the preamble information of the corresponding base station or the legacy repeater using the information on the base station or the legacy repeater received in step 203 and synchronizes with the corresponding base station or the legacy repeater in step 204. Also, in step 203, a connection identifier of the target terminal included in the initial access information received from the target terminal is acquired (205).

The base station or legacy repeater transmits a data frame to the target terminal (207), and the personal repeater overlays (206) the data frame transmitted to the target terminal.

The personal repeater receives the data frame transmitted from the base station or the legacy repeater, decodes the data transmitted to the target terminal according to the data map information, and stores the decoded data in a buffer or a storage medium (208). The target terminal also receives a data frame from a base station or a legacy repeater that provides data service to the target terminal, and decodes the data transmitted to the target frame using the data map information (209). The target terminal analyzes the decoded data to determine whether there is an error. If there is an error in the decoded data, the target terminal transmits an error report signal corresponding to the data to the personal repeater (210). According to one embodiment of the present invention, the error report signal may be a NACK signal.

The personal repeater receives an error report signal from the target terminal. In order to retransmit the data corresponding to the error report signal to the target terminal, the personal repeater scans / measures the power of the received signal for the entire frequency band in the (i + 1) th interval after receiving the i < th > data frame transmitted from the base station or the legacy repeater , And selects a frequency band having a power value lower than the predetermined threshold value as a data retransmission band (211). Then, the data corresponding to the error report signal is retrieved from the buffer or storage medium and retransmitted to the target terminal in the i + 1 < th > ). The above-mentioned steps 211 and 212 are described in detail below with reference to FIG.

According to another embodiment of the present invention, a personal repeater that receives an error report signal transmitted from a target terminal according to an implementation of a personal repeater checks whether there is an error in the corresponding data corresponding to the error report signal, If there is an error in the data, the error report signal may be transmitted to the base station or the legacy repeater without retransmitting the data to the target terminal. When the personal repeater becomes increasingly intelligent and the implementation cost is gradually reduced, by adding the error checking function of retransmission target data to the personal repeater, resource waste for retransmitting the erroneous data to the target terminal can be reduced.

The target terminal receives the retransmitted data from the personal repeater, and decodes the received data using the downlink map (DL_MAP) information included in the control information (213). The target terminal analyzes the decoded data to determine whether there is an error. If there is an error in the decoded data, the target terminal transmits an error report signal corresponding to the data to the base station or the legacy repeater (214). According to one embodiment of the present invention, the error report signal may be a NACK signal.

3 is a flowchart illustrating an operation method of a personal repeater according to an exemplary embodiment of the present invention.

2, the personal repeater transmits control information including a preamble and a downlink map (DL_MAP) information to the target terminal, and transmits the control information including the preamble and the DL_MAP information from the target terminal to the base station or the legacy repeater And initial access information including a connection identifier (CID) of the target terminal is set (301).

In step 301, the preamble is received from the base station or the legacy repeater using information on the base station or the legacy repeater obtained from the target terminal, and synchronized with the base station or the legacy repeater. A data frame transmitted from the base station or the legacy repeater to the target terminal is received, and the corresponding data frame is decoded using the received data map information (302). The decoded data is stored in a buffer or a storage medium of the personal repeater.

The personal repeater that receives the data frame through the i-th base station sub-frame (BS_subframe) or the i-th legacy repeater sub-frame (RS_subframe) from the base station or the legacy repeater scans the entire transmission frequency band in the (i + And measures the received signal power for the frequency band. A frequency band having a value less than a predetermined threshold value among the measured received signal power values is selected as a data retransmission band (303).

In step 301, the target terminal connected to the personal repeater receives a data frame from the base station or the legacy repeater. If there is an error in the decoded data, the target terminal transmits an error report signal corresponding to the data to the personal repeater. The personal repeater receives the error report signal transmitted from the target terminal, finds data corresponding to the error report signal from the decoded data in step 302, and transmits the data through the selected data retransmission band in step 303 And retransmits it to the terminal (304).

In step 304, the personal repeater transmits,

(1) If the target terminal is receiving data service from the base station, the data to be retransmitted to the target terminal and the data map information of the (i + 1) th BS_subframe among the i-th BS_subframe are taken into consideration (BS_subframe is transmitted directly to the target terminal (DL MAP) information necessary for retransmitting data to the target terminal, and transmits the downlink map (DL MAP) information to the target terminal,

(2) When the target terminal receives data service from the legacy repeater, it configures downlink map (DL MAP) information necessary for retransmitting data to the target terminal in consideration of data to be retransmitted to the target terminal among the i-th RS_subframe, Lt; / RTI >

According to one embodiment of the present invention, in step 304, the personal repeater may allocate transmission power in the following manner to minimize the effect of interference on other wireless terminals within the service coverage of the personal repeater during data retransmission .

(1) After obtaining the number of subcarriers necessary for retransmission of the data, the number of subchannels required for the retransmission is calculated in descending order of interference power.

(2) Subcarriers corresponding to data having a modulation scheme of a high order are sequentially allocated to the subchannels calculated in (1) above. Higher signal-to-noise interference ratios can transmit data using a higher-order modulation scheme. For example, QPSK, 16QAM, 64QAM, and 256QAM are higher order modulation schemes. That is, the number of subchannels required for retransmission can be allocated in the order of small interference power, and data corresponding to a high-order modulation scheme can be transmitted in descending order of interference power.

(3) For each sub-channel, the power allocation value is calculated according to Equation (1) below and the data is retransmitted to the target terminal.

는 개인용 중계기 k의 a번째 서브채널에 할당된 전력,

는 개인용 중계기 k의 나머지 전력, SINR₁는 a번째 서브채널에서 개인용 중계기와 단말 간 SINR 값,

는 a번째 서브채널의 간섭 전력,

는 잡음 전력,

은 페이딩 마진,

은 중계기와 단말 간 경로 손실을 의미한다.In the above equation (1)

The power allocated to the a-th subchannel of the personal repeater k,

SINR ₁ is the SINR value between the private repeater and the terminal in the a-th subchannel,

Is the interference power of the a-th sub-channel,

Noise power,

The fading margin,

Means the path loss between the repeater and the terminal.

4 is a diagram illustrating an example of a data frame structure of a personal repeater according to an embodiment of the present invention.

Referring to FIG. 4, the interval 401 is an interval for overhearing / receiving data transmitted from a base station or a legacy repeater to a target terminal.

Section 402 is a Receiving / Transmitting Gap period.

The interval 403 is a period for transmitting the preamble of the personal repeater and the downlink map (DL_MAP) information necessary for data retransmission to the target terminal.

The interval 404 is a period in which the personal repeater retransmits the data corresponding to the error report signal received from the target terminal to the target terminal.

The data frame of the personal repeater shown in FIG. 4 is merely an example, and various modifications and variations will be apparent to those skilled in the art.

5 is a block diagram illustrating a configuration module of a personal repeater in accordance with an embodiment of the present invention.

5, the personal repeater according to an exemplary embodiment of the present invention may include a data receiving unit 510, a radio resource managing unit 520, a data retransmitting unit 530, and a connection managing unit 540.

The data receiving unit 510 decodes the data transmitted to the target terminal by restoring the data map information transmitted from the base station or the legacy repeater to the target terminal.

The radio resource management unit 520 may include a power measurement unit 521, a resource allocation unit 522, an interference detection unit 523, and a power allocation unit 524.

The power measuring unit 521 scans the entire transmission frequency band of the base station or the legacy repeater under the control of the resource allocating unit 522 and measures the received signal power for the entire frequency band.

The resource allocation unit 522 analyzes the power value of the received signal measured by the power measurement unit 521 and outputs a frequency band having a value smaller than a predetermined threshold value of the measured received signal power value to a data retransmission band .

The interference recognizer 523 calculates the number of subcarriers required for retransmitting data according to the error report signal transmitted from the target terminal and calculates the number of subchannels with a small interference power.

The power allocating unit 524 sequentially allocates subcarriers corresponding to data having a high-order modulation scheme to the subchannels for the subchannels calculated in the interference recognizer 523 in order. According to an embodiment of the present invention, the power allocation unit 524 allocates the power allocated to each subchannel based on at least one of the SINR, the fading margin value, the path loss value between the personal repeater and the target terminal, The value can be calculated.

The data retransmission unit 530 retransmits the data to the target terminal using the power value allocated for each subchannel in the power allocation unit 524 through the data retransmission band allocated by the resource allocation unit 522. [

The connection management unit 540 transmits downlink map (DL_MAP) information and control information including a preamble to a target terminal, and receives initial access information corresponding to the control information from the target terminal. Since the control signal transmitted to the target terminal and the initial access information received from the target terminal have been described in detail with reference to FIG. 3, the description will be omitted.

As described above, the personal repeater according to an embodiment of the present invention shown in FIG. 5 may be defined as a repeater that provides a dedicated data relay service to a specific wireless terminal connected thereto. The personal repeater may be a device specially designed to perform the functions described herein, and other terminals located near a specific wireless terminal may be operated as a personal repeater according to an embodiment of the present invention.

Also, as described above, the personal repeater according to an embodiment of the present invention receives the error report signal transmitted from the target terminal, checks whether the corresponding data corresponding to the error report signal is erroneous, And to transmit the error report signal to the base station or the legacy repeater without re-transmitting the data to the target terminal when there is an error. When the personal repeater becomes increasingly intelligent and the implementation cost is gradually reduced, by adding the error checking function of retransmission target data to the personal repeater, resource waste for retransmitting the erroneous data to the target terminal can be reduced.

6 is a flowchart illustrating an operation of a wireless terminal that communicates with a personal repeater to receive data according to an exemplary embodiment of the present invention.

The target terminal performs initial connection establishment with the personal repeater (601). As described above, the target terminal receives the control information including the preamble and the downlink map (DL_MAP) information from the personal repeater, and informs the personal repeater of information about the base station or the legacy repeater currently being served by the target terminal, And transmits initial access information including a connection identifier (CID) of the target terminal.

The target terminal receives the data frame from the base station or the legacy repeater, and decodes the data frame using the received data map information (602).

The target terminal determines whether there is an error in the decoded data (603). If there is an error as a result of the determination, the target terminal transmits an error report signal corresponding to the data to the personal repeater (604). In step 604, the error report signal may be a NACK. If it is determined in step 603 that there is no error in the decoded data, data is received from the base station or the legacy repeater in step 602.

The personal repeater decodes and stores a data frame transmitted to the target terminal, finds data corresponding to the error report signal transmitted from the target terminal, retransmits the data to the target terminal, and the target terminal retransmits the retransmitted data (605).

The target terminal determines whether there is an error in the retransmitted data in step 605 and receives data from the base station or the legacy repeater in step 602 if there is no error. If it is determined in step 605 that there is an error in the retransmitted data, the target terminal transmits an error report signal corresponding to the data to the base station or the legacy repeater (607). In step 607, the error report signal may be a NACK. As described above, if the personal repeater according to the embodiment of the present invention is intelligent and has a function of checking whether there is an error in the corresponding data corresponding to the error report signal transmitted from the target terminal, the step 607 is omitted The corresponding error reporting signal can be communicated from the private repeater to the base station or legacy repeater.

A method of relaying data in a wireless network and a method of operating a terminal for communicating with a personal repeater according to an aspect of the present invention may be implemented in the form of a program command that can be executed through various computer means and recorded in 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 medium may be those specially designed and constructed for the present invention or may be available to those skilled in the art of computer software. Examples of computer-readable media include magnetic media such as hard disks, floppy disks and magnetic tape; optical media such as CD-ROMs and DVDs; magnetic media such as floppy disks; Magneto-optical media, and hardware devices specifically configured to store and execute program instructions such as ROM, RAM, flash memory, and the like. Examples of program instructions include machine language code such as those produced by 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 as one or more software modules to perform the operations of the present invention, and vice versa.

While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those of ordinary skill 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 by the appended claims. This is possible.

Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined by the equivalents of the claims, as well as the claims.

1 is a diagram illustrating an example of a wireless network to which a personal repeater according to an aspect of the present invention is applied.

2 is a diagram illustrating a method of transmitting data according to an aspect of the present invention performed by network components included in a wireless network.

3 is a flowchart illustrating an operation method of a personal repeater according to an exemplary embodiment of the present invention.

4 is a diagram illustrating an example of a data frame structure of a personal repeater according to an embodiment of the present invention.

5 is a block diagram illustrating a configuration module of a personal repeater in accordance with an embodiment of the present invention.

6 is a flowchart illustrating an operation of a wireless terminal that communicates with a personal repeater to receive data according to an exemplary embodiment of the present invention.

Claims (25)

Decoding data transmitted from a base station or a legacy repeater to a target terminal in a private repeater; Receiving an error report signal for the data received from the target terminal in the private repeater from the base station or the legacy repeater; Selecting a data retransmission band based on the power of the received signal for the entire frequency band in the personal repeater; And And transmitting data corresponding to the error report signal to the target terminal through the data retransmission band at the personal repeater, Wherein the step of selecting the data retransmission band comprises: Calculating a number of subcarriers required for transmission of data corresponding to the error report signal and calculating the number of subchannels with a small interference power; And And assigning subcarriers corresponding to data having a modulation scheme of a higher order to the subchannel in order A method for relaying data in a wireless network. delete The method according to claim 1, And the error report signal is a NACK. delete The method according to claim 1, Wherein the step of assigning the subcarriers to the subchannel comprises: Calculating a power value allocated to each subchannel based on at least one of the SINR, the fading margin value, and the path loss value between the personal repeater and the target terminal; The method comprising the steps of: The method according to claim 1, Wherein the step of transmitting data corresponding to the error report signal to the target terminal comprises: Transmitting control information including downlink map (DL_MAP) information to the target terminal; And Receiving initial access information from the target terminal Lt; / RTI > And the data is decoded according to the downlink map (DL_MAP) information received by the target terminal. The method according to claim 6, Wherein the initial access information includes connection information for the base station or the legacy relay device providing the service to the target terminal or connection identifier information of the target terminal. 8. The method of claim 7, Receiving the preamble from the base station or the legacy repeater using the access information for the base station or the legacy repeater, and synchronizing The method comprising the steps of: The method according to claim 1, Wherein the step of selecting the data retransmission band comprises: Measuring a received signal power for the entire frequency band; And Determining a frequency band having a power lower than a predetermined threshold value as the data retransmission band The method comprising the steps of: A data receiver for restoring data map information transmitted from a base station or a legacy repeater to a target terminal and decoding data transmitted to the target terminal; A radio resource manager for selecting a data retransmission band based on a power of a received signal for the entire frequency band; And And a data retransmitting unit for receiving an error report signal for the data received from the target terminal from the base station or the legacy repeater and transmitting data corresponding to the error report signal through the data retransmission band to the target terminal , The radio resource management unit, An interference recognizing unit for calculating the number of subcarriers necessary for transmission of data corresponding to the error report signal and calculating the number of subchannels with a small interference power; And And a power allocation unit that sequentially allocates subcarriers corresponding to data having a high-order modulation scheme to the subchannels Personal Repeater. delete 11. The method of claim 10, Wherein the power allocator calculates a power value allocated to each sub-channel based on at least one of an SINR, a fading margin value, and a path loss value between the personal repeater and the target terminal for each sub-channel. delete 11. The method of claim 10, And the error report signal is a NACK. 11. The method of claim 10, (DL_MAP) information to the target terminal, and receives initial access information corresponding to the control information from the target terminal, Lt; / RTI > Wherein the data is decoded at the target terminal according to the downlink map (DL_MAP) information. 16. The method of claim 15, Wherein the initial access information includes access information for the base station or the legacy repeater providing the service to the target terminal, or connection identifier information of the target terminal. 17. The method of claim 16, And the data receiving unit receives the preamble from the base station or the legacy repeater using the access information for the base station or the legacy repeater. 11. The method of claim 10, The radio resource management unit, A power measuring unit measuring a received signal power for the entire frequency band; And And determines a frequency band having a power lower than a predetermined threshold value as the data retransmission band, . 11. The method of claim 10, Wherein the personal repeater is a terminal near the target terminal. delete delete delete delete delete delete

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