KR20160058694A - Method for transmitting frame supporting legacy system, method and apparatus for cell detection using the same, and terminal - Google Patents

Abstract

Provided are a frame transmission method for supporting a legacy system, and a method and terminal for detecting a cell using the same. A frame which includes a first frequency band adapted to support a mobile communication system and a second frequency band adapted to support a legacy system and which has an overall frequency band larger than the second frequency band is generated. Primary broadcast information related to a frequency bandwidth is transmitted via a physical broadcasting channel of the second frequency band.

Description

[0001] The present invention relates to a frame transmission method for supporting a legacy system, and a cell search method and a terminal using the same,

The present invention relates to a frame transmission method for supporting a legacy system in a wireless communication system, and a cell search method and terminal using the same.

There is a legacy-zone support method as a legacy technology for supporting a legacy system in a new system in a mobile communication environment. Here, a legacy system represents a system already defined, and a legacy terminal represents a terminal supported by a legacy system. For example, in view of the 3GPP LTE-A system, the 3GPP LTE system corresponds to a legacy system.

In order to support a legacy system in a wireless communication system, a DL (downlink) zone is divided into a legacy zone, which is a region for supporting a legacy terminal through a time division multiplexing scheme, and a New Zone, which is a region for supporting a terminal of a new system There is a way to divide and separate.

In such a frame structure, time intervals for supporting legacy systems inevitably occur between newzones, thereby increasing the minimum access time in services for low latency. Also, basically, each system can access only the zones allocated to each system, making it difficult to meet dynamic service demands.

A problem to be solved by the present invention is to provide a method for transmitting a frame to support a legacy system operating in an existing frame structure in a system supporting a new service such as a low-delay service, and a cell search method and a terminal using the method .

A method of transmitting a frame supporting a legacy system in a mobile communication system, the method comprising: transmitting a frame supporting a legacy system in a first frequency band for supporting the mobile communication system, Generating a frame including a second frequency band, wherein the entire frequency band is larger than the second frequency band; And transmitting the primary broadcasting information through the broadcasting physical channel of the second frequency band.

The primary broadcast information may include a legacy system bandwidth and an entire frequency bandwidth.

The frame transmission method may further include transmitting secondary broadcast information through a data area of the second frequency band, and the secondary broadcast information may include band configuration information of the mobile communication system .

The frame transmission method may further include setting a part of the subframes of the second frequency band not to be used by the terminal connecting to the legacy system and for the terminal requesting the low delay service of the mobile communication system The method further comprises the step In this case, the setting may be performed in a downlink frame of the legacy system of the second frequency band through a configuration of a MBSFN (Multimedia Broadcast Single Frequency Network) subframe or an ABS (Almost Blank Subframe) Constraining the operation in some subframes; And limiting uplink transmission scheduling of a terminal connected to a legacy system in a subframe of a legacy system of the second frequency band in a subframe and using the resource for service of the terminal of the mobile communication system . ≪ / RTI >

Wherein a frame of the mobile communication system has a transmission time interval (TTI) structure that is shorter than that of the legacy system, and some of the radio resources constituting each TTI of the first frequency band is used as a control region, May have a predetermined size or may have different sizes for each TTI.

The primary broadcasting information includes indication information indicating that the size of the control area is fixed or variable. When the primary broadcasting information is variable, indication information on the control area size may be transmitted through a short physical control format indicator channel (sPCFICH) have.

If the period in which the size of the control area changes is greater than one TTI size, the sPCFICH is configured once per period, and the primary broadcast information may include period information in which the size of the control area changes.

The size of the control area is determined by CFI (Control Format Indicator) information. The size of the control area is determined by the number of radio resources constituting the control area, the ratio of the control area occupied by all the radio resources, It can represent one of the maximum sizes.

A control region is formed from a sub-carrier index having an offset per radio resource among sub-carrier indexes of radio resources, and the offset may be set differently for each cell.

Selects radio resources to be mapped to the sPCFICH, assigns the sPCFICH to a plurality of radio resources from a first radio resource among the selected radio resources, and a channel other than the sPCFICH allocates remaining radio resources And a channel other than the sPCFICH may be one of a short physical downlink control channel (sPDCCH) and a short physical HARQ indicator channel (sPHICH).

A cell search method according to another aspect of the present invention is a cell search method for a terminal in a mobile communication system supporting a legacy system, the method comprising: a first frequency band for supporting the mobile communication system; Receiving a primary broadcasting information through a broadcasting physical channel of the second frequency band in a structure including a second frequency band for supporting the first frequency band; Receiving the system information through the control and data areas of the first frequency band based on the primary broadcasting information; And performing connection to the mobile communication system based on the received system information.

The primary broadcast information may include a legacy system bandwidth and an entire frequency bandwidth. The cell search method may further include: calculating a bandwidth of the mobile communication system based on the legacy system bandwidth and the total system bandwidth after receiving the primary broadcasting information; And adjusting the overall system bandwidth based on the calculated mobile communication system bandwidth and the legacy system bandwidth.

The total system bandwidth included in the primary broadcast information and the adjusted overall system bandwidth may have the same value when both the legacy system bandwidth and the total system bandwidth are odd or both are even, If one of the total system bandwidths is an odd number and one is an even number, the adjusted total system bandwidth may be one less than the total system bandwidth included in the primary broadcast information.

The cell search method may further include a step of receiving the legacy synchronization signal or the mobile communication system synchronization signal and synchronizing the terminal before the step of receiving the primary broadcasting information.

The method of searching for a cell may further include receiving secondary broadcasting information through the control and data area of the second frequency band and the secondary broadcasting information including setting information of the mobile communication system after the connecting step Step < / RTI >

Wherein the primary broadcasting information includes indication information indicating that the size of the control area is fixed or variable, and when the primary broadcasting information is variable, indication information on the control area size is transmitted through a short physical control format indicator channel (sPCFICH) The terminal can configure the channels of the control area by determining the size of the control area using the instruction information.

According to another aspect of the present invention, there is provided a terminal in a mobile communication system supporting a legacy system, comprising: a radio frequency converter for transmitting and receiving signals through an antenna; a processor connected to the radio frequency converter, Wherein the processor comprises: a frame including a first frequency band for supporting the mobile communication system and a second frequency band for supporting the legacy system, the broadcast physical channel of the second frequency band A primary broadcasting information processing unit for receiving and processing the primary broadcasting information through the first broadcasting information processing unit; And a connection processing unit for receiving the system information through the control and data areas of the first frequency band based on the primary broadcasting information, and for performing connection based on the received system information.

Wherein the primary broadcast information includes a legacy system bandwidth and an entire frequency bandwidth, and the processor calculates the bandwidth of the mobile communication system based on the legacy system bandwidth and the total system bandwidth, And a bandwidth processor for adjusting the overall system bandwidth based on the system bandwidth.

The processor may further include a synchronization processing unit for receiving a legacy synchronization signal or a synchronization signal of the mobile communication system and synchronizing the synchronization before receiving the primary broadcasting information.

The processor may further include a secondary broadcasting information processing unit for receiving and processing secondary broadcasting information through the control and data areas of the second frequency band, and the secondary broadcasting information includes setting information of the mobile communication system .

According to the embodiment of the present invention, through a frame of a structure in which a low-delay system and a legacy system coexist, both devices capable of connecting only a legacy system and devices for a low-delay service when one frequency band is available .

In addition, it is possible to support low-latency systems and legacy systems at the same time, thereby efficiently supporting the legacy system without affecting the delay time, which is the core of the low-latency service.

In addition, since the resource areas of the low delay system and the legacy system can be dynamically configured not only in the frequency band but also in the subframe unit, optimal resource allocation can be performed reflecting the load of each system.

1 is a diagram showing a frame structure of a legacy system.
2 is a diagram illustrating a frame structure of a mobile communication system supporting a low-latency service.
3 shows another frame structure of the low-delay system.
4 is a diagram illustrating a frame structure according to asymmetric FDD.
5 is a diagram illustrating a basic structure of a frame according to an embodiment of the present invention.
6 is a diagram illustrating bandwidths of systems in accordance with an embodiment of the present invention.
FIG. 7 is a flowchart illustrating a cell search procedure of a low-delay UE according to an embodiment of the present invention.
8 is a flowchart illustrating another cell search procedure of the low-delay UE according to the embodiment of the present invention.
9 is a diagram illustrating a structure in which a legacy area is variable in a frame according to an embodiment of the present invention.
FIG. 10 is a diagram illustrating a downlink frame structure in which a legacy area is variable according to an exemplary embodiment of the present invention. FIG. 11 is a diagram illustrating an uplink frame structure in which a legacy area is varied according to an exemplary embodiment of the present invention. to be.
FIG. 12 is an exemplary diagram illustrating the construction of a control region of a low-delay system according to an embodiment of the present invention.
13 is a diagram illustrating mapping of a position of a channel sPCFICH indicating the size of a control area according to an embodiment of the present invention.
14 illustrates a control region and resource allocation in a system according to an embodiment of the present invention.
FIG. 15 is a diagram illustrating transmission of a synchronization signal and a physical channel in a system according to an embodiment of the present invention.
16 is an exemplary diagram illustrating transmission of HARQ retransmission time in a system according to an embodiment of the present invention.
17 is a structural diagram of a terminal according to an 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.

Throughout the specification, a terminal is referred to as a mobile terminal (MT), a mobile station (MS), an advanced mobile station (AMS), a high reliability mobile station (HR- A subscriber station (SS), a portable subscriber station (PSS), an access terminal (AT), a user equipment (UE) , HR-MS, SS, PSS, AT, UE, and the like.

Hereinafter, a frame transmission method supporting a legacy system according to an embodiment of the present invention, a cell search method using the same, and a terminal will be described with reference to the drawings.

1 is a diagram showing a frame structure of a legacy system.

A frame of a legacy system (also referred to as a "legacy frame" for convenience of description) includes a plurality of subframes and has a normal transmission time interval (TTI) structure as shown in FIG. Each subframe constituting the TTI is composed of about 14 Orthogonal Frequency Division Multiplexing (OFDM) symbols each consisting of, for example, two slots. Here, a legacy system represents a system that has already been defined.

2 is a diagram illustrating a frame structure of a mobile communication system supporting a low-latency service.

A system supporting a new service, for example, a mobile communication system supporting a low latency service (hereinafter referred to as a low delay system for convenience of explanation) A short TTI structure is used. Each subframe constituting the TTI, that is, a short frame may be composed of, for example, at least about 100 us, and may be composed of one symbol. The TTI of a low delay system is, for example, 100us, a time shorter than 1/10 of a 1ms TTI of a legacy system (e.g., 3GPP LTE / LTE-A system). Basically, a terminal connected to a mobile communication system must receive control information every transmission time unit. Therefore, in a system using a short transmission time unit of 1/10, it is necessary to receive control information 10 times more times.

The low-delay system uses an OFDM symbol such as a legacy system for interference prevention and minimum compatibility with a legacy system, and the number of OFDM symbols constituting the TTI can be determined by the time constraint of the TTI. For example, a TTI may be composed of one symbol. In addition to the 1-symbol TTI, the TTI may be composed of 2 to 7 symbols.

3 shows another frame structure of the low-delay system.

In the frame structure of the low-delay system, as shown in FIG. 3, the TTI may have a TTI composed of two symbols or three symbols in addition to one symbol. In FIG. 3 (a), each TTI is composed of two symbols. Also, in FIG. 3 (b), the 0th, 1st, 2nd, and 3rd TTIs are composed of 3 symbols.

In the case of configuring the TTI with 2 symbols or 3 symbols, there is a possibility that the TTI may not be configured according to the subframe composed of 14 symbols as shown in FIG. That is, as shown in FIG. 3 (b), when a TTI is composed of 3 symbols in a subframe consisting of 14 symbols, there is a redundancy of 1 or 2 symbols. These extra symbols may be referred to as Special Shortframes. Special shot frames can be used for specific purposes such as data transmission or control signaling.

Since the special shot frame has fewer symbols than the short frame, when data is used for data transmission, data transmission using fewer resources than short frames should be performed. Therefore, this resource can be used for a terminal having a good channel environment, or for data transmission of a small size. In addition, the resource may be used for transmission of hybrid automatic repeat request (HARQ) feedback, scheduling information, channel state information, or a sounding reference signal for channel state information.

On the other hand, in a frequency division duplexing (FDD) environment, DL (downlink) and UL (uplink) can operate in different TTI units. This can be called asymmetric FDD. As an example where asymmetric FDD can be utilized, the TTI of the UL frame is composed of a larger number of symbols than the number of TTI symbols of the DL frame, so that transmission using control information or data information can be performed using more energy The uplink coverage problem can be solved.

4 is a diagram illustrating a frame structure according to asymmetric FDD.

The DL frame and the UP frame shown in FIG. 4 attached thereto operate in different TTI units. Specifically, in a DL environment, a frame operates in a 1-symbol TTI unit, and in a UL environment, a frame operates in a 3-symbol TTI unit. In this asymmetric FDD environment, DL TTI and UL TTI must be separately defined and transmitted to the terminal through broadcasting information (for example, Master Information Block or System Information Block).

In the embodiment of the present invention, in order to support a legacy system in a low delay system which is a system for providing a new service, for example, a low delay service, a frame composed of a short frame TTI and a frame structure of a legacy system It integrates and uses the new frame structure.

5 is a diagram illustrating a basic structure of a frame according to an embodiment of the present invention.

The frequency bandwidth of the low delay system according to the embodiment of the present invention is configured to be larger than the frequency bandwidth of the legacy system. 5, a new frame of the low-delay system according to an embodiment of the present invention includes an area for supporting a low-latency system (also referred to as a low-latency area for convenience of explanation) (Referred to as a legacy area for convenience of explanation). That is, the frequency band of the legacy system is constituted at a part of the total bandwidth of the frame. Therefore, the frequency bandwidth of the entire low-delay system should be configured to be greater than the frequency bandwidth of the legacy system.

The terminals that want to access the legacy system can obtain the system information through the synchronization signal and the broadcasting physical channel in the frequency band of the legacy system, and the system information such as bandwidth is transmitted based on the legacy system. The terminals connected to the legacy system can connect and operate the legacy terminal by recognizing the frequency band to be operated as the frequency band of the legacy system.

Among the terminals connected to the system in which the low-latency system and the legacy system coexist, a terminal (also referred to as a low-delay terminal for convenience of explanation) wishing to access the low-latency system, based on the information transmitted from the legacy system, To be able to configure the bandwidth of the network.

In order to configure the bandwidth of the low-delay system in the low-delay UE, there is a method of using the primary broadcasting information and a method of using the secondary broadcasting information.

The primary broadcast information is information transmitted from a broadcast physical channel of a frequency band of a legacy system, that is, a physical broadcasting channel (PBCH), and is in the form of a master information block (MIB) to be. The low latency terminal receives the legacy system bandwidth (N_System) and the total system bandwidth (N_Total) in the MIB which is the primary broadcasting information of the legacy system. The unit of each bandwidth information is the number of RBs (resource blocks) constituted. The bandwidth of the legacy system and the low-delay system using the two received information can be obtained as follows.

Here, N ^{DL _Legacy} _RB represents the legacy system bandwidth of the downlink, and N ^DL_System _RB represents the low-delay system bandwidth of the downlink. N ^{DL _total} _RB represents the total system bandwidth of the downlink. N ^DL _sRB Represents the low delay system bandwidth calculated based on the legacy system bandwidth and the overall system bandwidth.

The low delay system bandwidth N ^DL _sRB and the legacy system bandwidth N ^{DL _Legacy} _The total system bandwidth is adjusted based on _RB , and the adjusted total system bandwidth (N_Total ') is obtained as follows.

In the above Equation 2, if the received total system bandwidth N_Total and the adjusted system bandwidth N_Total 'are both odd numbers or the total system bandwidth N_Total is even, same. Also, if the legacy system bandwidth N_System is odd, the total system bandwidth N_Total is even, or if the legacy system bandwidth N_System is even and the overall system bandwidth N_Total is odd, the adjusted total system bandwidth (N_Total ') is determined to be one less than the total system bandwidth (N_Total) received. This is due to constraints on the placement of RBs in legacy systems. This constraint is caused by the fact that, when a terminal accessing a legacy system attempts to access a legacy system using the center frequency and the bandwidth of the legacy system, the RB allocation must be the same regardless of the bandwidth size of the low-delay system.

6 is a diagram illustrating bandwidths of systems in accordance with an embodiment of the present invention.

6 (a), when the legacy system bandwidth N_System is 6 RB and the total system bandwidth N_Total is 15 RB as shown in FIG. 6 (b), the RB configuration of the legacy system bandwidth The adjusted total system bandwidth (N_Total ') should be configured to a maximum of 14 RB as shown in FIG. 6 (c). The RB of the low-delay system band (which may also be referred to as the low-delay region) in the adjusted whole system bandwidth is equal to the lower and upper bands based on the band constituted by the RB of the legacy system, Lt; / RTI >

The secondary broadcast information is in the form of a system information block (SIB) transmitted through a physical downlink shared channel (PDSCH) in a frequency band of a legacy system, and is information that can be received after accessing the system.

After connecting to the legacy system, the low-delay UE can receive the SIB information related to the low-delay system band configuration through the data area of the legacy system. The low-delay system band configuration information is, for example, the bandwidth of the low-delay system in terms of the number of RBs.

On the other hand, the band of the legacy system may or may not be configured in some frequency band of the entire system band. When the bandwidth of the legacy system is not configured, the frequency bandwidth of the entire system is used for the low delay system.

If the bandwidth of the legacy system is not configured, the legacy terminal can not be supported. In this case, the legacy terminal can not be connected. In order to disable connection of the legacy terminal, different types of synchronization signals may be used. This will be described later in more detail.

If the band of the legacy system is not configured, the entire system band is used for the low-delay system, and a procedure for adjusting the entire system band in consideration of the legacy system band (representing the legacy region) is unnecessary. In this case, N = N ^{DL DL} _sRB ^_total _RB .

Next, the cell search procedure of the low-delay UE will be described.

FIG. 7 is a flowchart illustrating a cell search procedure of a low-delay UE according to an embodiment of the present invention.

Here, when low-delay system band information is transmitted using primary broadcast information, a low-delay terminal performs cell search.

First, as shown in FIG. 7, the low-delay UE performs cell search using a legacy sync signal and a broadcast channel and receives primary broadcast information (S100). The primary broadcast information is transmitted through the PBCH in the frequency band of the legacy system.

The low-delay UE synchronizes using the legacy synchronization signal (S110, S120). When receiving the primary broadcasting information, the size and position of the low-delay system band are determined using the legacy system bandwidth and the overall system bandwidth of the primary broadcasting information (S130, S140). Next, the low-delay UE receives the system information through the control of the low-delay system band and the data area (S150), and performs the subsequent connection procedure based on the received system information (S160).

On the other hand, if the reception of the legacy synchronization signal fails, the low-delay terminal receives a new synchronization signal, that is, a synchronization signal for the low-delay system and primary broadcasting information. Then, synchronization is performed using the low-delay synchronization signal (S170). As described above, the size and position of the low-delay system band are grasped based on the primary broadcast information, and the connection procedure is performed based on the system information received through the control of the low-delay system band and the data area reception (S 130 To S160).

8 is a flowchart illustrating another cell search procedure of the low-delay UE according to the embodiment of the present invention.

Here, when the low-delay system band information is transmitted using the secondary broadcast information, the low-delay terminal performs cell search.

First, as shown in FIG. 8, the low-delay UE performs cell search using a legacy sync signal and a broadcast channel, and receives primary broadcast information. The primary broadcast information is transmitted through the PBCH in the frequency band of the legacy system.

The low-latency terminal synchronizes using the legacy synchronization signal. In receiving the primary broadcasting information, the size and position of the low-delay system band are determined using the legacy system band and the entire system band of the first broadcasting information (S300 to S330). Next, the low-delay UE receives the system information through the control and data area of the low-delay system band, and performs a subsequent connection procedure based on the received system information (S340, S350).

Also, the low-delay UE receives low-delay system setting information, which is secondary broadcast information, through the control of the legacy system band and the data area. The low delay system setup information may include low delay system band information (S360, S370).

Meanwhile, in the frame according to the embodiment of the present invention, the legacy system band, that is, the legacy area, can be varied.

9 is a diagram illustrating a structure in which a legacy area is variable in a frame according to an embodiment of the present invention.

It is necessary to dynamically change the resource area of the low delay system and the resource area of the legacy system in consideration of the load of the terminals connected to each of the low delay system and the legacy system in the cell. For this purpose, the size of resources for terminals connected to each system can be adjusted by adjusting the legacy system band supporting the legacy system.

For example, as shown in FIG. 9, a legacy system band, that is, a part R1 of a subframe in a legacy area is set not to be used by terminals connected to a legacy system, that is, a legacy terminal, And may be used by terminals requesting a delay service. The method of not using a part of the subframes may be implemented by applying a method of constructing a MBSFN (Multimedia Broadcast Single Frequency Network) subframe or an ABS (Almost Blank Subframe) of a legacy system.

FIG. 10 is a diagram illustrating a downlink frame structure in which a legacy area is variable according to an exemplary embodiment of the present invention. FIG. 11 is a diagram illustrating an uplink frame structure in which a legacy area is varied according to an exemplary embodiment of the present invention. to be.

In the DL frame, as shown in FIG. 10, the low-delay region and the legacy region are included, and some of the sub-frames R11 of the legacy region are set not to be used by the legacy terminals. A subframe set in this way is referred to as a "legacy unassigned subframe ". The legacy unassigned subframe of this legacy region may be used for terminals requesting a low delay service.

On the other hand, in the UL frame, there is no way to explicitly use some subframes of the legacy area. Accordingly, as shown in FIG. 11, a sub-frame R12 in which data transmission or control signal transmission to the legacy terminal does not occur in the legacy area can be opportunely used for the low-delay system.

FIG. 12 is an exemplary diagram illustrating the construction of a control region of a low-delay system according to an embodiment of the present invention.

The control region in the low-delay system band exists every TTI (Short-TTI) and is composed of a RE among the Resource Elements (REs) constituting the TTI. The control region is used to transmit resource allocation information, HARQ feedback information, control channel configuration information, and the like, rather than transmission of upper layer data.

The size of the control region in the low-delay system band may be fixed to a predetermined size, or may be varied to different sizes for each TTI. In order to construct a control region having a fixed or variable size, it is possible to inform that the control region is fixed or variable through the primary broadcast information. If the size of the control area is variable, a short physical control format indicator channel (sPCFICH) for informing the size of the control area may be configured. In Fig. 11, "REG" indicates "Resource Element Group ".

The indication information indicating that the control area is fixed or variable through the primary broadcast information may be configured as shown in Table 1 below.

Field Size Description sPCFICH Information 1 bit 0: Fixed Control Region Size (sPCFICH may not be configured)
1: Dynamic Control Region Size (sPCFICH may not be configured)

In order to reduce the overhead of the sPCFICH, which is a channel for informing the size of the control region, the period in which the size of the control region varies may be varied. When the period in which the size of the control area changes is larger than one TTI size, the sPCFICH is configured once per cycle. In this case, period information in which the size of the control area is changed may be included in the primary broadcast information.

In this case, the indication information indicating that the control region is fixed or variable through the primary broadcast information may include period information in which the size of the control region changes, and may be configured as shown in Table 2 below.

field size Description sPCFICH Information 2 bits 0: Fixed control area size (sPCFICH may not be configured)
1: dynamic control area size, changes per subframe (sPCFICH can be configured in the first TTI every subframe)
2: dynamic control area size, changes per TTI (sPCFICH can be configured every TTI)

For example, as shown in Table 2, 2-bit indication information, that is, CFI (Control Format Indicator) information, can be transmitted through the sPCFICH indicating the size of the control region. The terminal uses the 2-bit CFI information to determine the size of the control area and construct channels of the control area. The control area according to the CFI information can be configured as follows.

CFI value (Value) Description 0 4 REs per sRB assigned to control area One 6 REs per sRB assigned to control area 2 8 REs per sRB assigned to control area

In Table 3, the unit for varying the size of the control area is the number of REs. However, in addition to the above, the ratio (for example, 20%, 30%, 40%) of the control region among the entire REs, or the maximum size (e.g., 1 symbol) . It is assumed that the REs constituting the control region do not include an RE for the reference signal. However, in some cases, the control region may be defined as a region including the reference signal.

The control region can be configured from the lowest subcarrier index among the subcarrier indexes of each RB for each RB. Or a subcarrier index having a constant offset (Offset). In the latter case, a control region is formed from a subcarrier index having an offset in order to prevent the position of the control region from being the same for each cell in consideration of the case of Inter-cell Interference Randomization. For different control region configurations for different cells, different offsets can be set as follows.

here,

Indicates a cell ID (Identifier)

Represents the number of subcarriers per RB.

Based on the offset set as above, the control region for each RB can be configured as follows.

Where k0 represents the starting RE index among the RB indexes K. REs

. ≪ / RTI >

, N = 0, 1, ... , N-1 and

to be. Here, N represents the number of REs between the control region and the control region.

Even when the size of the control area is variable, the position to which the channel sPCFICH indicating the size of the control area is mapped should be independent of the size of the variable control area. For example, the index of the RBs to which the sPCFICH channel is allocated is determined, and the first four REs of the control regions of the determined RBs are allocated to the RE The sPCFICH can be mapped.

13 is a diagram illustrating mapping of a position of a channel sPCFICH indicating the size of a control area according to an embodiment of the present invention.

For example, as shown in FIG. 13, the RB (sRB1) to which a channel is to be mapped is selected and the first four REs of the selected RBs are mapped to virtual REGs (virtual REGs) can do.

Here, the method of selecting RB can be expressed by the following equation.

The remaining channels except for the sPCFICH channel indicating the size of the control region can be configured in the remaining REs not allocated to the sPCFICH among the REs in the control region. For example, the remaining REs of the control region are grouped into REGs each consisting of four REs, and a short physical downlink control channel (sPDCCH) and a short physical HARQ indicator channel (sPHICH) have.

The sPHICH can be configured, for example, as follows.

here,

Represents the REG index to which the sPHICH is assigned,

SPHICH group index,

Represents the total number of REGs in a subslot.

The sPDCCH channel for transmitting the resource allocation information may be configured in the REG among the REGs in which the sPHICH is not configured. The configured REG can be used as sPDCCH for control information transmission by configuring CCE (Control Channel Element) in 9 REG units.

Based on such a frame structure, the embodiment of the present invention provides a coexistence system in which a low-delay system and a legacy system coexist.

14 illustrates a control region and resource allocation in a system according to an embodiment of the present invention.

In a coexistence system in which a low-latency system and a legacy system coexist according to an embodiment of the present invention, resource allocation of a legacy region for legacy terminals is performed in a control region of a legacy system (e.g., PDCCH Physical Downlink Control Channel). Also, the resource allocation for the terminals of the low-delay system is performed in the control region of the low-delay system.

In addition, for the flexibility of resource allocation, resource allocation for unallocated data regions (e.g., Physical Downlink Shared Channel (PDSCH), legacy unassigned subframes) for legacy terminals in the band of the legacy domain) As shown in FIG.

Meanwhile, in the embodiment of the present invention, the synchronization and system information (for example, a master information block (MIB)) are transmitted to the terminals, which are intended to be connected to the low-delay system as well as the legacy system, And may be transmitted to terminals to be connected to the system.

FIG. 15 is a diagram illustrating transmission of a synchronization signal and a physical channel in a system according to an embodiment of the present invention.

In the embodiment of the present invention, the synchronization and system information for the terminals to be connected to the low-delay system as well as the legacy system are synchronized with the synchronization signal and the broadcast signal existing in the legacy area, which is the frequency band for the legacy system, And is transmitted to the UEs via the physical channel (PBCH).

Further, the additional information (e.g., the entire system band) for the terminals connected to the low-delay system may be added to the MIB transmitted through the broadcasting physical channel existing in the legacy area, SIB (System Information Block).

Meanwhile, in a coexistence system in which a low-delay system and a legacy system coexist according to an embodiment of the present invention, a hybrid automatic repeat request (HARQ) procedure follows an HARQ procedure defined in a legacy system.

16 is an exemplary diagram illustrating transmission of HARQ retransmission time in a system according to an embodiment of the present invention.

The HARQ procedure for HARQ feedback and retransmission of a transport block (TB) performed in a band of a legacy system follows an HARQ procedure defined in a legacy system.

Likewise, the HARQ procedure of the transport block performed in the frequency band of the low delay system follows the HARQ procedure in the low delay system. The HARQ procedure of the transport block in the frequency band of the legacy system allocated through the control region of the low-delay system also follows the HARQ procedure in the low-delay system.

17 is a structural diagram of a terminal for connection and operation of a low-delay system according to an embodiment of the present invention.

17, a terminal 100 according to an embodiment of the present invention includes a processor 110, a memory 120, and a radio frequency (RF) converter 130. The processor 110 may be configured to implement the methods described above based on Figures 5-16.

The processor 110 includes a synchronization processing unit 111, a primary broadcasting information processing unit 112, a bandwidth acquisition unit 113, a connection processing unit 114, and a secondary broadcasting information processing unit 115.

The synchronization processing unit 111 receives the legacy synchronization signal or the low-delay system synchronization signal and synchronizes them.

The primary broadcasting information processing unit 112 receives and processes the primary broadcasting information transmitted through the broadcasting physical channel of the legacy system band.

The bandwidth acquisition unit 113 calculates the low-delay system bandwidth based on the legacy system bandwidth and the overall system bandwidth included in the primary broadcasting information. And adjusts the overall system bandwidth based on the calculated low delay system bandwidth and legacy system bandwidth.

The connection processing unit 114 performs a connection to the low-delay system based on the low-delay system bandwidth provided from the bandwidth obtaining unit 113. That is, it receives the system information through the control of the low-delay system band and the data area, and performs the connection based on the received system information.

The secondary broadcasting information processing unit 115 receives the secondary broadcasting information transmitted through the control and data areas of the legacy system band and the low delay system setting information from the secondary broadcasting information after the terminal is connected to the low-delay system .

The memory 120 is coupled to the processor 110 and stores various information related to the operation of the processor 110. [ The RF converter 130 is connected to the processor 110 and transmits or receives radio signals.

The embodiments of the present invention are not limited to the above-described apparatuses and / or methods, but may be implemented through a program for realizing functions corresponding to the configuration of the embodiment of the present invention, a recording medium on which the program is recorded And such an embodiment can be easily implemented by those skilled in the art from the description of the embodiments described above.

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 (20)

In a method for transmitting a frame supporting a legacy system in a mobile communication system,
Generating a frame including a first frequency band for supporting the mobile communication system and a second frequency band for supporting the legacy system, the entire frequency band being larger than the second frequency band; And
Transmitting first broadcast information through a broadcast physical channel of the second frequency band
/ RTI > The method of claim 1, wherein
Wherein the primary broadcast information comprises a legacy system bandwidth and an entire frequency bandwidth. The method of claim 1, wherein
Transmitting secondary broadcast information through a data area of the second frequency band
Further comprising:
Wherein the secondary broadcast information includes bandwidth configuration information of the mobile communication system
Is a frame transmission method. The method of claim 1, wherein
Setting a part of the subframe of the second frequency band not to be used by a terminal connecting to the legacy system and setting the part to be used for a terminal requesting a low delay service of the mobile communication system
Further comprising:
The setting step
The operation of a terminal connected to a legacy system is controlled in a subframe in a downlink frame of the second frequency band through a configuration of an MBSFN (Multimedia Broadcast Single Frequency Network) subframe or an ABS (Almost Blank Subframe) ; And
Limiting uplink transmission scheduling of a terminal connected to a legacy system in an uplink frame of the legacy system of the second frequency band in some subframes and using the resource for service of the terminal of the mobile communication system
/ RTI > The method of claim 1, wherein
Wherein a frame of the mobile communication system has a transmission time interval (TTI) structure that is shorter than that of the legacy system, and some of the radio resources constituting each TTI of the first frequency band is used as a control region, Has a predetermined size or has a different size for each TTI. The method of claim 5, wherein
Wherein the primary broadcasting information includes indication information indicating that the size of the control area is fixed or variable and when the indication information is variable, indication information on the size of the control area is transmitted through a short physical control format indicator channel (sPCFICH) Frame transmission method. The method of claim 6, wherein
Wherein when the period of the size of the control area is greater than one TTI size, the sPCFICH is configured once per period, and the primary broadcasting information includes period information of which the size of the control area is changed. The method of claim 6, wherein
The size of the control area is determined by CFI (Control Format Indicator) information. The size of the control area is determined by the number of radio resources constituting the control area, the ratio of the control area occupied by all the radio resources, A frame transmission method, indicating one of the maximum sizes. The method of claim 5, wherein
Wherein a control region is configured from a subcarrier index having an offset per radio resource among subcarrier indices of radio resources, and the offset is set differently for each cell. The method of claim 5, wherein
Selects radio resources to be mapped to the sPCFICH, assigns the sPCFICH to a plurality of radio resources from a first radio resource among the selected radio resources, and a channel other than the sPCFICH allocates remaining radio resources Wherein a channel other than the sPCFICH includes one of a short physical downlink control channel (sPDCCH) and a short physical HARQ indicator channel (sPHICH). A cell search method of a terminal in a mobile communication system supporting a legacy system includes:
Wherein the frame includes a first frequency band for supporting the mobile communication system and a second frequency band for supporting the legacy system, wherein the terminal transmits the primary broadcasting information through the broadcast physical channel of the second frequency band, ;
Receiving the system information through the control and data areas of the first frequency band based on the primary broadcasting information; And
Performing connection to the mobile communication system based on the received system information
/ RTI > The method of claim 11, wherein
Wherein the primary broadcast information includes a legacy system bandwidth and an entire frequency bandwidth,
After receiving the primary broadcast information,
Calculating bandwidth of the mobile communication system based on the legacy system bandwidth and the total system bandwidth; And
Adjusting the overall system bandwidth based on the calculated mobile communication system bandwidth and the legacy system bandwidth
Further comprising the steps of: The method of claim 12, wherein
If the legacy system bandwidth and the total system bandwidth are all odd or both are even, then the total system bandwidth included in the primary broadcast information and the adjusted total system bandwidth have the same value,
Wherein the adjusted total system bandwidth is one less than the total system bandwidth included in the primary broadcast information if one of the legacy system bandwidth and the overall system bandwidth is an odd number and the even number is an even number, . The method of claim 11, wherein
Before the step of receiving the primary broadcasting information
The terminal receiving the legacy synchronization signal or the mobile communication system synchronization signal and synchronizing
Further comprising the steps of: The method of claim 11, wherein
After the connecting step,
Receiving secondary broadcasting information through the control and data area of the second frequency band, and the secondary broadcasting information including setting information of the mobile communication system
Further comprising the steps of: The method of claim 11, wherein
Wherein the primary broadcasting information includes indication information indicating that the size of the control area is fixed or variable, and when the primary broadcasting information is variable, indication information on the control area size is transmitted through a short physical control format indicator channel (sPCFICH)
Wherein the terminal constructs channels of the control region by grasping the size of the control region using the instruction information. In a mobile communication system supporting a legacy system,
A radio frequency converter for transmitting and receiving signals through an antenna, and
A processor coupled to the radio frequency translator and performing a cell search,
The processor comprising:
Wherein the frame includes a first frequency band for supporting the mobile communication system and a second frequency band for supporting the legacy system, wherein the terminal transmits the primary broadcasting information through the broadcast physical channel of the second frequency band, A first broadcast information processor for receiving and processing the first broadcast information; And
A connection processing unit for receiving system information through the control and data areas of the first frequency band based on the primary broadcasting information and performing connection based on the received system information,
. The method of claim 17, wherein
Wherein the primary broadcast information includes a legacy system bandwidth and an entire frequency bandwidth,
The processor comprising:
A bandwidth processor for calculating the bandwidth of the mobile communication system based on the legacy system bandwidth and the total system bandwidth and adjusting the overall system bandwidth based on the calculated mobile communication system bandwidth and the legacy system bandwidth,
Further comprising: The method of claim 17, wherein
The processor comprising:
A synchronization processing unit for receiving a legacy synchronization signal or a synchronization signal of a mobile communication system and synchronizing the synchronization signal before receiving the primary broadcasting information;
Further comprising: The method of claim 17, wherein
The processor comprising:
A secondary broadcast information processor for receiving and processing secondary broadcast information through the control and data area of the second frequency band, the secondary broadcast information including configuration information of the mobile communication system,
Further comprising:

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