KR20160134475A - Method and apparatus for acquiring time uplink frame and time downlink frame structure in wireless communication cellular system of unlicensed frequency band, and method and apparatus for transmitting and receiving signal - Google Patents

Abstract

Provided is a method for transmitting a signal of a base station. The base station: transmits grant information for uplink transmission to a terminal through a channel of an unlicensed band; and transmits an initial signal including first information representing a time when the grant information is transmitted to the terminal through the channel of the unlicensed band.

Description

TECHNICAL FIELD [0001] The present invention relates to a method and apparatus for acquiring a time-up frame and a time-down frame structure in a wireless communication cellular system in a license-exempt frequency band, and a method and apparatus for transmitting and receiving signals. UNLICENSED FREQUENCY BAND, AND METHOD AND APPARATUS FOR TRANSMITTING AND RECEIVING SIGNAL}

The present invention relates to a method and apparatus for obtaining a time uplink frame and a time downlink frame structure in a wireless communication cellular system in a license-free frequency band, and a method and apparatus for transmitting and receiving signals.

Conventional long term evolution (LTE) cellular networks have only been operating in the licensed band. As the demand for high capacity and high-speed data services has increased, LTE standards are not limited to existing licensed bands but increase capacity by accepting unlicensed bands. . This capacity increase scheme is currently in the standardization stage of the 3rd generation partnership project (3GPP).

However, for license-exempt bands, the issue of coexistence with devices operating in other license-exempt bands must be resolved, unlike license bands that do not interfere with other providers or devices and have a high degree of freedom. That is, there is a need for a channel access and occupancy scheme that can be used for a limited time when opportunities are given, without significantly degrading the performance of other devices on the same unlicensed band.

In order to solve such a coexistence problem, a method known as a "carrier sense transmission method" (eg, clear channel assessment (CCA), or listen before talk (LBT)) is widely used. The channel access method is first performed by channel monitoring. That is, the device senses the activity of the license-exempt band channel shared with other devices, suspends transmission of the radio signal when the energy of the corresponding channel is measured, and conversely, when the energy of the corresponding channel is not detected channel idle state), the corresponding channel is used (radio signal transmission or output).

When a device detects an idle state of a channel and transmits a signal, other devices detect energy on the channel, determine that the channel is busy, and suspend signal transmission. That is, the channel access method of the license-exempt band may be a form of a time-division multiple access method in which a plurality of devices are connected to a wireless channel by dividing time.

On the other hand, there is a need for an efficient uplink transmission and retransmission mechanism for the unlicensed band.

Also, there may be a case where the uplink transmission time for first transmitting new data in the license-exempt band and the timing for UL retransmission must be considered at the same time. For this case, there is a need to allocate channel resources and timing and access channels.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method and apparatus for configuring a guard period for an unlicensed LTE system supporting uplink and downlink in time division duplexing (TDD) mode. It is another object of the present invention to provide a method and apparatus for constructing a guard interval that minimizes interference.

It is another object of the present invention to provide a method and apparatus for constructing a LTE-LAA (license assisted access) TDD frame structure and a frame format indicator suitable for a license-exempt band.

Another object of the present invention is to provide a method and apparatus for determining an uplink signal transmission timing that is suitable for a license-exempt band and is opportunistic and adaptive, using a collective uplink grant signal will be.

According to an embodiment of the present invention, a signal transmission method of a base station is provided. The method of transmitting a signal of the base station includes transmitting grant information for uplink transmission to a terminal through a channel of a license-exempt band; And transmitting an initial signal including first information indicating a time point at which the permission information is transmitted to the terminal through the license-exempt band channel.

According to the embodiment of the present invention, it is possible to solve an interference inducing problem that may be caused by using an LTE frame format based on a time division duplexing in which an uplink and a downlink exist in a license-exempt band.

According to an embodiment of the present invention, by adding a function that is not previously supported, the structure of a special subframe in the TDD-LTE frame format can be changed to provide an interference problem caused at a guard interval and an uplink transmission time Can be solved. As a result, it is possible to increase the transmission efficiency and to prevent the signal collision on the radio channel, thereby increasing the overall network throughput.

Also, according to the embodiment of the present invention, the frame format related to the ratio and timing between the uplink subframe and the downlink subframe can be changed according to the scheduling change of the base station, and the information on the frame format can be efficiently transmitted.

According to an embodiment of the present invention, a frame format indicator signal is used not only for providing information on a frame format but also for estimating frequency synchronization such as a carrier frequency offset, And can be utilized as a channel estimation application for demodulating a data signal. This makes it possible to increase the transmission efficiency in the unlicensed band LTE operation.

In addition, according to the embodiment of the present invention, the efficiency of the LTE-LAA network as well as the network efficiency of all the systems sharing the license-exempted band are effectively applied by considering the license- Can be increased.

1 is a diagram illustrating uplink and downlink multiplexing transmission based on time, which is applied to an LTE frame structure-type 2.
FIG. 2 is a diagram showing a timing relationship between an UL grant of a license band and a physical hybrid automatic repeat request indicator channel (PHICH) transmission.
FIG. 3 is a diagram illustrating a problem that may occur when an uplink signal and a downlink signal are transmitted at a predetermined timing in a license-exempt band.
4 is a diagram illustrating a case where an uplink transmission fails or a collision is issued due to a long guard interval in an LTE uplink and a downlink frame structure for a license-exempt band.
5 is a diagram illustrating a method of reducing a length of a guard interval by transmitting a variable length reserved signal after DwPTS (downlink pilot time slot) transmission according to an embodiment of the present invention.
6 is a diagram illustrating a method of adjusting a length of a guard interval by copying a baseband signal of a license band according to an embodiment of the present invention.
7 is a diagram illustrating a TDD-LTE frame format configuration for an LAA when the maximum continuous transmission length is 4 ms, according to an embodiment of the present invention.
8 is a diagram illustrating a structure of a frame format indicator-type 2 according to various bandwidths according to an embodiment of the present invention.
9 is a diagram illustrating a CRS (cell-specific reference signal) mapping method of a frequency axis and a modulation method for each symbol when the number of PRBs corresponding to the entire bandwidth is 25 according to an embodiment of the present invention.
10 is a diagram illustrating a CRS mapping flow after encoding of a frame format indicator according to an embodiment of the present invention.
11 is a diagram illustrating a TDD-LTE frame format configuration for an LAA when the maximum continuous transmission length is 10 ms according to an embodiment of the present invention.
12 is a diagram illustrating a relationship between aggregated uplink transmission time indicator signal (AUTTIS) information and uplink transmission according to an embodiment of the present invention.
13 is a diagram illustrating a relationship between an AUTTIS binary bit structure and an UL grant according to an embodiment of the present invention.
14 is a diagram illustrating a short LBT performed immediately before an uplink transmission according to an embodiment of the present invention.
15 is a diagram illustrating a base station according to an embodiment of the present invention.
16 is a diagram illustrating 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, a terminal may be referred to as a mobile terminal, a mobile station, an advanced mobile station, a high reliability mobile station, a subscriber station, A mobile subscriber station, a mobile subscriber station, an access terminal, a user equipment, and the like, and may also be referred to as a terminal, a mobile terminal, a mobile station, an advanced mobile station, An access terminal, a user equipment, and the like.

In addition, a base station (BS) includes an advanced base station, a high reliability base station, a node B, an evolved node B (eNodeB) an access point, a radio access station, a base transceiver station, a mobile multihop relay (MMR) -BS, a relay station serving as a base station, a high reliability repeater BS, Node B, eNodeB, access point, radio access station, transmitting / receiving base station, MMR-BS, and so on, may be referred to as a high reliability relay station, a repeater, A repeater, a high reliability repeater, a repeater, a macro base station, a small base station, and the like.

In the present specification, 'A or B' may include 'A', 'B', or 'both A and B'.

The method and apparatus according to embodiments of the present invention may belong to the physical layer of an LTE wireless mobile communication system. Specifically, the method and apparatus according to the embodiment of the present invention consider a UL (uplink) signal and a DL (downlink) signal of an LTE system in a license-exempt band where signals are discontinuously transmitted Transmission, and control techniques.

The LTE frame of the license-exempt band is basically divided into the downlink and the uplink, as in the LTE frame of the license band. Therefore, the frame structure (FS: Type 2) of the existing license band can be applied to the license-exempt band with priority.

FIG. 1 is a diagram illustrating uplink and downlink multiplexing transmission based on time, which is applied to LTE TS-Type 2.

One radio frame illustrated in FIG. 1 may have a length of T _f . Here, T _f may be 10 ms (= 307200 * T _s ). T _s can be defined as 1 / 30.72 MHz = 32.552 ns. One radio frame may include 10 subframes (0 to 9). One subframe may have a length of _{1ms (= 30720 * T s)} . One time slot may have a length of T _slot . Where T _slot can be 15360 * T _s .

The special subframe may include a downlink pilot time slot (DwPTS), a guard period (GP), and an uplink pilot time slot (UpPTS).

As illustrated in FIG. 1, FS-Type 2 of the license band can be divided into a transmission interval for the base station and a transmission interval for the UE.

The interval Txp1 illustrated in FIG. 1 is a period during which the terminal transmits a signal. The period Txp2 illustrated in FIG. 1 is a period during which the base station transmits a signal, excluding the period (Txp1) and the GP, from among the entire period. Therefore, DwPTS is a transmission interval for a base station, and UpPTS is a transmission interval for a UE.

The GP interval is the interval between DwPTS and UpPTS and can have a minimum length of 47.396 us (= 1456 * T _s ). Specifically, GP is a period in which a base station and a terminal do not transmit signals, and a time period in which a propagation delay due to a distance difference between a transmitting terminal and a receiving terminal and a switching time of a radio frequency (RF) Lt; / RTI > The minimum time of the GP is 1456 / 30.72MHz = 47.39us according to the current LTE standard. This idle time is sufficient time for the license-exempt band device (eg, Wi-Fi device) to perform the CCA and occupy the channel.

Also, due to the relatively low power, the existing GP lengths may not be adequate for the characteristics of the license-exempt band with less coverage than small cells. The small cell coverage of the license-exempted band is set to a maximum of 140ms, and the round trip time of reception after transmission is only about 0.5us calculated using the speed of light. Even if the switching time of the RF is added to the round trip delay time, the total may not be 15 us.

Therefore, it is necessary to determine the appropriate GP length for small cells. When the length of the GP is set to be shorter or similar to an IFS (inter frame space) time such as WiFi's distributed coordinate function interframe space (DIFS), an unrevoked band LTE transmission burst composed of an uplink and a downlink, It is possible to essentially prevent the interference caused by the transmission signal output after the CCA determination of the device.

However, in order to define a GP length shorter than the existing minimum GP length, it is necessary to transmit arbitrary continuous signals after DwPTS (or UpPTS). However, the 71us orthogonal frequency division multiplexing (OFDM) symbol unit of the present standard is too long and inappropriate to fill a portion of the existing GP to create a short GP length (47.39us minimum length according to the current standard Kim). Therefore, to create a GP with a length similar to that of a WiFi IFS (eg 34us in DIFS) shorter than 47.39us, it is necessary to fill a continuous signal, such as a preamble, between DwPTS and GP, It is necessary to define.

The LTE subframe in the license-exempt band is based on the application of the CA (carrier aggregation) function supporting principle that the time synchronization with the LTE subframe operating in the license band should not be allowed to deviate by more than a predetermined value. In the case where a device occupies a channel through the LBT, it rarely starts to occupy the channel at the boundary of the subframe, and it is common to occupy the channel after the LBT in the middle part of the subframe. In this case, data transmission should be performed in the form of partial subframes. In the current LTE standard, partial subframe transmission is supported only in the form of DwPTS and UpPTS.

However, since the time when the device starts to occupy the channel after LBT is unpredictable and the length of DwPTS and UpPTS is limited, a problem of data transmission efficiency arises. In order to increase the transmission efficiency of the license-exempt band, a new partial sub-frame needs to be defined.

Especially in regions such as Europe and Japan, there is a restriction on the length of the maximum continuous signal transmission due to radio wave and communication regulations, so a new partial subframe is required.

Specifically, in the case of Japan, continuous signal transmission of 4 ms or more is impossible. Therefore, continuous signal transmission in Japan can not follow the time division duplexing (TDD) -LTE frame format-type 2 criterion of the license band designed based on 10ms length. In particular, when the continuous signal transmission is limited to 10 ms or less, the smaller the special subframe (including DwPTS, GP, and UpPTS) illustrated in FIG. 1, the higher the transmission efficiency.

Therefore, since the TDD-LTE standard of the current license band is defined such that there are two special subframes in units of 10ms, a problem that is not supported in the current LTE standard is solved in order to make one special subframe exist in 10ms unit . Therefore, a new TDD-LTE specification suitable for license-exempt band LTE operation needs to be defined.

As described above, the LTE frame of the license-exempt band is basically divided into the TDD-type downlink and the uplink, as well as the LTE frame of the license band. The uplink data transmission can be performed after the grant of the base station.

In the case of the existing license band, a terminal granted a grant from a base station transmits an uplink signal at a predetermined time.

FIG. 2 is a diagram showing a timing relationship between a UL grant of a license band and a physical hybrid automatic repeat request indicator channel (PHICH) transmission.

Specifically, FIG. 2 illustrates a case where a downlink signal and an uplink signal are transmitted in an LTE frequency division duplexing (FDD) system in a license band.

As illustrated in (a1) of FIG. 2, when the UE receives the downlink control information (including the UL grant) transmitted through the downlink control information (DCI) at the time Ts1a and Ts2a, , Ts2a) at a predetermined time (Ts1b, Ts2b). The base station transmits PHICH (ACK) information indicating that there is no problem in demodulating the signal of the UE.

As illustrated in (a1) of FIG. 2, since signal transmission and reception are performed for each subframe unit, when the base station transmits an UL grant at different time instants Ts1a and Ts2a, each time point Ts1a, (PHICH) to the mobile station at the time when 8 ms elapses from the time Ts2a. In summary, when an uplink signal is transmitted at a time point Ts1b, Ts2b at which 4 ms has elapsed from the time point Ts1a, Ts2a at which the UL grant is transmitted, and 4 ms at the time point Ts1b, Ts2b, (E.g., an ACK signal or a NACK (negative acknowledgment) signal) to the terminal.

As illustrated in (a2) of FIG. 2, when a base station receives a demodulation error or an uplink signal from an uplink transmission signal received from a mobile station, the base station uses a PHICH channel to downlink the NACK signal to the mobile station Link signal, and requests the terminal to retransmit the uplink signal.

The time difference between transmissions and responses made by the base station and the terminal is fixed at 4 ms, and the retransmission mechanism (eg, hybrid acknowledgment) is performed synchronously at 4 ms intervals. Therefore, in the license band, the above transmission / reception response time interval can be maintained at a constant synchronous timing without a separate signal indicator relating to the transmission timing.

However, in the license-exempt band, the above mechanism and response for synchronous transmission are not guaranteed. In case of uplink transmission, if the result of the LBT performed after a predetermined time difference (e.g., 4 ms) between transmission and response is that the corresponding channel is busy, the UE can not transmit the uplink signal , The UE attempts retransmission of the uplink signal. As a result, the uplink transmission efficiency is degraded, and in the worst case, the terminal may continue to retransmit only.

FIG. 3 is a diagram illustrating a problem that may occur when an uplink signal and a downlink signal are transmitted at a predetermined timing in a license-exempt band.

Specifically, FIG. 3 illustrates a WiFi device WFD1, a base station LLa1, a plurality of terminals UE1 and UE2, and a base station LLa2 operating in a license band.

3, when the shared channel is occupied by another device (e.g., WFD1) and the corresponding channel is busy at the time Ts3b, the terminal UE2 transmits the DCI (For example, 4 ms) from the time Ts3a at which the UL signal (including the UL acknowledgment) is transmitted at a time point Ts3b.

For example, when the terminal UE2 fails to transmit the uplink signal due to occupation of the channel of the WiFi device WFD1 at the time Ts3b, a NACK signal and a new UL grant from the base station LLa1 at the time Ts3c, . The terminal UE2 tries to retransmit the uplink signal at the time Ts3d after 4 ms from the time Ts3c but fails to retransmit due to occupation of the channel of the WiFi device WFD1.

In another example, the terminal UE1 transmits an uplink signal at a time Ts4b when 4 ms has elapsed from the time Ts4a at which the UL grant of the base station LLa1 is transmitted. The base station LLa1 fails to transmit the response signal due to the occupation of the channel of the WiFi device WFD1 at the time point Ts4c when 4 ms has elapsed from the time point Ts4b. The terminal UE1 that has not received the response signal retransmits the uplink signal at a time Ts4d after 4 ms has elapsed from the time Ts4c.

As illustrated in FIG. 3, when the channel is busy at the transmission timing designated for the uplink or the transmission timing designated for the downlink, the retransmission process proceeds. In this case, if the license band mechanism is directly applied to the license-exempt band and the uplink transmission proceeds, the transmission efficiency may be very low.

Therefore, efficient uplink transmission and retransmission mechanisms for the license-exempt band are needed. Specifically, flexibility of the uplink transmission time point is required. In addition, when the uplink transmission time and the retransmission timing for the first transmission of the new data should be considered simultaneously, a channel resource, a timing allocation method, and a channel access method are required.

4 is a diagram illustrating a case where an uplink transmission fails or a collision is issued due to a long guard interval in an LTE uplink and a downlink frame structure for a license-exempt band. Specifically, FIG. 4 illustrates the WLAN devices STA1 and STA2 operating in the license-exempt band, the LTE base station LLa1, and the base station LLa2 operating in the license band.

Referring to FIG. 4, a method of designing a GP or an extended DwPTS preamble for preventing or minimizing interference will be described. The GP or DwPTS preamble may be applied to a frame supporting uplink and downlink.

The periods (PSF1a, PSF1b), DwPTS, and UpPTS of the subframe illustrated in FIG. 4 correspond to partial subframes.

Specifically, FIG. 4 shows a case where the LTE base station LLa1 operating in the license-exempt band is in the same license-exempt band as the two IEEE 802.11a / n / ac WLAN (STA1, STA2) ) Is used. In this case, we explain how to keep coexistence and motivation between the license-exempt and licensed bands. The LTE base station LLa1 may be a LTE license assisted access (LAA) device. Meanwhile, the LTE base station LLa1 may be operated in both the license-exempt band and the license band, and in this case, the signal of the license-exempt band and the signal of the license band may be simultaneously transmitted.

CCA is a method of determining whether a wireless channel is in use or not by using an energy level. Likewise, the LBT performs the same function as the CCA. A successful CCA or LBT for a channel means that a device that has performed CCA or LBT occupies that channel. The busy state of the channel indicates the occupied state of the corresponding channel, and the idle state of the channel indicates that no device is using the corresponding channel.

The WLAN device STA2 and the LTE base station LLa1 each transmit a signal occupying a channel of the license-exempt band in time, as illustrated in FIG. 4, busy), and suspends signal transmission.

When the transmission of the WLAN device STA1 is finished, the WLAN device STA2 and the LTE base station LLa1 detect that the corresponding channel is in an idle state.

When the WLAN device (STA2) detects the idle state of the corresponding channel using the CCA check function, the STA2 prepares to transmit the signal. However, the standard DIFS and random back-off time delay interval Transmission should be performed after rough (e.g., DCF (Distributed Coordinate Function), which is a function of the channel access scheme for WLAN).

Likewise, the LTE base station LLa1 performs an LBT function including a channel activity detection and an arbitrary delay function to prepare for signal transmission after a random delay if the idle state of the channel is detected (Eg, the LBT function of the european telecommunications standards institute (ETSI) standard).

At this time, the WLAN device STA2 and the LTE base station LLa1 compete to use the license-exempt band, and the device that has passed the above-mentioned arbitrary delay time q first can win the competition and transmit the signal have. Here, q is a time concept, and can be a counter of us unit.

Thus, each of the WLAN device STA2 and the LTE base station LLa1 can transmit a signal after a certain total delay time q between a certain delay and a random backoff. In the case of WLAN device STA2, q is the time between DIFS time (e.g., 34us) and random backoff (e.g., a multiple of 9us, inclusive, i.e., 0 to N * 9us, where N is IEEE 802.11 According to the specification). In the case of the LTE base station LLa1, the q by the LBT function is an xIFS value similar to the DIFS of the WLAN and a random backoff (e.g., N * 20us, where N is essentially random, Lt; RTI ID = 0.0 > 24 < / RTI >

For example, in the first idle period, when the LTE base station LLa1 is undergoing a random backoff interval (xIFS + CCA check), the WLAN device STA2 first passes a 'DIFS + random backoff interval' , And starts to transmit the WLAN frame at the time point Ts5a.

As another example, in the second idle period, the LTE base station LLa1 wins the competition with the WLAN device STA1 and the WLAN device STA2, and starts to transmit the signal to the time point Ts5b. At this time, the LTE frame transmitted by the LTE base station LLa1 may be in the form of an FS-type 2 composed of an uplink and a downlink. Therefore, the uplink transmission is performed after the downlink transmission, and the GP can be located between the downlink transmission and the uplink transmission. However, during the GP interval, the WLAN device STA1 detects the corresponding channel as an idle state, passes the CCA + random backoff time, and starts transmitting the WLAN frame at the time Ts5c.

In this case, if the terminal ignores the signal transmission of the WLAN device STA1 for LTE uplink transmission in the license-exempt band and performs signal transmission (electronic), or detects that the corresponding channel is busy, Link signal transmission (the latter). In the former case, both the LTE signal and the Wi-Fi signal are adversely affected by the signal collision. In the latter case, since the UE can not perform uplink transmission, the throughput of the LTE-LAA system is lowered. In order to prevent this situation from occurring, it is necessary to reduce the length of the GP, but according to the current LTE standard, it is impossible to reduce the GP to match the time corresponding to the DIFS period of the WiFi.

Accordingly, a method of reducing GP by transmitting a reservation signal having a variable length after DwPTS transmission will be described below.

5 is a diagram illustrating a method of reducing a length of a guard interval by transmitting a reserved signal of a variable length after DwPTS transmission according to an embodiment of the present invention.

As illustrated in FIG. 5, a variable length reserved signal (or preamble) may be transmitted following the DwPTS after the DwPTS transmission.

Specifically, FIG. 5 illustrates a structure of a preamble (reservation signal) according to an embodiment of the present invention. The s (n) region of the reservation signal characterized by a variable length may include a minimum signal unit transmission interval having a length of about 0.521 us. When the digital sample rate of LTE is 30.72 MHz, the time (T _s ) required to transmit one sample is 1 / (30.72e6) = 0.326us.

Thus, the transmission time of a sequence having a length of 16 according to an embodiment of the present invention is approximately 0.521us (= 16 / (30.72e6)). For reference, the transmission time of the LTE OFDM symbol is 2048 / (30.72e6) = 66.67us. The transmission time (or length) of the cyclic prefix is 144 / (30.72e6) = 4.69us or 160 / (30.72e6) = 5.2083us. The length (or transmission time) of one LTE t subframe is 30720 / (30.72e6) = 1 ms. That is, when 1920 consecutive sequences as a basic unit of the preamble (reservation signal) are transmitted, 1 ms is obtained (that is, one LTE subframe can be divided into 1920 intervals).

A sequence s (n) in the time domain having a length of 16 can be generated by the following equation (1).

[Equation 1]

을 나타낸다.Where p is a constant for normalizing the signal,

.

The sequence z (k) of the frequency domain and the index k can be defined as Equation (2) below.

In Equation (2), a _{- 5} to a ₅ are complex numbers and can be defined by a binary bit as shown in Equation (3) below.

과

에 의해 결정되어, 아래의 수학식 4에 매핑될 수 있다.Binary bits b _{- 5} to b ₅ are the physical cell IDs of the base stations defined in the LTE specification

and

And can be mapped to the following equation (4).

=2 이고

=97 라고 가정하면, 바이너리 수

는 0110000110로 결정된다. 따라서 z(k)는

가 된다.Where B (.) Is a binary operator function that converts to binary numbers. E.g,

= 2

= 97, then the number of binaries

Is determined as 0110000110. Therefore, z (k)

.

If p is 4, then z (k) is transformed into the time domain based on Equation (1), then the next s (n) sequence can be generated.

Since the variable length preamble (reservation signal) according to the embodiment of the present invention has granularity of about 0.521 us, it can have a high degree of freedom with respect to the extended DwPTS length adjustment. As a result, the length of the GP can be freely designed. For example, when the special subframe configuration of TDD-LTE assuming a normal cyclic prefix is set to '3', the lengths of DwPTS and UpPTS are 24144 * T _s and 2192 * T _s . Finally, the length of the GP is 4384 * T _s . 4384 * T _s corresponds to a length of 4384 / 30.72 MHz = 142.7 us. The length of the reservation signal should be 108.7us (= 142.7us-34us) so that the length of GP is close to the WiFi DIFS value of 34us by reducing this length. Therefore, when 209 sequences s (n) are generated, the length of the reserved signal becomes 108.85us (= 209 * 16 / 30.72MHz) and GP has a length of 33.85us close to 34us.

6 is a diagram illustrating a method of adjusting a length of a guard interval GP by copying a baseband signal of a license band according to an embodiment of the present invention.

As illustrated in FIG. 6, the baseband signal (OFDM-modulated signal) transmitted in the license band may be copied as it is and transmitted in the license-exempt band without the above-mentioned reservation signal. Specifically, after the DwPTS transmission in the license-exempt band, the baseband signal of the license band can be copied and transmitted following the DwPTS.

In the method illustrated in Fig. 6, the signal of the license band can be copied in multiple T _s samples.

On the other hand, another method of adjusting the length of the GP is to generate an arbitrary signal having energy and transmit it instead of the above-mentioned reserved signal.

Therefore, the GP length adjusting method according to the embodiment of the present invention is a method of adjusting the GP length by transmitting energy through a license-exempt band channel in any form, preventing the channel from idle after detecting the CCA, To correspond to the IFS section.

Hereinafter, a method of configuring an LTE-LAA frame structure and a frame format indicator (FFI) suitable for a license-exempt band will be described.

7 is a diagram illustrating a TDD-LTE frame format configuration for an LAA when the maximum continuous transmission length is 4 ms, according to an embodiment of the present invention.

In the case where the special subframe is limited to one in the TDD LTE frame structure and the frame type has the uplink and downlink burst formats, the TDD-LTE frame format for the license-exempt band can be generalized have.

Specifically, the TDD-LTE frame format for the license-exempt band illustrated in FIG. 7 can be applied to a downlink dedicated frame.

In the TDD-LTE frame format illustrated in FIG. 7, six bits out of the n bits allocated to the FFI are used to indicate the location of the special subframe and the total transmission burst length of the TDD-LTE frame format . For example, in the LAA frame format 4, the location of the special subframe and the total transmission burst length in the TDD-LTE frame format can be expressed as 000100. For another example, in the LAA frame format 3, the location of the special subframe and the total transmission burst length in the TDD-LTE frame format can be expressed as 000011. For another example, in the LAA frame format 2, the location of the special subframe and the total transmission burst length in the TDD-LTE frame format can be expressed as 000010.

7, the structure of a TDD-based frame format (e.g., LAA frame format 4, 3, 2, ..., x) suitable for a license-exempt band includes a reservation signal, FFI, Link sub-frame, DwPTS, GP, UpPTS, uplink sub-frame, and uplink partial sub-frame.

The reservation signal and the FFI may be included in the initial signal. The FFI may include at least two OFDM symbols.

The transmission of the UpPTS is canceled, and the reservation signal located before the GP may be transmitted longer.

Hereinafter, a method of configuring the FFI will be described.

The FFI can be expressed in the frequency domain, as illustrated in FIG. 8 or FIG.

8 is a diagram illustrating a structure of a frame format indicator (FFI) -type 2 according to various bandwidths according to an embodiment of the present invention.

The FFI may include a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a cell-specific reference signal (CRS) along the frequency axis.

First, the PSS will be described.

The PSS has the same signal configuration and mapping form of the frequency axis as the LTE system of the licensed band. As illustrated in FIG. 8, the PSS region may occupy six PRBs belonging to an intermediate point among physical resource blocks (PRB) s (e.g., 24 to 100) corresponding to the entire frequency bandwidth defined by the system. Here, one PRB corresponds to 12 subcarriers.

The process of generating and mapping the frequency domain sequence d _u (n) for the PSS to the frequency domain can be defined as Equation (5) below.

U in Equation (5) can be defined as shown in Table 1 below.

Root indices for the PSS

Root index  u 0 25 One 29 2 34

(단, n=0,1,2,...,61)와 같이 정의될 수 있다.The frequency subcarrier index k of the PSS, which is mapped to the frequency domain,

(Where n = 0, 1, 2, ..., 61).

는 시스템의 전체 대역폭에 대응하는 PRB 개수를 나타내고,

는 12이다. 비면허 대역에서 고려되는

는 25, 50, 75, 또는 100일 수 있다.here,

Represents the number of PRBs corresponding to the entire bandwidth of the system,

Lt; / RTI > Considered in the license-exempt zone

May be 25, 50, 75, or 100.

(단, n=-5,-4,...,-1,62,63,...66)와 같이 정의될 수 있다.The frequency subcarrier index k of the PSS mapped to the void region is given by:

(Where n = -5, -4, ..., -1, 62, 63, ..., 66).

Describe the SSS.

The SSS can be divided in half. Specifically, as illustrated in FIG. 8, the area corresponding to each half of the SSS (three PRBs) is mapped to a lower or higher frequency region than the PSS region. The method of generating the SSS region can be defined as Equation (6) below.

에 의해 결정될 수 있다. And 0≤n≤30 in equation (6), the index m ₀ and m ₁ are as mathematical expressions and below, the physical layer cell ID group (physical layer cell identity group)

Lt; / RTI >

는 아래의 표 2의 값들 중 하나일 수 있다. 즉,

는 0 ~ 167 중 하나일 수 있다.here,

May be one of the values in Table 2 below. In other words,

Can be one of 0 to 167.

Mapping between physical-layer cell-identity group and the indices m ₀ and m ₁

m ₀ m ₁

m ₀ m ₁

m ₀ m ₁

m ₀ m ₁

m ₀ m ₁ 0 0 One 34 4 6 68 9 12 102 15 19 136 22 27 One One 2 35 5 7 69 10 13 103 16 20 137 23 28 2 2 3 36 6 8 70 11 14 104 17 21 138 24 29 3 3 4 37 7 9 71 12 15 105 18 22 139 25 30 4 4 5 38 8 10 72 13 16 106 19 23 140 0 6 5 5 6 39 9 11 73 14 17 107 20 24 141 One 7 6 6 7 40 10 12 74 15 18 108 21 25 142 2 8 7 7 8 41 11 13 75 16 19 109 22 26 143 3 9 8 8 9 42 12 14 76 17 20 110 23 27 144 4 10 9 9 10 43 13 15 77 18 21 111 24 28 145 5 11 10 10 11 44 14 16 78 19 22 112 25 29 146 6 12 11 11 12 45 15 17 79 20 23 113 26 30 147 7 13 12 12 13 46 16 18 80 21 24 114 0 5 148 8 14 13 13 14 47 17 19 81 22 25 115 One 6 149 9 15 14 14 15 48 18 20 82 23 26 116 2 7 150 10 16 15 15 16 49 19 21 83 24 27 117 3 8 151 11 17 16 16 17 50 20 22 84 25 28 118 4 9 152 12 18 17 17 18 51 21 23 85 26 29 119 5 10 153 13 19 18 18 19 52 22 24 86 27 30 120 6 11 154 14 20 19 19 20 53 23 25 87 0 4 121 7 12 155 15 21 20 20 21 54 24 26 88 One 5 122 8 13 156 16 22 21 21 22 55 25 27 89 2 6 123 9 14 157 17 23 22 22 23 56 26 28 90 3 7 124 10 15 158 18 24 23 23 24 57 27 29 91 4 8 125 11 16 159 19 25 24 24 25 58 28 30 92 5 9 126 12 17 160 20 26 25 25 26 59 0 3 93 6 10 127 13 18 161 21 27 26 26 27 60 One 4 94 7 11 128 14 19 162 22 28 27 27 28 61 2 5 95 8 12 129 15 20 163 23 29 28 28 29 62 3 6 96 9 13 130 16 21 164 24 30 29 29 30 63 4 7 97 10 14 131 17 22 165 0 7 30 0 2 64 5 8 98 11 15 132 18 23 166 One 8 31 One 3 65 6 9 99 12 16 133 19 24 167 2 9 32 2 4 66 7 10 100 13 17 134 20 25 - - - 33 3 5 67 8 11 101 14 18 135 21 26 - - -

와

에 적용되는 m₀와 m₁ 값(표 2에서 정의된 값)이

의 m-sequence를 시프트(shift)시키는 요소가 된다. 그리고 그 과정은 아래의 수학식과 같이 정의될 수 있다.Two sequences

Wow

The values of m ₀ and m ₁ (defined in Table 2) applied to

Quot; m-sequence " And the process can be defined as the following equation.

는

(단, 0≤i≤30)로 정의되며, x(i)는

와 같이 정의될 수 있다. 그리고 초기 상태는,

와 같다.here,

The

(Where 0? I? 30), and x (i) is defined as

Can be defined as follows. In the initial state,

.

에 의해 결정될 수 있다.c ₀ (n) and c ₁ (n) are two scrambling sequences, which are determined by the PSS ID (identity) and are composed of the following two m-

Lt; / RTI >

는 PSS ID 그룹(identity group)을 나타낸다. here,

Represents a PSS ID group (identity group).

는

(단, 0≤i≤30)로 정의될 수 있고, x(i)는

와 같이 정의될 수 있다. 그리고 초기 상태는,

와 같다.

The

(Where 0? I? 30), and x (i)

Can be defined as follows. In the initial state,

.

와

는 아래의 m-sequence로 구성된

의 시퀀스로 구성될 수 있다.Scrambling sequence

Wow

Consists of the following m-sequences

≪ / RTI >

는

(단, 0≤i≤30) 이다. 그리고 x(i)는Where m ₀ and m ₁ depend on the values in Table 2,

The

(Where 0? I? 30). And x (i)

와 같이 정의될 수 있다. 그리고 초기 상태는

와 같다.

Can be defined as follows. And the initial state is

.

(단, n=0,1,2,...,30) 그리고

(단, n=31,32,...,61) 와 같다.On the other hand, the frequency subcarrier index k of the SSS mapped to the frequency domain,

(N = 0, 1, 2, ..., 30) and

(Where n = 31, 32, ..., 61).

는 25, 50, 75, 또는 100일 수 있다. Considered in the license-exempt zone

May be 25, 50, 75, or 100.

(단, n=-36,-35,...,-32,93,94,...,97) 과 같다.The frequency subcarrier index k of the SSS mapped to the void region is given by:

(N = -36, -35, ..., -32, 93, 94, ..., 97).

One subcarrier has a bandwidth of 15 KHz. Thus, the six PRBs occupy a bandwidth of 1.08 MHz.

Finally, a CRS including frame information and uplink scheduling information will be described. As illustrated in FIG. 8, the CRS region before or after the synchronization signal (PSS, SSS) region may occupy 6 to 41 PRBs. The structure of the CRS will be described in detail with reference to FIG.

9 is a diagram illustrating a CRS (cell-specific reference signal) mapping method of a frequency axis and a modulation method for each symbol when the number of PRBs corresponding to the entire bandwidth is 25 according to an embodiment of the present invention.

S ₀ , S ₁ , ..., S ₁₂ illustrated in FIG. 9 represent the modulation symbols constituting the CRS

The CRS region (the region to which the CRS is mapped) has a CRS structure (using two antenna ports (e.g., antenna ports 0 and 1) mapped to the existing LTE OFDM symbol 0) Lt; / RTI >

In Equation (7), a represents a signal input to an inverse fast Fourier transform (IFFT) block as a complex symbol. In Equation (7), p represents an antenna port number and corresponds to index k of the frequency axis and index l of the OFDM symbol.

In Equation (7), k, l, m can be defined as follows.

로 정의될 수 있고, v_shift 는

로 정의될 수 있다.

는 물리적 셀 ID를 나타낸다.Where v is

, And v _shift can be defined as

. ≪ / RTI >

Represents a physical cell ID.

가 25인 경우(즉, 시스템의 전체 대역폭이 5MHz인 경우)에, 주파수 축의 CRS 매핑이 예시되어 있다.Specifically, in Fig. 9

Is 25 (i.e., the total bandwidth of the system is 5 MHz), the CRS mapping of the frequency axis is illustrated.

In Equation (7), r _l (m) is composed of a differential quadrature phase shift keying (D-QPSK) symbol and can be mapped as Equation (8) below.

이다. 여기서

는 채널 코딩이 적용된, 코드화된 비트(coded bit)이며, 길이 46을 가질 수 있다(예,

).s _init is a QPSK symbol (x = I + jQ), and in-phase and quadrature-phase

to be. here

Is a coded bit with channel coding applied and may have a length 46 (e.g.,

).

).Therefore, the length of the information b _i to be transmitted is a variable length n smaller than 32 and is input as the input bit length n of a second order RM (Reed Muller) code 32, n. C ₀ , c ₁ , ..., c _{13, which} are the 14 most significant bits (MSB) among the coded bits c ₀ , c ₁ , ..., c ₃₁ , , Concatenated with the outputs c ₀ , c ₁ , ..., c ₃₁ and finally generates 46 bits (e.g.,

).

FIG. 10 is a diagram illustrating a CRS mapping flow after encoding of a frame format indicator (FFI) according to an embodiment of the present invention.

이 된다. 그리고 비트 스트림

에는 비트 확장(bit extension)이 적용된 후, D-QPSK 변조가 적용된다. D-QPSK 변조를 통해 생성된 r_l(i)에 대해서, 부반송파 매핑이 적용된다.The transmission information n bits (e.g., b ₀ , b ₁ , ..., b _n-1 ) to which the encoding is applied includes 6 bits indicating the length of the transmission frame burst and the location of the special subframe, And (n-6) bits for an aggregated uplink transmission time indicator signal (AUTTIS). The transmission information n bits (e.g., b ₀ , b ₁ , ..., b _n-1 ) are encoded through RM code encoding,

. Then,

D-QPSK modulation is applied after a bit extension is applied. For the r _l (i) generated by the D-QPSK modulation, a sub-carrier mapping is applied.

Also, the FFI can be used for frequency offset and channel estimation of the LAA TDD-LTE frame. As illustrated in FIG. 7 or 8, two OFDM symbols included in the FFI are repeatedly transmitted. By utilizing the characteristics of the FFI, the UE can estimate an accurate carrier frequency offset (CFO) in the time domain .

FFI can also be used for channel estimation functions. When channel coding demodulation is performed, bit decoding is performed on the bits transmitted by the base station. When a UE performs estimation using a decoded bit sequence to construct a transmission D-QPSK symbol, the UE can determine a reference symbol that the base station originally intended to transmit. Then, since the UE can estimate the phase difference with respect to the actually received CRS, the FFI can be used as a channel estimation purpose for the received data. Of course, the terminal can also decode the synchronization signals PSS and SSS. More specifically, the UE may perform channel estimation on the central 12 PRBs corresponding to the synchronization signals PSS and SSS, by restoring the reference symbols and comparing the reference symbols with the actual received signals.

The partial subframe is used for the case where only a part of the subframe is transmitted, such as the DwPTS or the UpPTS, instead of taking the complete subframe form as illustrated in Fig. In the present TDD-LTE standard, only a DwPTS composed of 3, 6, 9, 10, 11, or 12 OFDM symbols is defined, but according to the embodiment of the present invention, one DwPTS or UpPTS , 2, 4, 5, 7, or 8 OFDM symbols.

11 is a diagram illustrating a TDD-LTE frame format configuration for an LAA when the maximum continuous transmission length is 10 ms according to an embodiment of the present invention.

Specifically, FIG. 11 illustrates an LTE-LAA TDD frame format that may be added through the extended structure of FIG. 7, where the maximum continuous transmission limit is 10ms.

In FIG. 11, it is exemplified that 6 bits excluding the AUTTIS information among n bits allocated to FFI can be expressed. The FFI may include AUTTIS information, the location of the special subframe, and the total transmission burst length of the TDD-LTE frame format. The structure (or principle) of the LAA frame format illustrated in FIG. 11 is the same as or similar to the structure (or principle) of the LAA frame format illustrated in FIG.

For example, in the LAA frame format 6 illustrated in FIG. 11, the location of the special subframe and the total transmission burst length of the TDD-LTE frame format can be expressed as 010110. For another example, in the LAA frame format 7, the location of the special subframe and the total length of the transmission burst in the TDD-LTE frame format can be expressed as 010111. For another example, in the LAA frame format 8, the location of the special subframe and the total length of the transmission burst in the TDD-LTE frame format can be expressed as 011000. For another example, in the LAA frame format 15, the location of the special subframe and the total length of the transmission burst in the TDD-LTE frame format can be expressed as 011111.

As illustrated in FIG. 11, the LAA frame format (e.g., LAA frame format 15, ..., 8-6, ..., x) includes a reservation signal, an FFI, a downlink partial subframe, , DwPTS, GP, UpPTS, uplink subframe, and uplink partial subframe.

Hereinafter, a method for determining an opportunistic and adaptive uplink signal transmission timing suitable for a license-exempt band using the aggregated uplink grant transmission timing enable signal AUTTIS will be described.

The transmission time point of the uplink signal can be efficiently configured according to the license-exempt band based on the frame structure illustrated in FIG. 7 and FIG.

12 is a diagram illustrating a relationship between aggregated uplink transmission time indicator signal (AUTTIS) information and uplink transmission according to an embodiment of the present invention. Specifically, FIG. 12 illustrates a WiFi device WFD1, a base station LLa1, terminals UE1 and UE2, and a base station LLa2 operating in a license band, operating in a license-exempt band.

As illustrated in FIG. 12, the AUTTIS included in the FFI includes information about an uplink frame response transmission instruction for a subframe time (grant) granted (transmitted) within the window length for AUTTIS . Here, the window for AUTTIS corresponds to N (e.g., twelve) subframes of the past based on a time point at which the AUTTIS signal is transmitted.

That is, when the terminals that receive the grant demodulate the AUTTIS, the sub-frame having the grant (transmitted) from among the past N (e.g., 12) subframes based on the subframe time at which the AUTTIS is transmitted It is possible to confirm a transmission grant signal that matches the timing of the frame.

FIG. 12 illustrates a case where an UL grant is transmitted (transmitted) at subframe numbers 373, 375, and 379. That is, the UL grant (UL grant # 1) for the UE 2 is downloaded (transmitted) in SFN 373 and the UL grant (UL grant # 2, UL grant # 3) is sent (transmitted).

For example, the base station LLa1 accesses the license-exempt band channel at the timing of SFN 378, confirms that the channel is idle, and transmits an initial signal after a certain back-off send. The initial signal includes the reservation signal and FFI (including AUTTIS). When the UE1 demodulates the AUTTIS included in the initial signal, the terminal UE1 can confirm from the time point when the demodulation is performed that the grant (UL grant # 3) has been received in the previous subframe in the past. That is, from another viewpoint, the UEs UE1 and UE2 can obtain information on when the uplink transmission can be performed through demodulation of AUTTIS.

13 is a diagram illustrating a relationship between an AUTTIS binary bit structure and an UL grant according to an embodiment of the present invention. Specifically, FIG. 13 illustrates a WiFi device WFD1, a base station LLa1, terminals UE1 and UE2, and a base station LLa2 operating in a license band, operating in a license-exempt band.

As illustrated in FIG. 13, AUTTIS represents a subframe in which grant information is transmitted among N (e.g., twelve) subframes in the past based on a subframe time at which AUTTIS is transmitted, in units of subframes . For example, in the case of N = 12, AUTTIS may be composed of 12 bits.

Since the order of the terminals is determined from the bit closest to the MSB of the AUTTIS, the transmission order of the terminals can be automatically determined. In a case where a plurality of terminals grant a grant in the same subframe time and transmit a signal, a plurality of terminals simultaneously transmit a signal through frequency division multiplexing as in the operation of an existing license band .

13, the base station LLa1 sends (transmits) the UL grant (UL grant # 1) for the UE1 to the SFN 373 and transmits UL grant (UL grant) for the UE2 to the SFN 375 and the SFN 379, (UL grant # 2, UL grant # 3) is transmitted (transmitted).

As illustrated in FIG. 13, when bits for SFN 373 and SFN 375 are set to 1 among 12 bits of AUTTIS belonging to the FFI transmitted in SFN 378, the UEs UE 1 and UE 2 Receive AUTTIS at SFN 378 and then demodulate. Then, the UE (UE1) related to the granted (granted) grant in SFN 373 performs the uplink transmission at the timing of SFN 380. Then, the UE (UE2) related to the granted (granted) grant in SFN 375 performs the uplink transmission at the timing of SFN 381.

Therefore, the AUTTIS sent in SFN 378 is 000000010100 (when N = 12), and the AUTTIS sent in SFN 384 is 000100010000 (when N = 12). That is, among the bits of the AUTTIS transmitted in SFN 378, there are two bits having a value of 1, and the bit closest to the MSB among the two bits having the value of 1 is transmitted by the base station (LLa1) Corresponds to the transmitted UL grant (UL grant # 1), and the MSB and the next closest bit correspond to the UL grant (UL grant # 2) transmitted by the base station LLa1 in SFN 375.

  Therefore, since there is no grant transmitted in SFN 374, the UEs UE1 and UE2 can perform uplink transmission sequentially in the SFNs 380 and SFN 381, and the base station LLa1 It can be seen that the UEs UE1 and UE2 sequentially transmit uplink signals without a gap. That is, the terminal UE1 corresponding to the bit closest to the MSB among the bits of the value 1 belonging to AUTTIS can transmit the uplink signal before the other terminal UE2.

As a result, when the initial signal transmission by the base station LLa1 is enabled in the license-exempted band, the base station LLa1 is in an asynchronous, adaptive, and aggregated form using AUTTIS, The transmission timing can be efficiently notified to the terminal. Also, the method of utilizing AUTTIS has an advantage that uplink transmission is not required when 4 ms elapses from the UL grant point.

The AUTTIS according to the embodiment of the present invention may have a function of separately reporting a retransmission request. In the method according to an embodiment of the present invention, asynchronous retransmission scheduling is performed differently from a synchronous type hybrid automatic repeat request (HARQ) uplink transmission timing basis for an existing license band.

13, the base station LLa1 transmits retransmission for the uplink subframe transmitted from the SFN # 381 by the UE # 2 via the AUTTIS belonging to the FFI transmitted in the SFN # 384 to the UE # . And the UE2 performs retransmission for the corresponding uplink subframe in SFN 385.

Since AUTTIS transmitted in SFN 384 indicates an UL grant (UL grant # 2) transmitted in SFN 375, retransmission of the uplink signal received by the base station (LLa1) in SFN 381 .

The AUTTIS transmitted in SFN 384 is 000100010000 (in case of N = 12), where the bit closest to the MSB among the two bits having a value of 1 is the UL grant transmitted by the base station (LLa1) grant # 2), and the MSB and the next closest bit correspond to the UL grant (UL grant # 3) transmitted by the base station LLa1 in SFN 379. That is, since the bit closest to the MSB among the two bits having the value of 1 corresponds to the retransmission, the UE 2 retransmits in SFN 385, and the UL grant received in SFN 379 # 3) is transmitted in SFN # 386.

14 is a diagram illustrating a short LBT performed immediately before an uplink transmission according to an embodiment of the present invention. Specifically, FIG. 14 illustrates a Wi-Fi device WFD1, a base station LLa1, and a terminal UE2 operating in a license-exempt band, and a base station LLa2 operating in a license band.

Specifically, FIG. 14 illustrates a case where the UE1 performs an LBT operation and transmits an uplink signal before performing the uplink transmission. A case where a short LBT is not applied corresponds to a default.

The method illustrated in FIG. 14 may be a method of additionally applying a short LBT to the method illustrated in FIG. For example, the UE2 can perform a short LBT before performing an uplink transmission in SFN 381. [ In another example, the UE2 performs a short LBT before performing the retransmission for the uplink signal transmitted in the SFN 381 at the SFN 385, and a short LBT before performing the uplink transmission at the SFN 386 Can be performed. On the other hand, the length of a sub-frame after a short LBT (e.g., 13 OFDM symbol lengths) may be different from the length of an LTE sub-frame (e.g., 14 OFDM symbol lengths).

If the shared channel is busy during a short LBT interval, the UE1 cancels the uplink transmission.

However, when a short LBT is applied (e.g., FIG. 14) and when a short LBT is not applied (e.g., FIG. 13), the overall uplink transmission timing and mechanism in subframe units indicated by AUTTIS There is no difference.

On the other hand, the length of the short LBT may be (16 + 9 * k) us. Where k is a parameter determined by the system.

15 is a diagram illustrating a base station according to an embodiment of the present invention.

The base station 100 includes a processor 110, a memory 120, and a radio frequency (RF)

The processor 110 may be configured to implement the procedures, functions, and methods described herein in connection with a base station. In addition, the processor 110 can control each configuration of the base station 100.

The memory 120 is coupled to the processor 110 and stores various information related to the operation of the processor 110. [

RF converter 130 is coupled to processor 110 and transmits or receives radio signals. The base station 100 may have a single antenna or multiple antennas.

16 is a diagram illustrating a terminal according to an embodiment of the present invention.

The terminal 200 includes a processor 210, a memory 220, and an RF converter 230.

The processor 210 may be configured to implement the procedures, functions, and methods described herein in connection with a terminal. In addition, the processor 210 can control each configuration of the terminal 200. [

The memory 220 is coupled to the processor 210 and stores various information related to the operation of the processor 210. [

The RF converter 230 is connected to the processor 210 and transmits or receives a radio signal. The terminal 200 may have a single antenna or multiple antennas.

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 (1)

Transmitting grant information for uplink transmission to a terminal through a channel of a license-exempt band; And
Transmitting an initial signal including first information indicating a time point at which the permission information is transmitted to the terminal through the license-exempt band channel
And transmitting the signal to the base station.

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