WO2019088804A1 - Method and apparatus for terminal to transmit and receive sidelink signal in wireless communication system - Google Patents

Abstract

One embodiment of the present invention relates to a method for a first terminal to transmit and receive a sidelink signal in a wireless communication system, the method comprising: a step in which the first terminal determines whether there is a collision in each subchannel within a time window; and a step in which the first terminal transmits collision-related information associated with a result of the determination, wherein the collision-related information includes a signal generated from a K-sparse signal, and the K-sparse signal is a signal in which the number of subchannels, from among all subchannels within the time window, determined to have a collision occurring therein is limited to K.

Description

Method and apparatus for transmitting and receiving a side link signal in a wireless communication system

The following description relates to a wireless communication system, and more particularly, to a method and apparatus for sensing whether a terminal collides with a resource in a side link and transmitting the sensing result to another terminal.

Background of the Invention [0002] Wireless communication systems are widely deployed to provide various types of communication services such as voice and data. Generally, a wireless communication system is a multiple access system capable of supporting communication with multiple users by sharing available system resources (bandwidth, transmission power, etc.). Examples of multiple access systems include a code division multiple access (CDMA) system, a frequency division multiple access (FDMA) system, a time division multiple access (TDMA) system, an orthogonal frequency division multiple access (OFDMA) system, a single carrier frequency division multiple access (MC-FDMA) system, and a multi-carrier frequency division multiple access (MC-FDMA) system.

A direct link between User Equipment (UE) and a device-to-device (D2D) communication establishes a communication method in which voice, data, and the like are directly exchanged without going through an evolved NodeB (eNB) It says. D2D communication may include a scheme such as UE-to-UE communication, peer-to-peer communication, and the like. Also, the D2D communication method can be applied to M2M (Machine-to-Machine) communication, MTC (Machine Type Communication), and the like.

D2D communication is considered as a solution to overcome the burden of the base station due to the rapidly increasing data traffic. For example, according to D2D communication, unlike a conventional wireless communication system, since data is exchanged between devices without going through a base station, overload of the network can be reduced. In addition, by introducing D2D communication, it is expected to reduce the procedure of the base station, reduce the power consumption of devices participating in D2D, increase the data transmission speed, increase the capacity of the network, load distribution, and increase the cell coverage.

Currently, discussions are underway on V2X (Vehicle to Everything) communication in a form linked to D2D communication. V2X is a concept that includes V2V communication between vehicles, V2P between vehicle and other types, and V2I communication between vehicle and RSU (roadside unit).

According to the present invention, a terminal is configured to sense whether a resource is collided and transmit it to another terminal, and convert / generate measurement results to apply compression sensing, and transmit the measurement results.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention, unless further departing from the spirit and scope of the invention as defined by the appended claims. It will be possible.

According to an embodiment of the present invention, there is provided a method of transmitting and receiving a sidelink signal by a first terminal in a wireless communication system, the method comprising: determining whether the first terminal collides with each subchannel within a time window; And the collision-related information includes a signal generated from a K-sparse signal, and the K-sparse signal is included in the time window And the number of subchannels determined to have collided among all the subchannels is limited to K.

A first terminal device for transmitting a sidelink signal in a wireless communication system, the first terminal device comprising: a memory; And a processor coupled to the memory, wherein the processor determines collision on a sub-channel basis within a time window and transmits collision-related information related to the determination result, wherein the collision-related information includes K-sparse signal, and the K-sparse signal is a first terminal device in which the number of subchannels determined to have collided among all the subchannels in the time window is limited to K.

K is common to the first terminal and the terminals receiving the collision-related information, and K may be a value smaller than the number (N) of all sub-channels in the time window.

The collision-related information may include at least one of an average value, a maximum value, and a minimum value of the measurement values in each sub-channel.

The first terminal may receive the collision-related information of the second terminal from the second terminal, and may recover collision information on the entire subchannel within the time window from the collision-related information of the second terminal.

The first terminal performs resource selection based on collision information for all subchannels in the time window determined by the first terminal and collision information for all subchannels in the time window determined by the second terminal .

The K-sparse signal is a vector including an element corresponding to each of all the subchannels, and the number of elements having non-zero coefficient values in the vector may be K.

The signal generated from the K-sparse signal may be obtained by sequentially multiplying the K-sparse signal by the conversion matrix and the measurement matrix.

The transformation matrix may be common to the first terminal and the terminals receiving the collision-related information.

The size of the time window may be a preset or a value received by the first terminal through higher layer / physical layer signaling.

The first terminal may determine that a collision has occurred in the subchannel if the RSSI of the subchannel is equal to or greater than a preset threshold and the decoding of the subchannel fails.

The first terminal may generate a K-sparse signal by selecting K sub-channels from a sub-channel having a large RSSI.

The first terminal may generate a K-sparse signal by selecting K sub-channels to which an important message is transmitted among sub-channels in which a collision occurs.

The first terminal can generate a K-sparse signal by selecting K subchannels having a high priority among the subchannels in which a collision has occurred.

The collision-related information may be generated and transmitted for each antenna panel of the terminal.

According to the present invention, power can be efficiently used by synchronizing each CC to a synchronous reference having the highest priority when transmitting and receiving signals from various CCs.

The effects obtained by the present invention are not limited to the above-mentioned effects, and other effects not mentioned can be clearly understood by those skilled in the art from the following description will be.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included to provide a further understanding of the invention, illustrate various embodiments of the invention and, together with the description, serve to explain the principles of the invention.

1 is a diagram showing a structure of a radio frame.

2 is a diagram illustrating a resource grid in a downlink slot.

3 is a diagram showing a structure of a downlink sub-frame.

4 is a diagram illustrating the structure of an uplink subframe.

5 is a configuration diagram of a wireless communication system having multiple antennas.

6 shows a subframe in which the D2D synchronization signal is transmitted.

7 is a diagram for explaining the relay of the D2D signal.

FIG. 8 shows an example of a D2D resource pool for D2D communication.

9 is a diagram for explaining a transmission mode and a scheduling method used in V2X.

FIG. 10 shows a method of performing resource selection in V2X.

11 is a diagram for explaining data transmission in SA in D2D.

Fig. 12 is a diagram for explaining data transmission with SA in V2X. Fig.

13 shows a frame structure of NRAT.

14 is a flowchart for explaining an embodiment of the present invention.

FIG. 15 is a diagram illustrating a method for indicating whether a collision has occurred in a predetermined resource according to an embodiment of the present invention. Referring to FIG.

16 is a block diagram of wireless communication devices in accordance with an embodiment of the present invention.

17 is a view schematically showing a wireless communication apparatus according to an embodiment of the present invention.

18 is a block diagram briefly showing a transceiver of the radio communication apparatus.

19 is a block diagram briefly showing another example of a transceiver of the radio communication apparatus.

20 is a flowchart for explaining the operation of the wireless device related to the side link.

21 is a flowchart for explaining a network node operation related to a side link.

22 is a block diagram briefly showing a configuration of a wireless device and a network node.

The following embodiments are a combination of elements and features of the present invention in a predetermined form. Each component or characteristic may be considered optional unless otherwise expressly stated. Each component or feature may be implemented in a form that is not combined with other components or features. In addition, some of the elements and / or features may be combined to form an embodiment of the present invention. The order of the operations described in the embodiments of the present invention may be changed. Some configurations or features of certain embodiments may be included in other embodiments, or may be replaced with corresponding configurations or features of other embodiments.

Embodiments of the present invention will be described herein with reference to the relationship between data transmission and reception between a base station and a terminal. Here, the BS has a meaning as a terminal node of a network that directly communicates with the MS. The specific operation described herein as performed by the base station may be performed by an upper node of the base station, as the case may be.

That is, it is apparent that various operations performed for communication with a terminal in a network composed of a plurality of network nodes including a base station can be performed by a network node other than the base station or the base station. A 'base station (BS)' may be replaced by a term such as a fixed station, a Node B, an eNode B (eNB), an access point (AP) Repeaters can be replaced by terms such as Relay Node (RN), Relay Station (RS), and so on. The term 'terminal' may be replaced with terms such as User Equipment (UE), Mobile Station (MS), Mobile Subscriber Station (MSS), and Subscriber Station (SS). In the following description, a base station may also be used to mean a scheduling execution node, a cluster header, or the like. If a BS or a relay transmits a signal transmitted by the MS, it can be regarded as a kind of MS.

The name of a cell described below is applied to a transmission / reception point of a base station (eNB), a sector, a remote radio head (RRH), a relay, May be used as a generic term for identifying component carriers.

The specific terminology used in the following description is provided to aid understanding of the present invention, and the use of such specific terminology may be changed into other forms without departing from the technical idea of the present invention.

In some instances, well-known structures and devices may be omitted or may be shown in block diagram form, centering on the core functionality of each structure and device, to avoid obscuring the concepts of the present invention. In the following description, the same components are denoted by the same reference numerals throughout the specification.

Embodiments of the present invention may be supported by standard documents disclosed in at least one of the IEEE 802 systems, 3GPP systems, 3GPP LTE and LTE-Advanced (LTE-Advanced) systems, and 3GPP2 systems, which are wireless access systems. That is, the steps or portions of the embodiments of the present invention that are not described in order to clearly illustrate the technical idea of the present invention can be supported by the documents. In addition, all terms disclosed in this document may be described by the standard document.

The following description will be made on the assumption that the present invention is applicable to a CDMA system such as Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Orthogonal Frequency Division Multiple Access (OFDMA), and Single Carrier Frequency Division Multiple Access And can be used in various wireless access systems. CDMA may be implemented in radio technology such as Universal Terrestrial Radio Access (UTRA) or CDMA2000. The TDMA may be implemented in a wireless technology such as Global System for Mobile communications (GSM) / General Packet Radio Service (GPRS) / Enhanced Data Rates for GSM Evolution (EDGE). OFDMA may be implemented in wireless technologies such as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, and Evolved UTRA (E-UTRA). UTRA is part of the Universal Mobile Telecommunications System (UMTS). 3GPP (3rd Generation Partnership Project) LTE (Long Term Evolution) is a part of E-UMTS (Evolved UMTS) using E-UTRA, adopting OFDMA in downlink and SC-FDMA in uplink. LTE-A (Advanced) is the evolution of 3GPP LTE. WiMAX can be described by the IEEE 802.16e standard (WirelessMAN-OFDMA Reference System) and the advanced IEEE 802.16m standard (WirelessMAN-OFDMA Advanced system). For the sake of clarity, the 3GPP LTE and 3GPP LTE-A systems will be described below, but the technical idea of the present invention is not limited thereto.

LTE / LTE-A resource structure / channel

The structure of the radio frame will be described with reference to Fig.

In a cellular OFDM wireless packet communication system, uplink / downlink data packet transmission is performed on a subframe basis, and one subframe is defined as a predetermined time interval including a plurality of OFDM symbols. The 3GPP LTE standard supports a Type 1 radio frame structure applicable to Frequency Division Duplex (FDD) and a Type 2 radio frame structure applicable to TDD (Time Division Duplex).

1 (a) is a diagram showing a structure of a type 1 radio frame. A downlink radio frame is composed of 10 subframes, and one subframe is composed of two slots in a time domain. The time taken for one subframe to be transmitted is referred to as a transmission time interval (TTI). For example, the length of one subframe may be 1 ms and the length of one slot may be 0.5 ms. One slot includes a plurality of OFDM symbols in the time domain and a plurality of resource blocks (RBs) in the frequency domain. In the 3GPP LTE / LTE-A system, OFDMA is used in the downlink, so an OFDM symbol represents one symbol period. The OFDM symbol may also be referred to as an SC-FDMA symbol or a symbol interval. A resource block (RB) is a resource allocation unit and may include a plurality of consecutive subcarriers in one block.

The number of OFDM symbols included in one slot may vary according to the configuration of a CP (Cyclic Prefix). The CP has an extended CP and a normal CP. For example, when an OFDM symbol is configured by a general CP, the number of OFDM symbols included in one slot may be seven. When the OFDM symbol is configured by an extended CP, since the length of one OFDM symbol is increased, the number of OFDM symbols included in one slot is smaller than that of a normal CP. In the case of the extended CP, for example, the number of OFDM symbols included in one slot may be six. If the channel condition is unstable, such as when the UE moves at a high speed, an extended CP may be used to further reduce inter-symbol interference.

When a normal CP is used, one slot includes 7 OFDM symbols, and therefore one subframe includes 14 OFDM symbols. At this time, the first two or three OFDM symbols of each subframe may be allocated to a physical downlink control channel (PDCCH), and the remaining OFDM symbols may be allocated to a physical downlink shared channel (PDSCH).

1 (b) is a diagram showing a structure of a type 2 radio frame. The Type 2 radio frame is composed of two half frames. Each half frame includes five subframes, a downlink pilot time slot (DwPTS), a guard period (GP), an uplink pilot time slot (UpPTS) One of the subframes is composed of two slots. The DwPTS is used for initial cell search, synchronization, or channel estimation in the UE. UpPTS is used to match the channel estimation at the base station and the uplink transmission synchronization of the terminal. The guard interval is a period for eliminating the interference occurring in the uplink due to the multi-path delay of the downlink signal between the uplink and the downlink. On the other hand, one subframe consists of two slots regardless of the type of the radio frame.

The structure of the radio frame is merely an example, and the number of subframes included in a radio frame, the number of slots included in a subframe, and the number of symbols included in a slot can be variously changed.

2 is a diagram illustrating a resource grid in a downlink slot. One downlink slot includes seven OFDM symbols in the time domain, and one resource block (RB) includes 12 subcarriers in the frequency domain, but the present invention is not limited thereto. For example, one slot includes 7 OFDM symbols in the case of a normal CP (Cyclic Prefix), but one slot may include 6 OFDM symbols in an extended CP (CP). Each element on the resource grid is called a resource element. One resource block includes 12 x 7 resource elements. The number N ^DL of resource blocks included in the downlink slot depends on the downlink transmission bandwidth. The structure of the uplink slot may be the same as the structure of the downlink slot.

3 is a diagram showing a structure of a downlink sub-frame. In a subframe, a maximum of three OFDM symbols in the first part of the first slot corresponds to a control area to which a control channel is allocated. The remaining OFDM symbols correspond to a data area to which a Physical Downlink Shared Channel (PDSCH) is allocated. The downlink control channels used in the 3GPP LTE / LTE-A system include, for example, a Physical Control Format Indicator Channel (PCFICH), a Physical Downlink Control Channel (PDCCH) And a Physical Hybrid Automatic Repeat Request Indicator Channel (PHICH). The PCFICH includes information on the number of OFDM symbols transmitted in the first OFDM symbol of the subframe and used for control channel transmission in the subframe. The PHICH includes an HARQ ACK / NACK signal as a response to the uplink transmission. The control information transmitted through the PDCCH is referred to as downlink control information (DCI). The DCI includes uplink or downlink scheduling information or includes an uplink transmission power control command for an arbitrary terminal group. The PDCCH includes a resource allocation and transmission format of a downlink shared channel (DL-SCH), resource allocation information of an uplink shared channel (UL-SCH), paging information of a paging channel (PCH), system information on a DL- A set of transmission power control commands for individual terminals in an arbitrary terminal group, transmission power control information, activation of VoIP (Voice over IP), resource allocation of upper layer control messages such as random access response And the like. A plurality of PDCCHs may be transmitted within the control domain. The UE can monitor a plurality of PDCCHs. The PDCCH is transmitted in an aggregation of one or more contiguous Control Channel Elements (CCEs). The CCE is a logical allocation unit used to provide the PDCCH with a coding rate based on the state of the wireless channel. The CCE corresponds to a plurality of resource element groups. The number of CCEs required for the PDCCH may vary depending on the size of the DCI, the coding rate, and the like. For example, for the PDCCH transmission, any one of the CCE numbers 1, 2, 4, and 8 (corresponding to the PDCCH formats 0, 1, 2, and 3 respectively) can be used, and when the size of the DCI is large and / A relatively large number of CCEs can be used for one PDCCH transmission if a low coding rate is required. The BS determines the PDCCH format in consideration of the size of the DCI transmitted to the UE, the cell bandwidth, the number of downlink antenna ports, the amount of PHICH resources, and adds a cyclic redundancy check (CRC) to the control information. The CRC is masked with an identifier called a Radio Network Temporary Identifier (RNTI) according to the owner or use of the PDCCH. If the PDCCH is for a particular UE, the cell-RNTI (C-RNTI) identifier of the UE may be masked in the CRC. Alternatively, if the PDCCH is for a paging message, a Paging Indicator Identifier (P-RNTI) may be masked in the CRC. If the PDCCH is for system information (more specifically, the System Information Block (SIB)), the system information identifier and the system information RNTI (SI-RNTI) may be masked to the CRC. A random access-RNTI (RA-RNTI) may be masked to the CRC to indicate a random access response that is a response to the transmission of the UE's random access preamble.

4 is a diagram illustrating the structure of an uplink subframe. The UL subframe may be divided into a control region and a data region in the frequency domain. A physical uplink control channel (PUCCH) including uplink control information is allocated to the control region. A physical uplink shared channel (PUSCH) including user data is allocated to the data area. To maintain a single carrier characteristic, one terminal does not transmit PUCCH and PUSCH at the same time. A PUCCH for one terminal is allocated to a resource block pair (RB pair) in a subframe. Resource blocks belonging to a resource block pair occupy different subcarriers for two slots. It is assumed that the resource block pair allocated to the PUCCH is frequency-hopped at the slot boundary.

A reference signal (RS)

When a packet is transmitted in a wireless communication system, since the transmitted packet is transmitted through a wireless channel, signal distortion may occur in the transmission process. In order to properly receive the distorted signal at the receiving side, the distortion should be corrected in the received signal using the channel information. In order to determine the channel information, a method is used in which a signal known to both the transmitting side and the receiving side is transmitted, and channel information is detected with a degree of distortion when the signal is received through the channel. The signal is referred to as a pilot signal or a reference signal.

When transmitting and receiving data using multiple antennas, it is necessary to know the channel condition between each transmitting antenna and the receiving antenna so that a correct signal can be received. Therefore, there is a separate reference signal for each transmission antenna, more specifically, for each antenna port.

The reference signal may be divided into an uplink reference signal and a downlink reference signal. In the current LTE system, as an uplink reference signal,

i) a demodulation reference signal (DM-RS) for channel estimation for coherent demodulation of information transmitted via PUSCH and PUCCH,

ii) The base station has a Sounding Reference Signal (SRS) for the network to measure the uplink channel quality at different frequencies.

On the other hand, in the downlink reference signal,

i) a cell-specific reference signal (CRS) shared by all terminals in a cell,

ii) a UE-specific reference signal for a specific UE only;

iii) a DeModulation-Reference Signal (DM-RS) transmitted for coherent demodulation when the PDSCH is transmitted;

iv) Channel State Information-Reference Signal (CSI-RS) for transmitting channel state information (CSI) when the downlink DMRS is transmitted.

v) MBSFN Reference Signal (MBSFN Reference Signal) transmitted for coherent demodulation on a signal transmitted in MBSFN (Multimedia Broadcast Single Frequency Network) mode,

vi) There is a positioning reference signal used to estimate the geographical location information of the terminal.

The reference signal can be roughly classified into two types according to its purpose. There are a target reference signal for channel information acquisition and a reference signal used for data demodulation. The former must be transmitted in a wide band because the UE obtains channel information for the downlink, and even a terminal that does not receive downlink data in a specific subframe must receive the reference signal. It is also used in situations such as handover. The latter is a reference signal transmitted together with the resource when the base station transmits the downlink, and the terminal can demodulate the data by measuring the channel by receiving the reference signal. This reference signal should be transmitted in the area where data is transmitted.

Modeling of Multi-antenna (MIMO) Systems

5 is a configuration diagram of a wireless communication system having multiple antennas.

As shown in FIG. 5A, when the number of transmission antennas is increased to Nt and the number of reception antennas is increased to NR, unlike the case where a plurality of antennas are used only in a transmitter and a receiver, a theoretical channel transmission Capacity increases. Therefore, the transmission rate can be improved and the frequency efficiency can be remarkably improved. As the channel transmission capacity increases, the transmission rate can theoretically increase by the rate of rate increase Ri multiplied by the maximum transmission rate Ro in single antenna use.

For example, in a MIMO communication system using four transmit antennas and four receive antennas, it is possible to obtain a transmission rate four times higher than the single antenna system. After the theoretical capacity increase of the multi-antenna system has been proved in the mid-90s, various techniques have been actively researched to bring it up to practical data rate improvement. In addition, several technologies have already been reflected in various wireless communication standards such as 3G mobile communication and next generation wireless LAN.

The research trends related to multi-antenna up to now include information theory study related to calculation of multi-antenna communication capacity in various channel environment and multiple access environment, study of wireless channel measurement and modeling of multi-antenna system, improvement of transmission reliability and improvement of transmission rate And research on space-time signal processing technology.

A communication method in a multi-antenna system will be described in more detail using mathematical modeling. It is assumed that there are Nt transmit antennas and Nt receive antennas in the system.

Looking at the transmitted signal, if there are Nt transmit antennas, the maximum transmittable information is NT. The transmission information can be expressed as follows.

Each transmission information

The transmission power may be different. Each transmission power

, The transmission information whose transmission power is adjusted can be expressed as follows.

Also,

Is a diagonal matrix of transmit power

Can be expressed as follows.

Transmission power adjusted information vector

A weighting matrix

Lt; RTI ID = 0.0 > Nt < / RTI > transmitted signals

. Weighting matrix

Which distributes the transmission information to each antenna according to the transmission channel condition and the like.

Vector

Can be expressed as follows.

From here,

Denotes a weight between the i- th transmit antenna and the j- th information.

Is also referred to as a precoding matrix.

If there are Nr reception antennas,

Can be expressed as a vector as follows.

When a channel is modeled in a multi-antenna wireless communication system, the channel may be classified according to the transmission / reception antenna index. The channel passing through the receiving antenna i from the transmitting antenna j

.

, It is noted that the order of the index is the reception antenna index, and the index of the transmission antenna is the order of the index.

On the other hand, FIG. 5 (b) shows a channel from the NR transmission antenna to the reception antenna i . The channels can be grouped and displayed in vector and matrix form. In FIG. 5 (b), a channel arriving from a total of NT transmit antennas to receive antennas i may be expressed as follows.

Thus, all channels arriving from the Nt transmit antennas to the Nr receive antennas can be expressed as:

The actual channel includes a channel matrix

And additive white Gaussian noise (AWGN) is added. White noise added to each NR receive antenna

Can be expressed as follows.

Through the above-described equation modeling, the received signal can be expressed as follows.

On the other hand, a channel matrix

The number of rows and columns of the antenna is determined by the number of transmitting and receiving antennas. Channel matrix

The number of rows is equal to the number of receiving antennas NR and the number of columns is equal to the number of transmitting antennas Nt. That is,

The matrix is NR x Nt.

The rank of a matrix is defined as the minimum number of independent rows or columns. Thus, the rank of the matrix can not be greater than the number of rows or columns. Channel matrix

Rank of

) Is limited as follows.

Another definition of the rank is defined as the number of eigenvalues that are not zero when the matrix is eigenvalue decomposition. Similarly, another definition of a rank is defined as the number of non-zero singular values when singular value decomposition is performed. Thus, the rank in the channel matrix. The physical meaning of a channel is the maximum number that can transmit different information on a given channel.

In the description of this document, 'Rank' for MIMO transmission indicates the number of paths that can independently transmit signals at a specific time and specific frequency resources, and 'number of layers' ≪ / RTI > In general, since the transmitting end transmits a number of layers corresponding to the number of ranks used for signal transmission, the rank has the same meaning as the number of layers unless otherwise specified.

D2D  Acquisition of synchronization of terminal

Hereinafter, the inter-terminal synchronization acquisition in the D2D communication will be described based on the above description and the existing LTE / LTE-A system. In the OFDM system, if the time / frequency synchronization does not match, multiplexing between different terminals in an OFDM signal may be impossible due to inter-cell interference. In order to synchronize, it is inefficient for D2D terminals to send and receive a direct synchronization signal so that all terminals synchronize individually. Therefore, in a distributed node system such as D2D, a specific node transmits a representative synchronous signal and the remaining UEs can synchronize with the synchronous signal. In other words, in order to transmit / receive a D2D signal, some nodes (in this case, a node may be called an eNB, a UE, or a synchronization reference node or SRN) may transmit a D2D synchronization signal (D2DSS, D2D Synchronization Signal) , And the other terminals transmit and receive signals in synchronization with each other.

The D2D synchronization signal may include a primary synchronization signal PD2DSS (Primary D2DSS or Primary Synchronization Synchronization Signal (PSSS)) and a secondary synchronization signal (SD2DSS (Secondary D2DSS or Secondary Sidelink synchronization signal SSSS) It is possible to use a Zadoff-Chu sequence (similar to Zadoff-chu sequence) or a similar / modified / repeated structure to PSS, etc. Also, it is possible to use another Zadoffu root index (for example, 26, 37) unlike DL PSS. Sequence or SSS similar / modified / repeated structure, etc. If the UEs synchronize from the eNB, the SRN becomes the eNB and the D2DSS becomes the PSS / SSS. Unlike the PSS / SSS of the DL, the PD2DSS / SD2DSS conforms to the UL subcarrier mapping scheme. [0053] A sub-frame in which a D2D synchronization signal is transmitted is shown in Figure 6. The PD2DSCH (Physical D2D synchronization channel) (Duplex Mode, DM, TDD UL / DL configuration, resource pool related information, type of application related to D2DSS, subframe offset, broadcast information, etc.) (Broadcast) channel on which the PD2 DSCH is transmitted. [0052] The PD2DSCH may be transmitted on the same subframe as the D2DSS or on a following subframe.

The SRN may be a node transmitting D2DSS, PD2DSCH (Physical D2D synchronization channel). The D2DSS may be in a specific sequence form and the PD2DSCH may be in the form of a codeword followed by a sequence or predetermined channel coding that represents specific information. Here, the SRN may be an eNB or a specific D2D terminal. In the case of partial network coverage or out of network coverage, the terminal may be an SRN.

In the situation shown in FIG. 7, the D2DSS can be relayed for D2D communication with an out of coverage terminal. Also, the D2DSS can be relayed through multiple hops. In the following description, the relaying of the synchronization signal includes not only relaying the synchronization signal of the direct base station to the AF relay but also transmitting the D2D synchronization signal of a different format in accordance with the synchronization signal reception timing. In this manner, the D2D synchronization signal is relayed so that the terminal not covered and the terminals outside the coverage can directly communicate with each other.

D2D resource  pool

FIG. 8 shows UE1, UE2, and D2D resource pools used by them for performing D2D communication. In FIG. 8 (a), a UE denotes a network equipment such as a base station that transmits / receives signals according to a terminal or a D2D communication scheme. A terminal can select a resource unit corresponding to a specific resource in a resource pool representing a set of resources and transmit the D2D signal using the resource unit. The receiving terminal UE2 may be configured with a resource pool in which UE1 can transmit signals and detect the signal of UE1 in the pool. Herein, the resource pool can inform the UE when the UE 1 is in the connection range of the base station, and may be informed by other UEs or determined as predetermined resources if the UE is outside the connection range of the base station. Generally, a resource pool is composed of a plurality of resource units, and each terminal can select one or a plurality of resource units and use the resource units for its own D2D signal transmission. The resource unit may be the same as that illustrated in Fig. 8 (b). Referring to FIG. 8 (b), it can be seen that the total frequency resources are divided into NF pieces and the total time resources are divided into NT pieces to define a total of NF * NT resource units. Here, it can be said that the resource pool is repeated at intervals of NT subframes. In particular, one resource unit may appear periodically and repeatedly as shown. Alternatively, in order to obtain the diversity effect in the time or frequency dimension, the magnitude of the physical resource unit to which one logical resource unit is mapped may change in a predetermined pattern according to time. In this resource unit structure, a resource pool may mean a set of resource units that a terminal to transmit a D2D signal can use for transmission.

Resource pools can be subdivided into different types. It can be distinguished according to the contents of the D2D signal transmitted from each resource pool. For example, the contents of the D2D signal can be distinguished, and a separate resource pool can be configured for each. As the contents of the D2D signal, there may be an SA (scheduling assignment or physical channel control channel (PSCCH)), a D2D data channel, and a discovery channel. The SA includes information such as a modulation and coding scheme (MCS), a MIMO transmission scheme, a timing advance (TA), and the like required for demodulating the data channel and the resource used for transmission of the D2D data channel, Lt; / RTI > It is also possible that this signal is multiplexed with the D2D data on the same resource unit and transmitted. In this case, the SA resource pool can be a pool of resources transmitted by being multiplexed with the D2D data by the SA. Alternatively, it may be referred to as a D2D control channel, or a physical sidelink control channel (PSCCH). The D2D data channel (or PSSCH (Physical Sidelink Shared Channel)) may be a pool of resources used by the transmitting terminal to transmit user data. If the SA is multiplexed with the D2D data on the same resource unit, only the D2D data channel in the form of excluding the SA information can be transmitted in the resource pool for the D2D data channel. In other words, the REs that were used to transfer SA information on the individual resource units in the SA resource pool can still be used to transfer D2D data in the D2D data channel resource pool. The discovery channel may be a resource pool for a message that allows a transmitting terminal to transmit information such as its own ID to allow a neighboring terminal to discover itself.

Even if the content of the D2D signal is the same, different resource pools can be used depending on the transmission / reception property of the D2D signal. For example, even if the same D2D data channel or a discovery message is used, the transmission timing determination method of the D2D signal (for example, whether it is transmitted at the reception timing of the synchronous reference signal or a certain TA applied thereto) (E.g., whether the eNB assigns a transmission resource of an individual signal to an individual transmitting UE, or whether an individual transmitting UE selects its own individual signaling resource in the pool), a signal format (e.g., each D2D signal occupies one subframe The number of symbols and the number of subframes used for transmission of one D2D signal), the signal strength from the eNB, the transmission power intensity of the D2D UE, and the like. In the D2D communication, the eNB directly indicates the transmission resource of the D2D transmission UE in the sidelink transmission mode 1, the transmission resource region is set in advance, or the eNB designates the transmission resource region, In the case of the D2D discovery, when the eNB directly indicates the resource, the method of selecting the direct transmission resource is Type 2, the UE directly transmits in the resource region designated by the eNB, When selecting a resource, it is called Type 1.

In V2X, a side link transmission mode 3 based on centralized scheduling and a side link transmission mode 4 using a distributed scheduling scheme are used. FIG. 9 shows a scheduling scheme according to these two transmission modes. Referring to FIG. 9, in the transmission mode 3 of the centralized scheduling scheme of FIG. 9A, when the vehicle requests a side link resource to the base station (S901a), the base station allocates resources (S902a) And carries out transmission to the vehicle (S903a). In the centralized transmission scheme, resources of other carriers can also be scheduled. In contrast, in the distributed scheduling method of FIG. 9B corresponding to the transmission mode 4, the vehicle senses resources and resource pools previously set (S901b) from the base station, selects a resource to be used for transmission (S902b) And transmission to another vehicle is performed through the selected resource (S903b). At this time, as shown in FIG. 10, a method of reserving transmission resources of the next packet is used for selection of transmission resources. In V2X, two transmissions are performed per MAC PDU. In selecting a resource for initial transmission, resources for retransmission are reserved with a certain time gap. A detailed description thereof is given in 3GPP TS 36.213 V14.6.0 document 14, and is incorporated into the specification as a prior art of the present invention.

SA transmission and reception

Side Link Transmission Mode 1 The UE can transmit an SA (or a D2D control signal, SCI (Sidelink Control Information)) through a resource configured from a base station. The side link transmission mode 2 terminal is configured with a resource to be used for D2D transmission from the base station. Then, the SA can be selected by selecting the time frequency resource from the configured resource.

In the side link transmission mode 1 or 2, the SA period may be defined as shown in FIG. Referring to FIG. 9, the first SA period may start in a subframe separated by a predetermined offset (SAOffsetIndicator) indicated by upper layer signaling from a specific system frame. Each SA period may include an SA resource pool and a subframe pool for D2D data transmission. The SA resource pool may include the last subframe among the subframes indicated as being transmitted from the first subframe of the SA period to the SA in the subframe bitmap (saSubframeBitmap). In the case of the mode 1, the resource pool for D2D data transmission can be determined to be a subframe used for actual data transmission by applying time-resource pattern for transmission (T-RPT) or time-resource pattern (TRP). As shown in the figure, when the number of subframes included in the SA period excluding the SA resource pool is greater than the number of T-RPT bits, the T-RPT can be repeatedly applied, and the last applied T- Can be applied as truncated. The transmitting terminal performs transmission at the T-RPT bitmap at the indicated T-RPT and transmits one MAC PDU four times.

V2X, i.e., the side link transmission mode 3 or 4, unlike D2D, SA (PSCCH) and data (PSSCH) are transmitted in the FDM scheme. In V2X, it is important to reduce delays due to the nature of vehicle communication. For this, SA and data are transmitted in FDM on different frequency resources on the same time resource. 12 shows an example of such a transmission scheme. One of the schemes in which the SA and the data are not directly adjacent to each other or the scheme in which the SA and the data are directly adjacent to each other may be used as shown in Fig. 12 (a) . The basic unit of such transmission is a subchannel, which is a resource unit having one or more RB sizes on a frequency axis on a predetermined time resource (e.g., a subframe). The number of RBs included in the subchannel, that is, the size of the subchannel and the start position on the frequency axis of the subchannel, is indicated by upper layer signaling.

Meanwhile, in inter-vehicle communication, a CAM (Cooperative Awareness Message) message of a periodic message type, a DENM (Decentralized Environmental Notification Message) message of an event triggered message type, and the like can be transmitted. The CAM may include basic vehicle information such as vehicle dynamic status information such as direction and speed, vehicle static data such as dimensions, external lighting conditions, and route history. The size of the CAM message may be 50-300 bytes. The CAM message shall be broadcast and the latency shall be less than 100 ms. The DENM can be a message generated in an unexpected situation such as a vehicle malfunction or an accident. The size of the DENM may be less than 3000 bytes, and any vehicle within the transmission range may receive the message. In this case, the DENM can have a higher priority than the CAM, and having a high priority at this time means that when a case of simultaneous transmission occurs in a UE viewpoint, it means that priority is given to a higher priority, May prefer to transmit a message with a higher priority in terms of time. From a multiple UE perspective, a message with a higher priority may be less likely to receive interference than a message with lower priority, thus lowering the probability of receiving errors. CAMs can also have a larger message size if they include security overhead.

NR  (New RAT (Radio Access Technology))

As more and more communication devices require more communication capacity, there is a need for improved mobile broadband communication over existing radio access technology. Massive MTC (Machine Type Communications), which provides various services by connecting many devices and objects, is one of the major issues to be considered in next generation communication. In addition, communication system design considering service / UE sensitive to reliability and latency is being discussed. The introduction of next generation radio access technology considering enhanced mobile broadband communication, massive MTC, URLLC (Ultra-Reliable and Low Latency Communication) is discussed. In the present invention, the technology is referred to as NR for convenience.

13 to 14 illustrate a frame structure that can be used for NR. Referring to FIG. 13, it is characterized by a self-contained structure in which a DL control channel, a DL or an UL data, and a UL control channel can be included in one frame unit. At this time, DL data scheduling information and UL data scheduling information can be transmitted in the DL control channel. In the UL control channel, ACK / NACK information, CSI information (modulation and coding scheme information, MIMO transmission related information, ), a scheduling request, and so on. There may be a time gap for DL-to-UL or UL-to-DL switching between the control and data areas. In addition, some of DL control / DL data / UL data / UL control may not be configured in one frame. Or the order of the channels constituting one frame may be changed. (For example, DL control / DL data / UL control / UL data or UL control / UL data / DL control / DL data)

On the other hand, carrier aggregation can be used to improve data transmission rate and reliability even in direct communication between terminals. For example, a receiving terminal may receive a signal from an aggregated carrier, perform combining or joint decoding, or transmit a decoded signal to an upper layer to perform soft combining on signals transmitted on different carriers.

Compression sensing

For a long time, theoretical research on representing a given analog signal with the smallest number of samples was of great interest. It is well known that the signal (digital signal) acquired at more than twice the sampling rate of analog signal bandwidth is reconstructed without any loss when converted back to analogue, and the minimum sampling rate is well known as the Nyquist rate. In this case, the analog signal is a baseband signal. If the signal is acquired at a sampling rate lower than the Nyquist rate, the signal is damaged / distorted. People have thought of this theory for a very long time to be self-evident, but since it is too general a theory for arbitrary baseband signals, research has been conducted on more sophisticated theories for specific signals.

Recently, it has been proved that the signal can be almost perfectly recovered even at a sampling rate lower than the Nyquist rate for sparse / scattered signals. This is called compressive sensing (CS). CS can be compressed / restored with very few samples when applied directly to signal compression. Thus, a very efficient new way to get away from traditional signal compression / reconstruction can be achieved. In the conventional method, a video signal is sampled according to a Nyquist rate, a digital signal is obtained, a wavelet / Fourier transform is performed, and then the largest coefficient is stored and compressed. One-dimensional signals can be considered for ease of explanation. When a 1-second signal with a bandwidth of 1 KHz is sampled at a Nyquist rate, 2000 samples are obtained. Assuming that this signal is re-expressed through some transformation, only 20 coefficients have very large values. Unlike this traditional approach, if we could get 20 coefficients of the scatter signal converted to just 40 samples in a 1 second signal, it would be a very efficient way. In addition, the cost of hardware for compression can be lowered, which can be expected to make a dramatic change. CS is the theoretical basis for this approach.

To understand CS, you first need to define a sparse signal. Let us assume an arbitrary N-dimensional linear space. If an interspersed signal is represented as a vector of this space, then this signal or vector is called a K-sparse signal if the number of nonzero values of this vector is K (<< N), which is much smaller than N. For example, in the case of N = 100 and K = 10, the K-sparse signal is the case where the ten coefficients are nonzero and the remaining 90 coefficients are all zero. These scattered signals are related to the basis of this signal. Depending on the basis or transformation used to represent the signal in a vector space, the signal may or may not be interspersed. For example, in the time domain, the constant signal has a nonzero value for all times. This signal is not a disturbance signal. However, when the signal is seen in the frequency domain through the Fourier transform, it is a scatter signal in the frequency domain where the frequency coefficient for 0 has a value other than 0 and the coefficients for other frequencies are all 0s.

Example  One

The first embodiment relates to a method for efficiently performing feedback in order to assist resource selection or resource reselection of a transmitting terminal in direct-to-terminal communication.

The UE can select resources in a certain frequency resource unit (for example, RB group or subchannel) in the frequency domain. In the following description, it is assumed that the minimum unit by which a terminal selects a resource is a subchannel. It is assumed that the UE can select a resource in an integer multiple of a subchannel. It is assumed that the terminal can maintain selected resources for a certain period of time at regular intervals. For example, it is assumed that a particular terminal maintains its corresponding resource usage at Xms intervals for N subchannels. At this time, N, X, and Y may be different for each mobile station. The terminal recognizes through the sensing which resource is being used by another terminal for frequency resource selection. At this time, the sensing method is 3GPP Rel. 14 V2X sensing techniques can be followed. More specifically, the terminal decodes control signals of other terminals, measures the RSRP of the data signal indicated by the control signal, and excludes the RSRP from the transmittable resources if the RSRP is equal to or larger than a predetermined threshold. Then, RSSI is measured in each subchannel to randomly select a transmission resource among the resources whose RSSI is less than a predetermined threshold. At this time, the resources to select are continuous in the frequency domain and are determined by the size of the message to be transmitted.

However, even if the transmission resource is selected by performing the sensing in this way, it is not possible to avoid a resource conflict with another terminal (hidden node) from the viewpoint of the receiving terminal. Unicast can mitigate this hidden node problem by using RTS / CTS technique. However, if several terminals send and receive broadcast messages to multiple terminals, RTS / CTS will require such hidden node overhead, and CTS It is difficult to solve the CTS problem. For example, since the RTS is transmitted to the unspecified UEs and the feedback is transmitted too much for the unspecified UEs to transmit the CTS, the system performance will be deteriorated because they lose their transmission and reception opportunities. Accordingly, in the following embodiments, a method of efficiently indicating resource status information in a case where terminals transmit and receive a multicast / broadcast message will be described.

The UE may select retransmission resources, in which case the interval between the two transmission resources may be within a maximum X SF. This is to reduce the burden of HARQ buffering of the receiving terminal. Where X may be set by the network or may be a predetermined value. The terminal transmits its message to neighboring terminals, and this message assumes that neighboring terminals attempt decoding. (Multicast / broadcast) At this time, the message of each terminal can be generated with a specific period.

Next, with reference to FIGS. 14 to 15, a description will be made of a method of transmitting / receiving side link signals and picoblocking according to an embodiment of the present invention. Referring to FIG. 14, the first UE can determine whether there is a collision per subchannel within a time window (S1401), and transmit (resource) collision related information related to the determination result (S1402). (SNR, SINR, INR, interference power, etc.) of the resource are relatively bad compared to other resources to the neighboring mobile stations. Such information may be referred to as resource conflict information or resource status information.

Here, the (resource) collision-related information (or resource status information) is generated from a K-sparse signal in which the number of subchannels judged to have collided (in bad condition) among all subchannels in the time window is limited to K Signal. K may be common to terminals that receive the first terminal and collision related information (state related information), and K may be a value less than the number of all subchannels in the time window. (Alternatively, K may be a value corresponding to the number of all subchannels in the time window.) This will be described in detail with reference to FIG. Concretely, a resource can be represented by a binary bit indicating that a (relatively) collision has occurred.

For example, assuming that one subframe consists of five subchannels, if the window length is 100 ms, the state of the channel and the occupancy state of the resource can be represented by a binary bit of 500 bits. As shown in FIG. 15, a subchannel determined to have collided with all 500 subchannels (N = 500) in the time window can be represented by 1. The terminal may transmit all of the binary bit information for all N subchannels (i.e., K = 500) but only some of the subchannels. If K is a value sufficiently smaller than the number N of all sub-channels N = 500 (for example, N = 10), it is determined whether or not the sub-channels determined to have collided again collide with each other according to a predetermined criterion. In FIG. 15, it is judged that the collision has occurred (indicated by a hatched portion in FIG. 15) by judging / displaying only the K sub-channels indicated as 1 according to the predetermined criterion. That is, a result of determining that a collision has occurred is generated / converted into a K-sparse signal limited to K by the number of subchannels determined to have collided among all the subchannels in the time window.

In other words, when indications of a resource collision or a sensing result, information can be transmitted only for some resources. This can be seen as generating a sparse signal in the compression sensing described below. In other words, only resources that satisfy certain conditions within a certain time window can be signaled as binary or L state. This may be to represent the subchannel in the time window as a K sparse signal. In other cases, the network determines the payload size of the feedback information, and the transmitting / receiving terminal determines the transport block size of the data based on the size of the feedback, or the RB size or MCS of the physical layer signal, and the RE size that is puncturing / You can decide. In this way, when the collision information is generated / converted by the K-sparse signal and the signal generated from the K-sparse signal is transmitted, the amount of information to be transmitted can be greatly reduced. Specifically, for example, when a (time) window size is 100 and each SF is composed of 4 subchannels, a payload of 400 bits was originally required. However, assuming that K (sparsity) is much smaller than 400 in the compression sensing technique, for example, when K = 20 (assuming a random sensing matrix), it is possible to express a payload plane of about 20 * log 20 to about 60 bits. Do. That is, the payload size of the sparsity level or feedback information can be signaled to the mobile station by the network at the physical layer or higher layer signal. This method facilitates the configuration of the physical layer channel in which the information is transmitted since the UE can assume a common feedback payload size. Even if this information is transmitted as an upper layer signal, it is possible to make a payload common to all the terminals when the total payload of the upper layer signal is configured. For example, when the terminal transmits data using 10RB, if the feedback requires 1RB, the size of the data can be reduced to 9RB and the TB size can be determined. That is, the above feedback information can be considered as: 1) a method of transmitting in a separate physical layer signal, 2) a method of being transmitted in an upper layer signal, and 3) a method of piggybacking in a data channel. The difference between 2) and 3) is that the transmitted resource is transmitted to the data channel area, but the difference is whether channel coding is applied to the data or separate channel coding is applied to the data. 3), since different channel coding is applied to the data, a different MCS level and power allocation per RE can be applied to the data. 3), a specific RE is used for feedback information transmission, and rate matching or puncturing of data can be performed by the number of REs used at this time

Whether or not the UE transmits such feedback information, the payload size of the feedback information, the sparsity level of the feedback information, and the window size of the feedback information may be signaled to the UE by the network.

A determination as to whether a collision has occurred in a specific subchannel may be determined as a method delegated to the terminal (terminal implementation) or a specific mechanism may be introduced. In the present invention, there is no particular limitation on how the terminal determines whether or not a collision has occurred. That is, the UE can use one or more of various methods for determining that a collision has occurred in a specific resource area in the prior art. For example, although the RSSI has exceeded a predetermined threshold, control using the corresponding subchannel has been decoded, but data of the corresponding subchannel can be assumed to have collided with the corresponding subchannel if decoding fails.

The information that a conflict has occurred may be relative. For example, if the RSSI of a particular resource is above a certain threshold and decoding fails, the resource may be considered to have collided, where a resource with a higher RSSI may be considered "more severely" collided. Alternatively, if the SINR can be measured for each subchannel, the worse the SINR, the more severe the collision may be. This may be a predetermined criterion used in the generation / conversion of the K-sparse signal described above. That is, it is determined whether or not a collision occurs based on RSSI and decoding, and K collisions are determined to occur in the order of a resource with a high RSSI (a resource with a severe collision).

Or a resource in which an important message is transmitted, or a resource having a higher priority, may be regarded as a resource in which a collision occurs more frequently or a resource in which a fast resource change is required. Successful decoding of the control information may be required for the receiving terminal to recognize that the priority is higher. If decoding of control information fails, other information can be used to derive resources that need to be changed quickly. For example, resources that collide in the same resource less than a certain period can be regarded as resources that need to be changed quickly. May be a predetermined criterion used in the generation / conversion of the K-sparse signal described above. That is, it is determined whether a collision occurs based on RSSI and decoding, and the UE can select K subchannels in which important messages are transmitted (or have high priority) among subchannels in which collisions occur.

On the other hand, if a K-sparse signal is generated / transformed from the result of the determination as to whether or not the collision is occurred, the UE may transmit the signal or may transmit the signal generated from the K-sparse signal. Here, the K-sparse signal is a vector including elements corresponding to all sub-channels, and the number of elements having non-zero coefficient values in the vector may be K signals. Alternatively, the K-sparse signal may be a representation of the N subchannels as a vector of length M by the sparsity K set by the network. This information is indicative of the relative resource situation from a particular terminal perspective.

After the K-sparse signal is generated / converted from the determination result of the collision, a signal obtained by sequentially multiplying the K-sparse signal by the conversion matrix and the measurement matrix (i.e., the signal generated from the K-sparse signal) have. This is for the terminal receiving this signal to recover the collision information for the entire subchannel using the compression sensing. Specifically, a signal as shown in the following Equation 12 is defined.

Where x is a scatter signal vector of length Nx1, A is an M * N sensing matrix, and M < N. In the above equation, the problem of determining x by y is the underdetermined system where the number of equations (M) is less than the number of variables (N), and the number of solutions is infinitely large. However, as described earlier, x is a K-sparse signal. Assuming that we can simply know the location of the values of K = M and nonzero x, we remove the matrix of A matrices corresponding to 0 from x

, a vector with a nonzero value removed from x

(12) can be written as &lt; RTI ID = 0.0 &gt;

Is M * M,

Can be obtained.

Here, the nature of the sensing matrix A plays an important role in restoring the original signal x from the acquired signal y. The following constants can be defined to check the nature of the sensing matrix.

here

Is the smallest constant among the constants satisfying the above inequality for all K-sparse signals x. These constants are called isometry constants.

Becomes closer to 0, the left and right terms of the two inequalities become close to each other. In this case, the sensing matrix is a very good sensing matrix that hardly loses information about the signal x. Especially, if M is small, it is a very good sensing matrix with good compression performance and without loss of original signal distortion.

If the matrix A satisfies the K-restricted isometry property (RIP) if it satisfies a certain positive integer K in equation (14). It is generally known that the original signal can be restored with a very high probability if the following condition is satisfied for a random sensing matrix A:

It can be seen that the number of samples, M, of the signal satisfying the expression (15) is not large when K is sufficiently small even if N is very large. In other words, it can be seen that M is determined by K. In the present invention, the design of the sensing matrix A is not discussed, and it is assumed that a good sensing matrix exists for specific information in advance.

In order to allow the second terminal to receive the signal of the first terminal and to recover the signal using the sensing matrix A, the first terminal transmits a signal K (k) obtained by successively multiplying the K-sparse signal -sparse signal). That is, as shown in the following equation (16), the K-sparse signal (x)

To obtain the scattering vector f.

It is assumed that the transformation matrix is known between the transceivers. Instead of directly transmitting and receiving the scatter signal, multiply f by the measurement matrix (metric matrix, M * N matrix). (17)

Suppose that we can obtain a signal that is much shorter than the signal f. The relationship between the acquired signal and the original signal is expressed by the following equation (18).

Therefore, the first terminal generates the signal (x) generated from the K-sparse signal

), And the second terminal can recover the original signal.

Similarly, the first terminal may receive the collision-related information of the second terminal from the second terminal, and may recover the collision information on the entire subchannel within the time window from the collision-related information of the second terminal. Therefore, the first terminal can perform resource selection based on the collision information for all the subchannels within the time window determined by the first terminal, and the collision information for all the subchannels within the time window determined by the second terminal. A signal generated from the K-sparse signal as described above,

To recover the K-sparse signal (x) from it, the K value, the matrix size, the transformation matrix

, Surveying matrix

, Information related to the entire subchannel on which the measurement is performed (for example, information on the time axis of the time window, the length of the time window, the position on the frequency axis, etc.) do. To this end, the base station or the second terminal may signal all or a portion of the described information to the first terminal.

The collision-related information may include at least one of an average value, a maximum value, and a minimum value of the measurement values in each sub-channel. That is, the average, maximum, and minimum of the mesaurement measured in the sub-channel indicated by K sparsity can be signaled together. As described later, the collision of each subchannel can be expressed as binary. In this case, it is considered that it is difficult to grasp the absolute state of each subchannel. With such a configuration, the transmitter can grasp to what degree the subchannel marked by the specific terminal is absolutely level. For example, if UEs indicate that subchannel X collides, UE A will determine that the channel condition is worse at the UE A point if the minimum measurement of the indicated subchannel is 10 and UE B has a measurement of 5. The UE simply reflects the maximum, average, or minimum value of the measurement transmitted by the individual UE, rather than determining whether to reselect the resource using the number of UEs that have indicated collision in a particular subchannel. For example, UE behavior can be determined on the basis of the sum of measurement values of 15 without determining the UE behavior as two UEs in the subchannel X simply indicating the collision in the previous embodiment.

On the other hand, in the above description, the subchannel in which a collision occurs is marked and transmitted. On the contrary, a binary bit can be used to broadcast which resource is (relatively) empty. For example, the terminal can broadcast all or some of the resources not excluded in the sensing process as binary bits. For example, 3GPP Rel. 14 In V2X Mode 4, the terminal reports 20% resources available (not excluded) to the upper layer through sensing. And a method of sharing this information with neighboring terminals can be considered. When the sensing information is shared with peripheral terminals, the terminal can perform resource selection considering both the result of sensing itself and the information sensed by the peripheral terminal.

The resource information related to the occurrence of the collision can be represented not only by binary but also by L states. For example, SINR can be quantized and mapped into L states. Or it may indicate the number of layers that are decoded and / or empty and / or collided if the terminal has multiple receive antennas.

The size of the time window may be predetermined or signaled by the network to the mobile station in the physical layer or higher layer signal at the base station or fixed node. The size of this window may be signaled separately for each carrier and / or resource area.

Information on the occurrence of the collision of the various schemes described above and the size of the time window can be signaled to the surrounding terminal in the physical layer or the upper layer signal in the whole or a part of the following information in a certain time window.

On the other hand, when a terminal uses a separate channel for transmitting data when transmitting status information / collision information of the resource, it may not be able to receive in the same subframe because it performs a new transmission. Therefore, in order to solve such a problem, the terminal can transmit this information at the same time as the data only when the terminal transmits the data. At this time, the physical layer channel to be transmitted may be a control signal channel, piggybacked to a data channel, or may be included in a data signal as an upper layer signal.

The feedback information transmitted by the UE may be information monitored before a certain point of time considering the processing time of the UE based on the subframe (SF N) in which the information is transmitted. For example, when feedback information and / or data are transmitted in the SF N, the feedback information may indicate a result of channel state monitoring at N-4 to N-4-W (where W is the size of the time window).

According to this method, since the feedback information is transmitted when the terminal transmits data, feedback timing for each terminal can be made asynchronous. In this case, the number of terminals monitoring feedback information in common may be variable, and there may be no terminal transmitting feedback information in a specific subframe.

In order to solve the problem of the above method, the UE proposes a method of aligning a period for monitoring feedback information. For example, a resource is divided into units of X ms, and a UE transmitting feedback information in the Nth SF may generate a rule for transmitting feedback information in the nearest X ms resource grid before the Nth.

On the other hand, if the terminal has several antenna pannels, this information can be signaled in the form of several sets. In the above-mentioned example, if the original signal of 400 bits is compressed to 60 bits, this information is transmitted for each pannel. In case of transmitting information about several pannels, 60 bits can be signaled in several sets. For example, for a terminal with two pannels, 2 set = 120 bits can be signaled. For example, in mmwave, collision resources can be different by direction (by antenna panel). At this time, this information is transmitted to a specific pannel which expresses each piece of information and compresses it individually.

If it is desired to transmit information of other pannels, the feedback information between the pannels may be compressed together or compression may be performed for each pannel.

Example  2

Hereinafter, a method of selecting a synchronization reference related to a side link synchronization signal (SLSS) when a plurality of component carriers (CC) are used for side link transmission and reception, and a method of transmitting and receiving an SLSS signal based on the method are described. In the following description, an anchor CC may mean a carrier capable of deriving a subframe boundary from the corresponding carrier. That is, an anchor CC means a synchronization reference carrier (or synchronization anchor carrier) among a plurality of CCs. In this case, not only the timing but also the frequency sync may be derived from the carrier, and the frequency sync may be derived from the sidelink signal received on an individual carrier. In the following description, a synchronization source is a device on which the side link UEs can acquire synchronization, such as a Global Navigation Satellite System (GNSS), an eNB / gNB, a UE, and the like. In addition, the following description is for the case of a plurality of constituent carriers, but the constituent carrier wave may be interpreted as a cell, a node, or the like. That is, the following description can be applied to a case where a plurality of cells exist and the priority is different for each cell.

The UE according to an embodiment of the present invention may select a synchronization reference among a plurality of synchronization sources (S1401) and transmit SLSS based on the selected synchronization reference (S1402). Wherein the synchronization reference may be selected from (all) synchronization sources on two or more CCs. That is, the synchronization source having the highest priority among the synchronization sources observed for each CC is selected as its synchronization reference. In other words, when more than one synchronization source is observed (monitored) for more than one CC, the synchronization reference is determined for all of the monitored synchronization sources at both CCs rather than for each CC. The UE may align the synchronization of the two or more CCs based on the selected synchronization reference. That is, if the UE selects a synchronization source in a specific CC, the other CC can continuously use the synchronization source to align the subframe boundary with the CC.

As mentioned briefly above, priority can be used when selecting a sync reference from multiple sync sources. Here, the priority indicates which of the eNBs and the GNSSs the UE should prioritize, and may be transmitted through upper layer signaling. The sync source priority for each CC must be the same, since the sync reference is selected from (all) sync sources on each CC. For this, the sync source priority and / or the priority between the GNSS / eNBs should be set so that the specific CC group is the same. To do this, the network can signal to the mobile station that a certain CC group has the same priority as the physical layer or higher layer signal. In this method, the highest priority synchronization source is selected so that high priority timing is commonly applied to other CCs so that a synchronization signal having a high priority is transmitted to peripheral terminals.

In summary, when the UE needs to (re) select a synchronization source, it monitors the synchronization sources of other CCs as well, selects the corresponding synchronization source if the highest priority is found among them, and matches the subframe boundary of all CCs to the corresponding synchronization source . If the synchronization source is selected for each CC separately, the different synchronization sources have different timing, so that the subframe / slot boundary may be shifted for each CC. In this case, the UE can not completely use the transmission power due to the subframe / slot boundary that is different from the CC in resource selection or transmission power allocation, or a case where a plurality of subframes / slots are influenced by another CC due to resource selection of some CC . Therefore, a method of selecting a common synchronization source is needed in order to align subframe / slot boundary between CCs. In this case, when different priority is observed, the timing of the highest priority can be selected, and the timing of the higher priority can be propagated to other CCs. In other words, aligning the subframe / slot boundary between the CCs according to the proposed method is preferable in terms of power efficiency when the UE performs the CA, or when the CCs transmit / receive signals, aligning the subframe / slot boundary for each CC .

As described above, when the UE selects the synchronization reference in one or more CCs and transmits the SLSS, the UE can transmit SLSS only in the CC in which the synchronization reference is selected. That is, SLSS / PSBCH transmission can be performed only on a carrier in which a high priority synchronization source is observed. When the UE selects GNSS or eNB as a synchronization source, the UE can select a specific carrier as a synchronization reference carrier among the sidelink synchronization reference carriers set by the network. If the UE does not select an eNB or GNSS The highest priority of the SLSS transmitted by the UE may be the observed / received / selected carrier. Thus, transmission power loss can be reduced by transmitting SLSS only on the CC selected for the synchronization source selection and the synchronization signal transmission (e.g., the carrier selected as the synchronization reference carrier or anchor). Specifically, if a terminal transmits SLSS / PSBCH to another carrier (on several carriers) at the same time, the terminal must distribute the transmission power to several carriers and also apply maximum power reduction (MPR) The transmission power is damaged. To prevent this, the SLSS / PSBCH can only transmit the SLSS / PSBCH on the carrier (the mobile station selects a synchronization reference carrier or an anchor carrier) only when the UE observes the highest priority synchronization source.

As another example, the UE may transmit SLSS in all CCs associated with the plurality of synchronization sources. That is, the UE can transmit SLSS in all CCs that have monitored the SLSS. In this case, it is possible to solve the problem of mutual synchronization which may occur in cases where the UEs have different synchronous reference carriers or when the UE's monitoring reference carriers are not included in other UE's synchronous reference carriers. More specifically, for example, when the terminal A transmits a synchronization signal only on a specific carrier (carrier X), if the other terminal (terminal B) selects a different carrier (carrier Y) as a sync reference, it is not possible to observe the signal, which may result in the problem of not being synchronized with each other. The terminal can solve this problem by transmitting all SLSS / PSBCH on the carrier that monitored the synchronization signal.

On the other hand, carriers that select the synchronization source can always transmit the synchronization signal (that is, the synchronization signal can always be determined to be transmitted from the carrier on which the synchronization source is selected). In this case, in a carrier other than the carrier selected as the synchronization source, the Tx capability of the UE is limited, so that transmission on all carriers may not be possible. In this case, the synchronization signal can be transmitted prior to the carrier transmitting the PSSCH / PSCCH. At this time, the synchronization signal can be determined to be transmitted from the N synchronization sources appearing before the actual transmission of the PSSCH / PSCCH. This is to ensure that the synchronization signal is transmitted N times before data transmission, so that the receiving terminal can prepare to receive the data signal with the correct synchronization signal. Where N may be predetermined or a value configured by the network.

On the other hand, if the Tx capability is extremely limited (for example, less than X Tx chains), and in this case, data or control signals are transmitted while switching several carriers, the synchronization source / The signal may not be transmitted. Especially, intraband CA has a limitation of the terminal operation because it can only transmit the synchronous signal from the adjacent carrier if the synchronous signal is always transmitted on the specific carrier. In this case, the rule that the SLSS / PSBCH is transmitted N times or more before the PSSCH / PSCCH transmission can be commonly applied to the carrier selected as the synchronous source / synchronous reference. Alternatively, a rule may be set to drop Y% sync signal transmissions on a carrier that has selected a sync source / sync reference, a candidate carrier that can be a sync reference carrier, or a carrier that is allowed to transmit a sync signal. Where Y is a rate value for an operation that allows dropping of a synchronization signal on each carrier, which can be set differently for each carrier. For example, a SLS / PSBCH dropping of Y1% may be allowed for a carrier selected for a synchronous source / synchronization reference, and a SLS / PSBCH dropping of Y2% may be allowed for other carriers. At this time, Y1, Y2 may be a predetermined value or a value signaled by the network. This method allows opportunistic dropping of the SLSS / PSBCH transmission on a specific carrier when the Tx capability of the UE is limited, but it makes the SLSS / PSBCH transmission drop less on a specific carrier, It is to keep stable. In this embodiment, the Y1 value may be set to be smaller than Y2 in order to protect the carrier selected by the synchronization source / synchronization reference from other carriers. If dropping of the synchronization signal is allowed for each carrier, the detailed dropping rule can be implemented according to the terminal implementation. For example, as mentioned above, a rule is set so that SLSS / PSBCH can not be dropped from N synchronous sources before a PSSCH / PSCCH transmission subframe or from a synchronization source appearing before J subframes. .

On the other hand, in the intraband CA, the terminal can simultaneously transmit signals on successive carriers. Otherwise, high MPR will not be able to fully utilize the transmitted power if the signal is transmitted on non-consecutive carriers. In this case, if it is assumed that the synchronous signal is always transmitted on the carrier selected as the synchronous source / synchronous reference, the terminal having the limited TX capability transmits SLSS / PSBCH only on the carrier adjacent to the synchronous reference carrier. Therefore, the rule of always transmitting a synchronous signal on a carrier selected as a synchronous source may cause inappropriate terminal operation in some cases. In this case, the UE may transmit a PSSCH / PSCCH and a carrier may fail to transmit a synchronization signal in the corresponding carrier. Therefore, in order to prevent such an operation, the operation of transmitting a synchronizing signal on a carrier selecting a synchronous source should be such that the network can configure according to the UE capability according to the situation. To do this, we propose a method of signaling whether the network should always transmit a synchronization signal on a carrier selected as a synchronization source.

In the case of Intraband CA, carriers set at both ends of a carrier monitoring the synchronization signal may be set not to select a synchronization reference / source. This is because, as mentioned above, if the user selects the synchronization source at the end carrier in the intraband CA, the carrier will transmit the synchronization signal only to the adjacent carrier. Therefore, it is possible to allow synchronous signal transmissions on multiple carriers by limiting the selection of the synchronous source / synchronous reference only in the possible intermediate carrier.

If all of the carriers monitoring the synchronization signal are all the same, the terminal may transmit the synchronization signal only to one of the carriers. This is because all the terminals are monitoring the synchronization signal of the corresponding carrier, so the terminal can transmit the synchronization signal only in a specific carrier. Therefore, a rule can be set to transmit a synchronous signal on at least one carrier among the carriers whose network is set to monitor the synchronous signal or set as the synchronous reference carrier. In this case, the synchronous signal can always be transmitted only on one carrier or can be transmitted on several carriers at the same time, which may determine the number of carriers according to the network configuration or the terminal itself transmits synchronous signals at the same time.

Meanwhile, when all of the carriers monitoring the synchronization signal are all the same, the UE can perform the synchronization selection by summing / averaging the measured values from several carriers when measuring the S-RSRP. In this case, when S-RSRPs can be summed, they can be limited to those having the same SLSS ID / PSBCH contents / PSSS / SSSS sequence. That is, since the mobile station selecting the same synchronous reference can transmit the synchronous signal on different carriers, the terminal adds and evaluates the synchronous signal measurement for the same SLSS ID / PSBCH contents.

When the SLSS / PSBCH resources of different positions are set in a plurality of carriers with respect to the transmission of the SLSS in all the CCs related to the plurality of synchronization sources, the UE sets a synchronization resource However, the synchronization signal resources of all other aggregated carriers must be excluded from the data transmission resource. If the location of the sync signal resource is the same for each CC, the number of excluded sync signal resources will be reduced. If the location of the resource is different for each CC, the number of sync signal resources excluded in data transmission will increase.

In order to transmit SLSS / PSBCH from all the carriers that have monitored the SLSS / PSBCH or a plurality of carriers (selected by the implementation of the terminal), the following operation can be considered.

First, the network sets the synchronization signal offset (sync signal resource position) to the same on a plurality of carriers, and the mobile station alternately transmits the SLSS / PSBCH on the carrier. If N carriers transmit SLSS / PSBCH, then N carriers are transmitted sequentially, i) sequentially, ii) according to a preset order, or iiii) SLSS / PSBCH alternately according to terminal implementation. In this method, the effective SLSS / PSBCH transmission period is increased for each carrier, but MPR can be avoided due to simultaneous transmission between CCs. For this operation a shorter period SLSS / PSBCH transmission period can be set by the network. This period may be predetermined by the network or may be selected by the terminal itself. Alternatively, this transmission period can be interlocked with the number of CCs selected by the UE for SLSS / PSBCH transmission. For example, a terminal that transmits SLSS / PSBCH on two carriers can set a synchronization transmission resource for each half of the existing SLSS / PSBCH transmission period. In this case, the period of transmission from the specific carrier is the same as the transmission period of the existing SLSS / PSBCH, but the period of the synchronization resource is shortened to half. If the UE needs to transmit SLSS / PSBCH on N carriers, the network sets the SLSS / PSBCH transmission period to a cycle shorter than N times, and the UE can transmit the SLSS / PSBCH alternately for each CC among the resources. In this case, the SLSS / PSBCH transmission period in each CC may be the same as the existing transmission period. The network can configure the maximum number of CCs to which the terminal transmits SLSS / PSBCH. Based on this, the synchronization signal cycle for each CC is set, and the actual SLSS / PSBCH transmission among these resources can occur alternately for each CC.

Secondly, the network intentionally sets the synch signal offset for each carrier differently, and the terminal can consider a method of transmitting the SLSS / PSBCH in a plurality of CCs. This method has the effect of not introducing a separate new SLSS / PSBCH transmission resource period although the half duplex problem in which transmission / reception can not be performed in another CC due to SLSS / PSBCH transmission in a plurality of CCs may be increased.

Third, the network establishes the same synch offset between CCs, but when the terminal transmits SLSS / PSBCH in a plurality of CCs, it proposes a method of transmitting SLSS / PSBCHs at longer CCs in each CC. For example, if the existing SLSS / PSBCH period is 160 ms, the transmission is performed every 320 ms when two CCs are transmitted. This method increases the transmission period in the CC so as to cause other terminals to lose the S-RSRP measurement value. However, since the MPR due to the simultaneous transmission does not need to be applied, the loss can be reduced. In addition, a new sync signal transmission period is not introduced, and the half duplex problem is the same. In this case, the order of transmitting the synchronization signal for each carrier may be predetermined or may be selected by the terminal itself or may be transmitted in a random order. Alternatively, the mobile station may transmit a synchronization signal in preference to a carrier to which data is transmitted, and may sequentially transmit the synchronization signal in a random order or a terminal implementation in the remaining carriers.

Fourth, the mobile station always transmits a SLSS / PSBCH on a carrier selected as a synchronization reference carrier, and an SLSS / PSBCH on an opportunistic carrier or a different transmission period. The UE can consider SLSS / PSBCH for each synch resource in the carrier selected by itself as a synch reference, and SLSS / PSBCH in a longer period in other carriers. This allows transmission over a longer period of time rather than not performing transmission on another carrier, allowing the other terminal to observe the synchronization signal when it seizes the signal opportunistically. If this method is generalized, the SLSS / PSBCH transmission period in the carrier selected by the UE as a synchronization reference carrier and the other carriers are set differently, and the period of each CC may be predetermined or signaled by the network .

If a PSCCH / PSSCH is transmitted on a carrier different from the anchor carrier, the UE can perform the following operations. And a method of excluding X subframes before transmission of the SLSS / PSBCH to transmit the synchronization signal (SLSS / PSBCH) from the PSCCH / PSSCH transmission. This is because Tx and / or Rx may not be possible if the Tx chain needs to be retuned for SLSS / PSBCH transmission. X may be a value determined in advance according to the capability of the UE or a value pre-configured by the network. In this case, since the period of resources excluded for transmission of the SLSS / PSBCH is equal to the transmission period of the SLSS / PSBCH (for example, 160 ms), when a resource is excluded from the sensing operation, We propose a method to perform resource exclusion operation.

Meanwhile, the network sets a plurality of anchor carriers, and the terminal can select a synchronization source having the highest priority among the anchors. If the same priority is observed for each carrier, the largest synchronization source and carrier can be selected by measuring the S-RSRP. In this case, the meaning of an anchor carrier may be a carrier that should search for SLSS or search for SLSS. The terminal can track / search the SLSS at the CC, which is instructed to search for the SLSS, and select the highest priority synchronization source.

Meanwhile, whether or not the UE actually transmits the SLSS / PSBCH in a specific CC deriving timing from the anchor carrier can be related to whether the UE transmits the PSCCH / PSSCH. For example, in a particular CC, the SLSS / PSBCH may be defined only once the network has allowed the SLSS / PSBCH transmission in the CC and / or the terminal performs the PSSCH / PSCCH transmission in the CC. In this case, when performing PSSCH / PSCCH transmission while switching several carriers in a limited Tx chain, it is possible to transmit SLSS / PSBCH to all carriers that perform PSCCH / PSSCH transmission, and SLSS / PSBCH can be transmitted only to carriers having high carrier priority Or SLSS / PSBCH transmission only on a carrier where a high priority synchronization source is observed.

As another example related to the selection of the synchronization reference, the CC to which the synchronization reference is to be selected may be predetermined in advance. That is, the subframe boundary of each CC is determined based on the observed synchronization source in the CC determined in advance. At this time, if no other sync signal is seen in the specified CC, we can observe the synchronous source in the lower priority CC and determine the subframe / slot boundary of each CC based on this. In general, if the synchronization source of a certain priority or higher is not visible in a certain CC, it can be expanded to a method of selecting a synchronization source in a subsequent CC. For this, priority for selecting a synchronization source for each CC, The minimum priority level of the synchronization source may be determined in advance, or may be signaled to the terminal by the physical layer or higher layer signal by the network. This method is to prevent synchronizing source selection of a specific CC even if the synchronization source of a high priority is not visible in a specific CC, thereby preventing unnecessary timing misalignment from occurring in another CC. If you do not see a high priority sync source in a particular CC and you see a better sync source in the other CC, then you should select the sync source for that CC.

As another example, in addition to or independently of the above method, when a UE receives a synchronization source of an LTE Release 15 (hereinafter, Rel. 15) UE and a synchronization source of an LTE Release 14 (Rel. 14) UE in a specific CC or a different CC If at the same time, and / or if the sync priority of the two UEs is the same, We propose a method to select the synchronization source of UE. For this purpose, there is an indicator to distinguish between Rel.14 and Rel.15 in the PSBCH (or Rel.15 UE may have an indicator indicating whether it is a Rel. 15 UE because Rel. 14 UE may change the PSBCH field configuration ), And / or you can set different sync resources for each release. For example, in CC # 0, Rel. 15 UE is visible and CC # 1 is Rel. 14 Rel. UE uses eNB as synchronization source. 14 When the UE is seen, Rel. 15 &lt; / RTI &gt; 14 Prioritize the synchronization source of the UE to select the synchronization source.

When two or more synchronization sources have the same priority in the selection of the synchronization reference, a synchronization source having a high signal strength can be selected. If multiple CCs show the same synchronization source priority, you can choose a higher S-RSRP measurement. Or you can choose a synchronous source of CC with a low carrier frequency. The reason for choosing the synchronization source when the carrier frequency is low is that the lower the carrier frequency, the farther it can propagate. In this case, the synchronization cluster can include more UEs. Or if the same sync source priority is shown, the priority by CC may be predefined or indicated by the network. Or an S-RSRP offset per carrier (which may be indicated or predefined by the network) to apply the offset to the S-RSRP measurement measured by the UE and then perform the final selection. Or if the same synchronization source priority is seen in different CCs, then the final selection may be selected randomly or by implementation of the terminal. It is not necessary to always select a synchronization source with the highest priority even when the priority of the synchronization source is different, but to select a synchronization source of the carrier having a certain quality difference (S-RSRP) Can be determined. Or, the order of the carriers to be preferentially selected, the priority between the carriers is predetermined, or the minimum S-RSRP measurement requirement per carrier / sync priority is predetermined or can be indicated by the network.

Meanwhile, the CC selected by the synchronization reference may be determined as a synchronization reference CC. Or, Rel. 15 From the UE perspective, Rel. 14 A carrier with UE may be considered as a synchronization anchor carrier. 14 UE is set as the carrier, and the remaining carriers are set as Rel. 14 If there is no UE, Rel. 15 UE can transmit / receive a synchronization signal only on an anchor carrier. To do this, 14 A carrier that is expected to have a UE can be set as a synchronization anchor carrier.

On the other hand, when an anchor carrier is set and a carrier having the same timing as an anchor carrier is set as a group, the DFD (D2D frame number or sidelink frame number) offset of each group must be set the same so that the final subframe boundary becomes the same. Therefore, the network proposes a method of setting the DFN offset equal to this carrier group (signaling can be performed separately for each CC), and signaling only one DFN offset per carrier group.

Hereinafter, a description will be given of a method in which a plurality of synchronization anchor carriers are set so that they can be used together with the above description or independently. This is because i) Rel. 14 UE can support up to 2 CCs, in this case Rel. 15 When there are multiple synchronization anchor carriers from UE point of view, ii) Rel. 14 The number of synchronization anchor carriers, regardless of UE, depends on the configuration of the network, and iii) the number of anchor carriers is predefined in conjunction with a band combination.

The network proposes a method of setting a plurality of synchronization anchor carriers and signaling the synchronization anchor carriers to the mobile station using a physical layer or an upper layer signal. The plurality of synchronization anchor carriers may be predetermined or may be set in the application layer of the UE.

The terminal may operate a plurality of anchor carriers. The terminal monitors sync at multiple anchor CCs and selects a synchronization source with higher priority among them. Alternatively, multiple anchor CCs can be operated at the same time. For example, a carrier group with different timing can be created, and a separate anchor for each group can be used to perform a synchronous source selection operation separately on an anchor carrier.

Anchor carriers can be set differently for each carrier or resource pool. For example, a specific group carrier can use CC #X as an anchor carrier, and another group carrier can set CC #Y as an anchor carrier.

How many anchor carriers can be set up by the terminal may vary depending on the capability of the terminal. For example, a plurality of anchor carriers may be used for a UE implementing a plurality of synchronization signal detectors, but a UE implementing a single synchronization signal detector may operate a single anchor carrier. The number or capability of anchor carriers may be called different types, for example, the ability to track synchronization signals independently at different timings, the ability to transmit or receive SLSS / PSBCH simultaneously or independently in different CCs , The ability to search for, transmit, or receive SLSS / PSBCHs simultaneously in different CCs, and so on. At this time, the capability of the anchor carrier and the SLSS / PSBCH searching capability may be given to the terminal separately from the capability of the CC that the terminal can simultaneously transmit or receive. This is because the number of transmission or reception chains of data, the number of synchronization signal detectors, and the number of synchronization signal transmitters may be implemented differently or separately.

If the maximum number of anchor carriers set by the network is different from the capability of the UE, the network can indicate in advance which order the anchor carrier should be used. For example, when four anchor carriers are assigned, the terminal can set up an anchor carrier with an anchor carrier sequence with low carrier frequency if the terminal capability is capable of tracking two asynchronous SLSS / PSBCHs. Or this sequence may be left to the implementation of the terminal. Alternatively, an anchor carrier can be set as a carrier showing a high-priority synchronization source, or an S-RSRP measurement can be set as an anchor carrier when the same priority is seen. Alternatively, when the priority of the carrier is predetermined, SLSS / PSBCH tracking can be performed by giving priority to the carrier of high priority.

In other words, in the anchor carrier set by the network, the number of carriers that can be monitored according to the capability or implementation of the terminal can be limited, and the terminal can monitor only a part of an anchor carrier and select a synchronization reference carrier. At this time, the carrier that the terminal partially monitors is called an anchor carrier subset. As mentioned above, since the priority order of the network to be monitored in an anchor carrier should be prioritized, a subset may be determined, and it may be determined by a carrier that the terminal simultaneously transmits or receives a PSSCH / PSCCH (data / control signal) Or may be determined according to the implementation of the terminal or may be determined according to the SLSS / PSBCH reception / transmission capability of the terminal. The UE can select a synchronization anchor carrier within this anchor carrier subset.

Meanwhile, when the terminal selects a synchronous source in a specific CC, it must decide which SLSS / PSBCH is transmitted from the CC and the other CC. The following methods can be considered.

First, the terminal transmits SLSS / PSBCH only in the CC that the network instructs to transmit SLSS / PSBCH or in the preconfigured CC. If there is any CC in Rel. 14 UE if there is no UE.

Alternatively, when the UE selects a synchronization source in a specific CC, it transmits a sync signal and a PSBCH corresponding to the lower priority of the synchronization source selected in the other CC. At this time, the sync signal offset indicator can follow the setting of each CC or follow the setting of the selected CC. This method is to maintain the existing operation as much as possible without changing the existing sync signal priority. The difference from the existing operation is that the subframe boundary is set based on the synchronization source selected in the other CC, and the SLSS / PSBCH is transmitted in the other CC by reflecting the same.

Alternatively, when the UE selects a synchronization source from a specific CC, it proposes a method of transmitting a sync signal and a PSBCH corresponding to the same priority as the synchronization source selected by another CC. For example, when the network has configured two sync resources and the GNSS is selected as the synchronization source in CC # 0, the existing terminal uses SLSS ID 0, Incoverage indicator = 1 and the terminal selected as the synchronization source SLSS ID 0, and Incoverage indicator = 0. This terminal proposes a method of using incoverage indicator = 1 instead of incoverage indicator = 0 when transmitting a synchronization source in another CC. At this time, the SLSS ID used by the terminal may use ID = 0 or a separate ID may be used. The reason for using a separate ID is to eliminate ambiguity with the terminal that directly selected GNSS as a synchronization source. However, since it is derived from the same timing anyway, there may not be a big problem, and you can use ID = 0 in that case. At this time, if the ID is not 0, it may be the ID selected by the terminal, set in advance, or set by the network. For this purpose, the sync resource offset indicator should be set differently for each CC. This operation is not applied to the top priority, and may be selectively applied only to the terminals that have selected the SLSS / PSBCH transmitted by the terminal as the synchronization source. For example, a terminal that has selected GNSS as the direct synchronization source transmits the SLSS / PSBCH when the other CC selects GNSS as the synchronization source. If a terminal selects the SLSS / PSBCH to be transmitted by the terminal selected as the synchronization source, it transmits the sync signal to the other CC. 15 UEs prioritize the synchronization sources selected on the anchor carrier. In this method, the synchronization source selection in the synchronization anchor carrier is shown as a higher priority in the other carrier. 14 UEs naturally receive Rel. 15 UE synchronization source.

Alternatively, the UE can signal to the neighboring UE whether the timing is derived based on a CC on the PSBCH. In this case, rel. 14 UE and rel. 15 The UE may not be able to make the sync signal SFN due to the PSBCH difference. To this end, the network can set different sync resources per release. Or the network is configured to allow Rel. 14 The reserved bits of the UE can be set to indicate an anchor carrier.

Meanwhile, let us consider again the method of setting the sync resource for each CC differently. For some reason, CC-based synch resources can be set to the same network. Especially in the intraband CA, it may be impossible to receive signals from other subframes by transmitting synchronous signals in a specific CC. In this case, subframes of other CCs overlapping with the sync subframes of each CC can not be sensed (or received) and thus transmission may not be performed. In order to solve this problem, the network can align the sync resource in the group CC. In this case, the transmission power of the sync signal is lowered in each CC, and the sync coverage may be reduced. To solve this problem, the following method can be considered.

If the sync resource is aligned between the CCs, we propose a method of setting the sync signal / PSBCH transmit power for each CC differently. For example, in a specific CC, the transmission power is increased to prevent the sync coverage in the CC from being excessively reduced. For example, Rel. The CC or synchronization anchor CC, which is expected to have 14 UEs, can set a higher SLSS / PSBCH transmit power. For this purpose, the network can signal to the MS information on how much SLSS / PSBCH transmission power should be set to which CC by the physical layer or higher layer signal. This information can be represented as an offset. These settings can be preconfigured.

If the network sets the same sync resource between the CCs, the receiving terminal can (re) select the synchronization source based on the sum of the CC measurements, the maximum / minimum / averages when performing the S-RSRP measurement have. Assuming that the same sync signal is transmitted in multiple CCs, the effective sync coverage is increased by combining the measurements.

The above description is not limited to direct communication between terminals but can also be used in uplink or downlink. In this case, a base station or a relay node can use the above-described method.

It is obvious that examples of the proposed method described above can also be included as one of the implementing methods of the present invention, and thus can be considered as a kind of proposed methods. In addition, the proposed schemes described above may be implemented independently, but may be implemented in a combination (or merging) of some of the proposed schemes. The information on whether or not the proposed methods are applied (or information on the rules of the proposed methods) is transmitted to the base station by notifying the terminal through a predefined signal (for example, a physical layer signal or an upper layer signal) A rule can be defined such that the receiving terminal signals to the terminal or requests the transmitting terminal.

The In the embodiment  Device configuration by

16 is a block diagram of wireless communication devices in accordance with an embodiment of the present invention.

Referring to FIG. 16, a wireless communication system may include a base station 2210 and a UE 2220. UE 2220 may be located within the coverage of the base station. In some embodiments, the wireless communication system may comprise a plurality of UEs. Referring to FIG. 16, a base station 2210 and a UE 2220 are illustrated, but the present invention is not limited thereto. For example, the base station 2210 may be replaced with a network node, a UE, a wireless device, and the like. Alternatively, each of the base station and the UE may be represented as a wireless communication device or a wireless device.

The UE 2220 may include at least one processor 2221, at least one memory 2222, and at least one transceiver 2223. The processor 2211 may process the necessary items in each embodiment to implement the functions, procedures, or methods described in the above-described embodiments. One or more protocols may be implemented by processor 2221. [ For example, the processor 2221 may implement one or more layers (e.g., functional layers) of the air interface protocol. Memory 2222 is coupled to processor 2221 and stores various types of information and / or instructions. The transceiver 2223 is electrically coupled to the processor 2221 and may be controlled by the processor 2221 to transmit and / or receive wireless signals.

Specifically, the processor 2221 may be configured to determine a collision on a sub-channel basis within a time window and to transmit collision-related information related to the determination result. The collision-related information may include a signal generated from a K-sparse signal in which the number of subchannels determined to have collided among all the subchannels in the time window is limited to K.

In addition, base station 2210 may include at least one processor 2211, at least one memory 2212, and at least one transceiver 2213. The processor 2211 may process the necessary items in each embodiment to implement the functions, procedures, or methods described in the above-described embodiments.

On the other hand, one or more protocols may be implemented by processor 2211. For example, the processor 2211 may implement one or more layers (e.g., functional layers) of the air interface protocol. The memory 2212 is coupled to the processor 2211 and stores various types of information and / or instructions. The transceiver 2213 is electrically coupled to the processor 2211 and may be controlled by the processor 2211 to transmit and / or receive wireless signals.

Memory 2212 and / or 2222, on the other hand, may be located within processors 2211 and / or 2221, respectively, and may be coupled to the processor via various technologies, such as wired or wireless connections.

The base station 2210 and / or the UE 2220 may have a single antenna or multiple antennas. For example, antennas 2214 and / or 2224 may be configured to transmit and receive wireless signals.

17 is a view schematically showing a wireless communication apparatus according to an embodiment of the present invention.

Referring to FIG. 17, the UE 2220 shown in FIG. 16 is described in detail. 17 is not limited to UE 2220, but may be a mobile computing device configured to be adapted to one or more implementations of the above-described embodiments. For example, the mobile computing device may include a vehicle communication system and / or device, a wearable device, a laptop or a smart phone, and the like.

17, the UE 2220 includes a processor 2210, a transceiver 2335, a power management module 2305, an antenna 2340, a battery 2355, a digital signal processor (DSP) At least one of a keypad 2320, a GPS (global positioning system) chip 2360, a sensor 2365, a memory 2330, a subscriber identity module (SIM) card 2325, a speaker 2345, and a microphone 2350 . UE 2220 may also include a single antenna or multiple antennas.

The processor 2310 may process the necessary information in each embodiment to implement the functions, procedures, or methods described in the above-described embodiments. In some embodiments, the processor 2310 may implement one or more protocols, such as a layer of a radio interface protocol (e.g., a functional layer).

Memory 2330 may be coupled to processor 2310 and may store information related to the operation of processor 2310. [ The memory 2330 may be located inside or outside the processor 2310 and may be coupled to the processor via various techniques, such as a wired or wireless connection.

The user can input various types of information (for example, instruction information such as a telephone number) through various techniques such as pressing a button on the keypad 2320 or voice recognition or activation using the microphone 2350 have. Processor 2310 may perform appropriate functions such as receiving and processing information of a user and dialing a telephone number. In some embodiments, data (e.g., operational data) may be loaded from SIM card 2325 or memory 2330 to perform a particular function (s). In some embodiments, processor 2310 may receive and process GPS information from GPS chip 2360 to perform functions (e.g., vehicle navigation, map service, etc.) associated with the location or location of the same UE. In one embodiment, the processor 2310 may display such various types of information and data on the display 2315 for user's reference and convenience.

The transceiver 2335 may be coupled to the processor 2310 to transmit and / or receive a radio signal such as a radio frequency (RF) signal. Processor 2310 may control transceiver 2335 to initiate communications and transmit wireless signals including various types of information or data, such as voice communication data. The transceiver 2335 includes a transmitter that receives and transmits a radio signal. The antenna 2340 is a device necessary for smoothly transmitting and receiving a radio signal. In some embodiments, when the transceiver 2335 receives a radio signal, the transceiver 2335 may convert and forward the received radio signal to a baseband frequency for processing by the processor 2310 convert and forward (the transceiver 2335 may forward and convert the signals to baseband frequency for processing by the processor 2310). The processed signal may be processed according to various techniques, such as converting it into audible or readable information to be output via speaker 2345 and / or display 2315.

In one embodiment, the sensor 2365 may be coupled to the processor 2310. Sensor 2365 may include one or more sensing devices configured to detect various types of information, such as velocity, acceleration, light, vibration, proximity, location, image, and the like. The processor 2310 receives and processes the sensor information obtained from the sensor 2365, and can perform various types of functions such as collision avoidance, autonomous travel, etc. based on the received sensor information.

Alternatively, as shown in FIG. 17, the UE may additionally include various components (e.g., a camera, a USB port, etc.). For example, the camera may be further connected to the processor 2310 and may be used for various services such as autonomous navigation, vehicle safety services, and the like. 17 is one embodiment of the UE, and the scope of the present invention is not limited to the configuration shown in FIG. For example, some configurations of keypad 2320, Global Positioning System (GPS) chip 2360, sensor 2365, speaker 2345 and / or microphone 2350 are not included in the UE for some embodiments It may not be implemented.

18 is a block diagram briefly showing a transceiver of a wireless communication apparatus according to an embodiment.

In particular, the transceiver shown in FIG. 18 may be a transceiver according to an example that may be implemented in a frequency division duplex (FDD) system.

In the transmit path, at least one processor, such as the processor described in FIGS. 16 and 17, can process the data to be transmitted and provide a signal, such as an analog output signal, to the transmitter 2410.

The analog output signal at the transmitter 2410 is filtered by a low pass filter (LPF) 2411 (e.g., to remove artifacts generated by a conventional digital-to-analog conversion (ADC) Upconverted from baseband to RF by an upconverter (e.g., mixer) 2412 and amplified by a variable gain amplifier (VGA) The amplified signal is filtered by a filter 2414, further amplified by a power amplifier (PA) 2415 and routed through a duplexer 2450 / antenna switch 2460 to an antenna 2470 ). &Lt; / RTI &gt;

In the receive path, antenna 2470 receives a signal from the radio environment and the received signal may be routed through antenna switch 2460 / duplexer 2450 and provided to receiver 2420.

For example, the signal received at the receiver 2420 is amplified by an amplifier comprising a low noise amplifier (LNA) 2423, filtered by a bandpass filter 2424, downconverted by a downconverter 2425, For example, from a mixer, RF to baseband.

The down-converted signal is filtered by a low-pass filter (LPF) 2426 and amplified by an amplifier including a VGA 2427 to obtain an analog input signal, which is provided to the processor described in Figures 16 and 17 do.

In addition, a local oscillator (LO) generator 2440 generates and provides transmit and receive LO signals to an upconverter 2412 and a downconverter 2425, respectively.

The present invention is not limited to the configuration shown in FIG. 18, and various components and circuits may be arranged differently from the example shown in FIG. 18 for the functions and effects according to the embodiments of the present invention.

19 shows another example of a transceiver of a wireless communication apparatus according to an embodiment of the present invention.

In particular, Figure 19 illustrates an example of a transceiver that may be implemented in a Time Division Duplex (TDD) system.

In some embodiments, the transmitter 2510 and the receiver 2520 included in the transceiver of the TDD system may include one or more similar features with the transmitter and receiver included in the transceiver of the FDD system. The structure of the transceiver of the TDD system will be described below.

In the transmit path, the signal amplified by the transmitter power amplifier (PA) 2515 is routed through band select switch 2550, band pass filter (BPF) 2560 and antenna switch 2570, And transmitted via an antenna 2580. [

In the receive path, antenna 2580 receives a signal from the radio environment and the received signal is routed through antenna switch (s) 2570, band pass filter (BPF) 2560 and band select switch 2550 and provided to a receiver 2520. [

20 is a flowchart for explaining the operation of the wireless device related to the side link.

Referring to FIG. 20, the wireless device may obtain information related to the side link (S2910). The information associated with the side link may be at least one resource configuration (s) and may be obtained from another wireless device or network node.

After obtaining the information, the wireless device may decode information related to the side link (S2920).

After decoding the information about the side link, the wireless device performs one or more side link operations based on the information about the side link (S2930). Here, the sidelink operation (s) performed by the wireless device may be one or more of the operations shown in the flowcharts.

Meanwhile, the flow chart shown in Fig. 20 is only an example of the operation of the wireless device associated with the side link, and the side link operation using various techniques can be performed by the wireless device. The side link may be an interface between the UEs for side link communication and / or side link discovery. The side link may correspond to the PC5 interface. The side link operation may be in the broad sense the transmission and / or reception of information between UEs.

21 is a flowchart for explaining a network node operation related to a side link.

The network node operation associated with the side link disclosed in FIG. 21 is not an example, and the side link operation using various techniques can be performed by the network node.

The network node may receive information related to the side link from the wireless device (S3010). For example, the information associated with a side link may be a 'SidelinkUEInformation' used to display side link information for a network node

After receiving the information, the network node determines whether to transmit one or more instructions related to the side link based on the received information (S3020).

If it is determined to transmit the command, the network node transmits a command related to the side link to the wireless device based on the command decided to transmit (S3030). In one example, a wireless device receiving an instruction transmitted by a network node may perform one or more side link operation (s) based on the received instruction.

22 is a block diagram briefly showing a configuration of a wireless device and a network node. Here, the network node 3120 may be replaced with the radio device or the UE shown in Fig.

For example, the wireless device 3110 may include a communication interface 3111 for communicating with one or more other wireless devices, network nodes, and / or other elements of the network. The communication interface 3111 may include one or more transmitters, one or more receivers, and / or one or more communication interfaces. In addition, the wireless device 3110 may include a processing circuit 3112. Processing circuitry 3112 may include at least one processor, such as processor 3113, and at least one memory device, such as memory 3114. [

The processing circuitry 3112 may control any one or more of the methods and / or processes described above, and such methods and / or processes may be performed by the wireless device 3110. [ The processor 3113 may correspond to one or more processors for performing the functions of the wireless device described herein. In addition, the wireless device 3110 includes a memory 3114 configured to store data, programmable software code, and / or other information described herein.

In one or more embodiments, the memory 3114 may include software code 3115, including some or all of the processes described with reference to Figure 20 by at least one processor, or instructions that cause embodiments of the methods described above to be executed Or &lt; / RTI &gt;

For example, at least one process associated with the transmission or reception of information may be performed by processor 3113 controlling transceiver 2223 of FIG. 21 to transmit or receive information.

Network node 3120 may include at least one of: one or more other network nodes, wireless devices, and a communications interface 3121 for communicating with other elements of the network. Here, the communication interface 3121 includes at least one transmitter, at least one receiver, and / or at least one communication interface. In addition, the network node 3120 may include a processing circuit 3122. Here, the processing circuitry may include a processor 3123 and a memory 3124.

For example, at least one process associated with the transmission or reception of information may be performed by processor 3123 controlling transceiver 2213 shown in FIG. 17 to transmit or receive information.

The above-described embodiments of the present invention can be implemented by various means. For example, embodiments of the present invention may be implemented by hardware, firmware, software, or a combination thereof.

In the case of hardware implementation, the method according to embodiments of the present invention may be implemented in one or more Application Specific Integrated Circuits (ASICs), Digital Signal Processors (DSPs), Digital Signal Processing Devices (DSPDs), Programmable Logic Devices (PLDs) , FPGAs (Field Programmable Gate Arrays), processors, controllers, microcontrollers, microprocessors, and the like.

In the case of firmware or software implementation, the method according to embodiments of the present invention may be implemented in the form of an apparatus, a procedure, or a function for performing the functions or operations described above. The software code can be stored in a memory unit and driven by the processor. The memory unit may be located inside or outside the processor, and may exchange data with the processor by various well-known means.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The foregoing description of the preferred embodiments of the invention disclosed herein has been presented to enable any person skilled in the art to make and use the present invention. While the present invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. For example, those skilled in the art can utilize each of the configurations described in the above-described embodiments in a manner of mutually combining them. Accordingly, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

The present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. Accordingly, the above description should not be construed in a limiting sense in all respects and should be considered illustrative. The scope of the present invention should be determined by rational interpretation of the appended claims, and all changes within the scope of equivalents of the present invention are included in the scope of the present invention. The present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein. In addition, claims that do not have an explicit citation in the claims may be combined to form an embodiment or be included in a new claim by amendment after the filing.

The embodiments of the present invention as described above can be applied to various mobile communication systems.

Claims (15)

1. A method for a first terminal transmitting and receiving a sidelink signal in a wireless communication system,

   Determining whether the first terminal collides with each sub-channel within a time window; And

   Transmitting, by the first terminal, the collision-related information related to the determination result;

   / RTI &gt;

   The collision-related information includes a signal generated from a K-sparse signal,

   Wherein the K-sparse signal is a signal in which the number of subchannels determined to have collided among all the subchannels in the time window is limited to K.
2. The method according to claim 1,

   K is common to the first terminal and the terminals receiving the collision-related information, and K is a value smaller than the number (N) of all sub-channels in the time window.
3. The method according to claim 1,

   Wherein the collision-related information includes at least one of an average value, a maximum value, and a minimum value of the measured values in each subchannel.
4. The method according to claim 1,

   Wherein the first terminal receives the collision-related information of the second terminal from the second terminal, and restores the collision information on the entire subchannel within the time window from the collision-related information of the second terminal, Way.
5. The method according to claim 1,

   The first terminal performs resource selection based on the collision information for all subchannels in the time window determined by the first terminal and the collision information for all subchannels in the time window determined by the second terminal And a side link signal transmission / reception method.
6. The method according to claim 1,

   Wherein the K-sparse signal is a vector including an element corresponding to each subchannel, and the number of elements having non-zero coefficient values in the vector is K.
7. The method according to claim 6,

   Wherein the signal generated from the K-sparse signal is obtained by sequentially multiplying the K-sparse signal by a conversion matrix and a measurement matrix.
8. The method according to claim 1,

   Wherein the transformation matrix is common to the first terminal and the terminals receiving the collision-related information.
9. The method according to claim 1,

   Wherein the size of the time window is one that has been received by the first terminal through a preset or higher layer / physical layer signaling.
10. The method according to claim 1,

    Wherein the first terminal determines that a collision has occurred in the subchannel if the RSSI of the subchannel is equal to or greater than a predetermined threshold and the decoding of the subchannel fails.
11. 11. The method of claim 10,

    Wherein the first terminal generates a K-sparse signal by selecting K sub-channels from a sub-channel having a large RSSI.
12. The method according to claim 1,

    Wherein the first terminal generates a K-sparse signal by selecting K sub-channels to which an important message is transmitted among sub-channels in which a collision occurs.
13. The method according to claim 1,

    Wherein the first terminal generates a K-sparse signal by selecting K sub-channels having a higher priority among sub-channels in which a collision has occurred.
14. The method according to claim 1,

    Wherein the collision-related information is generated and transmitted for each antenna panel of the terminal.
15. A first terminal apparatus for transmitting a sidelink signal in a wireless communication system,

    Memory; And

    A processor coupled to the memory,

    The processor determines whether a collision is generated for each subchannel within a time window, transmits collision-related information related to the determination result,

    The collision-related information includes a signal generated from a K-sparse signal,

    Wherein the K-sparse signal is limited to K subchannels in which it is determined that all the subchannels in the time window have collided.

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