WO2018062893A1 - Method and device for configuring synchronization signal for new radio access technology - Google Patents

Abstract

Embodiments of the present invention relate to a method and a device for configuring and transmitting a synchronization signal in an NR system, the method and the device being capable of configuring and transmitting a synchronization signal, which is configurable for a bandwidth part excluding the bandwidth part in which the synchronization signal is fundamentally transmitted, in one or more bandwidth parts formed by dividing the whole bandwidth of an NR system into one or more bandwidths. Therefore, performance improvement of a synchronization signal and efficient synchronization acquisition of a terminal can be supported in a flexible frame structure of an NR system.

Description

Method and apparatus for setting synchronization signal for new wireless access technology

Embodiments of the present invention relate to a method for establishing and transmitting a new synchronization signal for a new wireless communication system.

3GPP recently approved a study item "Study on New Radio Access Technology" for the study of next generation / 5G radio access technology, and based on this, RAN WG1 has frame structure, channel coding and modulation for NR (New Radio) respectively. Discussions on waveforms and multiple access schemes are underway.

NR is required to be designed to meet various requirements required for each segmented and detailed usage scenario as well as improved data rate compared to LTE / LTE-Advanced.

For example, enhancement mobile broadband (eMBB), massive MTC (MMTC), and ultra reliable and low latency communication (URLLC) are exemplified as typical usage scenarios of NR, and LTE / Ul as a method to satisfy requirements according to each usage scenario. There is a need for a flexible frame structure design compared to LTE-Advanced.

Each of these usage scenarios differs from each other in terms of data rate, latency, coverage, and so on, so that different neural (eg subcarrier spacing, subframe, TTI, etc.) based radios can be used to efficiently meet each requirement. There is a need for a method of efficiently multiplexing resource units.

Meanwhile, the wireless communication system needs to go through a cell search process in order for a terminal to access a cell. The cell search process is composed of a series of synchronization processes in which the UE can determine time / frequency parameters. The synchronization process enables the UE to demodulate the downlink signal and transmit the uplink signal at an appropriate time.

The cell search process of the conventional LTE / LTE-Advanced system includes Initial Synchronization and New Cell Identification. In the previous step of the cell search process, the terminal detects a synchronization signal transmitted from the base station.

The cell search process and synchronization signal detection are necessary processes for the UE to access the wireless communication system, but since the NR is designed to have a flexible frame structure compared to the LTE / LTE-Advanced system, the cell search process and the synchronization signal detection for the NR system are performed. There is a need for a new method of setting and transmitting a synchronization signal to perform the operation.

An object of the embodiments of the present invention is to provide a method for setting and transmitting a synchronization signal in an NR system, and a specific method for setting and transmitting a synchronization signal in a flexible frame structure of the NR system.

In one aspect, embodiments of the present invention provide a method for establishing a synchronization signal for a new wireless access technology, comprising: setting one or more synchronization signals to be transmitted within a full bandwidth, and transmitting one or more set synchronization signals through the full bandwidth It provides a method comprising the steps of.

In another aspect, embodiments of the present invention provide a method of establishing a synchronization signal for a new radio access technology, the method comprising: receiving one or more synchronization signals transmitted within the entire bandwidth, and using the received one or more synchronization signals to time It provides a method comprising the step of performing a frequency synchronization.

In another aspect, embodiments of the present invention provide a base station including a control unit for setting one or more synchronization signals to be transmitted within the entire bandwidth, and a transmitter for transmitting one or more set synchronization signals over the entire bandwidth.

In another aspect, embodiments of the present invention, in a terminal for receiving a synchronization signal for a new radio access technology, using a receiving unit for receiving one or more synchronization signals transmitted within the entire bandwidth, and using the received one or more synchronization signals It provides a terminal including a control unit for performing the synchronization of time and frequency.

According to embodiments of the present invention, there is provided a method for setting and transmitting a new synchronization signal suitable for a frame structure of an NR system, thereby supporting performance improvement of the synchronization signal and efficient acquisition of a terminal.

1 is a diagram illustrating information obtained at each step of a cell search process for accessing a wireless communication system.

2 is a diagram illustrating a frame structure of a main synchronization signal PSS and a floating signal SSS in FDD.

3 is a diagram illustrating a frame structure of a main synchronization signal PSS and a floating signal SSS in TDD.

FIG. 4 is a diagram illustrating a frame structure of a main synchronization signal PSS and a floating signal SSS in a frequency-time domain in an FDD cell.

5 is a diagram illustrating floating sequence signal (SSS) sequence mapping.

FIG. 6 is a diagram illustrating a resource block structure in TDM-based mixed numerology.

7 is a conceptual diagram of sequence correlation for deriving frequency offset using CRS port 0.

FIG. 8 is a diagram illustrating a concept of a configurable sync signal (FDM case) that can be set in a reference polymer band (FDM Case).

9 is a diagram illustrating the concept of synchronization signal alignment between different NR neurology (FDM Case).

10 and 11 illustrate an example of a process of a synchronization signal setting method for a new radio access technology according to embodiments of the present invention.

12 and 13 illustrate another example of a process of a synchronization signal setting method for a new radio access technology according to embodiments of the present invention.

14 illustrates a configuration of a base station according to embodiments of the present invention.

15 illustrates a configuration of a user terminal according to embodiments of the present invention.

Hereinafter, some embodiments of the present invention will be described in detail through exemplary drawings. In adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are assigned to the same components as much as possible even though they are shown in different drawings. In addition, in describing the present invention, when it is determined that the detailed description of the related well-known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

A base station or cell generally refers to a station that communicates with a user terminal, and includes a Node-B, an evolved Node-B, an eNB, a gNode-B, and a Low Power Node. ), Sector, site, various types of antennas, base transceiver system (BTS), access point, access point (for example, transmission point, reception point, transmission / reception point), relay node ( It is meant to encompass various coverage areas such as a relay node, a mega cell, a macro cell, a micro cell, a pico cell, a femto cell, a remote radio head (RRH), a radio unit (RU), and a small cell.

Since the various cells listed above have a base station for controlling each cell, the base station may be interpreted in two meanings. 1) the device providing the mega cell, the macro cell, the micro cell, the pico cell, the femto cell, the small cell in relation to the wireless area, or 2) the wireless area itself. In 1) all devices that provide a given radio area are controlled by the same entity or interact with each other to cooperatively configure the radio area to the base station. According to the configuration of the wireless area, a point, a transmission point, a transmission point, a reception point, and the like become one embodiment of a base station. In 2), the base station may indicate the radio area itself that receives or transmits a signal from the viewpoint of the user terminal or the position of a neighboring base station.

In the present specification, a cell refers to a component carrier having a coverage of a signal transmitted from a transmission / reception point or a signal transmitted from a transmission point or a transmission / reception point, and the transmission / reception point itself. Can be.

In the present specification, the user terminal and the base station are used in a comprehensive sense as two entities (uplink or downlink) transmitting and receiving subjects used to implement the technology or technical idea described in the present invention, and are not limited by the terms or words specifically referred to. Do not.

Here, the uplink (Uplink, UL, or uplink) refers to a method for transmitting and receiving data to the base station by the user terminal, the downlink (Downlink, DL, or downlink) means to transmit and receive data to the user terminal by the base station It means the way.

The uplink transmission and the downlink transmission may use a time division duplex (TDD) scheme that is transmitted using different times, and use a frequency division duplex (FDD) scheme, a TDD scheme, and an FDD scheme, which are transmitted using different frequencies. Mixed mode may be used.

In addition, in a wireless communication system, a standard is configured by configuring uplink and downlink based on one carrier or a pair of carriers.

The uplink and the downlink transmit control information through a control channel such as a physical downlink control channel (PDCCH), a physical uplink control channel (PUCCH), a physical downlink shared channel (PDSCH), a physical uplink shared channel (PUSCH), and the like. It is composed of the same data channel to transmit data.

Downlink (downlink) may mean a communication or communication path from the multiple transmission and reception points to the terminal, uplink (uplink) may mean a communication or communication path from the terminal to the multiple transmission and reception points. In this case, in the downlink, the transmitter may be part of multiple transmission / reception points, and the receiver may be part of the terminal. In addition, in uplink, a transmitter may be part of a terminal, and a receiver may be part of multiple transmission / reception points.

Hereinafter, a situation in which a signal is transmitted and received through a channel such as a PUCCH, a PUSCH, a PDCCH, and a PDSCH may be described in the form of 'sending and receiving a PUCCH, a PUSCH, a PDCCH, and a PDSCH.'

Meanwhile, high layer signaling described below includes RRC signaling for transmitting RRC information including an RRC parameter.

The base station performs downlink transmission to the terminals. The base station transmits downlink control information such as scheduling required for reception of a downlink data channel, which is a main physical channel for unicast transmission, and a physical downlink for transmitting scheduling grant information for transmission on an uplink data channel. The control channel can be transmitted. Hereinafter, the transmission and reception of signals through each channel will be described in the form of transmission and reception of the corresponding channel.

There is no limitation on the multiple access scheme applied in the wireless communication system. Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Code Division Multiple Access (CDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Non-Orthogonal Multiple Access (NOMA), OFDM-TDMA, OFDM-FDMA, Various multiple access techniques such as OFDM-CDMA can be used. Here, the NOMA includes a sparse code multiple access (SCMA) and a low density spreading (LDS).

One embodiment of the present invention is for asynchronous radio communication evolving to LTE / LTE-Advanced, IMT-2020 via GSM, WCDMA, HSPA, and synchronous radio communication evolving to CDMA, CDMA-2000 and UMB. Can be applied.

In the present specification, a MTC terminal may mean a terminal supporting low cost (or low complexity) or a terminal supporting coverage enhancement. Alternatively, in the present specification, the MTC terminal may mean a terminal defined in a specific category for supporting low cost (or low complexity) and / or coverage enhancement.

In other words, in the present specification, the MTC terminal may mean a newly defined 3GPP Release-13 low cost (or low complexity) UE category / type for performing LTE-based MTC related operations. Alternatively, in the present specification, the MTC terminal supports enhanced coverage compared to the existing LTE coverage, or supports UE category / type defined in the existing 3GPP Release-12 or lower, or newly defined Release-13 low cost (or lower power consumption). low complexity) can mean UE category / type. Or, it may mean a further Enhanced MTC terminal defined in Release-14.

In this specification, a NB-IoT (NarrowBand Internet of Things) terminal refers to a terminal that supports radio access for cellular IoT. The objectives of NB-IoT technology include improved Indoor coverage, support for large scale low speed terminals, low sensitivity, low cost terminal cost, low power consumption, and optimized network architecture.

As a typical usage scenario in New Radio (NR), which is recently discussed by 3GPP, enhanced Mobile BroadBand (eMBB), massive machine type communication (MMTC), and Ultra Reliable and Low Latency Communication (URLLC) are being raised.

In this specification, frequencies, frames, subframes, resources, resource blocks, regions, bands, subbands, control channels, data channels, synchronization signals, various reference signals, various signals, and various messages related to NR (New Radio). May be interpreted as meaning used in the past or present, or various meanings used in the future.

[Legacy Synchronization: PSS / SSS]

1 illustrates information obtained at each step of the cell search process.

Referring to FIG. 1, a UE needs to go through a cell search process in order to access an LTE / LTE-Advanced cell. The cell search process consists of a series of synchronization processes through which the UE can determine time / frequency parameters. Through the synchronization process, the UE can demodulate the DL signal and transmit the UL signal at an appropriate time.

There are two cell search processes of the LTE / LTE-Advanced system: Initial Synchronization and New Cell Identification.

Initial synchronization is when a UE first discovers an LTE / LTE-Advanced cell and decodes all information in order to register with the LTE / LTE-Advanced cell, and the UE is powered on or disconnected from the serving cell. Is executed.

The new cell check is performed in the process of detecting a new neighboring cell while the UE is connected to the LTE / LTE-Advanced cell, and the UE reports the measurement value related to the new cell to the serving cell for handover. do.

In every cell, the eNB transmits two physical channels, the Primary Synchronization Signal (PSS) and the Secondary Synchronization Signal (SSS), which is the first step in the cell search process (initial synchronization, new cell identification). Will be detected.

When the UE detects the PSS and SSS signals, not only time and frequency synchronization is possible, but also a physical cell ID and a cyclic prefix length can be checked, and the cell is an FDD scheme or a TDD scheme. You will find information about which of them you use.

Initial synchronization: After detecting the synchronization signal, the UE decodes the Physical Broadcast CHannel (PBCH) and obtains system information (downlink system bandwidth, etc.) from the result.

New cell identification: The UE does not need to decode the PBCH, and measures and reports the signal quality of the newly detected cell based on reference signals (RSs) to the serving cell (LTE / LTE). -Advanced is designed to measure / receive RSRP without decoding PBCH).

The synchronization signal is transmitted twice every 10 ms radio frame. PSS and SSS have different structures depending on whether the UE is connected to an FDD cell or a TDD cell.

2 shows a frame structure of PSS and SSS in FDD, and FIG. 3 shows a frame structure of PSS and SSS in TDD.

2 and 3, in the FDD cell, the PSS is located in the last OFDM symbol of 1 ^st slot and 11 ^th slot of a 10 ms radio frame. The slot has 6 or 7 OFDM symbols, depending on the cyclic prefix length. Since the PSS is located in the last symbol of the slot, the UE can obtain slot boundary timing regardless of the CP length. have.

The SSS is located in the symbol before the PSS, and it is possible to coherent detect the SSS based on the PSS under the assumption that the radio channel characteristics are constant for a longer time than the OFDM symbol length.

In the TDD cell, the PSS is located in the third symbol of 3 ^rd and 13 ^th slots, and the SSS is located before three symbols based on the PSS. In this case, coherent detection is possible under the assumption that the coherence time of the channel is longer than four OFDM symbol periods.

The exact location of the SSS changes with the length of the CP selected in that cell. Since the UE does not know the length of the CP in advance when the cell is detected, the UE identifies and detects two possible positions of the SSS for each of the normal CP and the extended CP. . If the UE performs a search for both FDD and TDD cells, a total of four possible SSS positions should be checked.

In a particular cell, the PSS is the same in every frame transmitted by the cell, whereas in each radio frame the two SSSs differ in sequence. Accordingly, the UE can know the 10 ms radio frame boundary using the SSS information.

4 shows a frame structure of a PSS and an SSS in a frequency-time domain in an FDD cell.

Referring to FIG. 4, in the frequency domain, the PSS and the SSS are mapped to subcarriers in six intermediate RBs (resource blocks).

The number of RBs ranges from 6 to 110 depending on the system bandwidth. Since the PSSs and SSSs are mapped to six intermediate RBs, the UE may use the same method regardless of the bandwidth of the signal transmitted by the base station. Can be detected. Since the PSS and SSS are each a sequence of 62 symbols in length, they are mapped to the intermediate 62 subcarriers around the DC subcarriers, and the DC subcarriers are not used.

Therefore, the REs in four of the six RBs are all used, but the two RBs at both ends use only seven REs and five REs are not used. The UE uses a 64 sized FFT to detect the PSS and the SSS, and the sampling rate is lower than when using 72 subcarriers.

The UE may obtain a physical layer cell ID by a specific sequence of PSS and SSS. LTE / LTE-Advanced has a total of 504 unique physical layer cell IDs, which are divided into 168 groups, and each group consists of three cell IDs. Three cell IDs are assigned to cells controlled by the same eNB. . Each group is distinguished by an SSS sequence, and a total of 168 SSS sequences are required to distinguish each group.

PSS uses the Zadoff-Chu sequence. The ZC sequence is used for a random access preamble and an uplink reference signal in addition to the PSS.

In LTE / LTE-Advanced, three ZC PSSs corresponding to three physical layer IDs are used in each cell group.

5 shows SSS sequence mapping.

Referring to FIG. 5, the SSS is based on an M-sequence in which a sequence of length (2n-1) is generated by n shift registers. Each SSS sequence is made of two BPSK modulated sync codes, SSC1 and SSC2, having a length of 31 in the frequency domain, and then inserted into two sequences by interleaving. Two codes for making SSC1 and SSC2 are generated by different cyclic shifts of M-sequences of length 31 differently.

At this time, the cyclic shift index is determined by a function of a physical layer cell ID group. SSC2 is scrambled by a sequence determined as a function of the index of SSC1 and again scrambled by a code determined as a function of the PSS.

[5G NR (New Radio)]

3GPP recently approved a study item "Study on New Radio Access Technology" for the study of next generation / 5G radio access technology, and based on this, RAN WG1 has frame structure, channel coding and modulation for NR (New Radio) respectively. Discussions began on waveforms and multiple access schemes.

In addition to improved data rates compared to LTE / LTE-Advanced, NR is required to be designed to meet various requirements required for each detailed and detailed usage scenario.

In particular, as the representative usage scenarios of NR, enhancement mobile broadband (eMBB), massive MTC (MMTC), and ultra reliable and low latency communications (URLLC) have been proposed. A contrastingly flexible frame structure design is required.

Specifically, eMBB, mMTC and URLLC are considered as representative usage scenarios of NR under discussion in 3GPP. Since different usage scenarios have different requirements for data rate, latency, coverage, etc., different neuralologies are used to efficiently satisfy the requirements of each usage scenario through a frequency band constituting an arbitrary NR system. There is a need for a method of efficiently multiplexing radio resource units based on (numerology) (eg subcarrier spacing, subframe, TTI, etc.).

For example, 1 ms subframe (or 0.5 ms slot) structure based on 15 kHz subcarrier spacing and 0.5 ms subframe (or 0.25 ms slot) structure based on 30 kHz subcarrier spacing, similar to the existing LTE / LTE-Advanced. And a need to support a 60 kHz based 0.25 ms subframe (0.125 ms slot) structure through one NR frequency band.

A subframe consisting of X OFDM symbols as a resource allocation unit in the time domain, that is, a scheduling unit in the time domain, even within any numerology, i.e., a subcarrier spacing structure (eg X = 14 or 7, or any other ) Or a slot of Y OFDM symbols (Y = 14 or 7 or any other natural number) is set, or Z OFDM symbols (ie Z <) with granularity smaller than the corresponding subframe or slot. Discussing how to define a mini-slot consisting of any natural number satisfying Y & Z <X).

6 illustrates a resource block structure in TDM-based mixed numerology.

As described above, when a plurality of numerologies are supported on any NR carrier, and each numerology-specific subcarrier spacing has a value of 2 ⁿ * 15 kHz, the respective carrier-specific subcarriers are 15 kHz. Subcarrier spacing is defined to be mapped in the frequency domain in a nested manner in the form of subset / superset.

In addition, when the frame structure is formed by multiplexing the TDM based between the corresponding neutralizers, the RB serving as a resource allocation unit on the frequency axis through the corresponding NR carrier has a subset / superset type for the 15 kHZ based RB grid as shown in FIG. It is defined to be configured in nested manner.

However, the number of subcarriers constituting one RB in each neurolage was determined to have a value of 12 or 16 regardless of the corresponding neuralology.

On the other hand, there is a new method for designing a synchronization signal suitable for the NR-related frame structure, embodiments of the present invention proposes a new method for designing a synchronization signal that can support a variety of neuronal NR.

7 illustrates a concept of sequence correlation for frequency offset derivation using CRS port 0.

The existing synchronization signal, that is, the PSS / SSS of LTE / LTE-Advanced is allocated to Center 6RB and transmitted.

Basically, in order to acquire synchronization, the UE can only detect the corresponding RB.

However, this method does not provide detailed synchronization functions such as actual phase error. This part is divided into the implementation area, and the current residual frequency offset (or phase error) is estimated by using some CRS ports.

For example, when the total number of sequences of the CRS port 0 is given as N _RS , the correlation between the corresponding two received sequences may be expressed as follows.

는

번째 심볼에 단말이 수신한

번째 수신 신호를 의미한다.

Is

Received by the terminal in the first symbol

Means the first received signal.

는 연속적인 두 OFDM 심볼 사이의 거리를 말한다.Additionally

Denotes the distance between two consecutive OFDM symbols.

는 CP 길이를 고려한 Normalized OFDM unit length이며 아래와 같이 표현된다.Finally

Is a normalized OFDM unit length in consideration of the CP length and is expressed as follows.

Here, the final equation for the terminal to finally obtain the frequency offset is as follows.

의 범위를 갖는다.From here

Has a range of.

Therefore, through the above-described method, the UE performs synchronization acquisition by compensating the initial frequency offset with the PSS / SSS of the center 6RB, obtains information on the entire transmission band through the PBCH, and then estimates an additional frequency offset using the CRS port. Do this.

This may be a reference signal for setting accurate synchronization for the entire frequency band since the CRS is allocated and transmitted in the entire frequency band regardless of the frequency band setting of the LTE / LTE-Advanced system. In addition, the higher RS density compared to other reference signals can provide more accurate synchronization acquisition performance.

In NR, the next-generation radio access system, the transmission of synchronization signals is expected to be limited to some narrow bands such as legacy PSS / SSS. This is because it has a structure that is advantageous for supporting flexible neurology and reducing signal overhead. Indeed, NR assumes some system design that avoids many system losses such as CRS.

In addition, a configurable synchronization structure can provide an advantage in the number of transmission cycles in order to keep the complexity of each neuron minimum.

Accordingly, the present invention proposes a method of designing a synchronization signal which is easier to support frequency offset in such an environment.

Example  One. reference Numerology (Reference numerology) A configurable sync signal is allocated to an additional band except for the sync signal transmission band of the band.

In this proposal, we basically assume a flexible band change of the same numerology.

That is, it is basically assumed that a synchronization signal is allocated to a specific narrow band, but it is assumed that the size of the reference neuron band is changed according to a specific configuration. In the existing LTE / LTE-Advanced, the synchronization signal of the PSS / SSS was transmitted only in the center 6RB, and the entire band 6 (1.4 MHz), 15 (3 MHz), 25 (5 MHz), 50 (10 MHz), 75 (15 MHz), and 100 RB ( 20MHz) to support a single PSS / SSS synchronization. However, in order to precisely synchronize the terminal, it is necessary to use a reference signal transmitted at a predetermined time period at the same location as the existing CRS. However, assuming that this structure is avoided as much as possible in the NR, when the NR synchronization signal is also transmitted in the center 'X' RBs, accurate acquisition of the remaining bands is required.

Therefore, the present proposal provides a structure for transmitting an additional synchronization signal for providing a synchronization acquisition quality suitable for the size change of the reference band for accurate synchronization acquisition of the terminal. The synchronization signal transmitted from the center 'X' RBs is used for synchronization acquisition for the initial access of the terminal, and further improves the quality of synchronization acquisition allocated to the remaining bands.

The additionally allocated sync signal may be additionally set in the gNB / eNB and may include contents such as a period of transmission, a type of sync signal, and a number of transmissions. Basically, the additionally transmitted sync signal assumes 'Y' RBs, but when X = Y, a sync signal of the same length may be repeatedly transmitted. The proposed method can be applied to multiple numerology regardless of TDM, FDM and FDM / TDM methods.

Example  1-1. reference  Out of band Neuerlodge  In the band, a configurable sync signal is allocated to an additional band except the initial sync signal transmission position.

In the present proposal, as in the above-described 'Example 1', additional synchronization signal transmission may be configured in a configurable manner when a band having a predetermined size or more is allocated to the remaining NMR band except for the reference NMR.

Example  1-2. Excluding the initial sync signal transmission position Additionally  The transmission period of the sending synchronization signal may be different from each other.

Basically, the synchronization signal of each neuronology is always transmitted based on a fixed position for the initial connection, and the period must be constant at all times. However, additionally allocated sync signals may have different periods.

For example, if a synchronization signal for initial access is transmitted in a 't _X ' period, the additional synchronization signal may be set and transmitted in a 'N xt _X ' period. For example, if N = 2, the additionally transmitted sync signal is transmitted only once when the basic sync signal is transmitted twice.

Example  1-3. Excluding the initial sync signal transmission position Additionally  The transmission position or resource (time-frequency) of the outgoing synchronization signal may be set at a constant pattern.

Basically, the synchronization signal of each neuron is always transmitted based on a fixed position for initial access. However, as in 'Example 1-2', additional synchronization signals may be transmitted at different periods, and the transmitted position may also have a predetermined pattern.

For example, the synchronization signal may be set to be transmitted with a predetermined period through different resources along a preset band such as frequency hopping.

Example  2. FDM-based multiple Neuerlodge (multiple numerology) In the case of multiplexing, the synchronization signal is aligned at a specific position.

Example  2-1. reference Pneumonic  Align to the sync signal transmission position.

This method proposes a method of aligning a synchronization signal when different NR neuronologies are set to FDM as shown in FIG. 9.

That is, it is easy to estimate all the synchronization signals at a specific position in frequency offset using the synchronization signal. That is, since the coherence time is shortened as the corresponding synchronization signals are simultaneously received, more accurate samples of the synchronization signals can be obtained and accurate synchronization can be obtained using the corresponding values.

Synchronization signals transmitted to each of the neuronologies may have the same length, but the size of the occupied band may be different according to the neuralology.

As for the alignment position of the synchronization signal, it is most preferable to set the boundary last symbol or start symbol such as a subframe / symbol period / minislot / slot as a position. However, depending on the situation, if there is a point where transmission points coincide or align in the middle region of a subframe / symbol period / minislot / slot, it may be used as an alignment position of a synchronization signal.

In the following TDM method, the same principle as that of the FDM cannot be applied because the periods of transmission of different neuronologies vary depending on the setting of the TDM-based neuronology transmission periods.

However, in order to align the position of the synchronization signal, a method of transmitting the synchronization signals with the same time interval is proposed. That is, although the timing of transmission of the synchronization signal is different for each numerology, the transmission period of the synchronization signal may be set in a predetermined multiple unit.

TABLE 1

In the present invention, a new synchronization signal setting method and transmission method for NR in 3GPP LTE / LTE-Advanced system have been proposed, and through this method, performance of the synchronization signal can be improved and efficient synchronization acquisition of the terminal can be supported.

10 and 11 illustrate a method of establishing a synchronization signal for a new radio access technology according to embodiments of the present invention.

Referring to FIG. 10, the base station may generate one or more bandwidth parts by dividing the entire system bandwidth into one or more parts (S1000).

That is, in the above-described embodiment, Type-0 numerology, Type-1 numerology, Type-2 numerology and the like may be bandwidth parts formed by dividing the entire system bandwidth.

The base station may signal configuration information on the generated one or more bandwidth parts to the terminal quasi-statically. For example, the bandwidth part configuration may be signaled to the terminal through RRC signaling.

The base station may set a sync signal or a sync signal block to be transmitted through a reference bandwidth part which is a first bandwidth part among one or more bandwidth parts. Here, the first bandwidth part refers to a bandwidth part through which a synchronization signal is necessarily transmitted among bandwidth parts created by dividing the entire system bandwidth, and may refer to reference numerology and Type-0 numerology in the above-described embodiment.

The base station transmits the synchronization signal set for the first bandwidth part to the terminal through the first bandwidth part (S1010).

The base station may set a synchronization signal for a second bandwidth part other than the first bandwidth part. The bandwidth of the first bandwidth part and the second bandwidth part may be equal to or greater than the bandwidth of the block in which the synchronization signal is transmitted.

Or, the base station may not set a synchronization signal for the second bandwidth part.

That is, the base station may generate one or more bandwidth parts by dividing the entire system bandwidth into one or more bandwidth parts and set a configurable sync signal for a second bandwidth part other than the first bandwidth part in which the synchronization signal is necessarily transmitted. have.

Further, the base station may set the period of the synchronization signal set for the first bandwidth part differently from the period of the synchronization signal set for the second bandwidth part.

In addition, the base station may set a synchronization signal additionally transmitted in a band other than the band in which the synchronization signal set in the first bandwidth part is transmitted. That is, by setting an additional sync signal when the bandwidth of the first bandwidth part where the sync signal is transmitted is large, the terminal can detect the sync signal.

The base station transmits a synchronization signal set for the second bandwidth part to the terminal (S1020).

Accordingly, according to embodiments of the present invention, in the NR system, the base station may basically set a synchronization signal that can be additionally set to a bandwidth part other than the bandwidth part where the synchronization signal is transmitted. In addition, an additional sync signal may be set to a band other than a band where the sync signal is transmitted in the bandwidth part where the sync signal is basically transmitted.

Through this, it is possible to set and transmit a synchronization signal suitable for a flexible frame structure such as an NR system.

Referring to FIG. 11, the terminal receives information regarding one or more bandwidth part settings from the base station (S1100).

The base station may generate one or more bandwidth parts by dividing the entire system bandwidth into one or more parts, and semi-statically signaled so that the UE knows information about one or more bandwidth part settings.

The terminal receives the synchronization signal transmitted through the first bandwidth part of the one or more bandwidth parts made by the base station (S1110).

Since the first bandwidth part is basically a band through which a synchronization signal is transmitted, the terminal may identify the first bandwidth part through the information on the bandwidth part setting received from the base station and receive the synchronization signal through the first bandwidth part.

In addition, the terminal may receive a synchronization signal transmitted through a second bandwidth part other than the first bandwidth part (S1120).

Alternatively, the terminal may not receive the synchronization signal through the second bandwidth part.

That is, the terminal basically receives the synchronization signal through the first bandwidth part through which the synchronization signal is transmitted, and may or may not receive the synchronization signal through the second bandwidth part other than the first bandwidth part.

Accordingly, the terminal can efficiently acquire a synchronization signal in a flexible frame structure like the NR system.

Alternatively, in the wireless communication system according to the embodiments of the present invention, the base station and the terminal may set and transmit one or more synchronization signals within the entire bandwidth without dividing the entire bandwidth into one or more bandwidth parts.

12 and 13 show another example of a synchronization signal setting method for a new radio access technology according to embodiments of the present invention.

Referring to FIG. 12, the base station may set one or more synchronization signals to be transmitted within the entire system bandwidth (S1200).

That is, regardless of dividing the entire bandwidth into one or more bandwidth parts, one or more synchronization signals to be transmitted within the entire bandwidth may be set, and a plurality of synchronization signals may be set for the entire bandwidth.

The base station transmits one or more set synchronization signals to the terminal through the entire bandwidth (S1210).

Accordingly, the base station may set and transmit one or more synchronization signals within the entire bandwidth, or may divide the entire bandwidth into one or more bandwidth parts and set a synchronization signal for each bandwidth part.

Referring to FIG. 13, the terminal may receive one or more synchronization signals set for the entire bandwidth from the base station (S1300).

One or more sync signals set through the full bandwidth, that is, wideband, may be received.

The terminal may perform time and frequency synchronization by using one or more synchronization signals received through the entire bandwidth from the base station (S1310), and check the cell ID.

Accordingly, according to embodiments of the present invention, in a flexible frame structure of a new wireless communication system, one or more synchronization signals transmitted within the entire bandwidth or a synchronization signal set for one or more bandwidth parts generated by dividing the entire bandwidth are transmitted. And receive.

14 is a diagram illustrating a configuration of a base station 1400 according to embodiments of the present invention.

Referring to FIG. 14, the base station 1400 according to the embodiments of the present invention includes a controller 1410, a transmitter 1420, and a receiver 1430.

The controller 1410 controls the overall operation of the base station 1400 by allocating a configurable sync signal to an additional band except for the initial sync signal transmission position in a band other than the reference band according to embodiments of the present invention. Alternatively, the overall operation of the base station 1400 is controlled by setting one or more synchronization signals to be transmitted within the entire bandwidth.

The transmitter 1420 and the receiver 1430 are used to transmit and receive signals, messages, and data necessary for carrying out the above-described present invention.

15 is a diagram illustrating a configuration of a user terminal 1500 according to embodiments of the present disclosure.

Referring to FIG. 15, a user terminal 1500 according to embodiments of the present invention includes a receiver 1510, a controller 1520, and a transmitter 1530.

The receiver 1510 receives downlink control information, data, and a message from a base station through a corresponding channel.

The controller 1520 controls the overall operation of the user terminal 1500 according to the reception of the configurable synchronization signal in an additional band except for the initial synchronization signal transmission position in a band other than the reference band according to embodiments of the present invention. Alternatively, the overall operation of the user terminal 1500 may be controlled by receiving one or more synchronization signals transmitted within the entire bandwidth.

The transmitter 1530 transmits uplink control information, data, and a message to a base station through a corresponding channel.

The standard contents or standard documents mentioned in the above embodiments are omitted to simplify the description of the specification and form a part of the present specification. Therefore, the addition of the contents of the standard and part of the standard documents to the specification or the description in the claims should be construed as falling within the scope of the present invention.

Appendix

[1] Ericsson, Huawei, "New SI proposal Study on Latency reduction techniques for LTE", RP-150465, Shanghai, China, March 9-12, 2015.

[2] R2-155008, "TR 36.881 v0.4.0 on Study on Latency reduction techniques for LTE", Ericsson (Rapporteur)

[3] R1-160927, "TR 36.881-v0.5.0 on Study on Latency reduction techniques for LTE", Ericsson (Rapporteur)

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and changes without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

CROSS-REFERENCE TO RELATED APPLICATION

This patent application is related to the patent application No. 10-2016-0127093 filed in Korea on September 30, 2016 and the patent application No. 10-2017-0124195 filed in Korea on September 26, 2017. Priority is claimed under section (a) (35 USC § 119 (a)), all of which is incorporated by reference in this patent application. In addition, if this patent application claims priority for the same reason for countries other than the United States, all its contents are incorporated into this patent application by reference.

Claims (17)

In the synchronization signal setting method for a new radio access technology, Establishing at least one sync signal to transmit within the full bandwidth; And Transmitting the set one or more synchronization signals over the full bandwidth. The method of claim 1, Generating one or more bandwidth parts by dividing the total bandwidth into one or more parts. The method of claim 2, Setting a synchronization signal for at least one bandwidth part of the generated at least one bandwidth part. The method of claim 2, Setting a synchronization signal to transmit on a first bandwidth part of the one or more bandwidth parts; And Setting a synchronization signal for at least one second bandwidth part except for the first bandwidth part, or setting a synchronization signal for at least one second bandwidth part. The method of claim 4, wherein The bandwidth of the first bandwidth part and the bandwidth of the second bandwidth part are greater than or equal to the bandwidth of the block in which the synchronization signal is transmitted. The method of claim 2, And signaling the at least one bandwidth part setting to a terminal semi-statically. In the synchronization signal setting method for a new radio access technology, Receiving one or more sync signals transmitted within the entire bandwidth; And Performing time and frequency synchronization using the received one or more synchronization signals. The method of claim 7, wherein And receiving a synchronization signal for one or more bandwidth parts of the one or more bandwidth parts generated by dividing the total bandwidth into one or more parts. The method of claim 8, Receiving a synchronization signal on a first bandwidth part of the one or more bandwidth parts; And And not receiving a synchronization signal on at least one second bandwidth part except the first bandwidth part, or receiving a synchronization signal on at least one second bandwidth part. The method of claim 9, The bandwidth of the first bandwidth part and the bandwidth of the second bandwidth part are greater than or equal to the bandwidth of the block in which the synchronization signal is transmitted. The method of claim 8, And quasi-statically receiving information about the one or more bandwidth part settings. A base station for setting a synchronization signal for a new radio access technology, A controller configured to set one or more synchronization signals to be transmitted within the entire bandwidth; And And a transmitter configured to transmit the one or more set synchronization signals through the entire bandwidth. The method of claim 12, The control unit, And a base station dividing the total bandwidth into one or more parts to generate one or more bandwidth parts. The method of claim 13, The control unit, And a base station for setting a synchronization signal for at least one bandwidth part of the generated at least one bandwidth part. The method of claim 13, The control unit, Set a synchronization signal to be transmitted through a first bandwidth part of the one or more bandwidth parts, and do not set a synchronization signal for one or more second bandwidth parts except the first bandwidth part, or for at least one or more second bandwidth parts. A base station for setting a synchronization signal. The method of claim 15, And a bandwidth of the first bandwidth part and a bandwidth of the second bandwidth part are greater than or equal to the bandwidth of the block in which the synchronization signal is transmitted. The method of claim 13, And a base station signaling the one or more bandwidth part settings to a terminal semi-statically.

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