KR20170125741A - Apparatus and method for initial access in wireless communication system - Google Patents

Abstract

The present disclosure relates to a 5^th generation (5G) or pre-5G communications system to support higher data transmission rates than a 4^th generation (4G) communications system such as a long term evolution (LTE). A base station apparatus in a wireless communications system comprises: at least one processor configured to map at least one initial access signal to a part or all of a plurality of predefined time locations in at least one periodicity; and a transceiver configured to transmit the mapped at least one initial access signal to a user terminal and to indicate orthogonal frequency division multiplexing (OFDM) symbols that are not mapped with the at least one initial access signal in the at least one periodicity to the user terminal. Each of the at least one initial access signal corresponds to one of a plurality of transmission beams.

Description

[0001] APPARATUS AND METHOD FOR INITIAL ACCESS IN WIRELESS COMMUNICATION SYSTEM [0002]

BACKGROUND OF THE INVENTION [0002] This disclosure relates generally to wireless communication systems, and more particularly to an apparatus and method for configuration and transmission of an initial access signal.

Efforts are underway to develop improved 5G (5 ^th generation) communication systems or pre-5G communication systems to meet the increasing demand for wireless data traffic after commercialization of 4G (4 ^th generation) communication systems. For this reason, a 5G communication system or a pre-5G communication system is referred to as a 4G network (Beyond 4G Network) communication system or a LTE (Long Term Evolution) system (Post LTE) system.

To achieve a high data rate, 5G communication systems are being considered for implementation in very high frequency (mmWave) bands (e.g., 28 gigahertz (28 GHz) or 60 gigahertz (60 GHz) bands). In the 5G communication system, beamforming, massive MIMO, full-dimensional MIMO, and FD-MIMO are used in order to mitigate the path loss of the radio wave in the very high frequency band and to increase the propagation distance of the radio wave. ), Array antennas, analog beam-forming, and large scale antenna technologies are being discussed.

In addition, in order to improve the network of the system, the 5G communication system has developed an advanced small cell, an advanced small cell, a cloud radio access network (cloud RAN), an ultra-dense network, (D2D), a wireless backhaul, a moving network, cooperative communication, Coordinated Multi-Points (CoMP), and interference cancellation Have been developed.

In addition, in the 5G system, the Advanced Coding Modulation (ACM) scheme, Hybrid Frequency Shift Keying and Quadrature Amplitude Modulation (FQAM) and Sliding Window Superposition Coding (SWSC), and the Advanced Connection Technology (FBMC) ), Non-Orthogonal Multiple Access (NOMA), and Sparse Code Multiple Access (SCMA).

Wireless communications is one of the most successful innovations in modern history. Recently, the number of subscribers of wireless communication service has surpassed 5 billion and is growing rapidly. The demand for wireless data traffic is rapidly increasing as consumers and businesses in smart phones and other devices of the machine type, eBook readers, netbooks, other mobile data devices such as "notepad" computers and tablets, . In order to meet the rapid growth of mobile data traffic and to support new applications and deployments, improving the efficiency and coverage of the air interface is of paramount importance.

Based on the above discussion, the disclosure provides an apparatus and method for efficiently using resources in a wireless communication system.

According to various embodiments of the disclosure, in a wireless communication system, a base station apparatus includes at least one processor that maps at least one initial access signal to at least one of a plurality of predefined time positions in at least one period And a transceiver that transmits the mapped at least one initial access signal to the terminal and indicates to the terminal the orthogonal frequency division multiplexing (OFDM) symbols that are not mapped to the at least one initial access signal in the at least one period . Each of the at least one initial access signal corresponds to one of a plurality of transmission beams.

According to various embodiments of the present disclosure, a method of operating a base station in a wireless communication system includes mapping at least one initial access signal to a portion or all of a plurality of predefined time locations in at least one period, Transmitting the mapped at least one initial access signal and indicating to the terminal the OFDM symbols that are not mapped to the at least one initial access signal in the at least one period. Each of the at least one initial access signal corresponds to one of a plurality of transmission beams.

According to various embodiments of the present disclosure, a terminal device in a wireless communication system includes: a transceiver that receives at least one initial access signal mapped to some or all of a plurality of predefined time locations in at least one period from a base station; Performing an initial access to the base station via one of a plurality of different beams based on the at least one initial access signal and receiving an indication of OFDM symbols not mapped to the at least one initial access signal And at least one processor. Each of the at least one initial access signal corresponds to one of a plurality of transmission beams.

An apparatus and method according to various embodiments of the disclosure can efficiently use resources by mapping initial access signals to some symbols of one subframe.

The effects obtainable from the present disclosure are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by those skilled in the art from the description below will be.

1 illustrates an example of a wireless network in accordance with various embodiments of the present disclosure.
2A and 2B illustrate examples of wireless transmission and reception paths in a wireless communication system according to various embodiments of the present disclosure.
3A shows an example of a user equipment (UE) in a wireless communication system according to various embodiments of the present disclosure.
3B shows an example of an enhanced NodeB (eNB) in a wireless communication system according to various embodiments of the present disclosure.
4 illustrates an example of an exemplary synchronization operation performed by a UE in a wireless communication system according to various embodiments of the present disclosure.
5 illustrates an example of an exemplary frame structure of a primary synchronization signal (PSS) / secondary synchronization signal (SSS) / physical broadcast channel (PBCH) transmission in an FDD configuration in a wireless communication system according to various embodiments of the present disclosure .
Figure 6 illustrates an example of a transmission technique applied by an eNB to utilize transmit beamforming in a wireless communication system in accordance with various embodiments of the present disclosure.
Figure 7 illustrates an example of PSS and SSS extension in a wireless communication system in accordance with various embodiments of the present disclosure.
8 shows an example of another extension of PSS and SSS in a wireless communication system according to various embodiments of the present disclosure.
9 shows an example of the placement of timing and cell identity synchronization signal (TCSS) and extended synchronization signal (ESS) in orthogonal frequency division multiplexing (OFDM) symbols transmitted in a wireless communication system according to various embodiments of the present disclosure. do.
10 illustrates an example of an alternative placement of an ESS region in ODM symbols in a wireless communication system in accordance with various embodiments of the present disclosure.
11 shows an example of another alternative arrangement of an ESS area in a wireless communication system according to various embodiments of the present disclosure.
FIG. 12 illustrates another alternative arrangement of an ESS region in a wireless communication system according to various embodiments of the present disclosure.
13 shows an example of the placement of the TSCC and PBCH in a wireless communication system according to various embodiments of the present disclosure.
14 illustrates an example of operations performed by an eNB for placing PBCH packets in an OFDM symbol in a wireless communication system according to various embodiments of the present disclosure.
15 illustrates an example of operations performed by a UE for recovering information regarding PBCH information bits and OFDM symbol index in a wireless communication system according to various embodiments of the present disclosure.
16 illustrates an example of a transceiver having a multi-antenna array using one or multiple transmission beams in a wireless communication system in accordance with various embodiments of the present disclosure.
17 illustrates an example of a high level initial access procedure in a wireless communication system according to various embodiments of the present disclosure.
18 shows an example of the transmission of initial access signals of an eNB in an initial access sub-frame in a wireless communication system according to various embodiments of the present disclosure;
19A-19C illustrate examples of the transmission of initial access signals in two adjacent sub-frames in a wireless communication system according to various embodiments of the present disclosure.
20 illustrates an example of the use of an initial access sub-frame for data and control messages in a wireless communication system in accordance with various embodiments of the present disclosure.
21 illustrates an example of the use of an initial access sub-frame for a physical uplink shared channel (PUSCH) in a wireless communication system according to various embodiments of the present disclosure.
22 illustrates an example of the use of an initial access sub-frame for a PSCH in a wireless communication system according to various embodiments of the present disclosure.
23 shows an example of an initial access signal mapping method in a wireless communication system according to various embodiments of the present disclosure.
24 illustrates an example of an initial access sub-frame in a wireless communication system according to various embodiments of the present disclosure.
25 shows an example of a measurement reference signal (MRS) transmission in a wireless communication system according to various embodiments of the present disclosure.
26 illustrates an example of frequency locations of an initial access signal in a wireless communication system in accordance with various embodiments of the present disclosure.

The terms used in this disclosure are used only to describe certain embodiments and may not be intended to limit the scope of other embodiments. The singular expressions may include plural expressions unless the context clearly dictates otherwise. Terms used herein, including technical or scientific terms, may have the same meaning as commonly understood by one of ordinary skill in the art. The general predefined terms used in this disclosure may be interpreted as having the same or similar meaning as the contextual meanings of the related art and, unless explicitly defined in the present disclosure, include ideally or in an excessively formal sense . In some cases, the terms defined in this disclosure can not be construed to exclude embodiments of the present disclosure.

In the various embodiments of the present disclosure described below, a hardware approach is illustrated by way of example. However, the various embodiments of the present disclosure do not exclude a software-based approach, since various embodiments of the present disclosure include techniques that use both hardware and software.

It should be understood that the Figures 1 to 26 and the various embodiments described below, which are used in describing the principles of the present invention in this patent document, are by way of example only and are to be construed as limiting the scope of the invention in any way Can not be done. Those skilled in the art will appreciate that the principles of the present invention may be implemented in any suitably arranged cellular system or device.

The following documents are incorporated herein by reference in their entireties as if fully set forth herein: 3 ^rd generation partnership project TS 36.211 v13.0.0, "E-UTRA, Physical channels and modulation"("REF1"); 3GPP TS 36.212 v13.0.0, " E-UTRA, Multiplexing and Channel coding "(" REF 2 "); 3GPP TS 36.213 v13.0.0, "E-UTRA, Physical Layer Procedures"("REF3"); 3GPP TS 36.331 v13.0.0, "E-UTRA, Radio Resource Control (RRC) Protocol Specification"("REF4").

Other embodiments of the invention may be derived by using some combination of the embodiments listed below. Further, other embodiments of the present disclosure may be derived by using a subset of certain operational steps as disclosed in each of these embodiments. It is to be understood that the present disclosure encompasses all such embodiments.

FIG. 1 illustrates an example wireless network 100 in accordance with various embodiments of the present disclosure. The embodiment of the wireless network 100 shown in Figure 1 is for illustrative purposes only. Other embodiments for wireless network 100 may be used without departing from the scope of the present invention.

As shown in FIG. 1, the wireless network 100 includes an eNB 101, an eNB 102, and an eNB 103. The eNB 101 communicates with the eNB 102 and the eNB 103. ENB 101 also communicates with at least one network 130, e.g., the Internet, a dedicated Internet Protocol (IP) network, or other data network.

Depending on the network type, other well-known terms may be used in place of "eNodeB" or "eNB" such as "base station" or "access point". For convenience, the terms "eNodeB" and "eNB" are used herein to refer to network infrastructure components that provide wireless access to remote terminals. Also, depending on the network type, other well-known terms may be used to refer to a "user equipment" or "user equipment ", such as" mobile station ", & "May be used instead. For convenience, the terms "user device" and "UE ", whether a UE is a mobile device (e.g., a mobile phone or a smart phone) or a fixed device (e.g., a desktop computer or a bending machine) refers to a remote wireless terminal that wirelessly accesses an eNB and is used in this patent specification.

The eNB 102 provides wireless broadband access to the network 130 to a first plurality of UEs in the coverage area 120 of the eNB 102. The first plurality of UEs comprises a UE 111, which may be located in a small business (SB); A UE 112, which may be located in a large enterprise (enterprise E); UE 113, which may be located in a Wi-Fi hotspot (HS); A UE 114, which may be located in a first residence (R); A UE 115, which may be located in a second residential area R; And a UE 116, which may be a mobile device (M), such as a cell phone, wireless laptop, wireless PDA, and the like. The eNB 103 provides wireless broadband access to the network 130 to a second plurality of UEs in the coverage area 125 of the eNB 103. The second plurality of UEs includes UE 115 and UE 116. In some embodiments, one or more of the eNBs 101-103 may communicate with each other and between the UEs 111-116 and < RTI ID = 0.0 > 111-116 < / RTI > using 5G, LTE, LTE-A, WiMAX, Wi- Communication.

The dashed lines represent the approximate ranges of coverage areas 120 and 125 shown in an approximate circle for purposes of illustration and explanation only. The coverage areas associated with eNBs, e.g., coverage areas 120 and 125, may have other forms, including irregular shapes, depending on the configuration of the eNBs and the changes in the radio environment associated with natural and artificial obstacles. Should be clearly understood.

As described in more detail below, one or more of BS 101, BS 102, and BS 103 includes a 2D antenna array as described in the embodiments of the present disclosure. In some embodiments, one or more of BS 101, BS 102, and BS 103 supports an initial access operation in the wireless system.

1 illustrates an example of a wireless network 100, various changes may be made to FIG. For example, the wireless network 100 may include any number of eNBs and any number of UEs in any suitable arrangement. ENB 101 may also communicate directly with any number of UEs to provide wireless broadband access to network 130 to these UEs. Similarly, each eNB 102-103 may communicate directly with the network 130 to provide direct wireless broadband access to the network 130 to the UEs. ENB 101, 102, and / or 103 may also provide access to other or additional external networks, such as external telephone networks or other types of data networks.

2A and 2B illustrate examples of wireless transmission and reception paths in a wireless communication system according to various embodiments of the present disclosure. In the following description, the receive path 250 is described as being implemented in a UE (e.g., UE 116), while the transmit path 200 can be described as being implemented in an eNB (e.g., eNB 102). However, the receive path 250 may be implemented in the eNB, and the transmit path 200 may be implemented in the UE. In some embodiments, the receive path 250 is configured to support an initial access operation in the wireless system.

The transmit path 200 includes a channel coding and modulation block 205, a serial-to-parallel (S-to-P) block 210, a size N inverse fast Fourier transform (IFFT) block 215, (P-to-S) block 220, a cyclic prefix addition block 225, and an up-converter (UC) The receive path 250 includes a down-converter (DC) 255, a cancellation prefix block 260, a S-to-P block 265, a size N Fast Fourier Transform (FFT) A parallel-to-serial (P-to-S) block 275, and a channel decoding and demodulation block 280.

In transmit path 200, channel coding and modulation block 205 receives a series of information bits, applies coding (e.g., LDPC coding), and modulates the input bits (e.g., Quadrature Phase Shift Keying (QPSK) QAM (Quadrature Amplitude Modulation)) to generate a sequence of frequency-domain modulation symbols. The serial-to-parallel block 210 converts the serial modulated symbols into parallel data (i.e., demultiplexes) to generate N parallel symbol streams, where N is the IFFT / FFT size used in BS 102 and UE 116. The size N IFFT block 215 performs an IFFT operation on the N parallel symbol streams to generate time-domain output signals. The parallel-to-serial block 220 transforms (i.e., multiplexes) the parallel time-domain output symbols from the size N IFFT block 215 to produce a serial time-domain signal. The cyclic prefix addition block 225 inserts a cyclic prefix into the time-domain signal. Finally, the up-converter 230 modulates (i.e., upconverts) the output of the cyclic prefix addition block 225 to an RF frequency for transmission over the wireless channel. The signal may also be filtered at the baseband before being converted to an RF frequency.

The transmitted RF signal arrives at the UE 116 after passing through the radio channel, and the reverse operations for the operations at the eNB 102 are performed. Downconverter 255 downconverts the received signal to a baseband frequency, and the cyclic prefix removal block 260 removes the cyclic prefix to generate a serial time-domain baseband signal. The serial-parallel block 265 converts the time-domain baseband signal into parallel time-domain signals. The size N FFT block 270 then performs an FFT algorithm to generate N parallel frequency-domain signals. A parallel-to-serial block 275 converts the parallel frequency-domain signals into a sequence of modulated data symbols. The channel decoding and demodulation block 280 demodulates the modulated symbols and then decodes them to recover the original input data stream.

Each of the eNBs 101-103 may implement a transmit path 200 similar to a downlink transmission to UEs 111-116 and may implement a receive path 250 similar to an uplink receive from UEs 111-116. Similarly, each of the UEs 111-116 may implement a transmit path 200 corresponding to an architecture for uplink transmission to eNBs 101-103, and may correspond to an architecture for downlink reception from eNBs 101-103 Lt; RTI ID = 0.0 > 250 < / RTI >

At least some of the components of FIGS. 2A and 2B may be implemented in software, and other components may be implemented by a mix of configurable hardware or software and configurable hardware. In particular, the FFT blocks and IFFT blocks described in this patent document can be implemented as configurable software algorithms, where the value of the size N can be modified according to its implementation.

Furthermore, while the present invention has been described with respect to embodiments implementing FFT (Fast Fourier Transform) and IFFT (Inverse Fast Fourier Transform), this is by way of example only and should not be construed as limiting the scope of the present invention . In an alternative embodiment of the present invention, the Fast Fourier Transform (FFT) functions and the Inverse Fast Fourier Transform (IFFT) functions are readily replaced with Discrete Fourier Transform (DFT) functions and Inverse Discrete Fourier Transform It will be appreciated. In the case of the DFT and IDFT functions, the value of the N variable may be any integer (i. E., 1, 2, 3, 4, etc.), and for FFT and IFFT functions, 1, 2, 4, 8, 16, etc.).

Although Figs. 2A and 2B illustrate examples of wireless transmission and reception paths, various modifications may be made to Figs. 2A and 2B. For example, the various components of FIGS. 2A and 2B may be combined, further subdivided or omitted, for example, and additional components may be added according to specific needs. 2a and 2b are intended to illustrate examples of types of transmit and receive paths that may be used in a wireless network. Other suitable architectures may be used to support wireless communication in a wireless network.

3A shows an example of a UE 116 in a wireless communication system according to various embodiments of the present disclosure. The embodiment of the UE 116 shown in FIG. 3A is for illustrative purposes only, and the UEs 111-115 in FIG. 1 may have the same or similar configuration. However, the UEs are made up of various diverse configurations, and Fig. 3a does not limit the scope of the invention to any particular implementation for the UE.

The UE 116 includes an antenna 305, a radio frequency (RF) transceiver 310, a transmit (TX) processing circuit 315, a microphone 320, and a receive (RX) processing circuit 325. The UE 116 also includes a speaker 330, a main processor 340, an input / output (I / O) interface 345, a touchscreen 350, a display 355, and a memory 360. Memory 360 includes an operating system (OS) 361 and one or more applications 362.

The RF transceiver 310 receives from the antenna 305 an inbound RF signal transmitted by the eNB of the network 100. The RF transceiver 310 down-converts the inbound RF signal to produce an intermediate frequency (IF) or baseband signal. The IF or baseband signal is sent to an RX processing circuit 325 that generates the processed baseband signal by filtering, decoding, and / or digitizing the baseband or IF signal. The RX processing circuitry 325 sends the processed baseband signal to the speaker 330 (e.g., for voice data), or to the main processor 340 for further processing (e.g., for web browsing data).

The TX processing circuitry 315 receives analog or digital voice data from the microphone 320 or receives other outbound baseband data (e.g., web data, e-mail, or interactive video game data) from the main processor 340. TX processing circuitry 315 encodes, multiplexes, and / or digitizes its outbound baseband data to produce a processed baseband or IF signal. The RF transceiver 310 receives the outbound processed baseband or IF signal from the TX processing circuitry 315 and up-converts the baseband or IF signal to an RF signal transmitted via the antenna 305.

The main processor 340 may include one or more processors and may control the overall operation of the UE 116 by executing a basic OS 361 stored in the memory 360. In this operation, the main processor 340 controls the reception of the forward channel signals and the transmission of the reverse channel signals by the RF transceiver 310, the RX processing circuit 325, and the TX processing circuit 315 in accordance with well-known principles. In some embodiments, the main processor 340 includes at least one microprocessor or microcontroller.

The main processor 340 may also execute other processors and programs, such as those for channel quality measurement and reporting, for systems having 2D antenna arrays as described in the embodiments of this disclosure resident in the memory 360. The main processor 340 may move data into or out of the memory 360 as required by the execution process. In some embodiments, main processor 360 is configured to run applications 362 in response to signals based on OS program 361 or received from an operator or an eNB. The main processor 340 is coupled to an I / O interface 345 to provide the UE 116 with the ability to connect with other devices such as laptop computers and handheld computers. The I / O interface 345 is a communication path between this accessory and the main processor 340.

In addition, main processor 340 is connected to touch screen 350 and display 355. An operator of the UE 116 may input data to the UE 116 using the touch screen 350. Display 355 may be, for example, a liquid crystal display, a light emitting diode display, or other display capable of rendering text and / or at least limited graphics from web sites.

The memory 360 is connected to the main processor 340. A portion of memory 360 may include random access memory (RAM), and another portion of memory 360 may include flash memory or other read only memory (ROM).

3A shows an example of a UE 116, but various changes may be made to FIG. 3A. For example, the various components of FIG. 3A may be combined, further subdivided, or omitted, and additional components may be added according to specific needs. As one specific example, the main processor 340 may be divided into a plurality of processors, for example, one or more central processing units (CPUs) and one or more graphics processing units (GPUs). In addition, although FIG. 3A shows a UE 116 configured as a mobile phone or smartphone, the UEs may be configured to operate as other types of mobile or fixed devices.

3B illustrates an example of an eNB 102 in a wireless communication system according to various embodiments of the present disclosure. The embodiment of eNB 102 shown in FIG. 3B is for illustrative purposes only, and the eNBs of FIG. 1 may have the same or similar configuration. However, the eNBs are comprised of various diverse configurations, and Fig. 3b does not limit the scope of the invention to any particular implementation of the eNB.

As shown in FIG. 3B, the eNB 102 includes a plurality of antennas 370a-370n, a plurality of RF transceivers 372a-372n, a TX processing circuit 374, and an RX processing circuit 376. In some embodiments, at least one of the plurality of antennas 370a-370n includes 2D antenna arrays. The eNB 102 also includes a controller / processor 378, memory 380, and a backhaul or network interface 382.

RF transceivers 372a-372n receive incoming RF signals, such as those transmitted by the UEs in network 100, from antennas 370a-370n. RF transceivers 372a-372n down-convert inbound RF signals to produce IF or baseband signals. The IF or baseband signals are sent to an RX processing circuit 376 that generates the processed baseband signals by filtering, decoding, and / or digitizing the baseband or IF signals. The RX processing circuitry 376 sends these processed baseband signals to the controller / processor 378 for further processing.

TX processing circuit 374 receives analog or digital data (e.g., voice data, web data, e-mail, or interactive video game data) from controller / processor 378. TX processing circuitry 374 encodes, multiplexes, and / or digitizes the outgoing baseband data to produce processed baseband or IF signals. RF transceivers 372a-372n receive outbound processed baseband or IF signals from TX processing circuitry 374 and up-convert the baseband or IF signals to RF signals transmitted via antennas 370a-370n .

Controller / processor 378 may include one or more processors or other processing devices that control the overall operation of eNB 102. For example, controller / processor 378 may control the reception of forward channel signals and the transmission of reverse channel signals by RF transceivers 372a-372n, RX processing circuitry 376, and TX processing circuitry 374 in accordance with well- have. Controller / processor 378 may also support additional functions such as more advanced wireless communication functions. For example, the controller / processor 378 may perform a BIS process such as performed by a blind interference sensing (BIS) algorithm, and the interference signals decode the subtracted received signal. Any of a variety of other various functions may be supported by the eNB 102 by the controller / processor 378. In some embodiments, the controller / processor 378 includes at least one microprocessor or microcontroller.

Controller / processor 378 may also execute programs and other processes, such as an OS, residing in memory 380. Controller / processor 378 may also support initial access operations in the wireless system, as described in the embodiments of this disclosure. In some embodiments, the controller / processor 378 may support inter-entity communication such as real-time communication (RTC). Controller / processor 378 may move data into or out of memory 380 as required by the execution process.

Controller / processor 378 is also coupled to backhaul or network interface 382. The backhaul or network interface 382 enables the eNB 102 to communicate with other devices or systems over a backhaul connection or over a network. The interface 382 may support communications over any suitable wired or wireless connection (s). For example, when the eNB 102 is implemented as part of a cellular communication system (e.g., supporting 5G, LTE, or LTE-A), the interface 382 may allow the eNB 102 to communicate with other eNBs Lt; / RTI > When the eNB 102 is implemented as an access point, the interface 382 enables the eNB 102 to transmit over a wired or wireless local area network or over a wired or wireless connection to a larger network (e.g., the Internet). The interface 382 includes any suitable structure that supports communications over a wired or wireless connection, e. G., An Ethernet or RF transceiver.

Memory 380 is coupled to controller / processor 378. A portion of memory 380 may include RAM, and another portion of memory 380 may include flash memory or other ROM. In some embodiments, a plurality of instructions, such as a BIS algorithm, are stored in memory. The multiple instructions cause the controller / processor 378 to perform the BIS process and to decode the received signal after subtracting at least one interfering signal determined by the BIS algorithm.

As described in more detail below, the transmit and receive paths (implemented using RF transceivers 372a-372n, TX processing circuitry 374, and / or RX processing circuitry 376) of the eNB 102 are coupled to FDD cells and TDD cells It supports communication by aggregation.

Although FIG. 3B shows an example of eNB 102, various changes may be made to FIG. 3B. For example, eNB 102 may include any number for each component shown in FIG. As one particular example, an access point may include multiple interfaces 382 and controller / processor 378 may support routing functions to route data between different network addresses. As another specific example, illustrated as including a single instance TX processing circuit 374 and a single instance RX processing circuit 376, the eNB 102 may include a plurality of instances for each (e.g., per RF transceiver one).

Before the UE sends data to or receives data from the eNB, the UE first requires performing a cell search procedure to obtain time and frequency synchronization with the eNB. The four major synchronization requirements are: Carrier frequency offset (CFO) correction, 3) sampling clock synchronization, and 4) PCI (physical cell identity) detection and potentially other cell specific parameters.

4 illustrates an exemplary synchronization operation performed by a UE according to embodiments.

In step 405, after the power is turned on, the UE tunes its RF and, in turn, transmits a received signal (e.g., a received signal) at specific frequencies (channels commanded by the upper layer) through a series of supported frequency bands strength indicator (RSSI), and ranks the related cells based on their respective RSSI values.

In step 410, the UE correlates with the received signal using downlink synchronization channels, i.e., a locally stored primary synchronization signal (PSS) and a secondary synchronization signal (SSS). The UE first looks for a PSS that is located for the FDD system, e.g., in the last symbol of the first time slot of the first and sixth subframes in the frame. This enables the UE to synchronize with the eNB at the subframe level. PSS detection assists the UE with slot timing detection and physical layer cell identity (PCI) detection (0, 1, 2) based on three sequences. The three sequences are used by the PSS to mitigate the so-called single frequency network (SFN) effect, where the correlation output may exceed the cyclic prefix (CP) length.

In step 415, the SSS symbols are also located in the same subframe as the PSS, but are located in the symbol prior to the PSS for the FDD system. From the SSS, the UE can obtain the PCI group number (0 to 167). The SSS enables determination of additional parameters such as wireless sub-frame timing determination, CP length determination, and whether the eNB uses FDD or TDD. This process is shown in the LTE cell search procedure shown in Fig.

In step 420, if the UE is aware of the PCI for a given cell, the UE may also select the cell-specific reference signals (CRS) used for channel estimation, cell selection / I know the location. After channel estimation using CRS, equalization is performed to remove channel impairments from received symbols.

In step 425, the UE decodes a primary broadcast channel (PBCH) to determine a DL bandwidth, a DRS transmission power, a number of eNB transmitter antennas, a system frame number (SFN), and a PHICH A master information block (MIB), which carries important system information such as the setting for the ARQ channel, can be obtained.

Table 1 below shows SSS locations for PSS locations for both TDD-based and FDD-based systems. In the case of FDD, the PSS is always transmitted in the last symbol of the slot, making it possible for the UE to obtain slot timing independent of the CP length. Since the UE does not know the CP length in advance, when the UE searches for one of FDD or TDD cells, the UE needs to check a total of four possible SSS positions. Two SSS codes are alternately repeated between the first and second SSS transmissions in the sub-frame that enable the UE to determine the radio timing from a single observation of the SSS, which is handed over from another RAT to the LTE May be beneficial for UEs.

<Table 1>

5 illustrates an exemplary frame structure of a PSS / SSS / PBCH transmission in an FDD configuration according to embodiments of the present invention.

The PSS and the SSS are always transmitted in the six central RBs, so that the UE of the minimum bandwidth can also detect the signals. For multiple transmit antennas, the PSS and SSS are always transmitted from the same antenna port in a given sub-frame, while they can be switched between sub-frames for antenna diversity. The PBCH carries a MIB with only 14 bits carrying some of the most frequently transmitted parameters essential for initial access to the cell, such as DL system bandwidth, PHICH size and SFN number. This is repeated every 40 milliseconds.

The PSS and the SSS are always transmitted in six resource blocks (RBs) in the center of the DL system bandwidth, and thus they can be detected by the UE before the UE determines the DL system bandwidth The bandwidth is assumed to be six RBs). The PSS is generated by a Zadoff-Chu (ZC) sequence of length 63 in the frequency domain, and the center element is punctured to avoid transmission on the DC subcarrier. The ZC sequence shows that the PSS is time-frequency flat (with low PAPR / CM and no dynamic range in the frequency domain), good auto / cross-correlation profile, low complexity detection in UE (complex conjugate property And constant amplitude zero autocorrelation (CAZAC), which makes it possible to have characteristics such as, for example, using the center symmetry characteristic in the time domain and the frequency domain, using u2 = 63-29 = 34) do. However, due to the CAZAC characteristic duality in the time and frequency domains, the ZC sequence shift in the frequency domain is also transformed in the time domain, and vice versa. Thus, in a timing synchronization environment using ZC sequences, the frequency / time offsets each represent a time / frequency offset, and the offsets of these two dimensions can not be distinguished. The root indexes of the available root ZC sequence index vectors have a low frequency offset sensitivity, and for this reason, root indices u = 25, 29 and 34 are selected in LTE to provide three cell IDs within the cell ID group. The selection of root indices also considered partial correlation to overcome the large frequency offset in the initial cell search. Because of the phase rotation in the time domain as a result of large frequency offsets, the partial correlation can be reduced to ZC &lt; RTI ID = 0.0 &gt; But need to be considered in other sequences as well as in sequences.

The A PSS sequence x (n) consists of a sequence of length N _ZC root u _i ZC and is given by:

(수학식 1)

(1)

The LTE ZC sequence is mapped to achieve a center symmetric property (i. E., Index 5 corresponds to a DC sub-carrier for an RB including 12 sub-carriers indexed from 0 to 11). SSS sequences are based on M-sequences. The 168 sequences are generated by frequency-domain interleaving of two length-31 BPSK-modulated M-sequences, where the two length-31 M-sequences are derived from two different cyclic shifts of a single length-31 M-sequence do. The two sub-structures of the SSS result in side-lobes during cross-correlation and mitigate this sidelobe using scrambling. In the case of SSS, coherent detection is possible if channel estimates can be obtained through PSS detection.

In order to achieve better performance of coherent detection on the SSS by estimating the channel from the PSS, multiple PSS sequences are used as a trade-off in the PSS detection complexity. Improved channel estimation accuracy can be enabled by mitigating the SFN effects that exist because they have a single PSS sequence from all cells as a result of different PSS sequences. Thus, the PSS / SSS design described above can support both coherent and non-coherent SSS detection. The UE needs to operate three parallel correlators for three different PSS sequences. However, the root indices 29 and 34 are conjugate complex numbers with respect to each other, which enables a 'one-shot' correlator-the two correlation outputs for u = 29 and 34 are u = 34 or u = 29 can be obtained from the correlation. The conjugate property maintains a center symmetric mapping in the frequency domain, for both the time domain and the frequency domain, for all sampling rates. Thus, only two parallel correlators are needed (one for u = 25 and the other for u = 29 (or u = 34)).

There is a need to improve existing synchronization and cell search procedures for new communication systems, such as 5G, for at least the following reasons: (1) beamforming support: to operate in high carrier frequency bands such as above 6 GHz In order to meet link budget requirements, beamforming is required for transmissions by the eNB (and possibly also by the UE). Thus, the synchronization and cell search procedures described above need to be updated for beamforming support. (2) Large Bandwidth Support: When operating at large system bandwidths, such as 100 MHz or higher, different sub-carrier spacings for operating in smaller system bandwidths may be applied and for synchronization and cell search procedure design This design needs to be considered. (3) Coverage enhancement: For some applications, such as those related to requirements for increased coverage that may arise due to placement of UEs in locations experiencing large path loss, the synchronization and cell search procedures may include coverage enhancement and synchronization It is necessary to support the repeated increase of the signals. (4) Performance improvement: The synchronization performance of the procedure described above is limited due to false alarms caused by splitting the cell ID into 1 PSS and 2 SSS, which causes erroneous combinations of PSS / SSS that can not be completely resolved by scrambling . A new synchronization procedure with improved false alarm performance can be designed. (5) Support for variable TTI: In the current LTE Rel-13, the TTI duration is fixed. However, for 5G systems, the TTI is expected to be variable due to support for different sub-carrier intervals, low latency considerations, and the like. In scenarios with this variable TTI, the synchronization sequences in the frame and the mapping of the cell search need to be specified.

Figure 6 illustrates an example of a transmission technique applied by an eNB to utilize transmit beamforming in a wireless communication system in accordance with various embodiments of the present disclosure.

That is, FIG. 6 shows that the transmission beamforming can be employed by the eNB to overcome higher propagation losses for a given propagation distance, observed at higher transmit carrier frequencies relative to lower transmit carrier frequencies. Lt; / RTI &gt; illustrates an exemplary transmission scheme. As shown in FIG. 6, the eNB 601 provides services to UEs in a specific geographic coverage area 602. The coverage area 602 may be an irregular shape in some implementations.

The eNB may form the transmit beam by applying appropriate gain and phase settings to the antenna array. The transmission gain, i.e., the amplification of the transmission signal power provided by the transmission beam, is typically inversely proportional to the width or area covered by the beam. At lower carrier frequencies, better propagation losses may enable the eNB 601 to provide coverage with a single transmit beam, i.e., at all UE locations within the coverage area 602 through the use of a single transmit beam, Thereby assuring the received signal quality. In other words, at lower transmission signal carrier frequencies, the transmit power amplification provided by the transmit beam having a width large enough to cover the coverage area 602 is sufficient to overcome the propagation losses to provide adequate reception at all UE locations within the coverage area 602 May be sufficient to ensure signal quality. However, at higher signal carrier frequencies, transmit beam power amplification corresponding to the same coverage area may not be sufficient to overcome higher propagation losses, resulting in signal quality received at UE locations within coverage area 602 .

To overcome this degradation of received signal quality, the eNB 601 may form multiple transmit beams, each transmit beam providing coverage over a narrower area than the entire coverage area 602, but the use of higher transmit signal carrier frequencies Lt; RTI ID = 0.0 &gt; of the &lt; / RTI &gt; As shown in FIG. 6, the eNB 601 forms N transmit beams indexed from 1 to N. 1 has a radiation pattern (i.e., a relative coverage area 603 with peak amplification gain, a peak transmit power direction 604 within the entire coverage area 602). Each of the transmit beams having a different peak power direction; The N indexed beam has a radiation pattern 605 with a peak transmit power direction 606 in the entire coverage area 602. A series of coverage areas, which are enabled by the use of a series of transmit beams indexed from 1 to N, taken together, are overlapped with the desired coverage area 602.

The eNB 301 may serve UEs over the entire coverage area 602 by utilizing the beam beams 1 through N utilizing the exemplary beam sweeping technique 607, where the eNB 601 is a continuous OFDM (orthogonal frequency division multiplexing &lt; / RTI &gt; symbols. Each OFDM symbol spans 608 T seconds and occupies S sub-carrier (SC) 609 frequencies equal to the bandwidth of W Hz. eNB 601 transmits OFDM symbol #N through transmission beam # 1, such as transmitting OFDM symbol # 1 through transmission beam # 1 and OFDM symbol # 2 through transmission beam # 2, and also transmits OFDM symbol # Can be repeated. With this technique, a transmission beam corresponding to a particular OFDM symbol provides an appropriate received signal quality for a set of UEs in the coverage area of that beam; The set of UEs and the coverage area of the beam are respectively a set of all UEs that need service and a sub-set of the entire coverage area 602. The N transmit beams, which are used with a set of N consecutive OFDM symbols each having a different coverage area in the overall coverage area 602, provide coverage to a set of UEs in the overall coverage area 602. Instead of using a specific beam direction for transmission of each OFDM symbol, it can be seen that the eNB can rotate the beam directions using the same beam direction to transmit a set of OFDM symbols rather than a single OFDM symbol.

The legacy synchronization and cell search procedure in LTE Rel 13, which is based on the use of PSS and SSS described above in the present invention, will also be used in the environment of the eNB using the beam sweep transmission technique as in 607 of FIG. 6 .

Figure 7 illustrates an example of PSS and SSS extension in a wireless communication system in accordance with various embodiments of the present disclosure. As shown in FIG. 7, the sub-frame (SF) 701 includes exemplary 14 OFDM symbols, which are one of the settings for the number of OFDM symbols in the SF according to legacy specifications. In this example, the eNB uses seven transmit beams, which provide the coverage needed for the UEs served by the eNB, as described in the context of FIG. As in the legacy system, SSS 702 and PSS 703 are each transmitted in 63 sub-carriers (SC) 704 symmetrically located around the DC SC 705 defining the center of the bandwidth occupied by SF 701. As in legacy systems, the SSS and PSS are transmitted in consecutive symbols in chronological order. However, different transmission beams are used for each set of SSS & PSS transmissions.

As shown in FIG. 7, a transmission beam indexed with 1 is used to transmit OFDM symbols indexed with 1 and 2, and SSS and PSS are transmitted in symbols 1 and 2, respectively. UEs within the coverage area of transmit beam # 1 can perform legacy PSS and SSS based synchronization cell ID acquisition operations using received samples corresponding to PSS and SSS frequency occupied regions, as described above in the present invention . The eNB then sends the SSS and PSS over transmit beam # 2 in symbols 3 and 4, respectively, and continues as shown in FIG. Thus, by using seven transmission beams in turn, through 14 symbols in SF 701, the eNB is able to guarantee the proper reception SSS / PSS signal quality for any location within the eNB coverage area, And PSS to the UEs. As a result, UEs within the entire eNB coverage area can perform legacy SSS & PSS-based synchronization and cell ID acquisition operations.

In an exemplary extension of the scheme of Figure 7, an eNB with N transmit beams can receive, via a beam sweep scheme, described above in the context of Figure 7, the received SSS / PSS signal quality for any location within the eNB coverage area 2N OFDM symbols to complete the SSS / PSS transmissions, while ensuring that it is adapted to enable UE synchronization. It should be noted that these beam sweeping-based SSS / PSS transmissions may span a sequence of multiple SFs and may also occupy some of the OFDM symbols in the last SF of this sequence.

The problems caused by this exemplary modification of the legacy synchronization and cell search procedure are as follows. In legacy systems, a single beam is used to transmit continuous OFDM symbols and SSS and PSS periodically every 5 ms. Thus, knowing the period of the PSS / SSS, the UE can obtain the OFDM symbol timing as well as the system frame timing using the PSS and SSS, as described in the context of Table 1. However, in the above exemplary modifications, the UE does not know a priori the number of beams N used by the eNB. The UE may obtain OFEM symbol timing and cell ID information from the PSS / SSS transmitted from the specific beam covering the UE location within the full coverage area of the eNB. However, because the beam generation order in the set of OFDM symbols being used by the eNB for PSS / SSS transmissions is unknown, the UE can not obtain further frame timing. In other words, if the UE completes the PSS / SSS-based synchronization and cell ID detection, the PSS / SSS does not know the locations of the OFDM symbols that were transmitted in the SF, so that even if the UE knows the number of OFDM symbols for each SF, SF and therefore frame boundaries.

FIG. 8 illustrates another example of an extension of the PSS and the SSS for solving the above-described timing ambiguity problem according to the embodiments of the present invention. As shown in FIG. 8, SF 801 includes 14 exemplary OFDM symbols. In this example, the eNB utilizes 14 transmit beams to provide the necessary coverage for the UEs served by the eNB, as described in the environment of FIG. In addition to the PSS and SSS, another synchronization signal, referred to as an Extended Synchronization Signal (ESS) 804, is defined. As with the SSS and PSS 802 and 803 respectively, the ESS 804 occupies 63 SCs in one symbol. As shown in FIG. 8, PSS, SSS, and ESS are transmitted in 63 * 3 = 189 SC 805 symmetrically located around the DC SC 806 defining the center of the bandwidth occupied by the SF 801. The PSS occupies 63 SCs in the center, and the SSS and the ESS occupy 63 SCs above and below the SC scope of the PSS, respectively.

In each of the symbols of SF 801, the sequence representing the index of the OFDM symbol is mapped to the ESS SCs of the corresponding symbol. An exemplary method for generating such sequences is as follows. The set of ZC sequences can be derived from the root ZC sequence by applying a set of cyclic shift (CS) values to the root ZC sequence. The system specifications can then define a mapping from each ZC sequence in the set to a particular OFDM symbol in the SF. In other words, the system specifications may define a mapping between the symbol index and the particular CS value to be used for the root ZC sequence to derive the ZC sequence to be mapped to the ESS region of the corresponding symbol of SF. In a particular exemplary system with 14 symbols and 14 transmit beams of SF 501, 14 CS shifts of the root ZC sequence need to uniquely identify each symbol through the ZC sequence mapped to it.

The eNB transmits each of the 14 symbols in the SF using different transmission beams and thus cycles through all 14 of its 14 transmission beams through the 14 symbol periods of SF 501. UEs in the coverage area of a particular transmit beam can then use the received samples corresponding to the PSS and SSS frequency occupied regions in the transmitted symbols using the corresponding beam to perform the legacy synchronization and cell ID acquisition operations . They can also derive symbol indices in the SF using received samples corresponding to the ESS frequency occupied areas within the same symbol. The derivation of the symbol index can be achieved in the context of the CS-Shift-based example technique described above as follows. Using the specification-based knowledge of the root ZC sequence, the UE can estimate CS from the received samples corresponding to the ESS frequency occupied region in the symbol. The CS value in the features closest to the estimated value can then be selected, from which the symbol index is reached via a specification-definition mapping between the CS and the symbol index. Then, by knowing the number of symbols and indexes of symbols in the SF, the UE is enabled to determine the SF and frame boundaries.

Further, as described in the context of FIG. 6, beam sweeping by the eNB allows UEs in the entire eNB coverage area to perform legacy SSS & PSS-based synchronization and cell ID acquisition operations, Can be used to ensure that the SF boundaries can be determined.

A problem that can arise with this technique is the requirement for multiple CS values. In a multi-cell scenario where multiple cells use these ZC sequences, the reliability of the CS detection of a particular ZC sequence depends on the relative CS between this sequence and other sequences transmitted at the same time. Generally, for ZC sequences of a given length, larger relative CS values can be guaranteed when the number of required CSs is smaller. The present invention provides several embodiments for reducing the number of CS values required for ESS operation.

Some terms to be used in some disclosures of embodiments of the present disclosure are now defined. The abbreviation TCSS (timing and cell identity synchronization signal) is used to refer to timing and cell ID synchronization signals. The TCSS enables the UE to recover OFDM symbol timing information and the cell ID of the eNB transmitting the TCSS. The TCSS also enables UE calibration for frequency offsets between the UE and eNB local oscillators. The TCSS may be composed of two separate parts by way of being transmitted at physically different time and / or frequency resources. The first part of the TCSS may enable UE recovery of OFDM symbol timing information and the second part may possibly enable cell ID recovery, possibly in combination with the first part. Both portions or either portion, alone or in combination, may enable correction of frequency offsets or other impairments. The legacy synchronization channel design is an example of such a partition where the PSS and the SSS each include the first and second portions of the TCSS. The abbreviation ESS (extended synchronization signal) is used to refer to the extended synchronization signal. The ESS makes it possible for the UE to determine the index of the OFDM symbol or symbols to which it is transmitted. The UE first performs symbol timing recovery and cell ID determination, and then determines an OFDM symbol index.

Example Set 1

The set of embodiments discloses the placement and description of TCSS and ESS in transmitted OFDM symbols such that the identity (including length) of the sequences mapped to the ESS determines the index of the OFDM symbol from which it is transmitted .

9 illustrates an example of the placement of TCSS and ESS in OFDM symbols transmitted in a wireless communication system in accordance with various embodiments of the present disclosure. Figure 9 shows K sequentially transmitted SFs 901, 905 and 906, each of which is numbered from S to (S + K-1), including NS OFDM symbols, and these component OFDM symbols All or part of which includes TCSS and ESS regions. Among these SFs, subframe 901 represents one SF in a series of SFs transmitted by an eNB including TCSS and ESS regions, and has an index S. Each OFDM symbol of SF 901 includes TCSS 902 and ESS 903 regions. The TCSS region 902 occupies N _TC = N _Lower + N _Upper + 1 SC in each OFDM symbol in which it occurs, where N _Lower may be zero or a positive integer, and so is N _Upper . As shown in FIG. 9, the N _TC SCs constituting the TCSS are arranged around the band center or the DC SC 904, of which the N _Upper is arranged in the SCs having a higher index than the DC SC 904, and the N _Lower Are arranged in the SCs having an index lower than the SC DC SC 904.

In some embodiments, if N _TC is an odd number, the TCSS region may be symmetrically disposed about DC SC 904 with N _power = N _Lower = (N _TC -1) / 2. In some embodiments, if N _TC is an even number, N _Upper may include one more SC than N _Lower (i.e., N _Upper = N _Lower + 1), or N _Lower may be one more than N _Upper SC (i.e., N _Lower = N _Upper + 1). In some embodiments, the TCSS and ESS regions are not provided starting from the first symbol of the first SF #S in the sequence of SFs, but are provided starting with a specific symbol #N _A of N _A NS . In other words, the first occurrence of the TCSS and ESS regions may be in a symbol other than the first symbol of the SF.

ESS region 903 occupies the maximum N _{E, Max} SCs in each symbol of SF 901, which are adjacent to the TCSS region and have SC indices lower than the TCSS SC indices. In the symbol of SF 901, the maximum occupation value of ESS is N _{E, Max} SC, but the actual occupancy value may be smaller than N _{E, Max} SC. This will be described in more detail in the following description.

As shown in Fig. 9, the eNB transmits each OFDM symbol including TCSS and ESS regions using different transmission beams. The rationale for such a beam sweep transmission scheme is as described in the context of FIGS. 6 and 7 herein. In the example of FIG. 9, the eNB has a certain number of N _B 907 transmit beams, where N _B may be zero or a positive integer. eNB uses all the N _S OFDM symbols of SF # S 901 to SF # (S + K - 2) 905 and the first N _P of N _S OFDM symbols of SF # (S + K - Accordingly, N _B = N _S (K - 1) + N _P.

및 N_P = N_B - N_S·K로서 계산될 수 있으며, 여기서

는 a의 플로어 연산(floor operation)을 나타내는 것으로서, a보다 작거나 같은 가장 큰 정수를 생성한다.A. Given a value N _{B for} the number of eNB transmission beams and a number N _S of OFDM symbols per SF including TCSS and ESS regions, K and N _P are

And N _P = N _B - N _S K, where

Represents the floor operation of a and produces the largest integer less than or equal to a.

FIG. 9 specifically shows a case where the number of transmission beams N _B is larger than the number N _S of OFDM symbols in SF. In some embodiments, the number N _B of transmit beams may be less than or equal to N _S. In embodiments where the number of transmit beams N _B is equal to N _S , the formula in (A) yields K = 1 and N _P = 0. That is, the eNB uses all N _S OFDM symbols in a single SF for beam sweeping TCSS and ESS transmissions. In the embodiments in which the number of transmission beams N _B is less than N _S , the formula of (A) above yields K = 0 and N _P = N _B. That is, the eNB uses the first N _B symbols of the N _S OFDM symbols in a single SF for beam sweeping TCSS and ESS transmissions.

In the case of each OFDM symbol including the ESS region in FIG. 9, the sequence indicating the index of the corresponding OFDM symbol in the SF in which it appears is mapped to the ESS SCs of the corresponding symbol. Thus, the sequence associated with the ESS region in a particular symbol in SF represents an integer between them, including 1 and N _S as the index of the corresponding OFDM symbol in the SF. In some embodiments, this sequence not only represents the index of the corresponding OFDM symbol in the SF in which it appears, but also the index of the corresponding SF in the sequence of consecutive SFs containing symbols with ESS regions.

Techniques for mapping the sequence to the ESS region, as well as the UE operation for the execution of the TCSS and ESS regions and other regions of the SF, are disclosed as follows. A particular sequence of sequences of sequences, all having the same length, may be mapped to the ESS region of a symbol with a particular index. In some embodiments, a sequence of ZC root sequences may be defined with a set of CS values for each ZC root sequence, with all ZC root sequences having the same length. 8, the set of ZC sequences is determined by applying a set of cyclic shift (CS) values defined for that root sequence to the corresponding root ZC sequence, Sequence. &Lt; / RTI &gt; This derived ZC sequence can be mapped to the ESS region of the symbol having the specific index. Thus, for each particular symbol index, a mapping may be defined that specifies a particular ZC root sequence and CS value used to derive the ZC sequence to be mapped to the SCs in the ESS area within that symbol.

In some embodiments, the sequence of ZC root sequences consists of a single ZC root sequence. In some embodiments, the length of the ZC root sequence is equal to the number of SCs in the ESS region. In some embodiments, the length of the ZC root sequence is the nearest prime number that is less than or equal to the number of SCs in the ESS region. In some embodiments, the cross-correlation between any pair of sequences in the set may be made with some suitable characteristics, such as an exemplary characteristic that is much smaller than the auto-correlation of either of them, All sets of pseudo-noise (PN) sequences may be derived. A first sequence with a first index in the set is then mapped to an OFDM symbol with a first index, a second sequence with a second index in the set is mapped to an OFDM symbol with a second index, The mapping between the sequences in the set and the OFDM symbol indices in the SF can be defined.

을 갖는 길이 N의 시퀀스의 경우, 자기 상관은

로 정의되며, 여기서

는

의 공액 복소수를 나타낸다.Sequence value

In the case of a sequence of length N with

Lt; / RTI &gt;

The

&Lt; / RTI &gt;

를 갖는 길이 N의 다른 시퀀스의 경우, 두 개의 시퀀스들 간의 교차 상관은

으로 정의된다.Sequence value

In the case of another sequence of length N with &lt; RTI ID = 0.0 &gt;

.

In some embodiments, the length of the PN sequences is equal to the number of SCs in the ESS region. In some embodiments, the length of the PN sequences is one less than the number of SCs in the ESS region.

The UE operation in this case will be described in detail below. The operation of the UE attempting the system entry is as follows. Based on the definition of the system specification, the UE recognizes the frequency location of the TCSS and ESS regions, and the details of the sequence of sequences mapped to the ESS region, i. In the context of this sequence example, the UE recognizes the sequence of ZC root sequences and the details of the set of CS shifts that can be applied to each of them. In the environment of the sequence example, the UE recognizes the details of the set of PN sequences.

Also, for each OFDM symbol in the SF, or for each OFDM symbol in the set of sequential SFs comprising TCSS and ESS regions, the UE recognizes a particular sequence in the sequence mapped to the ESS region of that symbol. In the context of this example of the sequence, for each OFDM symbol in the SF, the UE recognizes the particular ZC root sequence and CS value used to generate the ZC sequence mapped to the ESS area of the symbol. In the environment of the above sequence example, the UE recognizes the index of a specific PN sequence mapped to the ESS area of the corresponding symbol.

The UE first determines the symbol timing based on the received samples corresponding to the TCSS frequency occupied area. This allows the UE to determine the received samples corresponding to the ESS frequency occupied area in the symbol.

In the exemplary case of (i) above, where the ZC sequence is used, an exemplary UE operation for determining the index of a corresponding OFDM symbol is as follows. For each hypothesis regarding the ZC root sequence, the UE estimates the CS from the samples received via the ESS frequency occupied region in the symbol, and compares this estimated CS value with the set of allowed CS values defined for that route sequence Can be compared. For all root sequences and CS value hypotheses, the UE may select the root sequence and the estimated CS value that provide the closest match to the allowed root sequence and CS value as the correct hypothesis. The UE may use knowledge of the mapping between the ZC root sequence and the CS value combinations for the symbol indices to determine the symbol index from the assumed ZC root sequence and CS value.

For example, if PN sequences are used, an exemplary UE operation for determining the index of a corresponding OFDM symbol is as follows. For each hypothesis about the index of the PN sequence, the UE may estimate the correlation metric based on the correlation between the samples received via the ESS frequency occupied region in the symbol and the specific PN sequence corresponding to that index. The PN sequence index resulting in the highest value of such a metric can be selected as the correct hypothesis. Using knowledge of the mapping between PN sequence indices and symbol indices, the UE may determine a symbol index from a PN sequence index that is assumed to be correct.

The operation of the UE that has completed the system entry process and, as a result, determines positions at the sequence occurrence time of SFs including TCSS and ESS areas as in 901, 905 and 906 are as follows. Through definition of the system specification, this UE recognizes the locations of TCSS and ESS regions within the symbols of these SFs and recognizes that these areas are reserved by the eNB for transmission related to the synchronization function. As a result, if the resource allocation made for the UE by the eNB includes the TCSS and ESS regions of some symbols, the UE interprets the resource allocation as not including these regions. Likewise, when allocating resources for transmission to UEs in such SFs, the eNB is not limited to the parameters of the resource allocation, such as the number of information bits, but also the sub-carriers in the TCSS and ESS regions of the SF It may implicitly provide a modulation and coding scheme (MCS) for handling non-use. The UE may process transmissions received from the eNB, assuming such rate matching. As an example, when the eNB makes a resource allocation including the symbol # 2 in the SF # S 601, both the eNB and the UE implicitly interpret the allocation as not including the TCSS and the ESS region in the corresponding symbol. Conversely, when the eNB allocates a resource including the symbol # (N _P +1) to the SF # (S + K-1), both the eNB and the UE allocate the allocation implicitly Interpret.

는, 가능한 시퀀스 길이들 각각이 N_{E, Max}보다 작거나 같은 것으로, 즉

인 것으로 정의될 수 있다. 그 다음, SF의 각 N_S 심볼들의 ESS 영역들에 대한 L 시퀀스 길이들

의 맵핑이 정의될 수 있다. 일 예로서,

에 있어서, 길이

을 가진 시퀀스가 심볼 #1에 맵핑될 수 있고, 길이

를 가진 시퀀스가 심볼 #2에 맵핑될 수 있으며, 나머지도 이와 같이 되어 길이

의 시퀀스가 심볼 #L에 맵핑되고, 그 후에 길이

의 시퀀스가 심볼 #(L+1)에 맵핑되는 맵핑 반복이 뒤따르게 된다.A sequence of a specific length may be mapped to an ESS region of a symbol having a specific index by transmitting sequence values in the SCs of the ESS region within the symbol; The lengths of the sequences mapped to different symbols may be different. Since the ESS area 903 occupies the largest N _{E, Max} SCs, a sequence with a maximum length N _{E, Max} can be used. Set of L sequence length

Each of the possible sequence lengths is less than or equal to N _{E, Max} ,

. &Lt; / RTI &gt; Then, the L sequence lengths for the ESS regions of each N _S symbols of SF

Can be defined. As an example,

, The length

May be mapped to symbol &lt; RTI ID = 0.0 &gt;# 1, &lt; / RTI &

May be mapped to symbol # 2, and the remainder may be mapped to symbol # 2,

Is mapped to symbol &lt; RTI ID = 0.0 &gt;# L, &lt;

Followed by a mapping repetition in which the sequence of symbols # (L + 1) is mapped to symbol # (L + 1).

In some embodiments, L = 1, i. E., The lengths of the sequences mapped to the ESS region in any OFDM symbol of SF are the same.

III. Some embodiments may combine the techniques shown in (I) and (II) above. Thus, while a particular sequence of sequences of a first sequence, each of which has a predetermined first length, may be mapped to an ESS region of a symbol having a specific first index in the SF, each of which is different from the first sequence A particular one of the sequences of the second series, having a predetermined second length, may be mapped to an ESS region of a symbol having a second specific index different from the first index.

The operation of the UE attempting a system entry is as described above and has the following additional details: Based on the definition of the system specification, the UE determines the details of the sequence of sequences mapped to the ESS region, , And a generation rule. When attempting to identify an OFDM symbol index, the UE includes a possible sequence length in the hypothesis set. The operation of the UE completing the system entry process is the same as described above.

로 정의되며, 여기서

는 a의 플로어 연산(floor operation)을 나타내는 것으로서, a보다 작거나 같은 가장 큰 정수를 산출해 낸다.In some embodiments, the mapping of sequences for ESS regions in the symbols of SF may be determined by an ID, referred to as the ESS mapping ID, abbreviated as EMID, derived from the cell ID CID of the operating cell. Therefore, the first eNB having the first CID can derive the first EMID, while the second eNB having the second CID different from the first CID can derive the second EMID different from the first EMID. As a result, the first eNB with the first CID can use a specific first mapping of the sequences for the ESS regions of the symbols in the SFs transmitted thereby, as described in (I, II and III) above On the other hand, the second eNB having the second CID may possibly use the second mapping different from the first mapping. In some embodiments, the EMID is derived from the CID by the formula EMID = c.modulo (CID, k), where c is a constant that can be 1 and k is the number of sectors in the cell. Here, modulo (x, y) (where x and y are positive integers)

Lt; / RTI &gt;

Represents the floor operation of a, yielding the largest integer less than or equal to a.

The operation of the UE attempting a system entry is the same as in the above description and has the following additional details.

Based on the definition of the system specification, the UE recognizes the rule for calculating the EMID from the CID. Also, for each EMID, the UE recognizes the details of the sequence of sequences mapped to the ESS region for that EMID value, i. E. Structure and generation rules.

In addition to determining the symbol timing, using the received samples corresponding to the TCSS frequency occupied areas, the UE also determines the CID (cell ID) of the transmitting eNB. Thereafter, the UE computes an EMID corresponding to the corresponding CID, which allows the UE to determine the structure and generation rules of the sequence of sequences mapped to the ESS region for that EMID value.

When attempting to identify an OFDM symbol index, the UE limits the hypotheses about the sequences to retrieve a set of sequences corresponding to a particular computed EMID value.

The operation of the UE that has completed the system entry process is as described above.

This scheme has the advantage of reducing UE complexity by reducing the number of sequence characteristic hypotheses that the UE should search for. In addition, in a multi-cell scenario, this approach improves sequence detection reliability by allowing neighboring cells to use different sequence mapping rules and hence different sequences in a particular symbol.

In some embodiments, beam sweeping is not used, i.e., the number of beams N _B = 1 in the environment of FIG. 6 is used. A technique for mapping a sequence to an ESS region to indicate that the number of beams is one and a UE operation for interpreting TCSS and ESS regions as well as other regions of the SF in this embodiment are disclosed as follows. In some embodiments, the eNB only transmits the TCSS region in the first symbol of the first SF in the sequence of SFs designated for transmission of the TCSS and ESS regions, but does not map any of the predefined sequences to the ESS region . In this case, the operation of the UE attempting the system entry is as described above. The result of the operation in the previous embodiments was the identification of the index of the symbol containing the ESS region with the detection sequence mapped to it. In this case, since the ESS sequence is not mapped to the ESS region, the UE fails to detect the ESS. The UE inferred that the eNB is using a single transmit beam and also deduces that the detected TCSS corresponds to the first SF symbol, thereby determining the SF and frame boundaries.

The operation of the UE completing the system entry process is the same as that described in (I) (iv) above. In this case, the UE transmits only the TCSS region of the first symbol in the sequence of SFs designated for transmission of TCSS and ESS regions Is used for the TCSS transmission. In all resource allocations done for the UE and including the corresponding symbol, both the UE and the eNB implicitly discount the TCSS region of the symbol from that allocation. In some embodiments, the eNB transmits TCSS and ESS regions only in the first symbol in the first SF in the sequence of SFs designated for transmission of TCSS and ESS regions. Also, a special predefined sequence, representing N _B = 1, is mapped to the ESS region.

In this case, the operation of the UE attempting the system entry is as described above. In this case, a special sequence in the ESS region is detected, which indicates the number of transmission beams N _B = 1. The UE then infers that the TCSS and ESS correspond to the first symbol in the SF and accordingly also determines the SF and frame boundaries.

The operation of the UE that has completed the system entry process is as described above. As described above, in some embodiments, TCSS and ESS regions may be specified to exist with a specific symbol index #N _A > 1 (N _A &lt; N _S ). That is, the first occurrence of the TCSS and ESS regions may be in a symbol other than the first symbol of the SF.

The following two embodiments disclose alternative arrangements of ESS regions in OFDM symbols.

Example Set 2

Referring to the arrangement of ESS regions as shown in the embodiment set 1 and shown in Fig. 9, Fig. 10 shows an example of an alternative arrangement of ESS areas in ODM symbols in a wireless communication system according to various embodiments of the present disclosure / RTI &gt; In this set of embodiments, the ESS area 1003 occupies a maximum of N _{E, Max} SCs in each symbol of the SF 701, adjacent to the TCSS area and having SC indices higher than the TCSS SC indices.

All other explanations for Example Set 1 apply to Example Set 2 as well.

Example Set 3

Referring to the arrangement of the ESS regions as shown in the embodiment set 1 and as shown in Fig. 9, Fig. 11 shows an example of another alternative arrangement of the ESS area in a wireless communication system according to various embodiments of the present disclosure. For purposes of the present invention for ESS placement, only a first SF 801, similar to the first SF 601 in FIG. 9, is shown in FIG. 10; As in FIG. 9, it should be understood that a sequence of K SFs is also transmitted.

In the set of embodiments, the ESS region 803, including the maximum N _{E, Max} SCs, is divided into two parts including N _{E, Upper} and N _{E, Lower} adjacent SCs. As shown in FIG. 8, N _{E and Upper} SCs of the ESS occupy the area adjacent to the TCSS area and have SC indices higher than the TCSS area, whereas N _{E and Lower} SCs of the ESS occupy the area adjacent to the TCSS area And has SC indices lower than the TCSS region.

1. In some embodiments, if N _{E, Max} is an even number, then the ESS region may be symmetrically disposed around the TCSS region and N _{E, Upper} = N _{E, Lower} = N _{E, Max} / 2 .

2. In some embodiments, if N _{E, Max} is an odd number, N _{E, Upper} may include N _E, one more SC than _Lower (i.e. N _{E, Upper} = N _{E, Lower} + 1 ), Or N _{E, lower} N _E, and one more SC than _Upper (ie N _{E, Lower} = N _{E, Upper} + 1).

All other explanations relating to the embodiment set 1 apply to the embodiment set 3 as well.

Example Set 4

Referring to the arrangement of the ESS regions as shown in the embodiment set 1 and shown in Fig. 9, Fig. 12 shows an example of another alternative arrangement of the ESS area in a wireless communication system according to various embodiments of the present disclosure . In the set of embodiments, techniques for the placement of the ESS region with respect to the PSS and SSS portions of the TCSS are disclosed. For purposes of the present invention for PSS, SSS, and ESS placement, only a first SF 1201, similar to the first SF 901 in FIG. 9, is shown in FIG. 12; As in FIG. 12, it should be understood that a sequence of K SFs is also transmitted.

As shown in FIG. 12, the N _PSS SCs constituting the PSS 1202 are arranged around the band center or DC SC 1205, of which N _Upper is placed in SCs having an index higher than DC SC 1205, and N _{The lower} is placed in the SCs having an index lower than the DC SC 1205.

The SSS area 1203 occupies the N _SSS SCs in the symbol, while the ESS area 1204 occupies the maximum S _{E, Max} SCs in the symbols of the SF 1201.

In the set of embodiments, in any symbol, the SSS region may have SC indices that are closer to the PSS region and lower than the PSS region, while the ESS region may have SC indices that are higher than the PSS region, adjacent to the PSS region , Or the SSS region may have SC indices higher than the PSS region while being adjacent to the PSS region, while the ESS region may have SC indices that are adjacent to the PSS region and lower than the PSS region. An exemplary case is shown in FIG. 12, where in the first symbol of SF 1201, the PSS region has SC indices higher than the PSS region, adjacent to the PSS region, and the ESS region is adjacent to the PSS region, While the positions of the SSS and ESS regions are inverted in the second symbol of SF 1201. [

The predefined mappings may be specified in terms of their frequency occupancy or in relation to the PSS, defining the positions of the SSS and ESS in each SF symbol. The UE can determine the symbol index by using knowledge of this mapping, together with the detection sequence mapped to the ESS area, using the procedures described in the embodiment set 1 environment.

In some embodiments, the positions of the ESS and SSS regions are alternately repeated for each symbol.

The operation of the UE attempting a system entry is the same as described above, with the following additional details.

Based on the definition of the system specifications, the UE recognizes the location of the PSS region, and the possible frequency locations of the SSS and ESS regions within the symbols.

The UE determines symbol timing from samples corresponding to the PSS frequency domain. When attempting to determine a cell ID that may require received samples corresponding to the SSS region, the UE searches for all possible positions in the SSS frequency domain within the symbol.

When attempting to identify an OFDM symbol index, the UE searches for hypotheses about the characteristics of the sequence mapped to the ESS region and searches for all possible ESS region locations within the symbol.

All other explanations with respect to the embodiment set 1 apply to the embodiment set 4 as well.

The following set of embodiments discloses techniques for indicating an OFDM symbol index to a UE without requiring an ESS transmission.

Example Set 5

In the set of embodiments, an OFDM symbol index is indicated to the UE using a control channel referred to as a Physical Broadcast Channel (PBCH). Unlike the ESS described in the previous embodiments in which the sequence mapped to the ESS SCs carries the symbol index, the bits in the information packet mapped to the PBCH convey that information to the UE.

Figure 13 shows the arrangement of TCSS and PBCH in the set of embodiments. For purposes of the present invention for TCSS and PBCH, only a first SF 1301 similar to the first SF 901 of FIG. 9 is shown in FIG. 13; It should be understood that with the same mapping between the transmit beam index and the OFDM symbol index in the SFs, as in Figure 9, a sequence of K SFs is transmitted as well.

13 shows the arrangement of the PBCH area 1303 in the OFDM symbols of SF1301. PBCH area 1303 includes N _PBCH SCs adjacent to the SF symbols, N ₁ SCs located away from the TCSS area and having SC indices higher than the TCSS area. The PBCH region may include pilot or reference samples that enable the channel estimation to help demodulate and decode information bits that are mapped to the PBCH region.

In some embodiments, it may be implemented as follows.

1. N ₁ SCs spaced from the TCSS area and having SC indices lower than the TCSS area may be placed in the PBCH area.

2. N ₁ may be 0, i.e., the PBCH region may be adjacent to the TCSS region.

3. The PBCH region may include a pair of adjacent regions, the first of which is arranged adjacent to the TCSS region and has SC indices higher than the TCSS region, while the second region is disposed adjacent to the TCSS region And has SC indices lower than the TCSS region.

4. Referring to the description of previous embodiments in which the symbols include adjacent ESS regions, N ₁ may be selected such that the PBCH region is adjacent to the ESS region.

5. Referring to the description of previous embodiments, where the symbols include a pair of adjacent ESS areas that are adjacent to and also adjacent to the top of the TCSS area, the PBCH area may include a pair of neighboring areas , The first of which is located adjacent to the ESS region and has SC indices higher than the ESS and TCSS regions while the second region is located adjacent to the TCSS region and has lower SC indices than the ESS and TCSS regions.

14 illustrates an example of operations performed by an eNB for placing PBCH packets in an OFDM symbol in a wireless communication system according to various embodiments of the present disclosure. 14 illustrates operations performed by the eNB to generate a PBCH packet, insert information about the OFDM symbol index, map it to the PBCH area, and transmit it in the indicated OFDM symbol.

a. In block 1401, the eNB is called an I _PBCH and operates on PBCH information bits, including B _PBCH bits.

b. In block 1402, the eNB computes a set of C _PBCH cyclic redundancy check (CRC) bits, referred to as the CRC _PBCH , from the PBCH information bits I _PBCH . Each of the C _PBCH CRC bits is a specific linear combination of B _PBCH PBCH information bits as defined in the system specifications.

c. In order to map the PBCH information bits to the PBCH region in the symbol having the index OFDMSymbolIndexInSF, the eNB performs a bitwise XOR (exclusive OR) operation between the OFDMSymbolIndexInSF represented by the binary number and the C _PBCH CRC bits calculated at 1102 in block 1403 , Yielding a set of C _PBCH bits referred to as CRC1 _PBCH . The XOR operation has the following characteristics used in this embodiment. (A) XOR (C) = A for an n-bit binary number A and all zero binary numbers C of n bits. For an n-bit binary A, (A) XOR (A) = C, that is, an XOR operation between A and itself yields all zero values C of n bits. (A) XOR (B) XOR (A) = B in the case of n-bit binary number B.

d. In block 1404, the eNB appends the C _PBCH CRC1 _PBCH bit to the end of the _PBCH information bit I _PBCH to obtain a PBCH packet, referred to as T _PBCH , that includes (B _PBCH + C _PBCH ) bits. The bits are then encoded, modulated and transmitted after mapping the modulation samples to the SCs in the PBCH region of the OFDM symbol with index OFDMSymbolIndexInSF.

Figure 15 illustrates the operations performed by a UE to recover PBCH information bits and also to recover information about OFDM symbol indexes. At block 1501, the UE recovers the OFDM symbol timing information using the TCSS region 1002.

At block 1502, using the symbol timing information from 1201, the UE demodulates and decodes samples in the PBCH region to yield a received PBCH packet T _{Rx, PBCH} containing (B _PBCH + C _PBCH ) bits. Of these, the first B _PBCH bits correspond to the received version of the PBCH information bits I _PBCH and are referred to as I _{Rx, PBCH} . The last C _PBCH bits, referred to as CRC1 _{Rx, PBCH} , correspond to the received version of the CRC1 _PBCH calculated in the eNB.

At this point, the UE does not know whether the PBCH decoding was successful, i.e. whether the set of received PBCH information bits I _{Rx, PBCH} is equal to the set of PBCH information bits set I _PBCH . To determine if PBCH decoding was successful, the UE computes a CRC, referred to as CRC2 _{Rx, PBCH,} from the received PBCH information bits T _{Rx, PBCH} . If decoding is successful, CRC2 _{Rx, PBCH} must be equal to the CRC _PBCH computed by the eNB from the PBCH information bits in step B above. However, the UE only has the available CRC1 _{Rx, PBCH} corresponding to the received version of the CRC _PBCH XORed with the OFDM symbol index. Using the XOR characteristic, the UE XORs CRC1 _{Rx, PBCH} with the values of all possible OFDM symbol indexes _, and checks which one of them matches CRC2 _{Rx, PBCH} . This is shown in 1503 to 1508.

If, as in 1504 and 1505, the CRC2 _{Rx, PBCH} , matches the XOR operation output between a particular value of the CRC1 _{Rx, PBCH} and the OFDM symbol index, PBCH decoding is declared successful and the symbol index is determined as the corresponding specific value do. If such a match does not occur for any N _S value of the OFDM symbol index in the SF, the PBCH decode is declared unsuccessful and the UE retries the PBCH reception.

Note that, in 1503, the start value of the OFDM symbol index is set to 1. This corresponds to the numbering rule shown in Fig. 13, so that the symbol index in SF goes from 1 to N _s . Alternatively, the symbol index may proceed from 0 to N _S-1 , where the starting value of the OFDM symbol index is selected as 1503.

In some alternative embodiments of this set, the following I through III may be implemented:

I. Part of the PBCH information bits may carry the index of the OFDM symbol to which they are transmitted.

II. A portion of the PBCH information bits may carry the number of transmit beams used by the eNB. In some embodiments, the PBCH information bits may convey whether a single transmit beam or more than one transmit beam is used by the eNB.

III. The PBCH-based method can be operated together with the ESS-based symbol index determination method.

16 illustrates an example of a transceiver having a multi-antenna array using one or multiple transmission beams in a wireless communication system in accordance with various embodiments of the present disclosure.

For mm wavebands, the number of antenna elements can be increased for a given form factor. However, as shown in Fig. 16, the number of digital chains must be limited due to hardware constraints (e.g., the feasibility of installing a large number of ADCs / DACs at mm wave frequencies). In this case, one digital chain is mapped to a plurality of antenna elements that can be controlled by a bank of analog phase shifters 1601. Then, one digital chain may correspond to one subarray that produces a narrow analog beam through analog beamforming 1605. This analog beam can be configured to sweep to a wider range of angles 1620 by changing the phase shifter bank over the symbols or subframes.

The eNB may cover the entire area of one cell using one or more transmission beams. The eNB may apply appropriate gain and phase settings to the antenna array to form a transmit beam. The transmit gain, i.e., the power amplification for the transmit signal provided by the transmit beam, is typically inversely proportional to the width or area covered by the beam. At lower carrier frequencies, it may be possible for the eNB to provide coverage with a single transmit beam with better propagation loss, i. E. The use of a single transmit beam, Can be guaranteed. In other words, at lower transmission signal carrier frequencies, the transmission power amplification provided by the transmission beam with a width large enough to cover the area is propagated through radio waves to ensure adequate received signal quality at all UE locations within the coverage area It may be enough to overcome the loss. However, at higher signal carrier frequencies, the transmit beam power amplification corresponding to the same coverage area may not be sufficient to overcome the higher propagation loss, and consequently the signal quality of the received signal quality at UE locations within the coverage area It may cause deterioration. To overcome this degradation of received signal quality, the eNB may form multiple transmit beams, where each transmit beam provides coverage over a narrower area than the entire coverage area, but with the use of a higher transmit signal carrier frequency Thereby providing sufficient transmit power amplification to overcome the higher signal propagation losses resulting.

At least in the frequency domain the following are supported for NR:

a. A time period that may include one or more of the following X:

i. DL transmission part,

ii. Guard, and

iii. UL transmission part.

b. The FSS indicating whether the combinations can be supported and whether they are displayed dynamically and / or semi-statically.

c. In addition, the following are supported:

i DL transmission portion of a time interval X that includes downlink control information and / or downlink data transmissions and / or reference signals; And

ii UL transmission portion of time interval X that includes uplink control information and / or uplink data transmissions and / or reference signals.

d. FFS length (s) of time interval X.

e. FFS: Another characteristic of time interval X.

f. Note: The use of DL and UL does not exclude other deployment scenarios such as side-link, backhaul, relay, etc.

In some embodiments of the invention, "subframe" or "time slot" is another name referring to "time interval X ", and vice versa.

This section describes the possible alternatives to the integration framework and the implications of this alternative. These alternatives are different at that point in whether or not the UE recognizes the beamforming approach in the initial access procedure. The information of the beamforming approach may be transmitted as (1) binary information (i.e., single beam versus multiple beams), or (2) initial access signals (e.g., synchronization signals SS) , Beam measurement signals (MRS), and number of beams (N) used for RACH.

There are at least three alternative designs in the integration framework.

Alternative 1. The beamforming approach is notified during the initial access procedure. The initial access procedure and signal mapping that occur after this approach indication can be optimized individually.

Alternative 2. The beamforming approach is notified after the initial access procedure. The initial access procedure and signal mapping methods are the same but scalable to N. The UE operation after the initial access may be optimized after the approach indication. For example, the UE may apply an appropriate rate matching to data channels with knowledge of N; UL / DL control signaling can also be individually optimized for single beam versus multiple beams.

Alternative 3. The UE is completely independent of the beamforming approach. The initial access procedure and signal mapping methods are the same. No information about this approach is signaled to the UE.

A major difference between the multiple beam versus single beam based approach is whether beam sweeping is applied to the initial access signal. Although beam sweeping is required for multiple beams to provide basic coverage for the system, this may simply be unnecessary system overhead if the system uses a single beam approach. In addition, the beam sweeping mechanism is likely to introduce additional signaling components and mechanisms that are unnecessary in a single beam system.

Thus, the NR specification allows (1) beam sweeping to be used only when an eNB is needed; And (2) if the UE is able to obtain an indication of whether or not beam sweeping is being used. The UE indication may be used for at least data channel rate matching and may also be used to adapt the UL / DL signaling content in a set beamforming approach. Alternative 3 does not seem to provide these features, so it is less desirable for us. Alternatives 1 and 2 can provide these features, so that we can further study these two alternatives.

In Alternative 1, a beamforming approach is notified during the initial access process, and the information may be conveyed at any of the initial access steps shown in FIG. The initial access process includes: in step 1, the UE obtains time and frequency synchronization from the SS; In step 2, the UE obtains timing information; In step 3, the UE obtains master broadcast information; In step 4, the UE measures RSRP from a measurement reference signal (MRS); In step 5, the UE obtains secondary broadcast information; Also in step 6, the UE performs the RACH procedure.

Until there is an indication, the mapping structure of the signals should be the same for different beamforming approaches. Signals transmitted after the indication can be individually designed / optimized according to the set beamforming approach - the mapping structure of the signals and the signaling content can be completely different. During the initial access procedure, design constraints inherent to single-beam and multi-beam-based approaches to these signal / signaling designs can be considered.

In alternative 2, the beamforming approach is notified after the initial access process. In view of the initial approach procedure, the single beam approach is only a special case of a multi-beam approach. The system is scalable in that N for initial access signals can be selected differently by the network, e.g., to accommodate initial access signal overhead; However, the UE does not need to know whether the system is operating in multiple beam or single beam based methods during the initial access procedure. The information conveyed in subsequent steps may be used for rate matching and UL / DL signaling content determination, which may increase overall system throughput.

Based on the foregoing discussion, Table 1A summarizes the advantages and disadvantages of these two alternatives.

Table 1A Comparison of Alternative 1 and Alternative 2

The wireless system may allow more than one mode of operation for different types of UEs, or may allow for one of a plurality of candidate modes of operation in a general technical framework. Depending on the detected mode of operation of the UE, the UE is configured to interact differently with the network (or eNB); The UE procedure is set differently.

In some embodiments, the operational mode defines at least one of the following: a method by which the UE obtains synchronization and system information; A basic transmission mode that the UE should assume for initial xPDSCH reception; How the UE performs the xPRACH procedure, and so on.

In some embodiments, the UE may be set to one of at least two operating modes: (1) a beamforming mode of operation (or alternatively, a multi-beam-based approach) and (2) Mode of operation (or alternatively a single beam based approach).

In the present invention, "beamformed operation" can be used to refer to a "multi-beam based approach" and vice versa; Also, a "non-beamformed operation" can be used to refer to a " single beam based approach "and vice versa.

In the beamforming mode of operation, the eNB uses the initial access signals (at least one of the synchronization channel, broadcast channel, beam radio resource management (RRM) measurement signals) using multiple (N _B > Each of which may cover a portion of the coverage area of the cell. These initial access signals corresponding to the beam may be referred to as SS (sync signal) blocks, which may be transmitted in a predetermined number of OFDM symbols. Thus, when the system transmits N _B SS blocks, it can use N _B beams for initial access signals. In the non-beamforming mode, the eNB transmits an initial access signal using one (N _B = 1) beam, which can cover the entire coverage area of the cell.

Hereinafter, some details of the operation mode specific procedure of the UE will be described. Procedural items may not be listed in a time-sequential manner. That is, a higher numbered item may occur earlier than a lower numbered item. It is also noted that the UE may be configured to only pass through a subset of the procedure items described below.

When the beamforming operation mode is detected, the UE follows at least one of the following procedures.

• The UE acquires synchronization (via a sync channel / signal) and system information (via a broadcast channel), assuming beam sweeping is performed in the eNB. In this case, the UE may detect synchronization signals having the same sequence ID or physical ID for multiple OFDM symbols in the initial access sub-frame.

The UE receives RRM measurement reference signals (MRS) for a number of time-frequency resources corresponding to the serving cell associated with synchronization and system information: the MRS resources can be explicitly set; The beam ID for RSRP reporting is set per antenna port for each OFDM symbol.

• The UE performs RRM measurements on multiple Measurement Reference Signal (MRS) resources.

The UE is set to the default transmission mode x for xPDSCH reception.

• The UE is configured to perform an xPSD (extended physical downlink shared channel) / xPUSCH (extended physical uplink shared (xPSSCH)) scheme based on a plurality of initial access signal resources (synchronous signal, broadcast channel, MRS resource, channel.

• The UE receives (or is set at the upper layer) an indication of a number of xPRACH resources for beam sweeping of the UE.

The UE performs the RACH procedure for the set xPRACH resources.

When the non-beamforming operation mode is detected, the UE follows at least one of the following procedures.

The UE obtains synchronization and system information for specific time-frequency resources. The OFDM symbol number and subframe number for these time-frequency resources are set statically.

The UE identifies the resources of the MRS for non-beamforming operation for a particular OFDM symbol (s), and then performs RRM measurements accordingly. The OFDM symbol number and subframe number for the MRS are set to be static. The beam ID for RSRP reporting is set for each OFDM symbol.

The UE is set to the default transmission mode y; Thereby receiving the xPDSCH.

The UE performs rate matching on the xPDSCH / xPUSCH around specific initial access signal resources (sync signal, broadcast channel, MRS resource, etc.).

• The UE receives (or is set at the upper layer) an indication of a single xPRACH resource for non-beamforming operation.

• The UE performs the RACH procedure for the set xPRACH resources.

Initial Access Signal Mapping Option 1: For multiple consecutive OFDM symbols in the initial access subframe

A In some embodiments, the initial access signal are transmitted in one or multiple OFDM symbols in one sub-frame (or time slots), the sub-frame is l = 0, ..., _S N _-1 by an index, N _S consecutive OFDM symbols.

In one method, the initial access signals transmitted from the serving cell on each OFDM symbol are self-contained, from which the UE may extract the entire initial access information including the physical cell ID, the OFDM symbol index and the SF number.

The subframe to which the initial access signals are mapped is called the initial access subframe.

18 shows an example of the transmission of initial access signals of an eNB in an initial access sub-frame 1801 in a wireless communication system according to various embodiments of the present disclosure.

In these embodiments, the initial access signals occupy several OFDM symbols in each initial access sub-frame. The eNB transmits initial access signals in one or more consecutive OFDM symbols (l = 1, ..., L, L &lt; NV is a positive integer) of the initial access subframe. The initial access signals in the different OFDM symbols may be beamformed with different beamforming (or antenna virtualization) vectors. One exemplary use case is that an eNB operating in a beamforming mode of operation covers the entire coverage area of one cell using N _B beams (i.e., beam sweeping). the eNB transmits the initial access signals in the l OFDM symbols, each of which corresponds to one of these N _B beams; In this case, ℓ = N _B.

In one method, the initial access signals occupy l consecutive OFDM symbols in the initial access SF including the last OFDM symbol of the subframe. eNB transmits the initial access signal OFDM symbol N _S -l + 1 1812 to the last OFDM symbol (OFDM symbol N _S -1) 1811 of SF n 1801. One advantage of this method is that the remainder of the initial access sub-frame can be used for UL / DL control and data transmissions. In one example, the first part of the initial access sub-frame that is not used to map the initial access signals may be used for xPDCCH (physical downlink control channel) and xPDSCH (physical downlink shared channel) mapping; If the UE knows the initial access area boundary, the UE is configured to rate match the initial access area for the xPDSCH reception scheduled for the transmitted xPDCCH in the initial access subframe.

In some embodiments, the initial access signals include at least one of first, second, third signals and physical broadcast channels. In these embodiments, the first, second and third signals are denoted x-IS, y-IS and z-IS, where IS denotes an initial access signal; Physical broadcast channels are denoted xPBCH. In the case of serving cells, these signals can be mapped orthogonally on the OFDM time-frequency resource grid. In one example, three orthogonal sets of consecutive subcarriers are used to map these different IS and xPBCHs.

How to assign beam ID for BRS

In some embodiments, the initial access signals also include a beam metric reference signal (MRS or BMRS or BRS) for RRM measurement of the UE, which are also mapped to l consecutive OFDM symbols in the initial access SF. For BMRS, multiple antenna ports may be configured, for example the number of antenna ports N _P may be 1, 2, 4, 8. The UE measures the reference signal received power (RSRP) from the BMRS at each antenna port of each OFDM symbol. The RRM report of the UE includes information about the RSRP associated with the particular beam ID and antenna port index pair and accordingly reports the RSRP value with the associated beam ID and antenna port index pair. In subframe n _s, the antenna port p = 0, 1, ..., b of the beam ID BMRS for an OFDM symbol l on the N _P -1 is a sequence of BMRS ID, antenna port index p, the OFDM symbol index and the sub-l And a frame number (i.e., n _s ).

The total number of beam IDs is determined by at least one of the number of OFDM symbols per initial access subframe for mapping BMRS, L, and the number N _P of set antenna ports.

In one method, the total number of beam IDs is PLN _P (where P = 1, 2, 3, ...) and the BMRS is set to map to _P of the n _P consecutive subframes. In this case, a beam ID is assigned to each antenna port on each OFDM symbol.

In other methods, the total number of beam ID is determined independently of the number of antenna ports, the same as the PL (where, P = 1, 2, 3 , ...), are also BMRS the n successive subframes of _P And is set to be mapped to P subframes. In this case, the common beam ID is assigned to all antenna ports in the same OFDM symbol, and it is possible for the UE to derive the RSRP and to select the beam based on the total power received at all antenna ports in the OFDM symbol.

In some embodiments, the number L of OFDM symbols mapping BMRS in each initial access sub-frame is explicitly indicated in the xPBCH (or MIB) or ePBCH (or SIB) or via RRC signaling. Table 2 shows some ways of mapping the state of the BMRS configuration field to L of different values when the BMRS configuration field is 1 or 2 bits. Exemplary values for N _S (total number for OFDM symbols in the initial access sub-frame) include 6, 7, 8, 12, 14, 16; Exemplary values for offset x include 1, 2, 3, and 4.

<Table 2>

In one method, the number of antenna ports NP is explicitly indicated in the xPBCH (or MIB) or ePBCH (or SIB) or via RRC signaling. Table 3 below shows how the states of the antenna port configuration field are mapped to N _P of different values when the antenna port configuration field is 1 or 2 bits.

<Table 3>

Some exemplary methods for determining beam ID b are described below when the BMRS is mapped to a single sub-frame within a frame containing P consecutive sub-frames. In these examples, p corresponds to the antenna port index.

이것은 BMRS가 서브프레임의 OFDM 심볼들 l = 0, ..., L-1에 맵핑되는 경우이다. 하나의 안테나 포트만 맵핑되거나 또는 공통 빔 ID가 동일한 OFDM 심볼에 있는 모든 안테나 포트들에 할당되는 특수한 경우에 있어서, b = l이다.● Method 1:

This is the case where the BMRS is mapped to the OFDM symbols l = 0, ..., L-1 in the subframe. In a particular case where only one antenna port is mapped or the common beam ID is assigned to all antenna ports in the same OFDM symbol, b = l.

이것은 BMRS가 서브프레임의 OFDM 심볼들 l = (N_s-L), …,(N_s-1)에 맵핑되는 경우이다. 하나의 안테나 포트만 맵핑되거나 또는 공통 빔 ID가 동일한 OFDM 심볼에 있는 모든 안테나 포트들에 할당되는 특수한 경우에 있어서, b=N_s-l이다.● Method 2:

This means that the BMRS can calculate the OFDM symbols of the subframe l = (N _s -L), ... , And (N _s -1), respectively. In a particular case where only one antenna port is mapped or a common beam ID is assigned to all antenna ports in the same OFDM symbol, b = N _s -l.

● If the BMRS be mapped to two sub-frames in a frame comprising a number P of consecutive sub-frames (i.e., sub-frames _{n s ∈ {n 1, n} 2}), it is defined as follows:

The beam ID b is also determined by the following.

이것은 BMRS이 서브프레임의 OFDM 심볼들 l = 0, …, L-1에 맵핑될 경우이며; 이 경우, l = 0에서부터 OFDM 심볼 번호가 증가함에 따라 빔 ID들이 순차적으로 할당된다. 하나의 안테나 포트만 맵핑되거나 또는 공통 빔 ID가 동일한 OFDM 심볼에 있는 모든 안테나 포트들에 할당되는 특수한 경우에 있어서,

이다.●

This is because the BMRS is the OFDM symbols of the subframe l = 0, ... , L-1; &lt; / RTI &gt; In this case, as the OFDM symbol number increases from l = 0, the beam IDs are sequentially allocated. In the special case where only one antenna port is mapped or all beam ports in the same OFDM symbol with the common beam ID are assigned,

to be.

이것은 BMRS가 서브프레임의 OFDM 심볼들 l = (NV-L), …,(N_s-1)에 맵핑될 경우이며; 이 경우 l = N_S에서부터 OFDM 심볼 번호가 감소함에 따라 빔 ID들이 순차적으로 할당된다. 하나의 안테나 포트만 맵핑되거나 또는 공통 빔 ID가 동일한 OFDM 심볼에 있는 모든 안테나 포트들에 할당되는 특수한 경우에 있어서,

이다.●

This means that the BMRS uses the OFDM symbols of the subframe l = (NV-L), ... , (N _s -1); In this case, as the OFDM symbol number decreases from l = N _S , the beam IDs are sequentially allocated. In the special case where only one antenna port is mapped or all beam ports in the same OFDM symbol with the common beam ID are assigned,

to be.

이다.In the special case of n ₁ = 0 and n ₂ = 1:

to be.

In another special case where n ₁ = n _{s, max} - 2 and n ₂ = 0, n _{s, max} is the largest subframe number in the frame.

In some embodiments, the BRS measurement procedure is configured differently depending on whether the UE is set to a multi-beam based approach or a single beam based approach.

When the UE is set to a multi-beam-based operating mode: the UE receives RRM measurement reference signals (MRS) for a number of time-frequency resources corresponding to the serving cell associated with synchronization and system information; MRS resources may be explicitly set; The beam ID for RSRP reporting is set per antenna port for each OFDM symbol.

If the UE is set to a single beam based operating mode: The UE identifies the resources of the MRS of the non-beamforming operation for the particular OFDM symbol (s), and then performs the RRM measurement accordingly. The OFDM symbol number and subframe number for the MRS are set to be static; The beam ID for RSRP reporting is also set for each OFDM symbol, or a common beam ID is set for all antenna ports in each OFDM symbol.

In some embodiments, one of the initial access signals 321 (or two in one alternative), such as x-IS (or x-IS and y-IS) (Or first and second) sets of consecutive subcarriers for OFDM symbols used to map the physical cell ID of the serving cell, and the sequence for x-IS includes information about the physical cell ID of the serving cell. In this case, the x-IS (or x-IS and y-IS) sequences transmitted in these OFDM symbols are the same. On the other hand, another of the initial access signals, e. G., Z-IS, is transmitted in a different set of consecutive subcarriers for these OFDM symbols, which sequence includes OFDM symbol index dependent information; In one example, the scrambling initialization or cyclic shift of the ZC sequence of z-IS is determined according to the OFDM symbol index and the physical cell ID. In this case, the z-IS sequences transmitted in these OFDM symbols are different. The UE first detects x-IS (or x-IS and y-IS) to determine the physical cell ID of the serving cell, and then detects z-IS to determine the OFDM symbol index.

In some embodiments, initial access signals are transmitted in a period n _P subframes. As shown in Fig. 18, the initial access signal is transmitted in SF n 1801 and SF n + n _P 1802.

In some embodiments, the subframe index n to which initial access signals are transmitted is a constant. In this case, immediately after detecting the initial access signals, the UE may identify the subframe index (n) of the subframe in which the initial access signals are transmitted.

19A-19C illustrate examples of the transmission of initial access signals in two adjacent sub-frames in a wireless communication system according to various embodiments of the present disclosure.

As shown in FIG. 19A, the initial access signal is transmitted in the first-l OFDM symbols from the first OFDM symbols 1915a (l = 0) to the l-th OFDM symbol 1916a (l = l-1).

Initial Access Signal Mapping Option 1 ': For multiple consecutive OFDM symbols in a plurality of initial access sub-frames

In some embodiments, initial access signals are transmitted in two or more adjacent subframes. Although the following examples are illustrated with only two adjacent sub-frames, those skilled in the art will appreciate that based on these illustrative examples, more than two adjacent sub-frames may be similarly configured with corresponding initial access procedures when used to map initial access signals will be.

Fig. 19B shows another example in which the initial access signals are transmitted in two adjacent subframes, i.e., the first subframe and the second subframe. As illustrated in Fig. 19B, the first sub-frame 1901b corresponds to SF n and the second sub-frame 1903b corresponds to SF n + 1. It should be noted that instead of SF n + 1, a similar embodiment may be constructed using SFn-1 as the second sub-frame 1903b.

In some embodiments, the eNB sets N _B = (ℓ ₁ + ℓ ₂ ) OFDM symbols to map the initial access signal (where ℓ ₁ , ℓ ₂ = 1, ..., L) N _S is a positive integer representing the maximum number of OFDM symbols that can be used to map the initial access signals in each SF. In the first sub-frame 1901b, an initial access signal is transmitted in the last l ₁ OFDM symbols from the OFDM symbol 1912b to the last OFDM symbol 1911b. In the second sub frame 1903b, the initial access signal is transmitted in the last OFDM symbol ℓ ₂ from OFDM symbol to the last OFDM symbol 1914b 1913b. The transmission of the initial access signal is periodic with a period nV: if the first and second subframes are subframe n and n + 1, the initial access signal is SF n + n _P 1902b and SF n + n _P +1 1904b.

In some of these embodiments, the UE may be configured to detect an OFDM symbol index and a subframe index by detecting an initial access signal sequence of one of the initial access signals, e.g., zIS.

In one method, the initial access signal sequence of the zIS is configured differently according to certain integer values over 0, ..., 2L-1. Possible ways of constructing the signal sequence are: (1) scrambling initialization is done differently depending on the integer value; And (2) different ZC-sequence cyclic shift values are selected for different integer values.

The integer value transmitted in the initial access signal transmitted in the second SF 1903b is greater than L = l ₁ , the value can be decomposed into L + l ₂ ; Meanwhile, the integer value transmitted from the initial access signal transmitted in the first SF 1901b is l ₁ smaller than L ₁ . Here, l ₁ = 0, ... , l ₁ - 1; l ₂ = 0, ... , ℓ ₂ - 1.

When the UE detects that the integer value of the initial access signal is greater than L, the UE determines that the subframe index corresponds to the second subframe (e.g., subframe n + 1 or subframe n-1) do. Further, the UE decomposes the integer value into L + l ₂ , and identifies that the number for determining the OFDM symbol index carrying the initial access signal is 1 ₂ . On the other hand, when the UE detects that its integer value is L ₁ less than or equal to L, the UE identifies that the subframe index corresponds to the first subframe (i.e., subframe n); Also, the UE identifies that the number for determining the OFDM symbol index carrying the initial access signal is ₁ . To determine the OFDM symbol index, it will now be described for the two alternatives how the UE determines the OFDM symbol number among the numbers ₁₁ and ₁₂ (alternative 1 and alternative 2).

In a first alternative, Alternative 1, the UE identifies the OFDM symbol index to be (N _S -l _i ), that is, the l _i th OFDM symbol (i = 1 , 2) are carrying the initial access signal.

In a second alternative, Alternative 2, the UE identifies that the OFDM symbol index is (N _S -L + l _i ), i.e., the l _i th OFDM symbol counted in the forward direction from the first OFDM symbol in the i th subframe i = 1, 2) is identified as carrying the initial access signal. In a special case, N _S = L.

In some embodiments, initial access signals are transmitted in two or more non-adjacent subframes. FIG. 19C shows an example in which initial access signals are transmitted in two non-adjacent sub-frames: the first sub-frame 1901c and the second sub-frame 1903c are composed of SF n and SF n + n ₀ , respectively.

In some embodiments, the eNB may be configured to transmit DL / UL data and controls for different OFDM symbols, such as xPDSCH, xPDCCH, xPUSCH, and xPUCCH / RTI &gt; and / or &lt; / RTI &gt; A time-frequency resource corresponding to OFDM symbols to which initial access signals (synchronization channels and / or physical broadcast channels and / or beamforming measurement related reference signals) are mapped is referred to as an initial access signaling region.

Signaling may be introduced to allow the UE to identify the set and / or number of OFDM symbols available for sending and receiving data and control information; The UE is set to perform rate matching for the subsequent data / control signal transmission. In some embodiments, the signaling that facilitates rate matching of the UE (or that informs the UE of the initial access signaling region) may be communicated as follows:

● Through RRC signaling.

● Through dynamic DCI signaling on xPDCCH. An example is where the DCI represents the start and end symbol indexes of the xPDSCH or xPUSCH regions. Another example is that the DCI represents the end symbol index of the xPDSCH or xPUSCH region, and the xPDCCH or xPUSCH region begins immediately after the xPDCCH.

● System information block (SIB).

● With MIB on xPBCH.

• This information is coded jointly with other information (eg, physical cell ID, OFDM symbol number, etc.) for the initial access signal.

In some embodiments, the data / control area boundary indication (or initial access signaling area) may comprise an integer value. Examples include:

Example 1: This integer value corresponds to the last OFDM symbol index of the initial access sub-frame to which the data / control is mapped.

Example 2: This integer value corresponds to the number of L _i of OFDM symbols used to map the initial access signals in the initial access sub-frame i (e.g., SF n and SF n + 1). In this case, the UE may be configured with a maximum number of OFDM symbols L that can be used for initial access signals in the initial access sub-frame. In this case, l _i = 1, ..., L.

If the last l _i consecutive OFDM symbols in the initial access subframe are used to map the initial access signals, the PDSCH should be rate matched centered on the last l _i OFDM symbols.

20 illustrates an example of the use of an initial access sub-frame for data and control messages in a wireless communication system in accordance with various embodiments of the present disclosure. That is, FIG. 20 illustrates an example of mapping data and control messages to OFDM symbols that are not mapped to initial access signals in an initial access sub-frame in a wireless communication system according to various embodiments of the present disclosure.

When l _i consecutive OFDM symbols starting from an OFDM symbol (N _S -L) on an initial access sub-frame are used to map initial access signals, OFDM symbols 0, ..., , (N _S -L-1), i.e., the front remaining portion of the initial access sub-frame may be used for downlink control and / or data (e.g., xPDCCH and / or xPDSCH) Symbols (N _S -L + L ₁ +1), ... , N _S -1, i.e., the remaining remaining portion of the initial access sub-frame may be used for uplink control and / or data (e.g., xPUCCH and / or xPUSCH) transmissions.

In some embodiments, the detected (or mapped) OFDM symbol index of the initial access signals carries one bit of information for the initial mode of operation.

In one method: when the UE detects an initial access signal for a particular OFDM symbol in an initial access sub-frame, the UE is further configured to operate according to a non-beamforming mode of operation, while the UE is configured to operate with a specific OFDM symbol and another OFDM symbol The UE is further configured to operate in accordance with the beamforming mode of operation. Also, when configured in a non-beamforming mode of operation, the UE is further configured to perform xPDSCH / xPUSCH rate matching in an initial access subframe around a particular OFDM symbol, while when configured in a beamforming mode of operation, And is further configured to rate match around the access signaling region, the size of which may be indicated separately.

FIG. 21 shows an example of using an initial access subframe for the PUSCH. As shown in Figure 21, one or initial access signal of a plurality of transmission beam it is transmitted in the first OFDM symbol from 2115 up to the N _B th OFDM symbol 2116. The remaining OFDM symbols of the initial access subframe are used for the xPUSCH. After the initial access signal area, there is a gap 2150, followed by xPUSCH 2140.

In some embodiments, the UCI may be transmitted in the last one or a few OFDM symbols of the access subframe. An example of using an initial access sub-frame for PUSCH is shown in FIG. As shown in Fig. 22, the UCI 2260 is transmitted in the last symbol of the access sub-frame. In this case, the UCI transmission in the last OFDM symbol is signaled to the UE for xPUSCH rate matching.

Initial Access Signal Mapping Option 2: For a plurality of consecutive subframes

23 shows an example of an initial access signal mapping method in a wireless communication system according to various embodiments of the present disclosure.

In this figure, initial access signals are transmitted through a small number (e.g., one or two) OFDM symbols in each initial access SF. eNB transmits initial access signals using N _B beams; Also, the initial access signals of each beam are transmitted in one SF, and all initial access signals are transmitted in N _B neighboring downlink SFs. In one example, these downlink sub-frame SF is the n, n + 1, ..., n + N _B -1. In both initial access SFs, the same index OFDM symbol is used for initial access signal transmission.

In one method, the symbol index for the OFDM symbol (s) used to map the initial access signals is predefined to be a constant. In one example, the last OFDM symbol of the initial access SF is used.

In another method, the OFDM symbol index is determined as a function of an integer determined by the sequence ID (s) of one or more initial access signals. In this case, the UE calculates at least an OFDM symbol index using the detected sequence ID (s). In one example, the OFDM symbol index is determined as a function of the physical cell ID, which is an integer determined by the sequence ID (s).

In some of these embodiments, the UE may be configured to detect a subframe index by detecting an initial access signal sequence, e. G. ZIS, of the initial access signals. In one method, the initial access signal sequence zIS is configured to carry an integer value over 0, ..., L-1. Possible methods for constructing the signal sequence are: (1) scrambling initialization differently depending on the integer value; And (2) different ZC-sequence cyclic shift values are selected for different integer values. Let L be the maximum number of consecutive subframes starting in subframe n 2301 that can be used for initial access signal transmission. Also, L can not be greater than the initial access signal transmission period from one beam.

In one example, the initial access signal transmitted by the first beam is transmitted in a particular subframe, e.g., subframe n _SF0 . When the UE detects an integer value 1 _SF from the initial access signal zIS, the UE identifies that the subframe index is a subframe n _SF0 + 1 _SF .

In some embodiments, the presence of zIS is an indication that the system is operating in a beamforming mode of operation. Subsequent UE operations (rate matching, beamforming measurement reference signal detection, baseline transmission mode, etc.) are based on a beamforming mode of operation.

In some embodiments, the initial access signal is transmitted in only a single subframe that occurs periodically in the non-beamforming mode of operation. In the non-beamforming mode of operation, there is no zIS signal in the initial access signal transmission, and the UE is set to indicate that the absence of such a zIS signal is a non-beamforming mode of operation. Subsequent UE operations (rate matching, baseline transmission mode, etc.) are based on a beamforming mode of operation.

For a plurality of initial access signals, the encoding of the initial access information

In some embodiments, the initial access information includes a physical cell ID, an OFDM symbol index, and an SF number. The initial access information may be encoded with initial access sequences xIS, yIS, and zIS. In one method, sequence initialization depends on this information. Some exemplary methods are described below.

Only one initial access signal sequence xIS is used in the system. In some embodiments, the xIS carries full information on the physical cell ID, OFDM symbol index, sub-frame boundary and / or SF number information.

Two initial access signal sequences xIS and yIS are used in the system. In some embodiments, the xIS carries information of the physical cell ID. The yIS conveys OFDM symbol index information, subframe boundaries, and / or SF number information. In some embodiments, xIS carries physical cell ID information, OFDM symbol index information, and subframe boundaries. yIS carries the SF number information.

Three initial access signal sequences xIS, yIS and zIS are used in the system. In some embodiments, xIS conveys physical cell ID information. yIS carries OFDM symbol index information, subframe boundaries, and zIS carries SF number information. In some embodiments, xIS and yIS carry physical cell ID information. The zIS conveys OFDM symbol index information, subframe boundaries, and / or SF number information. In some embodiments, xIS and yIS carry physical cell ID information, OFDM symbol index information, and subframe boundaries. zIS conveys SF number information.

Indication of system operation mode

In some embodiments, the system operating mode (whether the system is operating in beam-forming mode or non-beam-framing mode) is indicated by implicit or explicit signaling methods during an initial access procedure.

Several alternative methods of indicating system operating modes (beam-forming operational mode and non-beam-forming operating mode) are listed below. The indication conveying the system operating mode is at least one bit so as to indicate whether the system is operating in a beam-forming mode or a non-beam-forming mode of operation.

The OFDM symbol index of the initial access signal. In one example, the initial access signals transmitted in a particular OFDM symbol indicate that the system is operating in a non-beamforming mode of operation; The initial access signal transmitted in the other OFDM symbols indicates that the system is operating in a beamforming mode of operation.

● The beam index of the detected initial access signal. In one example, beam index 0 represents a non-beamforming mode of operation; Any other beam indices represent the beamforming mode of operation. In another example, in one example, beam indices 0, 1, ... , N _P -1 represents a non-beamforming mode of operation, where N _P is the total number of antenna ports set for the MRS; Any other beam indices represent the beamforming mode of operation.

● Sequence ID of the initial access signal. Other information may also be jointly encoded as an indication of the sequence ID.

The presence of a particular initial access signal sequence. In one example, the presence of one specific signal sequence in the initial access signal indicates that the system is operating in a non-beamforming mode of operation; The presence of another specific signal sequence in the initial access signal indicates that the system is operating in a beamforming mode of operation.

• Presence and absence of certain initial access signals. The UE may use energy detection for a particular initial access signal to determine the signaled mode of operation. One example is that the eSS signal is mapped only in the beamforming mode of operation. In the non-beamforming mode of operation, no signals are mapped to resources of the eSS (or the resources are muting). The presence and absence of the eSS represents the mode of operation. In the non-beamforming mode of operation, the eSS is not present in the eSS time-frequency resource. In the beamforming mode of operation, the eSS is in the eSS resource and the signal sequence in the eSS carries information of the OFDM symbol index. If no UE detects the presence of an eSS in the eSS resource, then the UE is set to a non-beamforming mode of operation. When a UE detects the presence of an eSS in an eSS resource, the UE is set to a beamforming mode of operation and is set to decode OFDM symbol index information from the eSS.

● Physical cell ID. Physical cell IDs are divided into two sets. Physical cell IDs in set 1 are used in a system operating in a beamforming mode of operation and physical cell IDs in set 2 are used in a system operating in a non-beamforming mode of operation.

• 1 bit for the MIB on the xPBCH to indicate the operating mode.

• 1 bit for RRC signaling to indicate the operating mode.

1 bit for the system information block (SIB) to indicate the operating mode.

• One bit for dynamic DCI signaling on xPDCCH.

● 1 bit or a few bits in RAR (RACH response) to indicate the operation mode

In some embodiments, the number of swept beams (or the number of OFDM symbols used for beam metering reference signals), i.e., N _B , in the beamforming mode of operation is indicated by the initial access signals. In one method, the signal sequence ID of the initial access signal carries its number. In another method, the number is explicitly indicated by the xPBCH.

In some embodiments, in an initial access, the UE goes through a common cell search procedure, regardless of the system carrier frequency. System functions associated with beamforming operations (e.g. beam sweeping in the mm wave system) are conveyed as system parameters in the initial access signals. In one example, the UE detects full information about the physical cell ID, OFDM symbol index, sub-frame boundary and SF number from the initial access signals. The UE may also detect system parameters of the beamformed system via initial access signals.

24 illustrates an example of an initial access sub-frame in a wireless communication system according to various embodiments of the present disclosure. The initial access signals of the system operating in the non-beamforming mode of operation are transmitted in one specific symbol, e. G., The last OFDM symbol 2410 of the initial access SF. The initial access signals in the system operating in the beamforming mode of operation are transmitted in the different OFDM symbols 2411 of the initial access SF. In one such example, the OFDM symbol index information detected from the initial access signal provides 1-bit information for the system operating mode to one UE: non-beamforming or beamforming. The UE may detect the number and indices of OFDM symbols carrying initial access signals (e.g., zIS relays) according to some embodiments of the present invention.

In some embodiments, the UE determines the xPDSCH rate matching for the access subframe in accordance with the 1-bit information in the beamforming mode of operation. When 1-bit information indicates that the system is operating in a non-beamforming mode of operation, one UE performs xPDSCH rate matching according to the non-beamformed initial access signal and the OFDM symbol index used by the measurement RS do. When 1-bit information indicates that the system is operating in a beamforming mode of operation, one UE performs xPDSCH rate matching according to OFDM symbol indexes used by the beamformed initial access signal and measurement RS.

In some embodiments, a system operating in a beamforming mode of operation may transmit initial access signals in the same OFDM symbol as a system operating in a non-beamforming mode of operation, but different signal sequences may be transmitted in an initial access signal Lt; / RTI &gt; The UE determines whether the system is operating in a beamforming mode or a non-beamforming mode according to the detected initial access signal sequence.

25 shows an example of a measurement reference signal (MRS) transmission in a wireless communication system according to various embodiments of the present disclosure.

In some embodiments, the beam measurement RS (BRS, MRS or BMRS) is transmitted by the eNB for RRM measurement during the initial access procedure. Separate (orthogonal) measurement RS resources are provided for the beamforming operation mode and the non-beamforming operation mode. In one example, the MRS for the non-beamforming mode of operation 2510 is transmitted in the last OFDM symbol of one subframe; The MRS for beamforming mode of operation 2511 may be transmitted in multiple OFDM symbols other than the last OFDM symbol and may also be transmitted in multiple coverage beams.

In some embodiments, the one-bit information for the operating mode establishes one UE to detect the associated measurement reference signals. In one such embodiment, when the UE is set to operate in a beamforming mode of operation, the UE processes the xPBCH to generate time-frequency resources (e. G., OFDM symbols in the initial access subframe And the UE is also configured to perform RRM measurements using the beam measurement reference signals 611 set. When the UE is set to operate in a non-beamforming mode of operation, the UE is configured to perform RRM measurements using, for example, statically configured measurement reference signals 510 transmitted in the last OFDM symbol of the initial access subframe .

The frequency positions of the initial access signal

In some embodiments, the frequency locations (i.e., subcarrier indices) of the initial access signals in the NR carrier are not constant and are indicated separately. The initial access signals may be mapped to one or more candidate frequency positions in the initial access sub-frame. The UE is configured to detect the initial access signals and then calculate the frequency position of the detected initial access signals. Initial access signals transmitted at each frequency location may be self-contained, from which one UE may extract or calculate the frequency location (i.e., subcarrier indices) to which the initial access signal is mapped.

26 illustrates an example of frequency locations of an initial access signal in a wireless communication system in accordance with various embodiments of the present disclosure.

As shown in Fig. 26, there are N = 4 frequency position candidates with k _i = k _c + k _i , i = 1, 2, 3, 4. The initial access signals are mapped to one (or many) of these candidate frequency positions, according to some embodiments of the present invention. These frequency positions may be identified by N candidate indices. The central subcarrier index (or first subcarrier index) for mapping the initial access signal may be one (or more) of these N candidate indices. It should be noted that Fig. 26 is merely an example, and that the same principle applies to any other N values, for example N = 1, 2, 3, 4, 5, ....

In some embodiments, N may be explicitly set by an upper layer, for example via MIB, SIB, or RRC signaling.

the center subcarrier (or first subcarrier) of the xPBCH corresponding to the initial access signal centered at k _i = k _c + k _i is offset differently from the initial access signal.

In one method, the central subcarrier (or first subcarrier) for xPBCH is ci = ki + [Delta] c; In this case, the xPBCH frequency position is a constant offset (? C) different from the subband-specific initial access signal position.

Alternatively, a c _i = k + _c + Δc _i Δki, also alternatively, _{c i} = k c + Δc _i, wherein Δc _i is a positive integer (i = 1, ..., N ).

In one method, the sequence ID for the initial access signal may be used to indicate the subcarrier index k _i . In one example, for the ith candidate frequency location (subcarrier index k _i ), the sequence ID for the initial access signal belongs to set A _i , where A ₁ , A ₂ , ... Are mutually exclusive. The UE may then identify the subcarrier indices k _i and c _i for the initial access signal and may also identify the xPBCH based on the detected sequence ID. This is shown in Table 4.

<Table 4>

In one method, [Delta] c is a constant (generally applicable) for all N candidate frequency positions and indicates the subcarrier index k _i using the y-bit field in the xPBCH (MIB) or ePBCH (SIB) . In one example, y = 1 or 2 bits (s) are used to indicate the frequency location (subcarrier index ki) of the initial access signals. The UE may then identify the subcarrier index k _i for the initial access signal from the state of the decoded bits. An example is shown in Table 5.

<Table 5>

In one method, the initial access signal mapped to the i-th candidate frequency location is repeated in the time domain with a period of nP time intervals (subframes).

Methods according to the claims of the present disclosure or the embodiments described in the specification may be implemented in hardware, software, or a combination of hardware and software.

When implemented in software, a computer-readable storage medium storing one or more programs (software modules) may be provided. One or more programs stored on a computer-readable storage medium are configured for execution by one or more processors in an electronic device. The one or more programs include instructions that cause the electronic device to perform the methods in accordance with the embodiments of the present disclosure or the claims of the present disclosure.

Such programs (software modules, software) may be stored in a computer readable medium such as a random access memory, a non-volatile memory including a flash memory, a ROM (Read Only Memory), an electrically erasable programmable ROM (EEPROM), a magnetic disc storage device, a compact disc-ROM (CD-ROM), a digital versatile disc (DVDs) An optical storage device, or a magnetic cassette. Or a combination of some or all of these. In addition, a plurality of constituent memories may be included.

In addition, the program may be transmitted through a communication network composed of a communication network such as the Internet, an Intranet, a LAN (Local Area Network), a WLAN (Wide LAN), or a SAN (Storage Area Network) And can be stored in an attachable storage device that can be accessed. Such a storage device may be connected to an apparatus performing an embodiment of the present disclosure via an external port. Further, a separate storage device on the communication network may be connected to an apparatus performing the embodiments of the present disclosure.

In the specific embodiments of the present disclosure described above, the elements included in the disclosure have been expressed singular or plural, in accordance with the specific embodiments shown. It should be understood, however, that the singular or plural representations are selected appropriately according to the situations presented for the convenience of description, and the present disclosure is not limited to the singular or plural constituent elements, And may be composed of a plurality of elements even if they are expressed.

While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments. Therefore, the scope of the present disclosure should not be limited to the embodiments described, but should be determined by the scope of the appended claims, as well as the appended claims.

Claims (20)

A base station apparatus in a wireless communication system,
At least one processor for mapping at least one initial access signal to at least one of a plurality of predefined time positions in at least one period; and each of the at least one initial access signals corresponding to one of a plurality of transmit beams ,
And a transceiver that transmits the mapped at least one initial access signal to the terminal and indicates to the terminal the orthogonal frequency division multiplexing (OFDM) symbols that are not mapped to the at least one initial access signal in the at least one period. .
The method according to claim 1,
Wherein the at least one initial access signal comprises a plurality of initial access signals,
Wherein each of the plurality of initial access signals includes an OFDM symbol index and a physical cell identifier corresponding to each of the plurality of transmission beams,
Wherein the at least one processor maps each of the plurality of initial access signals to each of a plurality of OFDM symbols in a subframe.
The method of claim 2,
The plurality of OFDM symbols starting from one of the last OFDM symbol, the first OFDM symbol, or another OFDM symbol in the subframe,
Data and control messages are mapped to the OFDM symbols that are not mapped to the at least one initial access signal in the subframe.
The method of claim 2,
Wherein each of the plurality of OFDM symbols is located in the same OFDM symbol index of each of a plurality of subframes.
The method according to claim 1,
Wherein the at least one initial access signal comprises a physical cell identifier and an OFDM symbol index, and further comprising a number of subframes.
The method according to claim 1,
Wherein the transceiver sends an extended synchronization signal (ESS) to the terminal to allow the terminal to determine an index of each OFDM symbol to which the initial access signal block is transmitted.
The method according to claim 1,
The transceiver transmits a physical broadcast channel (PBCH) to the UE,
The first portion of the PBCH carrying an index of each of the OFDM symbols to which the initial access signal block is transmitted,
And wherein the second portion of the PBCH carries the number of the plurality of transmission beams used by the base station.
A method of operating a base station in a wireless communication system,
Mapping at least one initial access signal to some or all of a plurality of predefined time positions in at least one period; and each of the at least one initial access signals corresponding to one of a plurality of transmit beams,
Transmitting the mapped at least one initial access signal to a mobile station;
Indicating orthogonal frequency division multiplexing (OFDM) symbols that are not mapped to the at least one initial access signal in the at least one period.
The method of claim 8,
Further comprising mapping each of a plurality of initial access signals to each of a plurality of OFDM symbols in a subframe,
Wherein the at least one initial access signal comprises the plurality of initial access signals,
Wherein each of the plurality of initial access signals comprises a respective OFDM symbol index and a physical cell identifier corresponding to each of the plurality of transmit beams.
The method of claim 9,
The plurality of OFDM symbols starting from one of the last OFDM symbol, the first OFDM symbol, or another OFDM symbol in the subframe,
Wherein data and control messages are mapped to the OFDM symbols that are not mapped to the at least one initial access signal in the subframe.
The method of claim 9,
Wherein each of the plurality of OFDM symbols is located in the same OFDM symbol index of each of a plurality of subframes.
The method of claim 8,
Wherein the at least one initial access signal comprises a physical cell identifier and an OFDM symbol index, and further comprising a number of subframes.
The method of claim 8,
Further comprising the step of the terminal transmitting an extended synchronization signal (ESS) to the terminal to determine an index of each of the OFDM symbols to which the initial access signal block is to be transmitted.
The method of claim 8,
Further comprising the step of transmitting a physical broadcast channel (PBCH) to the UE,
The first portion of the PBCH carrying an index of each of the OFDM symbols to which the initial access signal block is transmitted,
Wherein the second portion of the PBCH carries the number of the plurality of transmission beams used by the base station.
A terminal apparatus in a wireless communication system,
A transceiver for receiving at least one initial access signal mapped to some or all of a plurality of predefined time locations in at least one period from a base station; and each of the at least one initial access signal corresponding to one of a plurality of transmit beams and,
Performing an initial access to the base station via one of a plurality of different beams based on the at least one initial access signal and performing orthogonal frequency division multiplexing (OFDM) ) At least one processor for receiving an indication of symbols.
16. The method of claim 15,
Wherein the at least one initial access signal comprises a plurality of initial access signals,
Wherein each of the plurality of initial access signals includes an OFDM symbol index and a physical cell identifier corresponding to each of the plurality of transmission beams,
Wherein the at least one processor maps each of the plurality of initial access signals to each of a plurality of OFDM symbols in a subframe.
18. The method of claim 16,
The plurality of OFDM symbols starting from one of the last OFDM symbol, the first OFDM symbol, or another OFDM symbol in the subframe,
Data and control messages are mapped to the OFDM symbols that are not mapped to the at least one initial access signal in the subframe.
18. The method of claim 16,
Wherein each of the plurality of OFDM symbols is located in the same OFDM symbol index of each of a plurality of subframes.
16. The method of claim 15,
Wherein the at least one initial access signal comprises a physical cell identifier and an OFDM symbol index, and further comprising a number of subframes.
16. The method of claim 15,
The transceiver receives an extended synchronization signal (ESS) to determine an index of each of the OFDM symbols to which the initial access signal block is to be transmitted and transmits the extended synchronization signal to the OFDM symbols that are not mapped to the at least one initial access signal in the subframe. A device for transmitting data and control messages.

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