Non-anchor carrier synchronization signal

Abstract

A method and apparatus for transmitting a synchronization signal in a non-anchor carrier is disclosed. A method includes: transmitting a carrier configuration on an anchor carrier; and transmitting a synchronization signal in a non-anchor carrier based on the carrier configuration.

Description

Technical Field

[0001] The subject matter disclosed herein relates generally to wireless communications, and more particularly to non-anchor carrier synchronization signals. Background Art

[0002] The following abbreviations are defined herein, at least some of which are referenced in the following description: 3rd Generation Partnership Project (3GPP), European Telecommunications Standards Institute (ETSI), frequency division duplex (FDD), frequency division multiple access (FDMA), long term evolution (LTE), new radio (NR), very large scale integration (VLSI), random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), compact disc read-only memory (CD-ROM), local area network (LAN), wide area network (WAN), personal digital assistant (PDA), user equipment (UE), uplink (UL), evolved Node B (eNB), next generation Node B (gNB), downlink (DL), central processing unit (CPU), graphics processing unit (GPU), field programmable gate array (FPGA), dynamic RAM (DRAM), synchronous dynamic RAM (SDRAM), static RAM (SRAM), liquid crystal display (LCD), light emitting diode (LED), organic LED (OLED), orthogonal frequency division multiplexing (OFDM), radio resource control (RRC C), Reference Signal (RS), Single Carrier Frequency Division Multiple Access (SC-FDMA), Time Division Duplex (TDD), Time Division Multiplexing (TDM), User Entity / Equipment (Mobile Terminal) (UE), Universal Mobile Telecommunications System (UMTS), Worldwide Interoperability for Microwave Access (WiMAX), Internet of Things (IoT), Narrowband Internet of Things (NB-IoT or NBIoT), Long Term Evolution (LTE), Narrowband (NB), Narrowband Primary Synchronization Signal (NPSS), Narrowband Secondary Synchronization Signal (NSSS), Narrowband Physical Broadcast Channel (NPBCH or NB-PBCH), System Information (SI), System Information Block (SIB), System Information Block Type 1-NB (NB-SIB1), Physical Downlink Shared Channel (PDSCH), Physical Uplink Shared Channel (PUSCH), Physical Resource Block (PRB), Universal Mobile Telecommunications System (UMTS), Evolved UMTS Terrestrial Radio Access (E-UT or EUTRA), Non-anchor Carrier Synchronization Signal (NSS), Enhanced Machine Type Communication (eMTC), Resynchronization Signal (RSS), Bandwidth Limited / Coverage Enhancement (BL / CE).

[0003] In NB-IoT, an anchor carrier is a carrier that carries at least synchronization signals and broadcast signals. The anchor carrier of NBIoT is a carrier that the UE assumes to send narrowband primary synchronization signal (NPSS), narrowband secondary synchronization signal (NSSS), and narrowband physical broadcast channel (NPBCH), where NPSS and NSSS are synchronization signals and NPBCH contains broadcast signals. On the other hand, a non-anchor carrier is a carrier that the UE does not assume to send NPSS, NSSS, and NPBCH.

[0004] In Rel.17 NBIoT, non-anchor carriers can be configured for PDSCH and PUSCH transmission. Therefore, it is expected to send additional synchronization signals (non-anchor carrier synchronization signals, hereinafter referred to as NSS) in non-fixed carriers. Non-anchor carrier synchronization signals (NSS) can be used for non-anchor carrier measurement, channel estimation, synchronization, and system information tracking. Summary of the invention

[0005] A method and apparatus for transmitting a synchronization signal in a non-anchor carrier are disclosed.

[0006] In one embodiment, a method includes: sending a carrier configuration on an anchor carrier; and sending a synchronization signal in a non-anchor carrier based on the carrier configuration.

[0007] In one embodiment, the non-anchor carrier is associated with a carrier index, and the carrier index is included in the carrier configuration or derived from the frequency position. The synchronization signal can be associated with a virtual ID, which is configured in the carrier configuration or determined by the cell ID of the anchor carrier. The timing offset of the synchronization signal in the non-anchor carrier is preferably configured in the carrier configuration.

[0008] In another embodiment, the non-anchor carrier is in an E-UTRA system. An ID offset of the virtual ID of the synchronization signal to the E-UTRA system cell ID may be included in the carrier configuration. The virtual ID divided by 6 may be equal to the E-UTRA system cell ID divided by 6 plus or minus the ID offset. When the non-anchor carrier is in an E-UTRA system, the E-UTRA system cell ID is included in the carrier configuration.

[0009] In a certain embodiment, the synchronization signal is sent in a first number of time units. In each time unit, the synchronization signal may include a random sequence of length L. The length L is determined by the operating mode of the non-anchor carrier. The initialization seed of the random sequence is determined by at least one of the following: carrier index, virtual ID, cell ID of the anchor carrier, and system information change indicator. The system information change indicator can be determined by the high-level parameter systemInfoValueTag of NBIoT. In particular, when the systemInfoValueTag of NBIoT in the time unit synchronization signal transmission time unit is different from the systemInfoValueTag of NBIoT in the previous T time units, the system information change indicator is equal to 1. T is configured in the carrier configuration or equal to the SI valid time. The synchronization signal can be mapped to the time-frequency resources of each time unit. The mapping method can be determined by the operating mode of the non-anchor carrier. The mapping method can be one of the following: symbol S to the last symbol of the time unit, and then symbol 0 to symbol S-1, symbol S to the last symbol of the time unit, and symbol 0 to the last symbol of the time unit. S is determined by the high layer or fixed to 3.

[0010] In a certain embodiment, in each time unit, the synchronization signal includes a Zadoff-Chu sequence, and the system information change indicator is included in the generation of the sequence. The system information change indicator is included in the root index of the Zadoff-Chu sequence of the synchronization signal. Or the synchronization signal also includes a cover code, and the system information change indicator is included in the cover code.

[0011] In one embodiment, a base unit includes a transmitter, and the transmitter is configured to: transmit a carrier configuration on an anchor carrier; and transmit a synchronization signal in a non-anchor carrier based on the carrier configuration.

[0012] In another embodiment, a method includes receiving a carrier configuration on an anchor carrier; and receiving a synchronization signal in a non-anchor carrier based on the carrier configuration.

[0013] In yet another embodiment, a remote unit includes a receiver, and the receiver is configured to: receive a carrier configuration on an anchor carrier; and receive a synchronization signal in a non-anchor carrier based on the carrier configuration. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] A more particular description of the embodiments briefly described above will be presented by reference to specific embodiments illustrated in the accompanying drawings. Understanding that these drawings depict only some embodiments and are not therefore to be considered limiting of scope, the embodiments will be described and explained with additional specificity and detail through the use of the accompanying drawings, in which:

[0015] Figure 1 is a schematic diagram showing an eMTC RSS;

[0016] Figure 2 is a schematic diagram showing the mapping of RSS;

[0017] Figure 3 is a schematic diagram showing the relationship between an anchor carrier and a non-anchor carrier;

[0018] Figure 4 is a schematic diagram showing the mapping of NSS;

[0019] Figures 5A to 5C is a schematic diagram showing other examples of mapping of NSS;

[0020] Figure 6 is a schematic diagram showing another NSS design;

[0021] Figure 7 is a schematic flow chart illustrating an embodiment of a method;

[0022] Figure 8 is a schematic flow chart illustrating another embodiment of a method; and

[0023] Fig. 9 is a schematic block diagram showing an apparatus according to one embodiment. DETAILED DESCRIPTION

[0024] As will be appreciated by those skilled in the art, certain aspects of the embodiments may be embodied as systems, devices, methods or program products. Therefore, the embodiments may take the form of a complete hardware embodiment, a complete software embodiment (including firmware, resident software, microcode, etc.), or a combination of software and hardware aspects, which may generally be referred to herein as "circuit", "module" or "system". In addition, the embodiments may take the form of a program product embodied in one or more computer-readable storage devices of machine-readable code, computer-readable code and / or program code, hereinafter referred to as "code". The storage device may be tangible, non-temporary and / or non-transmitting. The storage device may not embody a signal. In a certain embodiment, the storage device only employs a signal for accessing the code.

[0025] Certain functional units described in this specification may be labeled as "modules" in order to more particularly emphasize their independent implementation. For example, a module may be implemented as a hardware circuit including a custom very large scale integration (VLSI) circuit or gate array, an off-the-shelf semiconductor such as a logic chip, a transistor, or other discrete components. A module may also be implemented in a programmable hardware device such as a field programmable gate array, a programmable array logic, a programmable logic device, etc.

[0026] Modules can also be implemented in code and / or software to be executed by various types of processors. The identified code modules can, for example, include one or more physical or logical blocks of executable code, which can, for example, be organized as objects, processes or functions. However, the executable files of the identified modules do not need to be physically located together, but can include difference instructions stored in different locations, which, when logically connected together, include the modules and achieve the described purpose of the modules.

[0027] In fact, code modules can include single instructions or many instructions, and can even be distributed in several different code segments, among different programs and across several memory devices. Similarly, in this article, operating data can be identified and illustrated in the module, and can be embodied in any appropriate form and organized in the data structure of any appropriate type. Operating data can be collected as a single data set, or can be distributed in different locations, including on different computer-readable storage devices. When a module or part of a module is implemented with software, the software portion is stored on one or more computer-readable storage devices.

[0028] Any combination of one or more computer readable media may be utilized. The computer readable medium may be a computer readable storage medium. The computer readable storage medium may be a storage device storing code. The storage device may be, for example, but need not be, an electronic, magnetic, optical, electromagnetic, infrared, holographic, micromechanical or semiconductor system, apparatus or device, or any suitable combination of the foregoing.

[0029] A non-exhaustive list of more specific examples of storage devices would include the following: an electrical connection having one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this document, a computer-readable storage medium may be any tangible medium that can contain or store a program for use by or in connection with an instruction execution system, apparatus, or device.

[0030] The code for performing the operations of the embodiments may be any number of lines and may be written in any combination of one or more programming languages ​​including object-oriented programming languages ​​such as Python, Ruby, Java, Smalltalk, C++, and the like, and traditional procedural programming languages ​​such as the "C" programming language, and / or machine languages ​​such as assembly languages. The code may be executed entirely on the user's computer, partially on the user's computer, as a separate software package partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the latter case, the remote computer may be connected to the user's computer through any type of network including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0031] References to "one embodiment," "embodiment," or similar language in this specification mean that a particular feature, structure, or characteristic described in conjunction with the embodiment is included in at least one embodiment. Therefore, unless otherwise expressly stated, throughout the specification, the occurrences of the phrases "in one embodiment," "in an embodiment," and similar language may, but not necessarily, all refer to the same embodiment, but rather to "one or more but not all embodiments." Unless otherwise expressly stated, the terms "include," "comprises," "has," and variations thereof mean "including but not limited to." Unless otherwise expressly stated, an enumerated list of items does not imply that any or all items are mutually exclusive. Unless otherwise expressly stated, the terms "one," "an," and "the" also refer to "one or more."

[0032] In addition, the described features, structures or characteristics of the various embodiments may be combined in any appropriate manner. In the following description, many specific details are provided, such as examples of programming, software modules, user selections, network transactions, database queries, database structures, hardware modules, hardware circuits, hardware chips, etc., to provide a thorough understanding of the embodiments. However, those skilled in the relevant art will recognize that the embodiments may be practiced without one or more of the specific details, or using other methods, components, materials, etc. In other cases, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring some aspects of the embodiments.

[0033] Aspects of different embodiments are described below with reference to schematic flow charts and / or schematic block diagrams of methods, devices, systems, and program products according to embodiments. It will be understood that each frame of the schematic flow charts and / or schematic block diagrams and the combination of frames in the schematic flow charts and / or schematic block diagrams can be implemented by code. The code can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device to produce a machine, so that instructions executed by a processor of a computer or other programmable data processing device create a device for implementing the functions specified in the frame or some frames for the schematic flow charts and / or schematic block diagrams.

[0034] The code may also be stored in a storage device that is capable of instructing a computer, other programmable data processing apparatus, or other device to operate in a specific manner so that the instructions stored in the storage device produce an article of manufacture including instructions that implement the functions specified in a box or some boxes of the schematic flowchart and / or schematic block diagram.

[0035] The code may also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be performed on the computer, other programmable apparatus, or other device to produce a computer-implemented process, so that the code executed on the computer or other programmable apparatus provides a process for implementing the functions specified in a box or some boxes of the flowchart and / or block diagram.

[0036] The schematic flow charts and / or schematic block diagrams in the accompanying drawings illustrate possible implementation architectures, functions, and operations of the devices, systems, methods, and program products according to various embodiments. In this regard, each box in the schematic flow charts and / or schematic block diagrams may represent a module, a fragment, or a portion of a code, which includes one or more executable instructions of the code for implementing a specified logical function.

[0037] It should also be noted that in some alternative embodiments, the functions marked in the blocks may not occur in the order marked in the drawings. For example, two blocks shown in succession may actually be executed substantially simultaneously, or the blocks may sometimes be executed in the reverse order, depending on the functions involved. It is conceivable that other steps and methods are equivalent in function, logic or effect to one or more blocks or portions thereof of the illustrated drawings.

[0038] Although various arrow types and line types may be used in flow charts and / or block diagrams, it should be understood that they do not limit the scope of the corresponding embodiments. In fact, some arrows or other connecting lines may be used only to indicate the logical flow of the depicted embodiments. For example, an arrow may indicate a waiting or monitoring period of unspecified duration between the enumerated steps of the depicted embodiments. It will also be noted that each box of the block diagram and / or flow chart and the combination of boxes in the block diagram and / or flow chart can be implemented by a dedicated hardware-based system that performs a specific function or operation, or by a combination of dedicated hardware and code.

[0039] The description of an element in each figure may refer to an element of the previous figure. In all figures, the same numerals refer to the same elements, including alternative embodiments of the same elements.

[0040] In a first embodiment, when both NBIoT and eMTC are supported for a network, the eMTC RSS (Resynchronization Signal) may be reused as the NSS (Non-anchor Carrier Synchronization Signal) of NBIoT.

[0041] like Figure 1 As shown, for eMTC, the RSS is sent in two consecutive PRBs starting from a PRB number configured by a higher layer, for example, indicated by a parameter freqLocation in the RRC configuration.

[0042] In NBIoT, a non-anchor carrier occupies one PRB in the frequency domain. A carrier configuration including at least the frequency position of the non-anchor carrier is sent from the eNB to the UE on the anchor carrier to configure the non-anchor carrier associated with the anchor carrier. If the non-anchor carrier is configured to be at the PRB where the RSS of eMTC is transmitted, the RSS can be reused as the NSS of the non-anchor carrier. Figure 1 As shown, assuming that non-anchor carrier 0 transmits in the first of two consecutive PRBs that transmit RSS and non-anchor carrier 1 transmits in the second of two consecutive PRBs that transmit RSS, both non-anchor carrier 0 and non-anchor carrier 1 can use RSS (or more precisely, part of RSS) as NSS. For NBIoT, the frequency location of eMTC RSS should be included in the non-anchor carrier configuration.

[0043] In the time domain, RSS is N starts at the first BL / CE DL subframe in the radio frame RSS is sent in consecutive BL / CE DL subframes, where the RSS periodicity is P RSS and RSS time offset O RSSConfigured by a higher layer, for example, indicated by the periodicity parameter and the timeOffset parameter, when the eMTCRSS reuses the NBIoT, the periodicity parameter and the timeOffset parameter should be included in the NBIoT RSS configuration, and the RSS duration is 0. RSS It is also configured by higher layers, for example indicated by the parameter duration, which should be included in the NBIoT RSS configuration.

[0044] The sequence d for the i-th RSS subframe is generated according to Equation 1 i (n):

[0045]

[0046] In Equation 1, c(n) is a pseudo-random sequence. The pseudo-random sequence generator uses c init =Virtual ID+2 9 u is initialized. In the case of reusing the eMTC RSS as NSS, the NSS is associated with a virtual ID. The virtual ID can be an LTE cell ID (E-UTRA system cell ID). The range of the LTE cell ID is {0,…, 503}. Alternatively, when the virtual ID is equal to the NBIoT cell ID and the NBIoT cell ID is different from the LTE cell ID, a cell ID offset indicating the offset of the NBIoT cell ID (virtual ID) from the LTE cell ID should be configured. The LTE cell ID (E-UTRA system cell ID) or the cell ID offset can be indicated by the parameter CellIDOffset included in the NBIoT RSS configuration. In particular, because NBIoT cell ID%6=LTE cell ID%6, NBIoT cell ID / 6=LTE cell ID / 6+cell ID offset or NBIoT cell ID / 6=LTE cell ID / 6-cell ID offset is satisfied. In this case, the range of the cell ID offset is {-83,…, 83}. In eMTC, u is equal to the value of the high-level parameter systemInfoUnstable-BR as set in subframe i=0. The parameter systemInfoUnstable-BR indicates whether the system information is changed for eMTC. If the eNB schedules NBIoT and eMTC to change the system information (SIB or SI) at the same time, the parameter systemInfoUnstable-BR can be used as the value of u.

[0047] In Equation 1, b(i) is given by Table 1 below.

[0048] Table 1: Definition of b(i)

[0049]

[0050] In each subframe i used for RSS transmission, the RSS sequence bi(n) shall be mapped to resource elements in ascending order starting from di(0). Figure 2 As shown, in the time domain, one subframe is divided into 14 symbols, namely symbols #0 to #13. In the frequency domain, RSS occupies 2 PRBs, which is equal to 24 subcarriers. Therefore, one resource element is one symbol in the time domain and one subcarrier in the frequency domain. Therefore, for RSS transmitted in the frequency range of 2 PRBs (24 subcarriers), each subframe consists of 24*14 resource elements. The resource elements in each of symbols #0 to #2 on all 2 PRBs are the LTE control area. The resource elements in each symbol in symbols #3 to #13 in all 2 PRBs (a total of 11*24=264 resource elements) are the RSS mapping area.

[0051] The mapping can be "frequency first and time second". That is, the sequence d i (n) is mapped to resource elements in the RSS mapping area in the following manner: first in symbol #3, from a lower frequency subcarrier among 24 subcarriers to a higher frequency subcarrier; then in the next symbol #4, from a lower frequency subcarrier among 24 subcarriers to a higher frequency subcarrier; ..., until in the last symbol #13, from a lower frequency subcarrier among 24 subcarriers to a higher frequency subcarrier.

[0052] As described above, the UE knows the frequency location of the RSS through the parameter freqLocation also included in the NBIoT RSS configuration. When the non-anchor carrier is configured as one of the two PRBs in which the RSS is sent, the non-anchor carrier can use the RSS sent in one PRB as the NSS.

[0053] According to the second embodiment, the NSS is newly designed.

[0054] First, the UE may be configured with one or more non-anchor carriers associated with an anchor carrier. Each non-anchor carrier is associated with a non-anchor carrier index to the anchor carrier. The non-anchor carrier index may be implicitly derived from its frequency position or configured via RRC signaling. Preferably, a non-anchor carrier with a lower frequency has a smaller index than a non-anchor carrier with a higher frequency. For example, Figure 3 As shown, anchor carrier #0 has one non-anchor carrier #0, and anchor carrier #1 has two non-anchor carriers #0 and #1. Figure 3 It can be seen that the non-anchor carrier #0 of anchor carrier #0 and the non-anchor carrier #0 of anchor carrier #1 occupy the same frequency position.

[0055] The NSS of the non-anchor carrier is associated with a virtual ID. The virtual cell ID is configured by RRC signaling or at least determined by the cell ID of the anchor carrier. For example, the virtual ID can be the cell ID of the anchor carrier (i.e., the NBIoT cell ID) plus the non-anchor carrier index multiplied by 504.

[0056] Since non-anchor carriers of different anchor carriers (e.g. Figure 3 As shown, the non-anchor carrier #0 of anchor carrier #0 and the non-anchor carrier #0 of anchor carrier #1 may occupy the same frequency position. To avoid conflicts between transmissions of NSSs of different non-anchor carriers, NSSs associated with different anchor carriers are transmitted in a time division multiplexing manner.

[0057] In particular, the timing offset within a frame is configured by RRC signaling per non-anchor carrier per anchor carrier. That is, each non-anchor carrier is associated with a different timing offset to absolute timing (e.g., to subframe 0 of absolute frame 0). The timing offset of the NSS is included in the non-anchor carrier configuration.

[0058] like Figure 3 As shown in , non-anchor carrier #0 for anchor carrier #0 has a timing offset ΔT1, non-anchor carrier #0 for anchor carrier #1 has a timing offset ΔT2, and non-anchor carrier #1 for anchor carrier #1 has a timing offset ΔT3.

[0059] The timing offset determines the first subframe in which the NSS is sent.

[0060] In the time domain, the NSS of the non-anchor carrier is transmitted in N1 consecutive subframes of the non-anchor carrier starting from the first subframe determined by the timing offset, where the NSS duration N1 is configured by the higher layer. In the frequency domain, the NSS is transmitted on 12 subcarriers in one PRB for the non-anchor carrier.

[0061] The NSS sequence length L of each subframe is determined by the operation mode of the non-anchor carrier. In particular, for the intra-band operation mode, the sequence length is L=132 (12 subcarriers, in each subcarrier from symbol #3 to symbol #13, i.e., 12×11). For the guard band or independent operation mode, the sequence length is L=168 (12 subcarriers, in each subcarrier from symbol #0 to symbol #13, i.e., 12×14).

[0062] The sequence for the i-th NSS subframe is generated according to Equation 2:

[0063]

[0064] Equation 2 is substantially the same as Equation 1 except that the length L of Equation 2 is determined by the operation mode of the non-fixed carrier. In Equation 2, c(n) is a pseudo-random sequence. The pseudo-random sequence generator may be initialized in each subframe. Initialization seed c init The LTE system bandwidth n is determined by at least one of the following: virtual ID, cell ID of anchor carrier, system information change indicator, and LTE system bandwidth n. PRB Carrier index n within cc Or PRB index. For example, or

[0065] The virtual ID of the NSS can be an LTE cell ID, which is the cell ID of the anchor carrier. Alternatively, the virtual ID can be the cell ID of the anchor carrier (i.e., the NBIoT cell ID) plus the non-anchor carrier index multiplied by 504.

[0066] u is a system information change indicator, which is determined by the value of the high-level parameter systemInfoValueTag configured in the broadcast information. If the new systemInfoValueTag is different from the previous T duration of systemInfoValueTag, u is equal to 1, otherwise it is 0. T can be configured by RRC signaling, or T is equal to the SI validity period.

[0067] b(i) is given by Table 1 as listed above.

[0068] In each subframe used for NSS transmission, the NSS sequence shall be i (0) are mapped to resource elements in ascending order.

[0069] like Figure 4 As shown in Figure 1 (in-band operation mode), each subframe consists of 12*14 resource elements. In the time domain, one subframe is divided into 14 symbols, namely symbols #0 to #13. In the frequency domain, NSS occupies 1 PRB, i.e. 12 subcarriers. The resource elements in each of symbols #0 to #2 across 12 subcarriers are the LTE control region. The resource elements in each of symbols #3 to #13 across 12 subcarriers are the NSS mapping region.

[0070] The mapping can be "time first and frequency second". That is, the sequence d i(0) is first mapped to resource elements in a specific subcarrier (e.g., the lowest frequency subcarrier or the highest frequency subcarrier) from symbol #3 to symbol #13, and then mapped to resource elements in the next subcarrier (e.g., the second lowest frequency subcarrier or the second highest frequency subcarrier) from symbol #3 to symbol #13, ..., until the resource elements in the last subcarrier (e.g., the highest frequency subcarrier or the lowest frequency subcarrier) from symbol #3 to symbol #13.

[0071] Or, if Figures 5A to 5C As shown, the mapping can be "frequency first and time second". That is, the sequence d i (0) First mapped to the symbol from the lower frequency subcarrier to the higher frequency subcarrier, then mapped to the next symbol from the lower frequency subcarrier to the higher frequency subcarrier, ..., until mapped to the last symbol from the lower frequency subcarrier to the higher frequency subcarrier.

[0072] There are several implementations of a "frequency first and time second" mapping determined by the mode of operation.

[0073] like Figure 4 As shown in Figure 1, in the guard band or independent operation mode, the resource elements in each of symbols #0 to #13 across 12 subcarriers can be NSS mapping areas. The first symbol to be mapped is symbol #S, and the second symbol to be mapped is symbol #S+1, ..., until symbol #13. Then, NSS is mapped to symbol #0, symbol #1 until symbol #S. S can be fixed to 3 or configured by high-layer signaling.

[0074] Figure 4 B shows another implementation of "frequency first and time second" mapping in a guard band or independent operation mode, where the resource elements in each of symbols #0 to #13 across 12 subcarriers can be NSS mapping regions. In particular, the first symbol to be mapped is symbol #0, the second symbol to be mapped is symbol #2, ..., until the last symbol #13.

[0075] Figure 4 C shows an implementation of "frequency first and time second" mapping in the intra-band operation mode, where the resource elements in each of symbols #3 to #13 across 12 subcarriers can be NSS mapping regions. The first symbol to be mapped is symbol #S, the second symbol to be mapped is symbol #S+1, ..., until the last symbol #13. There is no mapping to symbol #0 as the LTE control region to symbol #S. S can be fixed to 3 or configured by high-layer signaling.

[0076] According to the third embodiment, the NSS is newly designed in another way.

[0077] The frequency location of the non-anchor carrier is obtained from the carrier configuration sent on the anchor carrier.

[0078] NSS (modified NB-PSS and optional NB-SSS) may be sent in non-anchor carriers. To avoid confusion with PSS detection in the anchor carrier, a modified NB-PSS sequence is generated (different from the NB-PSS in the anchor carrier). If NB-SSS in the non-anchor carrier is sent, it may use the same sequence as the NB-SSS in the anchor carrier.

[0079] The modified NB-PSS on the non-anchor carrier sequence is generated according to the frequency domain Zadoff-Chu sequence (Equation 3):

[0080]

[0081] In Equation 3, u is the root index of the Zadoff-Chu sequence. u may be a system information change indicator and may be configured as a value other than 5 ranging from 1 to 10. For example, for changed system information, u may be configured as 1, and for unchanged system information, u may be configured as 10. The changed or unchanged system information may be the same definition as in the above-described second embodiment.

[0082] Alternatively, in Equation 3, S0(l) may be configured as (-1)^(l%2)*S(l) for the changed system information, and (-1)^((l+1)%2)*S(l) for the changed system information. Alternatively, S0(l) may be configured as A(l)*S(l), where A(l) is an orthogonal sequence, such as a cover code, a shortened HADAMARD code. The system information change indicator is included in the cover code. S(l) for different symbol indexes l is given by Table 2:

[0083] Table 2: Definition of S(l).

[0084]

[0085] like Figure 6 As shown in , the NSS on the non-anchor carrier is transmitted in subframe #5 with a period of 10 ms, which is the same as the NB-PSS transmitted in the anchor carrier.

[0086] Optionally, the NB-SSS on the non-anchor carrier may be sent in the same manner as the NB-SSS sent on the anchor carrier, for example, using the same sequence as that of the NB-SSS on the anchor carrier and in subframe #9 having a period of 20 ms.

[0087] Figure 7700 is a schematic flow chart showing an embodiment of a method 700 according to the present application. In some embodiments, the method 700 is performed by a device such as a base unit. In some embodiments, the method 700 can be performed by a processor that executes program code, such as a microcontroller, a microprocessor, a CPU, a GPU, an auxiliary processing unit, an FPGA, etc.

[0088] The method 700 may include transmitting a carrier configuration on an anchor carrier at 702. The method 700 may also include transmitting a synchronization signal in a non-anchor carrier based on the carrier configuration at 704.

[0089] Figure 8 800 is a schematic flow chart showing another embodiment of a method 800 according to the present application. In some embodiments, the method 800 is performed by a device such as a remote unit. In some embodiments, the method 800 can be performed by a processor that executes program code, such as a microcontroller, a microprocessor, a CPU, a GPU, an auxiliary processing unit, an FPGA, etc.

[0090] The method 800 may include receiving a carrier configuration on an anchor carrier at 802. The method 800 may also include receiving a synchronization signal in a non-anchor carrier based on the carrier configuration at 804.

[0091] Fig. 9 is a schematic block diagram showing an apparatus according to one embodiment.

[0092] refer to Fig. 9 , UE (ie remote unit) includes a processor, a memory and a transceiver. Processor implementation Figure 8 The functions, processes and / or methods proposed in the present invention are as follows. The eNB (i.e., basic unit) includes a processor, a memory and a transceiver. The processor implements Figure 7 The functions, processes and / or methods proposed in the present invention are described in detail. The layers of the radio interface protocol can be implemented by a processor. The memory is connected to the processor to store various information for driving the processor. The transceiver is connected to the processor to send and / or receive radio signals. Needless to say, the transceiver can be implemented as a transmitter for sending radio signals and a receiver for receiving radio signals.

[0093] The memory may be located inside or outside the processor and connected to the processor through various well-known means.

[0094] In the above-described embodiments, the components and features of the embodiments are combined in a predetermined form. Unless otherwise explicitly stated, each component or feature should be considered as an option. It can be realized that each component or feature is not associated with other components or features. In addition, the embodiments can be configured by associating some components and / or features. The order of the operations described in the embodiments can be changed. Some components or features of any embodiment can be included in another embodiment, or replaced by components and features corresponding to another embodiment. Obviously, claims that are not explicitly cited in the claims are combined to form an embodiment or included in a new claim.

[0095] The embodiments may be implemented by hardware, firmware, software or a combination thereof. In the case of being implemented by hardware, the exemplary embodiments described herein may be implemented by using one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, etc., according to the hardware implementation.

[0096] Embodiments may be implemented in other specific forms. The described embodiments should be considered in all respects to be merely illustrative and not restrictive. Therefore, the scope of the present invention is indicated by the appended claims rather than by the foregoing description. All changes within the meaning and scope of the claims should be included within their scope.

Claims

1. A method performed by a base unit, the method comprising: transmitting a first synchronization signal and a first broadcast signal associated with the cell identifier on the anchor carrier; sending a non-anchor carrier configuration on the anchor carrier; as well as A second synchronization signal associated with a virtual cell identifier is sent on the non-anchor carrier based on the non-anchor carrier configuration.

2. The method according to claim 1, wherein: The non-anchor carrier is associated with a carrier index, and wherein the carrier index is configured in the non-anchor carrier configuration or wherein the carrier index is based on a frequency position of the non-anchor carrier.

3. The method according to claim 1, wherein: The virtual cell identifier is configured in the non-anchor carrier configuration or determined by a cell identifier associated with the anchor carrier.

4. The method according to claim 1, wherein: The timing offset of the second synchronization signal is configured in the non-anchor carrier configuration.

5. The method according to claim 1, wherein: An identifier offset of the virtual cell identifier of the second synchronization signal to an Evolved-UMTS Terrestrial Radio Access, E-UTRA system cell identifier is configured in the non-anchor carrier configuration.

6. The method according to claim 5, wherein: The virtual identifier divided by 6 is equal to the Evolved-UMTS Terrestrial Radio Access, E-UTRA, system cell identifier divided by 6 plus or minus the identifier offset.

7. The method according to claim 1, wherein: The non-anchor carrier is in an Evolved-UMTS Terrestrial Radio Access, E-UTRA system, and wherein an Evolved-UMTS Terrestrial Radio Access, E-UTRA system cell identifier is configured in the non-anchor carrier configuration.

8. The method according to claim 1, wherein: The second synchronization signal is sent in a first number of time units.

9. The method according to claim 8, wherein: In each time unit, the second synchronization signal includes a random sequence of length L, wherein the length L is determined by an operation mode of the non-anchor carrier.

10. The method according to claim 9, wherein: An initialization seed for the random sequence is based on at least one of: a carrier index, the virtual cell identifier, a cell identifier of the anchor carrier, or a system information (SI) change indicator.

11. The method according to claim 10, wherein: The SI change indicator is based on the high-level parameter systemInfoValueTag of the narrowband Internet of Things NBIoT.

12. The method according to claim 11, wherein: The SI change indicator is equal to 1 when the high-level parameter systemInfoValueTag of NBIoT is different from the previous high-level parameter systemInfoValueTag of NBIoT associated with the previous T time units, where T is configured in the non-anchor carrier configuration or is equal to the system information (SI) valid time.

13. The method of claim 8, further comprising mapping the second synchronization signal to one or more time-frequency resources per time unit according to a mapping method, the mapping method being determined by an operation mode of the non-anchor carrier.

14. The method according to claim 13, wherein: The mapping method is one of the following: symbol S to the last symbol of the time unit, and then symbol 0 to symbol S-1, symbol S to the last symbol of the time unit, and Symbol 0 to the last symbol of the time unit, Where S is based on the high layer or is fixed to 3.

15. The method according to claim 8, wherein: The second synchronization signal comprises a Zadoff-Chu sequence, and wherein a system information change indicator is included in generation of the Zadoff-Chu sequence.

16. The method according to claim 15, wherein: The system information change indicator is included in a root index of the Zadoff-Chu sequence of the second synchronization signal.

17. The method according to claim 15, wherein: The second synchronization signal further comprises a cover code, and wherein the system information change indicator is included in the cover code.

18. A basic unit, comprising: processor; as well as A memory, the memory being coupled to the processor, the memory comprising instructions executable by the processor to cause the basic unit to perform the following operations: transmitting a first synchronization signal and a first broadcast signal associated with the cell identifier on the anchor carrier; sending the non-anchor carrier configuration on the anchor carrier; and A second synchronization signal associated with a virtual cell identifier is sent on the non-anchor carrier based on the non-anchor carrier configuration.

19. The base unit according to claim 18, wherein: The non-anchor carrier is associated with a carrier index, and wherein the carrier index is configured in the non-anchor carrier configuration or wherein the carrier index is based on a frequency position of the non-anchor carrier.

20. The base unit according to claim 18, wherein: The virtual cell identifier is configured in the non-anchor carrier configuration or determined by a cell identifier associated with the anchor carrier.

21. The base unit according to claim 18, wherein: The timing offset of the second synchronization signal is configured in the non-anchor carrier configuration.

22. The base unit according to claim 18, wherein: An identifier offset of the virtual cell identifier of the second synchronization signal to an Evolved-UMTS Terrestrial Radio Access, E-UTRA system cell identifier is configured in the non-anchor carrier configuration.

23. The base unit according to claim 22, wherein: The virtual identifier divided by 6 is equal to the Evolved-UMTS Terrestrial Radio Access, E-UTRA, system cell identifier divided by 6 plus or minus the identifier offset.

24. The base unit according to claim 18, wherein: The non-anchor carrier is in an Evolved-UMTS Terrestrial Radio Access, E-UTRA system, and wherein an Evolved-UMTS Terrestrial Radio Access, E-UTRA system cell identifier is configured in the non-anchor carrier configuration.

25. The base unit according to claim 18, wherein: The second synchronization signal is sent in a first number of time units.

26. The base unit according to claim 25, wherein: In each time unit, the second synchronization signal includes a random sequence of length L, wherein the length L is determined by an operation mode of the non-anchor carrier.

27. The base unit according to claim 26, wherein: An initialization seed for the random sequence is based on at least one of: a carrier index, the virtual cell identifier, a cell identifier of the anchor carrier, or a system information (SI) change indicator.

28. The base unit according to claim 27, wherein: The SI change indicator is based on the high-level parameter systemInfoValueTag of the narrowband Internet of Things NBIoT.

29. The base unit according to claim 28, wherein: The SI change indicator is equal to 1 when the high-level parameter systemInfoValueTag of NBIoT is different from the previous high-level parameter systemInfoValueTag of NBIoT associated with the previous T time units, where T is configured in the non-anchor carrier configuration or is equal to the system information (SI) valid time.

30. The base unit according to claim 25, wherein: The second synchronization signal is mapped to one or more time-frequency resources of each time unit according to a mapping method, and the mapping method is determined by an operation mode of the non-anchor carrier.

31. The base unit according to claim 30, wherein: The mapping method is one of the following: symbol S to the last symbol of the time unit, and then symbol 0 to symbol S-1, symbol S to the last symbol of the time unit, and Symbol 0 to the last symbol of the time unit, Where S is based on the high layer or is fixed to 3.

32. The base unit according to claim 25, wherein: The second synchronization signal comprises a Zadoff-Chu sequence, and wherein a system information change indicator is included in generation of the Zadoff-Chu sequence.

33. The base unit according to claim 32, wherein: The system information change indicator is included in a root index of the Zadoff-Chu sequence of the second synchronization signal.

34. The base unit according to claim 32, wherein: The second synchronization signal further comprises a cover code, and wherein the system information change indicator is included in the cover code.

35. A method performed by a user equipment (UE), the method comprising: receiving a first synchronization signal and a first broadcast signal associated with a cell identifier on an anchor carrier; receiving a non-anchor carrier configuration on the anchor carrier; as well as A second synchronization signal associated with a virtual cell identifier is received on a non-anchor carrier based on the non-anchor carrier configuration.

36. The method of claim 35, wherein: The non-anchor carrier is associated with a carrier index, and wherein the carrier index is configured in the non-anchor carrier configuration or wherein the carrier index is based on a frequency position of the non-anchor carrier.

37. The method of claim 35, wherein: The virtual cell identifier is configured in the non-anchor carrier configuration or determined by a cell identifier associated with the anchor carrier.

38. The method of claim 35, wherein: The timing offset of the second synchronization signal is configured in the non-anchor carrier configuration.

39. The method of claim 35, wherein: An identifier offset of the virtual cell identifier of the second synchronization signal to an Evolved-UMTS Terrestrial Radio Access, E-UTRA system cell identifier is configured in the non-anchor carrier configuration.

40. The method of claim 39, wherein: The virtual identifier divided by 6 is equal to the Evolved-UMTS Terrestrial Radio Access, E-UTRA, system cell identifier divided by 6 plus or minus the identifier offset.

41. The method of claim 35, wherein: The non-anchor carrier is in an Evolved-UMTS Terrestrial Radio Access, E-UTRA system, and wherein an Evolved-UMTS Terrestrial Radio Access, E-UTRA system cell identifier is configured in the non-anchor carrier configuration.

42. The method of claim 35, wherein: The second synchronization signal is sent in a first number of time units.

43. The method of claim 42, wherein: In each time unit, the second synchronization signal includes a random sequence of length L, wherein the length L is determined by an operation mode of the non-anchor carrier.

44. The method of claim 43, wherein: An initialization seed for the random sequence is based on at least one of: a carrier index, the virtual cell identifier, a cell identifier of the anchor carrier, or a system information (SI) change indicator.

45. The method of claim 44, wherein: The SI change indicator is based on the high-level parameter systemInfoValueTag of the narrowband Internet of Things NBIoT.

46. ​​The method of claim 45, wherein: The SI change indicator is equal to 1 when the high-level parameter systemInfoValueTag of NBIoT is different from the previous high-level parameter systemInfoValueTag of NBIoT associated with the previous T time units, where T is configured in the non-anchor carrier configuration or is equal to the system information (SI) valid time.

47. The method of claim 42, further comprising mapping the second synchronization signal to one or more time-frequency resources per time unit according to a mapping method, the mapping method being determined by an operation mode of the non-anchor carrier.

48. The method of claim 47, wherein: The mapping method is one of the following: symbol S to the last symbol of the time unit, and then symbol 0 to symbol S-1, symbol S to the last symbol of the time unit, and Symbol 0 to the last symbol of the time unit, Where S is based on the high layer or is fixed to 3.

49. The method of claim 42, wherein: The second synchronization signal comprises a Zadoff-Chu sequence, and wherein a system information change indicator is included in generation of the Zadoff-Chu sequence.

50. The method of claim 49, wherein: The system information change indicator is included in a root index of the Zadoff-Chu sequence of the second synchronization signal.

51. The method of claim 49, wherein: The second synchronization signal further comprises a cover code, and wherein the system information change indicator is included in the cover code.

52. A remote unit, the remote unit comprising: processor; as well as a memory coupled to the processor, the memory comprising instructions executable by the processor to cause the remote unit to: receiving a first synchronization signal and a first broadcast signal associated with a cell identifier on an anchor carrier; receiving a non-anchor carrier configuration on the anchor carrier; and A second synchronization signal associated with a virtual cell identifier is received on a non-anchor carrier based on the non-anchor carrier configuration.

53. The remote unit of claim 52, wherein: The non-anchor carrier is associated with a carrier index, and wherein the carrier index is configured in the non-anchor carrier configuration or wherein the carrier index is based on a frequency position of the non-anchor carrier.

54. The remote unit of claim 52, wherein: The virtual cell identifier is configured in the non-anchor carrier configuration or determined by a cell identifier associated with the anchor carrier.

55. The remote unit of claim 52, wherein: The timing offset of the second synchronization signal is configured in the non-anchor carrier configuration.

56. The remote unit of claim 52, wherein: An identifier offset of the virtual cell identifier of the second synchronization signal to an Evolved-UMTS Terrestrial Radio Access, E-UTRA system cell identifier is configured in the non-anchor carrier configuration.

57. The remote unit of claim 56, wherein: The virtual identifier divided by 6 is equal to the Evolved-UMTS Terrestrial Radio Access, E-UTRA, system cell identifier divided by 6 plus or minus the identifier offset.

58. The remote unit of claim 52, wherein: The non-anchor carrier is in an Evolved-UMTS Terrestrial Radio Access, E-UTRA system, and wherein an Evolved-UMTS Terrestrial Radio Access, E-UTRA system cell identifier is configured in the non-anchor carrier configuration.

59. The remote unit of claim 52, wherein: The second synchronization signal is sent in a first number of time units.

60. The remote unit of claim 59, wherein: In each time unit, the second synchronization signal includes a random sequence of length L, wherein the length L is determined by an operation mode of the non-anchor carrier.

61. The remote unit of claim 60, wherein: An initialization seed for the random sequence is based on at least one of: a carrier index, the virtual cell identifier, a cell identifier of the anchor carrier, or a system information (SI) change indicator.

62. The remote unit of claim 61, wherein: The SI change indicator is based on the high-level parameter systemInfoValueTag of the narrowband Internet of Things NBIoT.

63. The remote unit of claim 62, wherein: The SI change indicator is equal to 1 when the high-level parameter systemInfoValueTag of NBIoT is different from the previous high-level parameter systemInfoValueTag of NBIoT associated with the previous T time units, where T is configured in the non-anchor carrier configuration or is equal to the system information (SI) valid time.

64. The remote unit of claim 59, wherein: The second synchronization signal is mapped to one or more time-frequency resources of each time unit according to a mapping method, wherein the mapping method is determined by an operation mode of the non-anchor carrier.

65. The remote unit of claim 64, wherein: The mapping method is one of the following: symbol S to the last symbol of the time unit, and then symbol 0 to symbol S-1, symbol S to the last symbol of the time unit, and Symbol 0 to the last symbol of the time unit, Where S is based on the high layer or is fixed to 3.

66. The remote unit of claim 59, wherein: The second synchronization signal comprises a Zadoff-Chu sequence, and wherein a system information change indicator is included in generation of the Zadoff-Chu sequence.

67. The remote unit of claim 66, wherein: The system information change indicator is included in a root index of the Zadoff-Chu sequence of the second synchronization signal.

68. The remote unit of claim 66, wherein: The second synchronization signal further comprises a cover code, and wherein the system information change indicator is included in the cover code.

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