synchronization

Abstract

According to an example aspect of the application, there is provided an apparatus configured to detect a synchronization signal from a base node of a network over an air interface, the synchronization signal comprising at least a primary synchronization signal, PSS, a secondary synchronization signal, SSS, and a physical broadcast channel, PBCH, wherein the synchronization signal is organized into a first part transmitted with a first time period and a second part transmitted with a second, lower time period, and wherein the apparatus is further caused to detect the first part based on the first time period and to detect the second part based on the second time period.

Description

Technical Field

[0001] This disclosure relates to synchronization processes in wireless communication networks. Background Technology

[0002] In cellular communication networks, user equipment (UE) roams within the network's coverage area and attaches itself to a cell within the network.

[0003] In order to obtain reliable communication with the cell, the UE needs to synchronize itself with the cell in both the time and frequency domains, thereby obtaining symbol timing and frequency synchronization, so that communication based on orthogonal frequency division multiplexing (OFDM) can be carried out between the UE and the cell.

[0004] Synchronization signals can be transmitted by the cell and detected by the UE to achieve synchronization. Summary of the Invention

[0005] The technical solutions of the independent claims are provided according to several aspects. Several embodiments are defined in the dependent claims. The scope of protection sought by the various embodiments of the invention is set forth in the independent claims. Embodiments, examples, and features (if any) described in this specification that do not fall within the scope of the independent claims are to be interpreted as examples useful for understanding the various embodiments of the invention.

[0006] According to a first aspect of this disclosure, an apparatus is provided comprising at least one processing core and at least one memory storing instructions, the instructions, when executed by the at least one processing core, causing the apparatus to at least: detect a synchronization signal from a base node of a network via an air interface, the synchronization signal comprising at least a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a physical broadcast channel (PBCH), wherein the synchronization signal is organized into a first portion transmitted at a first time period and a second portion transmitted at a lower second time period, and wherein the apparatus further causes to: detect the first portion based on the first time period; and detect the second portion based on the second time period.

[0007] According to a second aspect of this disclosure, an apparatus is provided comprising at least one processing core and at least one memory storing instructions, which, when executed by the at least one processing core, cause the apparatus to at least perform the following operations: transmit a synchronization signal of a network via an air interface, the synchronization signal comprising at least a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a physical broadcast channel (PBCH), wherein the synchronization signal is organized into a first portion causing the apparatus to transmit at a first time period and a second portion causing the apparatus to transmit at a lower second time period.

[0008] According to a third aspect of this disclosure, a method is provided, comprising: detecting a synchronization signal from a base node of a network via an air interface, the synchronization signal comprising at least a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a physical broadcast channel (PBCH), wherein the synchronization signal is organized into a first portion transmitted over a first time period and a second portion transmitted over a second, lower time period, and wherein the method further comprises: detecting the first portion based on the first time period and detecting the second portion based on the second time period.

[0009] According to a fourth aspect of this disclosure, a method is provided comprising: transmitting a synchronization signal of a network via an air interface, the synchronization signal comprising at least a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a physical broadcast channel (PBCH), wherein the synchronization signal is organized into a first portion transmitted at a first time period and a second portion transmitted at a lower second time period.

[0010] According to a fifth aspect of this disclosure, an apparatus is provided, comprising: components for detecting a synchronization signal from a base node of a network via an air interface, the synchronization signal including at least a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a physical broadcast channel (PBCH), wherein the synchronization signal is organized into a first portion transmitted at a first time period and a second portion transmitted at a lower second time period, and wherein the apparatus further comprises: components for detecting the first portion based on the first time period and detecting the second portion based on the second time period.

[0011] According to a sixth aspect of this disclosure, an apparatus is provided, comprising: a component for transmitting a synchronization signal of a network via an air interface, the synchronization signal including at least a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a physical broadcast channel (PBCH), wherein the synchronization signal is organized into a first portion transmitted by the apparatus at a first time period and a second portion transmitted by the apparatus at a second lower time period.

[0012] According to a seventh aspect of this disclosure, a non-transitory computer-readable medium is provided having a set of computer-readable instructions stored thereon, which, when executed by at least one processor, causes a device to perform at least the following operations: detecting a synchronization signal from a base node of a network over an air interface, the synchronization signal including at least a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a physical broadcast channel (PBCH), wherein the synchronization signal is organized into a first portion transmitted over a first time period and a second portion transmitted over a lower second time period, and wherein the device is also caused to detect the first portion based on the first time period and the second portion based on the second time period.

[0013] According to an eighth aspect of this disclosure, a non-transitory computer-readable medium is provided having a set of computer-readable instructions stored thereon, which, when executed by at least one processor, causes a device to perform at least the following operations: transmit a synchronization signal of a network via an air interface, the synchronization signal including at least a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a physical broadcast channel (PBCH), wherein the synchronization signal is organized into a first part and a second part, the computer-readable instructions causing the device to transmit at a first time period, and the computer-readable instructions causing the device to transmit at a lower second time period. Attached Figure Description

[0014] Figure 1 An example system according to at least some embodiments of the present invention is shown; Figure 2A An example of a synchronization signal according to the first embodiment is shown; Figure 2B It is a mapping from the SSS portion to the PRB according to at least some embodiments of the present invention; Figure 2C This is a flowchart of the UE behavior in the first embodiment of this disclosure; Figure 2D Synchronization signaling is shown; Figure 2E This is a flowchart of the UE behavior in the second embodiment of this disclosure; Appendix Figure 3 Exemplary apparatus capable of supporting at least some embodiments of the present invention is shown; Figure 4 Signaling according to at least some embodiments of the present invention is shown, and Figure 5 This is a flowchart of a method according to at least some embodiments of the present invention. Detailed Implementation

[0015] This paper discloses a synchronization mechanism in which multiple synchronization signals are provided from the cell to the UE. Specifically, the synchronization signals are provided in two parts, with different time periods. Furthermore, a secondary synchronization signal (SSS) can be provided as a first SSS part and a second SSS part, which together form the entire SSS, enabling the delivery of the SSS using a lower peak-to-average power ratio (PAPR), as discussed below. Moreover, splitting the synchronization signal into two parts provides a lower PAPR because the SSS is associated with a higher PAPR compared to the primary synchronization signal (PSS), allowing the primary synchronization signal (PSS) to be provided more frequently than the SSS.

[0016] Figure 1An example system according to at least some embodiments of the present invention is illustrated. The system includes base stations 130 and 135 communicating with a UE, such as UE 110. A radio link connects base station 130 to UE 110. The radio link may be bidirectional, including an uplink UL for transmitting information from UE 110 to base station 130, and a downlink DL for transmitting information from base station 130 to UE 110. A cellular communication system may include hundreds or thousands of base stations; for clarity of illustration, [the following is omitted as it is not explicitly stated]. Figure 1 Only two of them are shown in the image. Base stations can be distributed, as they consist of centralized units (CUs) and one or more distributed units (DUs). A base station is an example of a base node.

[0017] Base station 130 is also communicatively coupled to core network node 140, which may include, for example, a Mobility Management Entity (MME) or an Access and Mobility Management Function (AMF). Core network node 140 may be coupled to other core network nodes and to network 150, which may include, for example, the Internet or a corporate network. The system can communicate with other networks via network 150. For clarity, in Figure 1 Examples of other core network nodes not shown include gateways and subscriber information databases. Core network nodes can be virtualized because they can run as software modules on a computing substrate, allowing more than one virtualized network node to run on the same computing substrate. The network can be configured to operate according to a suitable cellular standard, such as LTE, 5G (also known as New Radio), or 6G, as defined by the 3GPP (3rd Generation Partnership Project). For interoperability, UEs attached to the network are configured to support the same standards as the network.

[0018] exist Figure 1 In the example, base station 130 controls cells 130A and 130B, where UE 110 is attached to cell 130A. Figure 1 The situation shown, and in Figure 1 In the example, base station 135 controls cells 135A and 135B. The number of cells or beams can exceed [number missing]. Figure 1 The number shown is not provided. It is also possible for a base station to have a single cell or beam. Although shown as a sector, cells of the same base station can be omnidirectional and, for example, operate on different frequencies. Mobility events can include switching from one beam of the same cell to another, or from one cell to another. To support mobility procedures, the UE, including UE 110, is configured to perform mobility measurements to measure the signal strength of adjacent beams and / or cells and report the results of these measurements to the network, which can then make decisions regarding mobility events such as beam changes or cell handovers.

[0019] Cells (such as cells 130A, 130B, 135A, and 135B) are configured to transmit synchronization signals (such as primary synchronization signal PSS and secondary synchronization signal SSS) to achieve synchronization of the UE with the cell's frame structure, for example, in conjunction with initial attachment or mobility procedures.

[0020] In 5G, for example, a cell provides a Synchronization Signal Block (SSB), which includes the PSS, SSS, Physical Broadcast Channel (PBCH), and Demodulation Reference Signal (DMRS) for PBCH demodulation. In 5G, the SSB can be provided using a single resource block of four OFDM symbols in the time domain and 20 Physical Resource Blocks (PRBs) in the frequency domain, where each PRB in 5G corresponds to twelve subcarriers. In 5G, the PSS is an m-sequence, and the SSS is a Gold sequence, obtained by XORing two m-sequences of equal length. 5G uses Binary Phase Shift Keying (BPSK) to transmit the PSS and SSS, while Quadrature Phase Shift Keying (QPSK) is used to transmit the PBCH. The PSS is used for time and frequency synchronization with the cell, while the SSS is used for more precise frequency synchronization, and the PBCH is used for frame and half-frame synchronization and to transmit the DMRS for slot timing. The PBCH can also be used to transmit configuration information available to the UE when accessing the cell, such as, for example, antenna configuration. Furthermore, the Physical Cell Identifier (PCI) is encoded into the PSS and SSS. Specifically, the PCI... It can be by Definition, where and PSS depends on The m-sequence, therefore, has three possible m-sequences that can be used as the PSS in 5G. The SSS depends on... and The Gold sequences of both.

[0021] Energy efficiency in cellular communication networks is relevant in terms of both power cost and total energy use, as industrial energy use also has environmental impacts. 6G networks will need to be more energy-efficient than existing systems, which can be achieved, for example, by dynamically shutting down or switching components and nodes to low-energy states and reducing network capacity when demand is low.

[0022] When transmitting signals from a cell or UE, a power amplifier (PA) is used. When a PA is driven beyond its normal linear operating range, it begins to generate spurious emissions, which are equivalent to the energy consumed in generating noise, and it also extends the bandwidth actually affected by the transmission, potentially causing interference to adjacent frequency channels. The amount of spurious emissions generated in adjacent frequency bands may be capped by regulations and / or 3GPP RAN4 RF requirements. These may include, for example, adjacent channel leakage ratio, ACLR requirements, and spectral emission masks. This can be mitigated by limiting the average PA output power to avoid driving the PA beyond its linear range. When using this approach, the peak power should not exceed 1 dB of the PA's output compression power to reduce spectral regrowth and improve bit error rate (BER) performance. When sufficient backoff is used, the error vector magnitude (EVM) (a measure of modulation quality at the transmitter) will therefore be smaller. The amount of backoff chosen for the modulated signal depends not only on the PAPR of the waveform used but also on the probability of PAPR peaks occurring. Backing off power to avoid PA compression will result in lower power efficiency and thus reduced coverage of the transmitted signal. In 6G, higher frequencies beyond the sub-6 GHz frequency range (1 FR1) are expected to become more important, which further increases the relevance of DL energy efficiency and coverage.

[0023] The table below shows the 98th percentile of the average sample-based PAPR values ​​for PSS, SSS, and SSB symbols 1, 2, and 3 with PBCH, PBCH DMRS, and SSS in 5G:

[0024] As can be seen from the table, PSS is associated with a lower PAPR compared to SSS, and also compared to SSS multiplexed with PBCH. Even though PSS is the first signal searched by the UE, SSS provided within the third symbol of the 5G SSB is the primary 5G signal used for main SSB-based beam measurements and mobility measurements in idle and connected modes. SSS transmission in the frequency domain, with or without multiplexing with PBCH PRB, involves a higher PAPR and requires high transmission power backoff, which reduces the reception quality or equivalent coverage of the SSS signal. In particular, the symbol-based PAPR indicates that multiplexing PBCH with SSS further increases the PAPR.

[0025] This paper describes synchronization mechanisms that enhance synchronization signal architecture to enable more energy-efficient transmission of synchronization signals, while also improving downlink coverage. In other words, these synchronization mechanisms provide low PAPR synchronization signal architecture and transmission, for example, for 6G-based systems. The reduced PAPR translates to improved synchronization signal coverage, improved energy efficiency (which can lead to reduced power consumption), and / or reduced synchronization signal overhead in beam-based cells. Downlink designs in 6G for the already defined FR1 band can be OFDM-based to enable multi-radio spectrum sharing, for example, between 5G and 6G systems. For higher frequency bands, such as the 7-15 GHz band for 6G, separate energy-efficient architectures can be considered, as no legacy systems need to coexist.

[0026] Based on performance studies, it has been found that in certain situations, such as urban 4GHz time-division duplex (TDD) scenarios or urban 28GHz TDD non-line-of-sight (NLOS) outdoor-to-indoor scenarios, SSB channels require coverage enhancement. Therefore, it can be concluded that SSB channels will generally benefit from coverage enhancement solutions in FR1 and FR2 above 6GHz, as well as in the 7-15 GHz band associated with 6GHz. A further motivation for improving SSB coverage is that it allows for wider transmission beams used to carry synchronization signals. This will reduce the number of beams required and correspondingly reduce synchronization signal overhead.

[0027] Similarly, even without increased coverage, reducing the PAPR waveform is a way to use (multiple) PAs more efficiently, thus reducing the amount of power dissipated. Therefore, energy savings can be achieved by using a lower PAPR signal. From the network's perspective, the SSB is a periodic signal block that transmits periodically, so reducing its PAPR will save energy in the network.

[0028] PAPR can be reduced by providing a synchronization signal that is organized into a first portion transmitted with a first time period and a second portion transmitted with a lower second time period. Alternatively, an SSS organized into a first SSS portion and a second SSS portion, together forming a complete SSS, can be provided to enable SSS delivery with a lower PAPR than when using a Gold sequence. The first and second SSS portions are low-PAPR sequences, such as m-sequences.

[0029] In a first embodiment, the first portion includes a PSS, and the second portion includes an SSS and a PBCH. In this embodiment, the same transmission beam from the base station can be used to provide both the first and second portions. In the first embodiment, the PSS and the second portion have different time-domain periods. For example, the PSS can be transmitted more frequently, and the higher PAPR second portion, including the SSS, can be transmitted at a lower frequency compared to the PSS. Therefore, in the first embodiment, a lower overall PAPR is achieved by transmitting the higher PAPR portion less frequently. Furthermore, the PSS involves the transmission of a single symbol, while the PSS, SSS, and PBCH together involve four symbols; therefore, transmitting the shorter PSS more frequently reduces the average transmission time, which saves energy.

[0030] The second part may include, for example, a first SSS portion, such as a first m-sequence transmitted in the first symbol of the second part of the synchronization signal. Furthermore, the second part may include PBCH symbols transmitted in the second symbol of the second part of the synchronization signal, a second SSS portion (e.g., a second m-sequence) transmitted in the third symbol of the second part of the synchronization signal, and PBCH symbols transmitted in the fourth symbol of the second part of the synchronization signal. Three PBCH symbols may also exist, such as PBCH symbols also present in the fifth symbol of the second part of the synchronization signal.

[0031] The first SSS portion and / or a separate second SSS portion can be used as a demodulation reference signal for the PBCH. Accordingly, the UE can be configured to assume that the SSS portion is transmitted using the same antenna port as the PBCH, and therefore shares the same quasi-co-located QCL characteristics, such as Doppler spread, Doppler shift, average delay and delay spread, and beamforming.

[0032] In the first embodiment, the symbols of the second part can also be ordered differently, such as the first SSS portion of the first symbol of the second part of the synchronization signal, the PBCH symbol in the second and third symbols, and the second SSS portion in the fourth symbol. This ordering provides the UE with a wider range for frequency offset estimation, but may have lower channel estimation performance in high-speed / high-Doppler situations.

[0033] In a first embodiment, the bandwidth (or frequency span) of at least one SSS portion is at least equal to the bandwidth of the PBCH and overlaps with the PBCH in the frequency domain. In this first embodiment, the UE is configured to combine complete SSS information from the first and second SSS portions. Information encoded in the SSS may include, for example, a physical cell identifier or timing information such as a block / beam index with the PBCH. In this first embodiment, the PBCH can be transmitted using a Discrete Fourier Transform Extended Orthogonal Frequency Division Multiplexing (DFT-s-OFDM) waveform. Alternatively, a Cyclic Prefix (CP-OFDM) waveform can be used to provide the PBCH.

[0034] In a variant of the first embodiment, diversity is used for the DFT-s-OFDM-based PBCH, and the first and second SSS portions are transmitted from two antenna ports using frequencies, wherein the signal at each antenna port is mapped in the frequency domain to every other subcarrier. In other words, a repetition factor of 2 can be used to transmit port-specific SSS portions from the two antenna ports. Furthermore, transmission diversity modes, such as Spatial Frequency Block Coding (SFBC), the frequency domain version of the Alamouti transmitter, can be used for the PBCH. The Alamouti block coding with two antenna ports can be implemented, for example, in a group of two consecutive subcarriers, such that the first subcarrier carries [s0, -s1*] for the first and second antenna ports respectively (s0 and s1 are modulation symbols for two consecutive modulation symbols, and * is the complex conjugate), and the second subcarrier carries [s1, s0*] for the first and second antenna ports respectively.

[0035] In the second embodiment, the first part of the synchronization signal includes a PSS, a first SSS part and a second SSS part, and the second part of the synchronization signal includes a PSS, two PBCH symbols and a second SSS part.

[0036] In the second embodiment, different transmission beams of the base station can be used to transmit the first and second portions of the synchronization signal. For example, a wider beam and higher power, facilitated by a lower PAPR, can be used to transmit the first portion, thereby allowing the UE to perform cell timing acquisition, frequency synchronization using SSS and PSS, and cell identifier detection. The second portion can then be transmitted using a narrower beam and lower power of the base station.

[0037] The UE can be configured to use the transmission beam of the base station for transmitting the second portion of the synchronization signal to determine the transmission beam for random access transmission. The UE can also be configured to use the transmission beam of the base station for transmitting the second portion of the synchronization signal to determine the receive beam for subsequent downlink transmission. A first reference signal characterizing the transmission beam of the base station for transmitting the first portion of the synchronization signal can be a quasi-co-located source, at least in terms of spatial receiver parameters, relative to the second reference signal characterizing the transmission beam of the base station for transmitting the second portion of the synchronization signal.

[0038] In the second embodiment, DFT-s-OFDM or CP-OFDM waveforms can be used to transmit PBCH symbols. The transmission beam for the second part of the synchronization signal can be used for the Physical Downlink Control Channel (PDCCH) and / or the Physical Downlink Shared Channel (PDSCH), for System Information Block 1 (SIB1), and for other common control signaling.

[0039] A quasi-co-located QCL source, such as a beam, can be defined by a second SSS portion transmitted in the same block as the PBCH symbol. If the UE detects the second portion of the synchronization signal first, it can obtain cell timing (FFT timing), but only a portion of the physical cell identifier instead of the complete physical cell identifier. In this second embodiment, the first SSS portion can be defined with fewer assumptions than the second SSS portion, such as cyclic shifts, and therefore the UE can try different first SSS portion assumptions when demodulating and decoding the PBCH—it can be assumed that the PBCH is scrambled with a scrambling code that depends at least on the complete physical cell identifier. Alternatively, the PBCH can be scrambled using a scrambling code that includes the index of the second SSS portion but not the index of the first SSS portion. The index of the first SSS portion, and therefore the missing portion of the physical cell identifier, will be provided in the PBCH payload or as part of the physical layer bits.

[0040] The synchronization index for providing time slot timing can be provided in the second SSS portion, or as part of the physical layer bits, or entirely in the PBCH payload. The time period for the first portion used to transmit the synchronization signal can be, for example, 10 or 20 milliseconds. The time period for the second portion used to transmit the synchronization signal can be, for example, 40 or 80 milliseconds.

[0041] In a second embodiment, if the first and second portions of the synchronization signal will fall within the same half-frame due to their time periods, the base station can be configured to transmit the second portion of the synchronization signal and avoid transmitting the first portion. To avoid this conflict, the first and second portions of the synchronization signal can be configured with half-frame-level or frame-level time offsets so that these portions do not overlap.

[0042] In a second embodiment, as an alternative to the above, the second part of the synchronization signal may include a symbol sequence of a first PBCH symbol, a first SSS portion, a second SSS portion, and a second PBCH symbol. Another alternative is a symbol sequence including a first SSS portion, a first PBCH symbol, a second SSS portion, and a second PBCH symbol; in this case, the first part of the synchronization signal is the first SSS portion, the PSS portion, and the second SSS portion.

[0043] In the presence of a time offset that prevents the first and second parts of the synchronization signal from overlapping, the second part of the synchronization signal may include a PSS and an SSS in the form of a Gold sequence constructed from two m sequences, a first SSS part and a second SSS part, and a PBCH that is time-multiplexed or also partially frequency-multiplexed, as in 5G SSB.

[0044] In the second embodiment, when using beams of different widths, the required number of wider beams (e.g., transmitted at a period of 20 ms) used for the first part can be reduced. Narrower beams, such as those used for PBCH decoding, QCL references for downlink data reception (e.g., PDCCH and PDSCH for SIB1, paging, and other system information reception), can be transmitted less frequently, as described above, to transmit the second part of the synchronization signal.

[0045] Figure 2A An example of a synchronization signal according to the first embodiment is shown. Five alternatives 201, 202, 203, 204, and 205 are shown for the second portion of the synchronization signal, where in the first embodiment, the first portion is only the PSS. In the figure, "1" represents the first SSS portion, "2" represents the second SSS portion, and "B" represents the PBCH symbol. The frequency is along the vertical direction, and the time is along the horizontal direction of the figure. When the periods of the first and second portions of the synchronization signal happen to coincide, the PSS can be part of a block, that is, the PSS can be transmitted in adjacent symbols of the block, either side is possible, or it can be transmitted alone. The length of the sequence (four units) is chosen for clarity of illustration and not intended to represent technical substance. In alternative 203, the first SSS portion and the first PBCH symbol appear to be abbreviated because in this alternative, the PBCH is divided into two portions with different transmission bandwidths. The bandwidth of the first PBCH symbol is aligned with the first SSS portion, and the bandwidth of the second PBCH symbol is aligned with the second SSS portion.

[0046] Figure 2BThis refers to the mapping of the SSS portion to the PRB according to at least some embodiments of the present invention. To support Alamouti transport diversity based on DFT-s-OFDM for PBCH, the first and second SSS portions are used to obtain channel estimates specific to the transport antenna port. The first and second SSS portions can each be mapped to the PRB, such as... Figure 2B As shown. In the SSS row, "1" indicates the first SSS section, and "2" indicates the second SSS section. The frequencies are along the horizontal line, and in the PRB row, the numbers represent the PRB numbers.

[0047] Figure 2C This is a flowchart of UE behavior in a first embodiment of this disclosure. The UE selects a frequency band to search for a PSS, for example in a 6G system. Initially, in phase 210, the UE determines the frequency band and the synchronization grid used for the frequency band, for example, based on a standardized synchronization grid defined for the frequency band.

[0048] Processing proceeds from stage 210 to stage 220, where the UE searches for the PSS around the synchronization grid points with a coarse frequency offset and FFT / symbol timing estimation. By searching around the grid points, this means that the UE performs a maximum likelihood ML search using, for example, a fixed grid of frequency locations around and on each synchronization grid point to determine the coarse frequency offset. Therefore, for example, when assuming a 30 kHz subcarrier spacing SCS, the UE can perform PSS detection at offsets of -N×6 kHz, 0, and +N×6 kHz relative to each synchronization grid point, where N can be, for example, 1 to 6 or 1 to 8.

[0049] Once a PSS is detected, processing proceeds to stage 230, where the first and second SSS portions are detected. Finally, in stage 240, the UE performs finer synchronization, determines the physical cell identifier from the first and second SSS portions, and receives at least one PBCH symbol. The UE can determine time slot timing based on the first and second SSS portions, and can determine Layer 1 Reference Signal Received Power (RSRP) measurement parameters for the cell and beam. For example, more accurate frequency synchronization can be obtained by calculating the phase shift on the same subcarrier between the first and second SSS portions. Furthermore, channel estimation for PBCH demodulation can be obtained, and the UE can perform PBCH demodulation and decoding.

[0050] Then, returning to the second embodiment, in which the system transmits a wider beam, for example including a PSS, a first SSS portion, and a second SSS portion, at a period of 20 or 25 milliseconds, thereby providing basic time and frequency synchronization and physical cell identifier supply. A narrower beam can be used to provide the PBCH, resulting in increased PBCH detection performance and further time (slot, half-frame, and frame) and frequency synchronization, for example, with a period of 40 or 80 milliseconds.

[0051] The second embodiment may involve transmitting the first portion of the synchronization signal using a beam wider than the beam used to transmit the second portion of the synchronization signal, in order to limit or reduce the number of SSBs required in the cell. To this end, the first portion of the synchronization signal is designed to have a low Output Backoff (OBO), thereby facilitating higher transmission power and, consequently, better coverage of the first portion with the wider beam pattern, at least comparable to the coverage of other downlink transmissions using narrower beams. Such downlink transmissions may include, for example, a PDCCH+PDSCH carrying SIB1, paging, and other system information. The low OBO also means that the first portion can be transmitted at maximum or near-maximum transmission power. The remaining portion of the entire synchronization signal (its second portion) can then be transmitted using a narrower beam and lower power, enabling the UE to estimate the narrower beam for detecting the PDCCH+PDSCH carrying SIB1 and, for example, for transmitting random access messages from the UE.

[0052] exist Figure 2D The diagram shows the first portion of the synchronization signal for the first five-millisecond half-frame block. In this figure, it is assumed that the beam used to transmit the first portion of the synchronization signal has double the beamwidth, thereby reducing the number of required synchronization signal transmission blocks 250 by half.

[0053] The second part of the synchronization signal is in Figure 2D The fifth half-frame block is shown. The second part is transmitted with a narrower beam and requires the transmission of 8 blocks 260. It should be noted that the positions of the PSS and the second SSS in the two parts of the synchronization signal remain unchanged. Assuming that existing 5G synchronization requires the transmission of the entire SSB of four symbols on 8 beams with a period of 20 milliseconds, the SSB occupies 8×4×2=64 symbols in a period of 40 milliseconds. On the other hand, in the second embodiment of this disclosure, the first part of the synchronization signal requires four beams, and the second part of the synchronization signal is transmitted on eight beams with a period of 40 milliseconds, and the synchronization signal in total occupies 4×3+8×4=44 symbols in a period of 40 milliseconds.

[0054] Figure 2EThis is a flowchart of UE behavior in a second embodiment of this disclosure. In stage 270, the UE determines the frequency band and the synchronization grid for the frequency band, for example, based on a standardized synchronization grid defined for the frequency band. Processing proceeds to stage 272, where the UE searches for the PSS around the synchronization grid points with a coarse frequency offset and FFT / symbol timing estimation. By searching around the grid points, this means that the UE performs a maximum likelihood ML search using, for example, a fixed frequency position grid around and on each synchronization grid point to determine the coarse frequency offset. Thus, for example, when assuming a 30 kHz subcarrier spacing SCS, the UE can perform PSS detection at offsets of -N×6 kHz, 0, and +N×6 kHz relative to the synchronization grid points, where N can be, for example, 1 to 6 or 1 to 8.

[0055] Upon detection of a PSS, the process proceeds to stage 274, where the UE searches for a second SSS portion and, once detected, uses it to fine-tune the frequency synchronization initially obtained using the PSS. Subsequently, the process proceeds to stage 276, where the UE determines whether the symbol following the PSS is the first SSS portion or the first PBCH symbol.

[0056] If it is the first SSS portion, processing proceeds to stage 278, where the UE obtains PCI from both the first and second SSS portions. In embodiments where slot timing is included in the SSS, the UE obtains slot timing from either the first or second SSS portions. Furthermore, more accurate frequency synchronization can be obtained by calculating the phase shift on the same subcarrier between the first and second SSS portions. Further still, channel estimation for PBCH demodulation can be determined, and layer 1 (L1) RSRP measurements of the cell can be obtained, for example, for mobility measurements.

[0057] Processing proceeds from stage 278 to stage 280, where the UE waits for the PBCH, and upon detection of the first PBCH symbol, the channel estimate from the second SSS portion can be used for PBCH demodulation. If the first SSS portion index is included in the PBCH payload, the UE can determine the PCI based on the SSS1 and SSS2 indices. In some embodiments, time slot timing is obtained from the first SSS portion and a portion or the entire PBCH content. The type of the first portion of the synchronization signal can be determined, and L1-RSRP measurements of the beam can be obtained.

[0058] Subsequently, the UE can obtain the cell's system information (phase 282) and estimate Doppler, time, and beam parameters for further downlink channel reception, such as for PDCCH and PDSCH reception (phase 284). These parameters can be reused from the second SSS section of communication.

[0059] On the other hand, if the symbol following the PSS is determined to be a PBCH symbol in stage 276, the process proceeds from stage 276 to stage 286, where the PBCH symbol is received, and the PCI may be determined, time slot timing estimated, and the L1-RSRP measurement of the beam obtained. Subsequently, in stage 288, the first SSS portion is searched, and when received, it is used to fine-tune frequency synchronization and define the L1-RSRP measurement of the cell. The process then proceeds to stage 282, which is the decision point regarding obtaining the SI. In stage 282, whether arriving from stage 280 or 288, if the SI is not obtained, the process proceeds from stage 282 back to stage 272.

[0060] Figure 3 Exemplary apparatus capable of supporting at least some embodiments of the present invention is shown. Device 300 is shown, which may include, for example, a mobile communication device, such as UE 110, or, in applicable portions, Figure 1 The base station 130. Device 300 includes a processor 310, which may include, for example, a single-core or multi-core processor, wherein a single-core processor includes one processing core, and a multi-core processor includes more than one processing core. Processor 310 typically includes a control device. Processor 310 may include more than one processor. When processor 310 includes more than one processor, device 300 may be a distributed device, wherein the processing of tasks occurs in more than one physical unit. Processor 310 may be a control device. Processing cores may include, for example, a Cortex-A8 processing core manufactured by ARM Holdings or a Zen processing core designed by Advanced Micro Devices. A processing core or processor may be or may include at least one qubit. Processor 310 may include at least one Qualcomm Snapdragon and / or Intel Atom processor. Processor 310 may include at least one application-specific integrated circuit (ASIC). Processor 310 may include at least one field-programmable gate array (FPGA). Processor 310 may optionally be, along with memory and computer instructions, a component for performing method steps (e.g., detection, acceptance, use, reception, or transmission) in device 300. The processor 310 can be configured, at least in part, by computer instructions to perform actions.

[0061] A processor may include, or be configured as, one or more circuits configured to perform stages of the methods according to embodiments described herein. As used herein, the term “circuit” may refer to one or more of the following: (a) a hardware circuit implementation only, such as an implementation in analog and / or digital circuits only; and (b) a combination of hardware circuits and software, such as applicable: (i) a combination of (multiple) analog and / or digital hardware circuits with software / firmware; and (ii) (multiple) hardware processors with any portion of software (including (multiple) digital signal processors), software, and (multiple) memories, which work together to enable a device such as a UE or base station to perform various functions; and (c) (multiple) hardware circuits and / or processors, such as (multiple) microprocessors or portions of microprocessors, which require software (e.g., firmware) to operate, but may be absent when the software is not required to operate.

[0062] This definition of "circuit" applies to all uses of the term in this application (including in any claim). As another example, as used in this application, the term "circuit" also covers implementations of hardware circuitry or processors (or processors in general) and their accompanying software and / or firmware. The term "circuit" also covers, for example and if applicable to a particular claim element, baseband integrated circuits or processor integrated circuits for mobile devices or similar integrated circuits in servers, cellular network devices, or other computing or network devices.

[0063] Device 300 may include memory 320. Memory 320 may include random access memory and / or permanent memory. Memory 320 may include at least one RAM chip. Memory 320 may be a computer-readable medium. For example, memory 320 may include solid-state, magnetic, optical, and / or holographic memory. Memory 320 may be at least partially accessible by processor 310. Memory 320 may be at least partially included in processor 310. Memory 320 may be a component for storing information. Memory 320 may include computer instructions configured to be executed by processor 310. When computer instructions configured to cause processor 310 to perform certain actions are stored in memory 320, and device 300 as a whole is configured to operate under the guidance of processor 310 using computer instructions from memory 320, processor 310 and / or at least one of its processing cores may be considered configured to perform certain actions. Memory 320 may be at least partially external to device 300, but accessible by device 300. Memory 320 may be transient or non-transient. As used herein, the term “non-transient” refers to a limitation on the medium itself (i.e., tangible, not a signal), rather than a limitation on the persistence of data storage (e.g., RAM vs. ROM).

[0064] Device 300 may include a transmitter 330. Device 300 may include a receiver 340. Transmitter 330 and receiver 340 may be configured to transmit and receive information according to at least one cellular or non-cellular standard, respectively. Transmitter 330 may include more than one transmitter. Receiver 340 may include more than one receiver. For example, transmitter 330 and / or receiver 340 may be configured to operate according to standards such as Global System for Mobile Communications (GSMO), GSM, Wideband Code Division Multiple Access (WCDMA), 5G, Long Term Evolution (LTE), LTE, IS-95, Wireless Local Area Network (WLAN), Ethernet, and / or Global Microwave Access Interoperability (GMI) and WiMAX.

[0065] Device 300 may include a near-field communication (NFC) transceiver 350. The NFC transceiver 350 may support at least one NFC technology, such as NFC, Bluetooth, Wibree, or similar technologies.

[0066] Device 300 may include a user interface (UI) 360. UI 360 may include at least one of a display, keyboard, touchscreen, vibrator arranged to signal to the user by causing device 300 to vibrate, speaker, or microphone. The user may be able to operate device 300 via UI 360, for example, to accept incoming telephone calls, initiate telephone or video calls, browse the internet, manage digital files stored in memory 320 or accessible in the cloud via transmitter 330 and receiver 340 or via NFC transceiver 350, and / or play games.

[0067] Device 300 may include or be arranged to accept a user identity module 370. User identity module 370 may include, for example, a subscriber identity module SIM card that can be installed in device 300. User identity module 370 may include subscription information identifying the user of device 300. User identity module 370 may include password information that can be used to verify the identity of the user of device 300 and / or facilitate the encryption of transmitted information and billing of the user of device 300 for communications performed via device 300.

[0068] Processor 310 may be equipped with a transmitter arranged to output information from processor 310 to other devices included in device 300 via electrical leads within device 300. Such a transmitter may include a serial bus transmitter arranged to output information to memory 320 for storage, for example, via at least one electrical lead. Alternatively, the transmitter may include a parallel bus transmitter. Similarly, processor 310 may include a receiver arranged to receive information from other devices included in device 300 via electrical leads within device 300. Such a receiver may include a serial bus receiver arranged to receive information from receiver 340, for example, via at least one electrical lead, for processing within processor 310. Alternatively, the receiver may include a parallel bus receiver.

[0069] Device 300 may include Figure 3 Other devices not shown. For example, in the case where device 300 includes a smartphone, it may include at least one digital camera. Some devices 300 may include a rear camera and a front camera, wherein the rear camera may be designed for digital photography and the front camera for video calling. Device 300 may include a fingerprint sensor arranged to at least partially authenticate the user of device 300. In some embodiments, device 300 lacks at least one of the above-mentioned devices. For example, some devices 300 may lack an NFC transceiver 350 and / or a user identity module 370.

[0070] Processor 310, memory 320, transmitter 330, receiver 340, NFC transceiver 350, UI 360, and / or user identity module 370 can be interconnected in various ways via electrical leads within device 300. For example, each of the above devices can be individually connected to the main bus within device 300 to allow the devices to exchange information. However, as those skilled in the art will understand, this is merely an example, and depending on the embodiment, various ways of interconnecting at least two of the above devices can be chosen without departing from the scope of the invention.

[0071] Figure 4 Signaling according to at least some embodiments of the present invention, particularly the first embodiment, is illustrated. On the vertical axis, a signal is provided on the left side. Figure 1 The UE 110, and set on the right side Figure 1 Base station 130. Time progresses from top to bottom.

[0072] In phase 410, base station 130 provides PSS to UE 110, which forms the first part of the synchronization signal. In phase 420, based on the PSS, the UE performs initial time and frequency synchronization with the cell. Subsequently, in phase 430, base station 130 provides the second part of the synchronization signal to UE 110, including SSS and PBCH, where SSS is provided as a first SSS part and a second SSS part, and these SSS parts are m-sequences. In phase 440, after receiving the second part of the synchronization signal, the UE completes synchronization with the cell, enabling subsequent transmission of the Random Access Channel (RACH) preamble to the base station in phase 450.

[0073] Figure 5 This is a flowchart of a method according to at least some embodiments of the present invention. For example, stages of the method shown may be performed in UE 110 or in a control device configured to control its functions when installed therein.

[0074] Phase 510 includes detecting synchronization signals from base nodes of the network via an air interface. The synchronization signals include at least a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a physical broadcast channel (PBCH). The synchronization signals are organized into a first portion transmitted over a first time period and a second portion transmitted over a lower second time period. The first portion is detected based on the first time period, and the second portion is detected based on the second time period.

[0075] It should be understood that the embodiments of the invention disclosed herein are not limited to the specific structures, processes, or materials disclosed herein, but extend to equivalents that will be recognized by those skilled in the art. It should also be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting.

[0076] Throughout this specification, any reference to an embodiment or embodiment means that a particular feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment of the invention. Therefore, the phrases "in one embodiment" or "in an embodiment" appearing throughout this specification do not necessarily refer to the same embodiment. Precise numerical values ​​are also disclosed where terms such as, for example, approximately or substantially, are used to refer to numerical values.

[0077] As used herein, for convenience, multiple items, structural elements, constituent elements, and / or materials may be presented in a common list. However, these lists should be interpreted as if each member of the list were individually identified as a separate and unique member. Therefore, without indication to the contrary, any individual member of such a list should not be construed as a de facto equivalent of any other member of the same list based solely on their presentation in the common group. Furthermore, various embodiments and examples of the invention may be cited herein together with alternatives to their various components. It should be understood that such embodiments, examples, and alternatives should not be construed as de facto equivalents of each other, but should be considered as separate and autonomous representations of the invention.

[0078] Furthermore, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Numerous specific details, such as examples of length, width, shape, etc., have been provided in the foregoing description to provide a thorough understanding of embodiments of the invention. However, those skilled in the art will recognize that the invention can be practiced without one or more specific details or using other methods, components, materials, etc. In other instances, well-known structures, materials, or operations have not been shown or described in detail to avoid obscuring aspects of the invention.

[0079] While the foregoing examples illustrate the principles of the invention in one or more specific applications, it will be apparent to those skilled in the art that many modifications in form, use, and detail can be made without inventive effort and without departing from the principles and concepts of the invention. Therefore, the invention is not intended to be limited except by the claims set forth below.

[0080] The verbs “comprising” and “including” are used herein as open-ended restrictions, neither excluding nor requiring the presence of any unlisted features. Unless otherwise expressly stated, the features recited in the dependent claims may be freely combined with each other. Furthermore, it should be understood that the use of “a” or “an,” i.e., the singular form, throughout this document does not exclude a plurality.

[0081] As used herein, “at least one of the following: a list of two or more elements” and “at least one of the following: a list of two or more elements” and similar wording (where the list of two or more elements is connected by “and” or “or”) means at least any one of the elements, or at least any two or more of the elements, or at least all of the elements.

[0082] Industrial applicability At least some embodiments of the present invention can be applied to wireless communication.

[0083] List of abbreviations DMRS demodulation reference signal NLOS (Non-Line of Sight) OBO output rollback OFDM (Orthogonal Frequency Division Multiplexing) PAPR peak-to-average power ratio PSS Master Synchronization Signal SSS auxiliary synchronization signal TDD (Time Division Duplex) QCL Quasi-co-located List of reference numerals

Claims

1. An apparatus comprising at least one processing core and at least one memory storing instructions, the instructions, when executed by said at least one processing core, causing the apparatus to at least: Synchronization signals from base nodes in the network are detected via the air interface. These synchronization signals include at least a Primary Synchronization Signal (PSS), a Secondary Synchronization Signal (SSS), and a Physical Broadcast Channel (PBCH). The synchronization signals are organized into a first portion transmitted with a first time period and a second portion transmitted with a lower second time period. It also enables the device to detect the first portion based on the first time period and the second portion based on the second time period.

2. The apparatus of claim 1, wherein the first portion comprises the PSS, and the second portion comprises the SSS and the PBCH.

3. The apparatus according to claim 1 or 2, wherein the SSS comprises a first SSS portion and a second SSS portion transmitted as separate synchronization signals.

4. The apparatus of claim 3, wherein the first portion comprises the PSS, the first SSS portion and the second SSS portion, and the second portion comprises the second SSS portion and the PBCH.

5. The apparatus of claim 4, wherein the second part further includes the PSS or the first SSS part.

6. The apparatus according to claim 4 or 5, wherein the PSS, the first SSS portion, and the second SSS portion are modulated by corresponding first m-sequence, second m-sequence, and third m-sequence. Furthermore, the first, second, and third parameters used to generate the corresponding first m-sequence, second m-sequence, and third m-sequence are based on the physical cell identifier.

7. The apparatus according to any one of claims 1 to 5, further comprising receiving the first portion via a first transmission beam of the base node and receiving the second portion via a second transmission beam of the base node, wherein the first transmission beam of the base node is different from the second transmission beam of the base node.

8. The apparatus according to any one of claims 1 to 7, wherein the apparatus is further configured to use Discrete Fourier Transform Extended Orthogonal Frequency Division Multiplexing (DFT-s-OFDM) to receive the PBCH.

9. The apparatus according to any one of claims 1 to 8, wherein the apparatus is further configured to use at least the first portion for one or more of the following: Acquire time and frequency synchronization with the base node; Obtain the physical cell identifier of the cell; or Community surveying Furthermore, it also enables the device to use at least the second part for one or more of the following: Acquire or adjust time and / or frequency synchronization with the base node; or Obtain the configuration for accessing the cell.

10. An apparatus comprising at least one processing core and at least one memory storing instructions, the instructions, when executed by said at least one processing core, causing the apparatus to at least: The synchronization signal of the network is transmitted via an air interface. The synchronization signal includes at least a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a physical broadcast channel (PBCH). The synchronization signal is organized into a first part that causes the device to transmit at a first time period and a second part that causes the device to transmit at a lower second time period.

11. The apparatus of claim 10, wherein the first portion comprises the PSS, and the second portion comprises the SSS and the PBCH.

12. The apparatus of claim 10 or 11, wherein the SSS comprises a first SSS portion and a second SSS portion, and wherein the apparatus further causes the first SSS portion and the second SSS portion to be transmitted as separate synchronization signals.

13. The apparatus of claim 12, wherein the first portion comprises the PSS, the first SSS portion and the second SSS portion, and the second portion comprises the second SSS portion and the PBCH.

14. The apparatus of claim 13, wherein the second portion further comprises the PSS or the first SSS portion.

15. The apparatus of claim 13 or 14, wherein the PSS, the first SSS portion, and the second SSS portion are modulated by corresponding first m-sequence, second m-sequence, and third m-sequence, wherein, It also enables the device to use a first parameter, a second parameter, and a third parameter to generate the corresponding first m sequence, the second m sequence, and the third m sequence, wherein the first parameter, the second parameter, and the third parameter are based on physical cell identifiers.

16. The apparatus according to any one of claims 10 to 15, wherein the apparatus further causes the first portion to be transmitted via a first transmission beam of the apparatus and the second portion to be transmitted via a second transmission beam of the apparatus, the first transmission beam being different from the second transmission beam.

17. The apparatus according to any one of claims 10 to 16, wherein the apparatus is further configured to use Discrete Fourier Transform Extended Orthogonal Frequency Division Multiplexing (DFT-s-OFDM) to transmit the PBCH.

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