CN113170452B

CN113170452B - Distinguishing between downlink and sidelink signal synchronization blocks in a wireless communication network

Info

Publication number: CN113170452B
Application number: CN201980078006.1A
Authority: CN
Inventors: 埃夫斯塔西奥斯·格德拉纳若斯
Original assignee: JRD Communication Shenzhen Ltd
Current assignee: JRD Communication Shenzhen Ltd
Priority date: 2018-12-20
Filing date: 2019-12-05
Publication date: 2022-12-09
Anticipated expiration: 2039-12-05
Also published as: GB2580050A; GB2580050B; WO2020125424A1; GB201820786D0; CN113170452A

Abstract

A method of distinguishing a Downlink (DL) Signal Synchronization Block (SSB) from a Sidelink (SL) SSB in a wireless communication network is provided. The network comprises: at least one base station, at least one first User Equipment (UE), at least one second UE, a SL between the first UE and the second UE, and a DL between the base station and the second UE. The method comprises the following steps: in the base station, configuring a candidate SSB location group for transmitting SSBs in an SSB burst set; specifying a subset of candidate SSB locations for the DL SSB; designating the remaining subset as a subset of candidate SSB locations for the SL SSB; transmitting an indication of the subset of candidate SSB locations for the SL SSB to the first UE; and transmitting an indication of the subset of candidate SSB locations for the DL SSB to the second UE; in the first UE, configuring the first UE to transmit the SL SSB on the subset of candidate SSB locations with the indication of the subset of candidate SSB locations for the SL SSB; and in the second UE, distinguishing the DL SSB received from the base station from the SL SSB received from the first UE by the indication of the subset of candidate SSB locations for the DL SSB.

Description

Differentiating downlink signal synchronization blocks from sidelink signal synchronization blocks in a wireless communication network

Technical Field

The present application relates to distinguishing between downlink signal synchronization blocks and sidelink signal synchronization blocks in a wireless communication network.

Background

Wireless communication systems, such as Third Generation (3G) mobile phone standards and technologies are well known. Such 3G standards and technologies are established by the Third generation partnership Project (3 GPP). The third generation of wireless communications is commonly developed to support macrocell mobile telephone communications. Communication systems and networks have evolved towards broadband and mobile systems.

In a cellular wireless communication system, a User Equipment (UE) is connected to a Radio Access Network (RAN) through a Radio link. The RAN comprises a set of base stations providing radio links for UEs located in cells covered by the base stations, and an interface to a Core Network (CN) providing overall Network control. As will be readily appreciated, the RAN and CN each perform functions related to the overall network. For convenience, the term "cellular network" refers to the combination of the RAN and the CN, and it is understood that this term is used to refer to the respective system performing the disclosed functions.

The 3GPP has developed a so-called Long Term Evolution (LTE) System, i.e. an Evolved Universal Mobile telecommunications System terrestrial radio access Network (E-UTRAN), for a Mobile access Network in which one or more macro cells are supported by base stations called enodebs or enbs (Evolved nodebs). Recently, LTE is further evolving towards so-called 5G or New Radio (NR) systems, where one or more cells are supported by base stations called next Generation node bs (gnbs). The NR is intended to employ an Orthogonal Frequency Division Multiplexing (OFDM) physical transmission format.

The NR protocol is intended to provide an option for operating on unlicensed radio frequency bands, the so-called NR-U. When operating on the unlicensed radio band, the gNB and UE must contend with other devices for physical medium/resource access. For example, wi-Fi, NR-U, and LAA may utilize the same physical resources.

One trend in wireless communications is to provide low latency and high reliability services. For example, NR is intended to support ultra-reliable and low-latency communication (U)Ultra-reliable and low-latency Communication, URLLC), large Machine-Type Communication (mtc) is intended to provide low latency and high reliability for small data packets (typically 32 bytes). A user plane delay of 1ms and a reliability of 99.99999% have been proposed, 10 ^-5 Or 10 ^-6 The packet loss rate of (2) is also proposed at the physical layer. URLLC is considered to be useful in the fields of factory automation, transportation, and power distribution. Depending on the type of service, data packets may arrive on an irregular or regular basis.

In order for a UE to connect to a cell provided by a base station (e.g., eNB or gNB), the UE needs information about the cell and information for the UE to perform synchronous communication with the base station. This information is provided by the Downlink (DL) signal of the base station. In LTE, this information includes Primary and Secondary Synchronization signals (PSS and Secondary Synchronization Signal, SSS). From these signals, the UE obtains the physical cell ID and slot and frame synchronization.

In NR, a DL Synchronization Signal and a Physical Broadcast Channel (PBCH) are contained in a single Block of DL, which is called a Synchronization Signal Block (SSB). The SSB includes PSS, SSS, PBCH DMRS, and PBCH payload. The content of the SSB is used for cell detection, coarse time/frequency DL synchronization and RRM measurements. Beam scanning of synchronization signals is supported in NR to enhance coverage. One or more SSBs make up one SS burst. One or more SSB bursts form a set of SSB bursts. All SSBs of a cell have a single SSB group period (default period is 5ms, but the UE can be configured higher up to 160ms after initially accessing the cell). Regardless of the period of the set of SSB bursts, the transmission of SSBs is limited to a 5ms window (i.e., half frame). Each slot (e.g., 1ms period of SCS =15 kHz) can support up to 2 SSB transmission opportunities, with only certain slots allowing transmission of SSBs. The maximum number Lmax of SSB burst sets for a cell is given in terms of frequency range (i.e., L < 3 GHz) _max =4; at 3-6GHz, L _max =8; at 6-52.6GHz, L _max = 64). In various SCS (15/30/120/240 kHz) and bands, there is a specific mapping of SSB to symbols, defined by the SS block pattern, to facilitateThere are time candidate positions for SSBs within a slot. The SSB index L for each set of SSB bursts is defined by FR1 (f)<6 GHz) PBCH DMRS sequence or FR2 (f)>6 GHz) and PBCH payload representation. From the SSB index and the fixed time location of each SSB, the UE may achieve DL synchronization with the cell.

In NR, the DL SSB does not have to be placed in the middle of the carrier, but can be transmitted in some possible location in the frequency domain, called a "synchronization raster". The synchronization raster indicates that when explicit signaling of SSB locations is not present (i.e., NR independent mode), the UE can use the frequency locations of the SSBs for system acquisition. The range of Global Synchronization Raster Channel (GSCN) is defined for all NR operating bands, which is basically a relatively wide step of searching for frequencies. To allow faster cell search and synchronization, the synchronization raster includes a more limited set of possible frequency locations for SSBs. The synchronization signal grid in NR is increased compared to LTE to limit the power consumption of the UE at initial cell selection. The frequency location of an SSB is defined as SS _REF And the corresponding number of GSCNs. The UE searches for a synchronized SSB by scanning bands with raster resolution (e.g., the UE calculates DL received signal power, detects a set of frequency candidate locations in all supported bands, and then searches for SSBs at the candidate locations). Therefore, the UE may attempt this blind detection multiple times to find the cell-defined SSB for synchronization. Finally, to ensure that there is at least one reception of an SSB, the UE must scan 5ms time candidates (SS burst setup window) and take the average over 20ms (since for initial cell search, the UE may assume that the SSB repeats at least every 20 ms).

In addition to DL and Uplink (UL) communications between the UE and the base station, the UE may further receive communications over one or more Sidelinks (SLs). In LTE, SL enables communication between two or more nearby devices using E-UTRAN technology without the need for a base station. The SL provides various functions for end-to-end communication, such as distributed control and management among devices, and direct communication in network coverage and out of coverage. SL is used for a variety of applications such as proximity services (D2D), loT, wearable devices, and vehicle-to-object (V2X) communication.

Among NR, there is an ongoing study of V2X. NR V2X will support advanced V2X services beyond LTE support. Advanced V2X services will require an enhanced NR system and new NR SLs to meet the stringent requirements of this application. It is expected that an NR V2X system will have a flexible design to support services with low latency and high reliability requirements. In NR V2X, SL communication may be performed in a dedicated Intelligent Transport System (ITS) carrier band (e.g., 5.9GHz unlicensed band) and an NR licensed carrier band (e.g., millimeter wave band around 30GHz and 63 GHz). In practice, the most likely spectrum for V2X is 5.9GHz for FR1 and 63G Hz for FR 2.

SL communication requires a synchronization mechanism, which is also an aspect of the NR SL design under study. This includes details of the synchronization source and program, synchronization channel structure, design rules, synchronization signals, waveforms, numerology, etc. One of the requirements of the NR SL synchronization mechanism for V2X and other applications is to protect the UE from out-of-coverage UEs when the DL and SL licensed carriers overlap. It is crucial to ensure good coexistence between SL and DL SSB transmissions. When the DL licensed band of NR and the SL band of NR overlap, the UE will search for DL SSB using a synchronization raster in order to initially access the cell. If the SL SSB is also transmitted by other UEs in the same cell, e.g. Vehicular UEs (VUEs), there is a risk of interference with the DL SSB. The UE may confuse the received SSB (see fig. 1). This confusion can lead to incorrect soft combining of DL and SL SSBs, access delays, and can disrupt the UE's initial cell access procedure.

Disclosure of Invention

This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the subject matter of the disclosure, nor is it intended to be used to identify the scope of the disclosure.

The present application presents a method of distinguishing a Downlink (DL) Signal Synchronization Block (SSB) from a Sidelink (SL) SSB in a wireless communication network. The network comprises: at least one base station, at least one first User Equipment (UE), at least one second UE, a SL between the first UE and the second UE, and a DL between the base station and the second UE. The method comprises the following steps: in the base station, configuring a candidate SSB location group for transmitting SSBs in an SSB burst set; specifying a subset of candidate SSB locations for the DL SSB; designating the remaining subset as a subset of candidate SSB locations for the SL SSB; transmitting an indication of the subset of candidate SSB locations for the SL SSB to the first UE; and transmitting an indication of the subset of candidate SSB locations for the DL SSB to the second UE; in the first UE, configuring the first UE to transmit the SL SSB on the subset of candidate SSB locations with the indication of the subset of candidate SSB locations for the SL SSB; and in the second UE, distinguishing the DL SSB received from the base station from the SL SSB received from the first UE by the indication of the subset of candidate SSB locations for the DL SSB.

The indication of the subset of candidate SSB locations for the SL SSB may include: the candidate SSB location for the SL SSB described by a field in a System Information Block (SIB) received by the first UE. The indication of the subset of candidate SSB locations for the SL SSB may include: the candidate SSB location for the SL SSB described by Radio Resource Control (RRC) signaling received by the first UE.

The indication of the subset of candidate SSB locations for the DL SSB may comprise: the candidate SSB location for the DL SSB described by a field in a System Information Block (SIB) received by the second UE. The indication of the subset of candidate SSB locations for the DL SSB may comprise: the candidate SSB location for the DL SSB described by a remaining lowest system information (RMSI) received by the second UE. The indication of the subset of candidate SSB locations for the DL SSB may comprise: the candidate SSB locations for the DL SSB described in a Physical Broadcast Channel (PBCH)/Physical Sidelink Broadcast Channel (PSBCH) -Management Information Base (MIB) received by the second UE. The indication of the subset of candidate SSB locations for the DL SSB may comprise: identification of the DL SSBs by fields introduced in each of the DL SSBs received by the second UE. The indication of the subset of candidate SSB locations for the SL SSB may be transmitted to the second UE and may include: identification of the SL SSBs by fields introduced in each of the SL SSBs received by the second UE.

The present application also proposes a method of distinguishing a Downlink (DL) Signal Synchronization Block (SSB) from a Sidelink (SL) SSB in a wireless communication network. The network comprises: a first base station defining a first cell, a second base station defining a second cell, at least one first User Equipment (UE) located at an edge of the first cell, and at least one second UE located within the second cell. The method comprises the following steps: the first base station and the second base station cooperatively exchange DL SSB and SL SSB transmission information.

The present application also proposes a method of distinguishing a Downlink (DL) Signal Synchronization Block (SSB) from a Sidelink (SL) SSB in a wireless communication network. The network comprises: at least one base station, at least one first User Equipment (UE), at least one second UE, a SL between the first UE and the second UE, and a DL between the base station and the second UE, wherein there is beam scanning of the DL SSB. The method comprises the following steps: in the base station, configuring a candidate SSB location group for transmitting SSBs in an SSB burst set; sharing the set of candidate SSB locations between the SL SSB and the DL SSB; and in the first UE, prioritizing DL SSB transmissions at the shared candidate SSB locations by muting SL SSB transmissions at the shared candidate SSB locations.

The first UE may mute the SL SSB transmission at the shared candidate SSB location by: receiving a DL SSB beam pattern from the base station, measuring from the beam pattern the transmission strengths of the expected DL SSB transmissions, and muting the SL SSB transmissions that collide in time or frequency with a predetermined number of the DL SSB transmissions having the greatest transmission strengths or that collide in time or frequency with a predetermined number of the DL SSB transmissions having transmission strengths exceeding a predetermined value. The second UE may transmit the SL SSB and align a SL SSB beam pattern of the second UE with the DL SSB beam pattern, thereby reducing interference between the DL SSB and the SL SSB.

The present application also proposes a method of distinguishing a Downlink (DL) Signal Synchronization Block (SSB) from a Sidelink (SL) SSB in a wireless communication network. The network comprises: at least one base station, at least one first User Equipment (UE), at least one second UE, a SL between the first UE and the second UE, and a DL between the base station and the second UE. The method comprises the following steps: in a base station, time-domain multiplexing the candidate SSB locations of the DL SSB and the SL SSB within a frame structure by assigning the DL SSB candidate SSB locations in a first field and the SL SSB candidate SSB locations in a second field with a fixed frequency offset between the DL SSB and the SL SSB; transmitting the frame structure and the DL SSB to the second UE; transmitting, in the first UE, the SL SSB to the second UE; and determining, in the second UE, whether the received SSB is located in the first field or the second field by the frame structure for candidate SSB location assignment and the fixed frequency offset, thereby distinguishing the DL SSB from the SL SSB.

The present application also proposes a method of distinguishing a Downlink (DL) Signal Synchronization Block (SSB) from a Sidelink (SL) SSB in a wireless communication network. The network includes at least one base station, at least one first User Equipment (UE), at least one second UE, a SL between the first UE and the second UE, and a DL between the base station and the second UE. The method comprises the following steps: in a base station, time-domain multiplexing the candidate SSB locations of the DL SSB and the SL SSB within a frame structure by a first mode for allocating candidate SSB locations for the DL SSB in a field and by a second mode for allocating candidate SSB locations for the SL SSB in the same field; transmitting the frame structure and the DL SSB to the second UE; transmitting, in the first UE, the SL SSB to the second UE; and in the second UE, distinguishing the DL SSB from the SL SSB by the frame structure for candidate SSB location assignment and additionally received SSBs within the half-frame.

The present application also proposes a method of distinguishing a Downlink (DL) Signal Synchronization Block (SSB) from a Sidelink (SL) SSB in a wireless communication network. The network includes at least one base station, at least one first User Equipment (UE), at least one second UE, a SL between the first UE and the second UE, and a DL between the base station and the second UE. The method comprises the following steps: configuring, in the base station, SL SSB transmission at a non-raster frequency position in a frequency domain; transmitting, in the first UE, the SL SSB transmission to the second UE with an indication of a non-raster frequency position offset; and in the second UE, by the indication of the non-raster frequency location offset, enabling the SL SSB received at the non-raster frequency location and improving detection of a raster DL SSB transmitted from the base station.

The first UE may be a vehicular UE. The second UE may be a legacy UE.

The present application also provides a non-transitory computer readable medium. The non-transitory computer readable medium may comprise at least one of the group of: hard disk, optical storage device, magnetic storage device, read-only memory, programmable read-only memory, erasable programmable read-only memory, EPROM, electrically erasable programmable read-only memory, and flash memory.

Drawings

The details, aspects and embodiments of the present application will be described, by way of example only, with reference to the accompanying drawings. Elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. Similar reference numerals have been included in the various drawings to facilitate understanding.

Fig. 1 shows interference of SL SSB to DL SSB.

Fig. 2 shows a schematic diagram of a cellular network.

Fig. 3 illustrates the use of SL SSB for free candidate SSB locations for a set of SSB bursts configured for a first UE.

Fig. 4 shows that DL SSB transmissions are prioritized by muting SL SSB transmissions at shared candidate SSB locations.

Fig. 5 shows the alignment of the SL SSB beam pattern with the DL SSB beam pattern.

Fig. 6 shows the use of a fixed frequency offset between the DL SSB of the first field and the SL SSB of the second field.

Fig. 7 shows that the first mode is used to place the DL SSB in a field and the second mode is used to place the SL SSB in the same field.

Fig. 8 shows the use of the same pattern for DL SSBs and SL SSBs, and assigning a predetermined time pattern offset for the SL SSBs.

Detailed Description

Those skilled in the art will recognize and appreciate that the specific details of the examples described are merely illustrative of some embodiments, and that the teachings set forth herein are applicable in a variety of alternative contexts.

Fig. 2 shows a schematic diagram of a cellular network composed of three base stations (e.g., enbs or gnbs, depending on the particular cellular network standard and terminology). Typically, each base station will be deployed by one cellular network operator, providing geographic coverage for UEs in that area. These base stations form a Radio Area Network (RAN). Each base station provides radio coverage for UEs of its area or cell. The base stations are interconnected via an X2 interface and are connected to the core network via an SI interface. It will be appreciated that only the essential details are shown in order to illustrate the main features of the cellular network.

Each base station includes hardware and software for performing RAN functions, including communication with the core network and other base stations, transmission of control and data signals between the core network and the UEs, and maintaining wireless communication with the UEs associated with each base station. The core network includes hardware and software that implement network functions, such as overall network management and control, and routing of calls and data.

In a wireless communication network, in the case of a shared carrier band, i.e. an overlap between licensed DL and SL carrier bands, UEs, such as NR Uu (DL/UL) UEs and NR PC5 (SL) UEs. The UE should be able to distinguish between synchronization signals transmitted from two different interfaces, i.e. to distinguish between DL SSBs and SL SSBs. Otherwise, misunderstanding of the received SSB may cause problems. In view of the need for improvements in flexibility, delay, search complexity, and interference between DL and SL SSBs, the present application proposes some methods of distinguishing DL and SL SSBs.

In a wireless communication network, at least one base station, at least one first UE, at least one second UE, a SL between the first UE and the second UE, and a DL between the base station and the second UE are included. The method of distinguishing the DL SSB and the SL SSB in the first embodiment includes: in a base station, configuring a candidate SSB location group for transmitting SSBs in an SSB burst set; specifying a subset of candidate SSB locations for DL SSBs; designating the remaining subset as a candidate SSB location subset for SL SSB; transmitting an indication of a subset of candidate SSB locations for the SL SSB to the first UE; transmitting an indication of a subset of candidate SSB locations for the DL SSB to the second UE; configuring, in the first UE, the first UE to transmit the SL SSB on a subset of candidate SSB locations with an indication of the subset of candidate SSB locations for the SL SSB; and in the second UE, distinguishing between the DL SSB received from the base station and the SL SSB received from the first UE by an indication of a subset of candidate SSB locations for the DL SSB.

Thus, the first UE is configured to use the free candidate SSB locations of the set of SSB bursts configured for the first UE (see fig. 3). To enable such use, an indication of an idle or remaining SSB location not designated for DL SSBs is sent to the first UE so that the UE may be configured to use the idle SSB location for transmitting SL SSBs. When the SSB locations employed by the base station are less than the maximum number of DL SSBs, the candidate SSB locations are free. This may occur, for example, if: a) the required coverage of the cell can be met with a low number of SSBs, b) the cell wants to reduce DL synchronization control overhead, and/or c) the UE of the cell can only monitor a limited number of SSB locations (less than the configured maximum number of DL SSBs) due to limited capabilities.

The candidate SSB locations for the DL SSB may be described by a field in the SIB received by the second UE. In one embodiment, this field (ssb-Positioninbunsf) includes two 8-bit bitmaps. The first bitmap (groupPresence) represents a group of 8 SSB locations for DL SSB (the first bit for indices 0 through 7DL SSB location, second bit for DL SSB location with index 8 to 15, etc.). This bitmap applies only to FR2 (i.e., in L) _max Case = 64). The second bitmap (inoneegroup) represents the SSB locations within each group for transmitting DL SSBs.

Similarly, the candidate SSB location for the SL SSB may be described by a field in the SIB received by the first UE. This field (SL-ssb-Positionineburst) may reuse the format of the ssb-Positionineburst field. Optionally, the format may be modified (e.g., to indicate at which SSB locations no SL SSBs are sent). The indication of the SL SSB candidate location for the first UE is not delay sensitive, as it does not require initial access to the cell by the first UE, but simply informs the already connected first UE which SSB location resources are to be used for SL SSB. The SL-SSB-positioningburst field of FR2 has more flexibility in resource allocation and can be designed to multiplex SL SSBs from different first UE/SL sources. For this purpose, the SL-ssb-positioningburst field may use a 64-bit bitmap. This field may be obtained during RRC synchronization reconfiguration, or may be provided in a unicast (per first UE) or multicast (per group of first UEs) manner, even with dynamic indications, such as DCI, to enable more flexibility in intra-cell SL SSB transmission.

The second UE may receive the candidate SSB location for the DL SSB by using the legacy RMSI. However, with this approach, the second UE will only realize if the received SSB is a DL SSB after the SIB is correctly decoded, which will cause a delay when the second UE initially accesses the cell. At the same time, decoding the SL SSB is not completely wasteful for the first UE, as it would be possible to use the same information between the DL SSB and the SL SSB (e.g., information for coarse time/frequency synchronization, and system timing and initial access in the MIB).

The DL SSBs may be identified by fields introduced in each DL SSB received by the second UE. The SL SSBs may be identified by a field introduced in each SL SSB received by the second UE. These fields may include 1 bit and allow the second UE to clarify the SSB type upon detection/decoding.

The candidate SSB location of the DL SSB may be described in the PBCH/PSBCH-MIB received by the second UE. The MIB may have a spare bit available for the DL SSB verification indication field. The content of this bit may be, for example, 1 for DL SSB and 0 for SL SSB. The DL SSB validation indication bits may also be communicated through SIBs, through PBCH-DMRS, PSS/PSSS, or SSS/SSS, so that the second UE can distinguish DL SSB from SL SSB before decoding the broadcast channel. For example, one skilled in the relevant art may consider placing a mask over the SSS sequence, or adding a new scrambling code value to scramble the SSS M sequence or the PSBCH, or using a different initialization for the DMRS-PBCH scrambling sequence generator.

This method of distinguishing DL SSBs from SL SSBs has minimal impact on the SSB specification and SSB interference to the UE. However, it can only function if the total number of SSBs required is less than the specified maximum number of SSBs.

Using the DL SSB location in the SSB burst set to transmit the SL SSB can optimize SSB resource efficiency, and when the carrier cannot accommodate more frequency I time resources, it can be multiplexed with the DL SSB, reducing the first complexity of the UE, reusing the existing timing acquisition circuit to the maximum extent, reducing the need to search for multiple SSBs on frequency simultaneously, avoiding long-time and power-intensive synchronization search procedures, and making it possible to use a short SSB burst period, such as 5ms.

In a wireless communication network including a first base station defining a first cell, a second base station defining a second cell, at least one first User Equipment (UE) located at an edge of the first cell, and at least one second UE located at the second cell, a second embodiment of a method of distinguishing between DL SSBs and SL SSBs includes: the first and second base stations cooperatively exchange DL SSB and SL SSB transmission information.

DL SSB and SL SSB transport information may be exchanged over the backhaul link. This approach avoids inter-cell interference.

In a wireless communication network including at least one base station, at least one first UE, at least one second UE, a SL between the first UE and the second UE, and a DL between the base station and the second UE, wherein there is beam sweeping of DL SSBs, a third embodiment of a method of distinguishing DL SSBs from SL SSBs includes: in a base station, configuring a set of candidate SSB locations in a set of SSB bursts to transmit SSBs; sharing the set of candidate SSB locations between the SL SSB and the DL SSB; and in the first UE, prioritizing DL SSB transmissions on the shared candidate SSB locations by muting SL SSB transmissions on the shared candidate SSB locations (see fig. 4).

The first UE may mute the SL SSB transmission at the shared candidate SSB location by: receive a DL SSB beam pattern from a base station, use the beam pattern to perform transmission strength measurements of intended DL SSB transmissions, and mute SL SSB transmissions that collide in time or frequency with the DL SSB transmission with the strongest measurement result. The DL SSB beam pattern may be retrieved at the first UE by signaling similar to the SSB-positioningburst field in the SIB. The muting operation may be configured by the base station. The network may configure a preset number of silent SL SSB transmissions, or a preset strength value of preferential DL SSB transmissions.

When the first UE is capable of transmitting SL SSBs, it may align its SL SSB beam pattern with the DL SSB beam pattern in order to reduce interference between DL SSBs and SL SSBs. The first UE may adjust its SL SSB beam pattern autonomously or through network configuration (see fig. 5).

When the above-described embodiments of the present invention are not practical (e.g., no free candidate SSB locations, no beam sweep) or are inefficient (e.g., no sufficient free candidate SSB locations, S-SSB muting is inefficient), time Division Multiplexing (TDM) may be considered to orthogonalize the DL SSB and SL SSB. As such, periodicity should not be limited; for SL SSB, at least a minimum periodicity of 5ms should be selectable.

In a wireless communication network including at least one base station, at least one first UE, at least one second UE, a SL between the first UE and the second UE, and a DL between the base station and the second UE, a fourth embodiment of a method of distinguishing a DL SSB from a SL SSB includes: in the base station, allocating candidate SSB positions for the DL SSB in the first half frame and candidate SSB positions for the SL SSB in the second half frame by using fixed frequency offset between the DL SSB and the SL SSB, thereby performing time domain multiplexing on the candidate SSB positions of the DL SSB and the candidate SSB positions of the SL SSB in the frame structure; transmitting the frame structure and the DL SSB to a second UE; transmitting, in a first UE, a SL SSB to a second UE; and in the second UE, determining whether the received SSB is located in the first field or the second field by the frame structure for the candidate SSB location assignment and the fixed frequency offset, thereby distinguishing the DL SSB from the SL SSB.

The fixed frequency offset pre-configured to the second UE between the DL SSB and the SL SSB (see fig. 6) allows the second UE to know whether it is detecting in the first or second half frame. The second UE, upon receiving the DL SSB and the SL SSB, will be able to distinguish between them.

In a wireless communication network including at least one base station, at least one first UE, at least one second UE, a SL between the first UE and the second UE, and a DL between the base station and the second UE, a fifth embodiment of a method of distinguishing a DL SSB from a SL SSB comprises: in the base station, performing time domain multiplexing on the candidate SSB position of the DL SSB and the candidate SSB position of the SL SSB in a frame structure through a first mode for allocating the candidate SSB position for the DL SSB in a half frame and through a second mode for allocating the candidate SSB position for the SL SSB in the same half frame; transmitting the frame structure and the DL SSB to the second UE; transmitting, in the first UE, the SL SSB to the second UE; and in the second UE, distinguishing between DL SSBs and SL SSBs by the frame structure for candidate SSB location assignment and additional received SSBs within the half-frame.

In embodiments of the present application, a specific pattern of SL SSBs (configured by the base station to the first UE in the cell) may be specified that is orthogonal or partially orthogonal in time to the DL SSBs (however, the correlation to the DL SSBs is low). FIG. 7 provides an example of one possible new L _max SL SSB specific pattern of =4, at "3<f<In the case of 6g hz, scs =30khz ", it can be orthogonal to the 8 DL SSBs employing mode B. The second UE may identify the DL SSBs from the SL SSBs by calculating additional received SSBs within the half-frame and/or unexpected time locations between received SSBs (or by reusing fixed frequency offsets of S-SSBs as before).

Alternatively, the DL SSB and SL SSB may use the same mode. A predetermined time pattern offset may be assigned to the SL SSB (and indicated to the first UE) for TDM with the DL SSB within a half frame (see fig. 8).

Multiplexing in the time domain, within a half-frame, makes it possible to configure a short SSB burst set period, e.g. 5ms, to reduce the delay introduced in time by the orthogonal split resources to avoid the impact from employing other solutions, UE complexity and FDM, different sequence/SSB structure.

The present application proposes a method of distinguishing a Downlink (DL) Signal Synchronization Block (SSB) from a Sidelink (SL) SSB in a wireless communication network, the network comprising at least one base station, at least one first User Equipment (UE), at least one second UE, a SL between the first UE and the second UE, and a DL between the base station and the second UE, the method comprising: in a base station, SL SSB transmission is configured at a non-raster frequency position of a frequency domain; transmitting, in the first UE, the SL SSB transmission to the second UE with the indication of the non-raster frequency position offset; and in the second UE, by the indication of the non-raster frequency position offset, enabling SL SSBs received on the non-raster frequency position and improving detection of raster DL SSBs transmitted from the base station.

It is an object of the present application to strengthen the initial access procedure of non-PC 5 UEs when they are able to detect/decode SL SSBs, in order to find the DL SSBs faster in a frequency scan at a given time.

Configuring the SL SSB transmission in the frequency domain in a non-raster position will reduce interference to the DL SSB of the second UE. The extremely time consuming synchronization procedure can also be avoided by reducing the number of SL SSB hypotheses.

However, even off-raster SSBs may be detected by non-PC 5 UEs that are searching for their first synchronization source. To avoid non-PC 5 UEs mistaking SL SSBs as DL SSBs, detecting MIB content of SL SSBs at non-raster locations, i.e., PSSS, SSSS, or PSBCH of SL SSBs, may be used to help UEs perform initial access to detect DL SSBs on the raster. For example, a non-raster frequency position shift index may be included. When interpreted by a non-PC 5 UE, it can be realized that this is a non-raster frequency and even some coarse frequency information can be obtained.

This application does not specifically show that any device or apparatus forming part of a network may comprise at least a processor, a memory unit, and a communication interface, wherein the processing unit, the memory unit, and the communication interface are configured to perform any of the methods described herein. Further options are described below.

Embodiments of the present invention, and in particular the signal processing functions of the gNB and UE, may be implemented using computing systems or architectures that are well known to those skilled in the art. For example, a desktop, laptop or computer, handheld computing device (PDA, cell phone, palmtop, etc.), mainframe, server, client, or any other type of special or general purpose computing device may be used as may be desirable or appropriate for a particular application or environment. A computing system may include one or more processors, which may be implemented using a general-purpose or special-purpose processing engine such as, for example, a microprocessor, microcontroller or other control module.

The computing system may also include a main memory, such as a Random Access Memory (RAM) or other dynamic memory, for storing information and instructions to be executed by the processor. The main memory may also be used for storing temporary variables or other intermediate information during execution of instructions by the processor. The computing system may also include a Read Only Memory (ROM) or other static storage device for storing static information and instructions for the processor.

The computing system may also include an information storage system that may include, for example, a media drive and a removable storage interface. The media drive may include a drive or other mechanism to support fixed or removable storage media, such as a hard disk drive, a floppy disk drive, a magnetic tape drive, an optical disk drive, a Compact Disk (CD) or Digital Video Drive (DVD), a read or write drive (R or RW), or other removable or fixed media drive. The storage medium may include, for example, a hard disk, floppy disk, single, optical disk, CD or DVD, or other fixed or removable medium that is read by and written to by a media drive. The storage media may include a computer-readable storage medium having stored therein particular computer software or data.

In other embodiments, information storage systems may include other similar components for allowing computer programs or other instructions or data to be loaded into the computing system. The components may include, for example, a removable storage unit and interface (e.g., a program cartridge and cartridge interface), a removable memory (e.g., a flash memory or other removable memory module) and memory slot, and other removable storage units and interfaces that allow software and data to be transferred from the removable storage unit to the computing system.

The computing system may also include a communications interface. The communication interface may be used to allow software and data to be transferred between the computer system and external devices. Examples of a communication interface may include a modem, a network interface (e.g., an ethernet or other NIC card), a communication port (e.g., a universal serial bus (USB port), a PCMCIA slot and card, etc. software and data transmitted over a communication interface are transmitted in the form of signals, which may be electronic, electromagnetic, and optical signals or other signals capable of being received by the communication interface medium.

In this application, the terms "computer program product," "computer-readable medium," and the like may generally refer to a tangible medium, such as a memory, a storage device, or a storage unit. These and other forms of computer-readable media may store one or more instructions for use by a processor, including a computer system, to cause the processor to perform specified operations. The instructions, generally referred to as "computer program code" (which may be in the form of a computer program or other groupings), when executed, enable the computing system to perform functions of embodiments of the present application. It should be noted that the code may directly cause the processor to perform specified operations, be compiled for execution, and/or be executed in conjunction with other software, hardware, and/or firmware elements (e.g., libraries for performing standard functions).

The non-transitory computer readable medium may comprise at least one of the group of: hard disk, optical storage device, magnetic storage device, read-only memory, programmable read-only memory, erasable programmable read-only memory, EPROM, electrically erasable programmable read-only memory, and flash memory. In embodiments where the elements are implemented using software, the software may be stored in a computer-readable medium and loaded into the computing system using, for example, a removable storage drive. When a processor in the computer system executes a control module (in this example, software instructions or executable computer program code), the processor performs the functions described herein.

Furthermore, the concepts of the present application may be applied to any circuit that performs signal processing functions within a network element. It is further contemplated that, for example, a semiconductor manufacturer may employ the concept in the design of a stand-alone device, such as a microcontroller of a Digital Signal Processor (DSP), or an Application Specific Integrated Circuit (ASIC), and/or any other subsystem element.

It will be appreciated that the above description, for clarity, has described embodiments of the application with reference to a single processing logic. However, the inventive concept may equally be implemented by a plurality of different functional units and processors to provide the signal processing functions. Hence, references to specific functional units are only to be seen as references to suitable means for providing the described functionality rather than indicative of a strict logical or physical structure or organization.

Aspects of the present application may be implemented in any suitable form including hardware, software, firmware or any combination of these. The present application may optionally be implemented at least partly as computer software running on one or more data processors and/or digital signal processors or configurable modular components such as FPGA devices.

Thus, the elements and components of an embodiment of the application may be physically, functionally and logically implemented in any suitable way. Indeed the functionality may be implemented in a single unit, in a plurality of units or as part of other functional units. Although the present application has been described in connection with some embodiments, the present application is not limited to the specific embodiments described. Rather, the scope of the present application is limited only by the accompanying claims. In addition, although a feature may appear to be described in connection with particular embodiments, one skilled in the art would recognize that various features of the described embodiments may be combined in accordance with the invention. In the claims, the term "comprising" does not exclude the presence of other elements or steps.

Furthermore, although individually listed, a plurality of means, elements or method steps may be implemented by e.g. a single unit or processor. Furthermore, although individual features may be included in different claims, these may possibly be combined. The inclusion in different claims does not imply that a combination of features is not feasible and/or advantageous. Furthermore, the inclusion of a feature in one category of claims does not imply a limitation to this category but rather indicates that the feature is equally applicable to other claim categories as appropriate.

Furthermore, the order of features in the claims does not imply any specific order in which the features must be performed and in particular the order of individual steps in a method claim does not imply that the steps must be performed in this order. Rather, the steps may be performed in any suitable order. Furthermore, singular references do not exclude a plurality. Thus, references to "a", "an", "first", "second", etc., do not preclude a plurality.

Although the present application has been described in connection with some embodiments, the present application is not limited to the specific embodiments described. Rather, the scope of the present application is limited only by the accompanying claims. In addition, although a feature may appear to be described in connection with particular embodiments, one skilled in the art would recognize that various features of the described embodiments may be combined in accordance with the invention. In the claims, the term "comprising" does not exclude the presence of other elements or steps.

Claims

1. A method of distinguishing between Downlink (DL) Signal Synchronization Block (SSB) and Sidelink (SL) SSB in a wireless communication network, the network comprising: at least one base station, at least one first User Equipment (UE), at least one second UE, a SL between the first UE and the second UE, and a DL between the base station and the second UE; the method comprises the following steps:

in the base station, the base station is configured to,

configuring a candidate SSB location group for transmitting SSBs in the SSB burst set;

specifying a subset of candidate SSB locations for the DL SSB;

designating the remaining subset as a subset of candidate SSB locations for the SL SSB;

transmitting an indication of the subset of candidate SSB locations for the SL SSB to the first UE; and

transmitting an indication of the subset of candidate SSB locations for the DL SSB to the second UE;

in the first UE, the first UE is configured to receive a first message from the first UE,

configuring the first UE to transmit the SL SSB on the subset of candidate SSB locations with the indication of the subset of candidate SSB locations for the SL SSB; and

in the second UE, the second UE is configured to perform a handover procedure,

distinguish between the DL SSB received from the base station and the SL SSB received from the first UE by the indication of the subset of candidate SSB locations for the DL SSB.

2. The method of claim 1, wherein the indication of the subset of candidate SSB locations for the SL SSB comprises: the candidate SSB location for the SL SSB described by a field in a System Information Block (SIB) received by the first UE.

3. The method of claim 1, wherein the indication of the subset of candidate SSB locations for the SL SSB comprises: the candidate SSB location for the SL SSB described by Radio Resource Control (RRC) signaling received by the first UE.

4. The method of any of claims 1-3, wherein the indication of the subset of candidate SSB locations for the DL SSB comprises: the candidate SSB locations for the DL SSB described by a field in a System Information Block (SIB) received by the second UE.

5. The method of any of claims 1-3, wherein the indication of the subset of candidate SSB locations for the DL SSB comprises: the candidate SSB location for the DL SSB described by a remaining lowest system information (RMSI) received by the second UE.

6. The method of any of claims 1-3, wherein the indication of the subset of candidate SSB locations for the DL SSB comprises: the candidate SSB locations for the DL SSB described in a Physical Broadcast Channel (PBCH)/Physical Sidelink Broadcast Channel (PSBCH) -Management Information Base (MIB) received by the second UE.

7. The method of any of claims 1-3, wherein the indication of the subset of candidate SSB locations for the DL SSB comprises: identification of the DL SSBs by fields introduced in each of the DL SSBs received by the second UE.

8. The method of any of claims 1-3, wherein the indication of the subset of candidate SSB locations for the SL SSB is transmitted to the second UE, and comprising: identification of the SL SSBs by fields introduced in each of the SL SSBs received by the second UE.

9. A method of distinguishing between Downlink (DL) Signal Synchronization Block (SSB) and Sidelink (SL) SSB in a wireless communication network, the network comprising: a first base station defining a first cell, a second base station defining a second cell, at least one first User Equipment (UE) located at an edge of the first cell, and at least one second UE located within the second cell; the method comprises the following steps: the first base station and the second base station cooperatively exchange DL SSB and SL SSB transmission information.

10. The method of claim 9, wherein the DL SSB and SL SSB transport information are exchanged over a backhaul link.

11. A method of distinguishing between Downlink (DL) Signal Synchronization Block (SSB) and Sidelink (SL) SSB in a wireless communication network, the network comprising: at least one base station, at least one first User Equipment (UE), at least one second UE, a SL between the first UE and the second UE, and a DL between the base station and the second UE, wherein there is beam scanning of the DL SSB; the method comprises the following steps:

in the base station, the base station is configured to,

configuring a set of candidate SSB locations for transmitting SSBs in an SSB burst set;

sharing the set of candidate SSB locations between the SL SSB and the DL SSB; and

in the first UE, the first UE is,

prioritizing DL SSB transmissions at the shared candidate SSB location by muting SL SSB transmissions at the shared candidate SSB location.

12. The method of claim 11, wherein the first UE mutes the SL SSB transmission at the shared candidate SSB location by: receiving a DL SSB beam pattern from the base station, measuring from the beam pattern the transmission strengths of the expected DL SSB transmissions, and muting the SL SSB transmissions that collide in time or frequency with a predetermined number of the DL SSB transmissions having the greatest transmission strengths or that collide in time or frequency with a predetermined number of the DL SSB transmissions having transmission strengths exceeding a predetermined value.

13. The method of claim 12, wherein the second UE is capable of transmitting the SL SSB and aligning a SL SSB beam pattern of the second UE with the DL SSB beam pattern to reduce interference between the DL SSB and the SL SSB.

14. A method of distinguishing between Downlink (DL) Signal Synchronization Block (SSB) and Sidelink (SL) SSB in a wireless communication network, the network comprising: at least one base station, at least one first User Equipment (UE), at least one second UE, a SL between the first UE and the second UE, and a DL between the base station and the second UE; the method comprises the following steps:

in the base station, the base station is,

time domain multiplexing the candidate SSB locations of the DL SSB and the SL SSB within a frame structure by assigning the DL SSB candidate SSB locations in a first field and the SL SSB candidate SSB locations in a second field with a fixed frequency offset between the DL SSB and the SL SSB;

transmitting the frame structure and the DL SSB to the second UE;

in the first UE, the first UE is configured to,

transmitting the SL SSB to the second UE; and

in the second UE, the second UE is configured to,

determining whether the received SSB is located in the first field or the second field by the frame structure for candidate SSB location assignment and the fixed frequency offset, thereby distinguishing the DL SSB from the SL SSB.

15. A method of distinguishing a Downlink (DL) Signal Synchronization Block (SSB) from a Sidelink (SL) SSB in a wireless communication network, the network comprising at least one base station, at least one first User Equipment (UE), at least one second UE, a SL between the first UE and the second UE, and a DL between the base station and the second UE; the method comprises the following steps:

in the base station, the base station is,

temporally multiplexing the candidate SSB locations of the DL SSB and the SL SSB within a frame structure by a first mode for assigning candidate SSB locations to the DL SSB in a field and by a second mode for assigning candidate SSB locations to the SL SSB in the same field;

transmitting the frame structure and the DL SSB to the second UE;

transmitting the SL SSB to the second UE; and

in the second UE, the second UE is configured to perform a handover procedure,

distinguishing the DL SSB from the SL SSB by the frame structure for candidate SSB location assignment and additionally received SSBs within the half-frame.

16. A method of distinguishing a Downlink (DL) Signal Synchronization Block (SSB) from a Sidelink (SL) SSB in a wireless communication network, the network comprising at least one base station, at least one first User Equipment (UE), at least one second UE, a SL between the first UE and the second UE, and a DL between the base station and the second UE; the method comprises the following steps:

in the base station, the base station is configured to,

configuring SL SSB transmission at a non-raster frequency position of a frequency domain;

in the first UE, the first UE is configured to,

transmitting the SL SSB transmission to the second UE with an indication of a non-raster frequency position offset; and

in the second UE, the second UE is configured to,

by the indication of the non-raster frequency position offset, the SL SSBs received at the non-raster frequency positions are achieved and detection of raster DL SSBs transmitted from the base station is improved.

17. The method of any of claims 1-3 and 9-16, wherein the first UE is a vehicular UE.

18. The method according to any of claims 1-3 and 9-16, wherein the second UE is a legacy UE.

19. A base station, characterized in that the base station comprises a processor, a memory unit and a communication interface, the processor, the memory unit and the communication interface being configured to perform the method of any of claims 1 to 18.

20. A user equipment, characterized in that the user equipment comprises a processor, a memory unit and a communication interface, the processor, the memory unit and the communication interface being configured to perform the method of any one of claims 1 to 18.