WO2019016987A1

WO2019016987A1 - System and methods for use in transmitting and receiving system information in an advanced wireless communication

Info

Publication number: WO2019016987A1
Application number: PCT/JP2018/004502
Authority: WO
Inventors: Phong Nguyen; Rajitha Palipana
Original assignee: Nec Corporation
Priority date: 2017-07-20
Filing date: 2018-02-02
Publication date: 2019-01-24

Abstract

The present invention relates to a method for use in a scalable NR system. The method comprises at the gNBs, determining a number of beams and beam's configuration to be serviced at each and every associated TRP. At the gNBs, the associated TRPs are configured with a SS Burst set periodicity, SS Burst set start, and/or anchored SS Burst set. At each gNB, the associated TRPs, that can have the same configured SS Burst set start or anchored SS Burst set, are configured with non-overlapping SSBs mapping patterns. At a configured TRP, in a periodically scheduled SS Burst set window within a PBCH TTI, the method involves transmitting beam-formed SSBs following the determined SSBs mapping patterns. At a NR-UE in a local radio interface cloud, the method involves performing SSBs detection and associated PBCHs decoding to identify at least available beams for wireless connectivity services.

Description

DESCRIPTION

Title of Invention

SYSTEM AND METHODS FOR USE IN TRANSMITTING AND RECEIVING SYSTEM INFORMATION IN AN ADVANCED WIRELESS COMMUNICATION

Technical Field

[0001]

The present invention generally relates to a next generation or 5G wireless

communication system. More specifically, the present invention generally relates to a system and methods for transmitting and receiving synchronisation signal blocks in a multi-beams environment of an establishing radio interface cloud.

Background Art

[0002]

The reference to any prior art in this specification is not, and should not be taken as an acknowledgement or any form of suggestion that the prior art forms part of the common general knowledge.

[0003]

A table of acronyms used throughout this specification is provided below:

3 GPP 3^rd Generation Partnership Project

4G 4th generation

5G 5th generation

DL Downlink

DMRS Demodulation Reference Signal

eMBB Enhanced MBB

gNB Logical Access node handling transmission/reception in multiple TRPs in a NR system. Commonly, corresponding to NR-base station

ID Identity

ITU International Telecommunication Union

LTE Long term evolution

LTE-A Advanced LTE or 4G

LTE- A Pro LTE Advanced Pro. 3 GPP LTE Release 13 and 14;

In layman's term it may be called 4.5G, 4.5G Pro, 4.9G

MBB Mobile Broadband mMTC Massive MTC

NR New Radio

N-RAT New RAT

NR-MIB New Radio - Master information Block or so called Minimum system information

NR-PBCH or New Radio - Physical Broadcast Channel

PBCH

NR-PSS or PSS New Radio - Primary Synchronisation Signal

NR-SSS or SSS New Radio - Secondary Synchronisation Signal

NR-UE or UE User equipment with new radio capability

OFDM Orthogonal Frequency-division multiplexing

RAN Radio Access network

RAN-WGl or Radio Access Network - Working Group 1 or Radio layer 1 working RANI group

RAT Radio Access technology

RMSI Remaining minimum system information

SCS Sub Carrier Spacing

SSB SS Block, Synchronisation Signal Block

TTI Transmission Time Interval

UL Uplink

[0004]

The 4th generation (4G) telecommunications systems have been successfully deployed at accelerating pace all over the world, which enables more and more advanced services and applications making use of the inherent benefit of LTE/LTE-A/LTE-A Pro technologies (such as higher data rate, lower latency, enhanced coverage, and sidelink communication). Attentions are now on the development of 5th generation (5G) technology and services. Although the design and deployment of any wireless system or cellular system takes many years, development of the 5G technology systems is now being investigated progressively in 3 GPP standardisation community. With the target for commercial deployment of 5G system being initially planned for 2020 and lately being brought forward to 2018, work has started in International

Telecommunication Union (ITU) and in third generation partnership project (3 GPP) to develop requirements and to perform feasibilities for technological specifications development for new radio (NR) systems as in ITU-R's "Framework and overall objectives of the future development of IMT for 2020 and beyond" Non Patent Literature 1 , in 3 GPP SAl 's "New Services and Markets Technology Enablers (SMARTER)" study item Non Patent Literature 2 and in 3 GPP SA2's "Architecture for NR System" study item Non Patent Literature 3.

[0005]

According to 3 GPP RAN-WGl, as part of initial access system design for NR system or 5G system, two type of synchronisation signals naming as NR-PSS and NR-SSS has been identified. NR-PSS is defined for initial symbol boundary synchronization to a NR cell, and NR-SSS is defined for detection of NR cell ID or at least part of NR cell ID. At least one non-scheduled broadcast channel (i.e. NR-PBCH) for carrying at least a part of minimum system information (i.e. NR-MIB) with fixed payload size and having TTI of 80ms has also been identified for the NR system. In both single beam and multi-beam operational scenarios in an NR system, NR-PSS, NR-SSS and NR-PBCH are time-division multiplexed and transmitted within every SS block which corresponds to N consecutive OFDM symbols and N is a constant. Within an SS Block, NR-SSS is mapped on one OFDM symbol, NR-PSS is mapped on another OFDM symbol and before NR-SSS, and there are at most 4 OFDM symbols are reserved for PBCH. From a detected SS Block, a UE shall be able to identify at least OFDM symbol index, slot index in a radio frame and radio frame number. One or multiple SS block(s) compose an SS burst set. Where the maximum number of SS blocks within a SS burst set (L) is defined for different frequency ranges i.e. L is 4 for frequency range up to 3 GHz; L is 8 For frequency range from 3 GHz to 6 GHz; and L is 64 For frequency range from 6 GHz to 52.6 GHz. SS Burst set transmission is periodic where SS Burst set periodicity is configurable which can be selected from the set of [5ms, 10ms, 20ms, 40ms, 80ms and 160ms]. Transmission of SS Blocks within a SS Burst set is confined to a 5ms window regardless of SS burst set periodicity. A UE may assume that a given SS block is repeated with a SS burst set periodicity. NR-PBCH contents in a given repeated SS block may change. By default, the UE may neither assume the gNB transmits the same number of physical beam(s), nor the same physical beam(s) across different SS-blocks within an SS burst set. For initial cell selection, UE can assume default SS burst set periodicity of 20ms regardless of frequency bands and configured SS burst set periodicity. Furthermore, 3 GPP RAN-WGl has identified that the contents in a NR-MIB shall include part of SFN having

[7-10] bits (i.e. s_g s₃ Non Patent Literature 11) for at least 80ms granularity indication, timing information within a radio frame having [0-7] bits for information such as SS block (i.e. SSB) time index [0-6] bits (i.e. b^b^b^ Non Patent Literature 11) and half radio frame timing [0-1] bit (i.e. c₀ Non Patent Literature 11), and RMSI scheduling information with yet defined number of bits. The contents in a NR-MIB may further include SS burst set periodicity of [0-3] bits or burst set index 10ms granularity within BCH TTI (i.e. s₂s_is_Q Non Patent Literature 11).

[0006]

From the above summarised requirement on NR-PSS, NR-SSS, PBCH, SS blocks, and SS burst set definition, relationship and transmission's requirement as well as associated contents that they may convey including 80ms TTI PBCH carrying NR-MIB, like LTE-based technology, it is apparent that 7-bits SFN should be sufficient for explicitly indicating part of SFN at 80ms granularity (i.e. s_g s₃ ) and eight differentiable scrambling codes for blind decoding of

PBCH at radio frame level would be sufficient for indicating 8 different radio frames within any PBCH TTI implicitly (i.e.. s₂S S₀ ). This means a UE in a NR system has to use 8 predefined scrambling codes for blind decoding of a redundancy or time version of PBCH at SS Block. For a configured 5ms burst set periodicity, half radio frame timing of 1 bit being included in a NR-MIB is necessary for differentiating a detected SS block within a SS burst set in the first half and the one in the second half of a radio frame (i.e. c₀ ). However, the introduction of half radio frame timing of 1 bit in a NR-MIB shall restrict soft combine of PBCH's redundancy or time version on a detected SS block within SS burst set in the first half radio frame and the repeated one in the second half radio frame to improve the decodability. Furthermore, the introduction of half radio frame timing of 1 bit in a NR-MIB shall violate the assumption that a given SS block is repeated with a SS burst set periodicity and therefore requires UE to handle 5ms burst set periodicity case differently (i.e. the PBCH of repeated SSBs in the burst set within the first half of a radio frame and the associated one the second half of the radio frame cannot be combined). A straight-forward solution for this case is to increase number of differentiable scrambling codes from 8 to 16 to assist the indication of 8 different radio frames within any PBCH TTI and whether the decodable SS block being in the 1st half of the radio frame or second half of the radio frame implicitly. The increase of number differentiable scrambling codes for blind decoding of PBCH to either 8 or 16 shall directly increase the number of blind decoding of

PBCH at a UE in NR system by 2-folds or 4-folds or more regardless of configured SS burst set periodicity when being compared to LTE-based technology. For the configured SS burst set periodicity of 5ms and 10ms, the utilisation of sixteen or eight differentiable scrambling codes for implicitly indicating of radio frame numbers within a PBCH TTI, may appear necessary. However, for the configured SS burst set periodicity of 20ms, 40ms, 80ms and 160ms, the adoption of sixteen or eight differentiable scrambling codes for implicitly indicating a radio frame number within a PBCH TTI shall become unnecessary overhead for UE in an NR system as a UE may have to perform twice or more numbers of blind decoding than it is required to detect & decode an NR-PBCH. This becomes increasingly important issue for UE at initial cell selection state as the UE can assume default SS burst set periodicity of 20ms regardless of frequency bands and configured SS burst set periodicity, and therefore it may attempt to combine PBCHs on detected SS blocks at 20ms intervals to detect PBCH TTI boundary and radio frame number. With an effort to minimise the unnecessary blind decoding overhead at NR-UEs while maintaining the flexibility and programmability for system configuration at gNB that shall allow a gNB to dynamically reconfigure one of its NR's TRP to change SS burst periodicity without impact on being serviced NR-UEs and NR-UEs at initial cell selection state, the preferred embodiment describes the method for generating a set scrambling codes for use within an SS burst set regardless of SS burst set periodicity and associated configuring method for use in a communication system with cloud radio interface that provides wireless connectivity services to mobile equipment in the region.

Citation List

Non Patent Literature

[0007]

NPL 1: ITU-R M.2083-0 (09/2015) - IMT Vision - Framework and overall objectives of the future development of IMT for 2020 and beyond

NPL 2: TR 22.891 vl4.0.0 (2016-03) - Feasibility Study on New Services and Markets Technology Enablers

NPL 3: TR 23.799 v0.5.0 (2016-05) - Study on Architecture for Next Generation System NPL 4: TR 38.802 - Study on NR New Radio Access Technology (Release 14)

NPL 5: TR 38.913 - Study on Scenarios and Requirements for Next Generation Access Technologies (Release 14)

NPL 6: TS 36.211 vl4.1.0 (2016-12) - Physical Channels and modulation (Release 14)

NPL 7: TS 36.212 vl4.1.0 (2016-12) - Multiplexing and channel coding (Release 14)

NPL 8: TS 36.213 vl4.1.0 (2016-12) - Physical layer procedures (Release 14)

NPL 9: TS 36.321 vH.l .O (2016-12) - Medium Access Control protocol (Release 14) NPL 10: TS 36.331 vl4.0.0 (2016-09) - Radio Resource Control (Release 14)

NPL 11: 3 GPP TSG RAN WG1 NR Ad-Hoc#2, RANI Chairman's Notes

Summary of Invention

[0008]

According to the present invention, there is provided a method for use in a scalable New Radio (NR) system that comprises at least one logical access node (gNB) and a plurality of associated transmission reception points (TRPs) forming virtual radio interface cloud that provides beam formed wireless connectivity services to a plurality of new radio-user equipments (NR-UEs), the method comprising the steps of:

1.1. at the gNB, determining a number of beams and beam's configuration to be serviced at each and every associated TRP to achieve desirable radio cloud coverage;

1.2. at the gNB, configuring the associated TRPs with a synchronisation Signal (SS) Burst set periodicity, SS Burst set start, and/or anchored SS Burst set;

1.3. at the gNB, further configuring the associated TRPs, that can have the same configured SS Burst set start or anchored SS Burst set, with non-overlapping SS Blocks (SSBs) mapping patterns;

1.4. at a configured TRP, in a periodically scheduled SS Burst set window within a physical broadcast channel (PBCH) transmission time interval (TTI), transmitting beam-formed SSBs following the determined SSBs mapping patterns, where a SSB can at least comprise PSS, SSSX and PBCH or PBCHs; and

1.5. at a NR-UE in a local radio interface cloud, performing SSBs detection and associated PBCHs decoding to identify at least available beams for connectivity services at its location, slot boundary, Virtual Cell's identities (IDs) or Virtual cloud radio interface IDs, orthogonal frequency-division multiplexing (OFDM) symbol index, slot index in a radio frame, radio frame number and/or any other minimum system information.

[0009]

An embodiment of the present invention is directed to systems and methods for use in an advanced wireless communication system, such as the fifth generation (5G) or New Radio (NR) as being defined in 3 GPP, with cloud radio interface providing wireless connectivity services including initial access services to plurality of new radio capable UEs, through coordinated transmission of synchronization signals blocks (SSBs) from multiple transmission and reception points (TRPs) without interfering with one another within a multi-beams environment, which may at least partially overcome at least one of the disadvantages, or fulfil at least one of the requirement identified or discussed in the Background Art section, or provide the consumer with a useful or commercial choice.

[0010]

In one broad form, an embodiment of the present invention is related to

configuration/reconfiguration and transmission/reception of synchronization signal Blocks (SSBs) comprising primary synchronisation signal (PSS), secondary synchronisation signals (SSS), and associated physical broadcast channels (PBCH) carrying minimum system information on a multi-beams cloud radio interface for services. The system providing beam-formed cloud radio interface for servicing at plurality of UEs may comprise a logical access node (gNB) and plurality of time-synchronised TRPs. The said TRPs forming the radio interface cloud may be configured or reconfigured to share the same carrier frequency and carrier/operational bandwidth in transmitting beam-formed SSB(s) periodically. A set of periodic beam-formed SSBs may appear in burst which is strictly confined within 5ms window, where the burst set periodicity is configurable with a value being selected from the set of [5, 10, 20, 40, 80 and 160ms]. Upon the detection of one or more indexed beam-formed SSBs, a UE may be required to implicitly and explicitly identify at least the 10ms radio frame number at 5ms granularity, slot index in the radio frame, OFDM symbol index in the slot and Virtual Cell's ID or Virtual cloud radio interface ID.

[0011]

In one embodiment of the present invention, there proposes 'SS Burst set start' IE (information element) to enable the interference coordination at 5ms granularity among time-synchronised TRPs in broadcasting beam-formed SSBs. According to the an embodiment of the present invention, a TRP may be configured to transmit its first SS burst set in the 1st, 2nd, 3rd or 4th window of 5ms within a PBCH TTI of 80ms using the 'SS Burst set start' IE. Multiple SFN-synchronised TRPs forming the cloud radio interface for local service may be

configured/reconfigured with different 'SS Burst set starts' for interference coordination at 5ms granularity.

[0012]

In another embodiment of the present invention, there proposes 'anchored SS Burst set' IE to enable a TRP to reconfigure its 'SS Burst set periodicity' on PBCH TTI basis. Regardless of SS Burst set periodicities, there is always a burst set being transmitted in the configured anchored SS Burst set window of 5ms. An 'anchored SS Burst set' may be configured or reconfigured to be in the 1st, 2nd, 3rd or 4th window of 5ms within a PBCH TTI of 80ms, and may be the same as the configured or reconfigured ' SS Burst set start' . Where two or more TRPs being configured or reconfigured with the same 'SS Burst set start' or 'anchored SS Burst set', they may be further configured with non-overlapping SSBs mapping patterns namely localised, distributed or combination of localised and distributed to enable inter TRPs

interference coordination in broadcasting beam-formed SSBs at SSB granularity. Furthermore, the said two or more TRPs may share the same set of beam indexes. According to

embodiments of the present invention, a SSB can be flexibly mapped in any possible candidate SSB locations within a burst set of 5ms, and the timing position of an SSB block within a 5ms burst set may be indicated using 7-bits information to assist the aforementioned versatile SSB mapping patterns. The 3 -bits among the said 7-bits may be used to indicate implicitly or explicitly whether a SSB is within the 1st, 2nd, 3rd, 4th or 5th lms-interval of a 5ms burst set interval, and the remaining 4-bits may be used to indicate explicitly the slot index within the 1ms interval that a SSB belongs to. When the implicit method is used for indicating whether a SSB is within the 1st, 2nd, 3rd, 4th or 5th lms-interval of a 5ms burst set interval, a periodic sequence of 5ms in length may be used. The said periodic sequence may be truncated into five equal lms-sequences, where the 1st , 2nd, 3rd, 4th, and 5th truncated sequences are used as DMRS for PBCHs transmission/reception within the 1st, 2nd, 3rd, 4th or 5th lms-interval of a 5ms burst set interval respectively. There may be two candidate SSB locations in a slot of 14 symbols, which result in the same 7-bits information. According to embodiments of the present invention, SSBs being mapped in the first half and second half of a 14-symbol slot may be further distinguishable by differentiable arrangement of PSS and SSS e.g. consecutive PSS and SSS (i.e. first format) vs spacing PSS and SSS (i.e. second format). The said implicit indication of SSBs being mapped in the first half and second half of a 14-symbol slot may further allow the PBCHs being associated with 2 normal SSBs mapping to a single 14-symbol slot to carry the same payload for soft combine at a UE. At a new-radio capable UE, upon detecting a PSS, it may further attempt to detect the associated SSS at 2 different time positions depending on whether an SSB being transmitted in the first half or second half of a 14-symbol slot. As the configured 'SS burst set periodicity' is 40ms and larger, the number of SS Bursts per PBCH TTI is 2 and less. In order to achieve the same minimum blind decoding performance, the extended SSB is proposed for used when SS Burst periodicity of 40ms or larger is configured. Where an extended SSB comprises the normal SSB and additional 2 OFDM-symbols for the mapping of additional PBCH redundancy or time version and there is at most one (1) extended SSB being mapped into a

14-symbol slot. When SS Burst periodicity of 80ms or 160ms is configured, the only scheduled SS burst set is retransmitted in the immediately followed 5ms window. In the scheduled SS burst set, the first extended SSB format may be used for SSB mapping, where the second extended SSB format may be used for SSB mapping in the retransmitted SS burst set or via versa.

[0013]

In a further embodiment of the present invention, there is 2 SSSX sequences namely SSS1 and SSS2 for use alternatively at SS Burst set level, where SSS1 may be used in every SSBs within the first burst set of a PBCH TTI to assist the missed detected SSBs at SS Burst set level or implicit indication of SS Burst set periodicity. When SS Burst periodicity of 80ms or 160ms is configured, SSS1 is used on every SSBs in the scheduled and retransmitted SS burst sets to assist the differentiation between retransmitted SS Burst set and Burst set with 5ms periodicity.

[0014]

In the final embodiment of the present invention, a set of four (4) differentiable scrambling codes for use on PBCH's scrambling are predefined to implicitly indicate the 80ms timing at 5 ms granularity.

[0015]

According to one approach, the 4 predefined scrambling codes may be used to generate a unique sequence of 16 scrambling code elements being indexed from 1 to 16, where each indexed element (i.e. 1, 2 to 16) in the said sequence points to the scrambling code and the corresponding PBCH redundancy or time version for use in transmitting PBCHs in the corresponding window of 5ms within a PBCH TTI (i.e. 1st 5m window, 2nd 5ms window, ... to 16th 5ms window). The first, second, third and fourth predefined scrambling codes may correspond to the first, second, third and fourth redundancy or time versions of a PBCH respectively. When applying this method with 5ms SS Burst set periodicity, a UE may perform at most 4 blind decoding attempts on a PBCH and may further perform blind decoding attempts on the same SSB in at most 2 neighbouring SS Bust sets (i.e. total of 4 3 = 12 blind decoding attempts) to determine the 80ms timing at 5ms granularity i.e. radio frame number and 1 st half or second half of the radio frame. When applying this method with other SS Burst set periodicities, a UE may perform at most 4 blind decoding attempts on a PBCH and may further use detected SSSX (i.e. SSS1 or SSS2) to determine the 80ms timing at 5ms granularity (i.e. radio frame number and 1st half or second half of the radio frame).

[0016]

According to alternative approach, the 4 predefined scrambling codes may be used for scrambling all four redundancy or time versions of a PBCH in generating 16 scrambled PBCH redundancy versions (i.e. 4 scrambling codes by 4 redundancies). Where the first redundancy version of a PBCH being scrambled with the first, second, third and fourth predefined

scrambling codes may be for the first 20ms window of a PBCH TTI at 5ms window granularity; the second redundancy version of a PBCH being scrambled with the first, second, third and fourth predefined scrambling codes may be for the second 20ms window of a PBCH TTI at 5ms window granularity; the third redundancy version of a PBCH being scrambled with the first, second, third and fourth predefined scrambling codes may be for the third 20ms window of a PBCH TTI at 5ms window granularity; and the fourth redundancy version of a PBCH being scrambled with the first, second, third and fourth predefined scrambling codes may be for the fourth (i.e. last) 20ms window of a PBCH TTI at 5ms window granularity. When applying this method for use at a TRP, regardless of the configured SS Burst set periodicity, a UE may perform at most 16 blind decoding attempts on a PBCH to determine the 80ms timing at 5ms granularity i.e. radio frame number and 1st half or second half of the radio frame.

[0017]

Any of the features described herein can be combined in any combination with any one or more of the other features described herein within the scope of the invention. Brief Description of Drawings

[0018]

Preferred features, embodiments and variations of the invention may be discerned from the following Detailed Description, which provides sufficient information for those skilled in the art to perform the invention. The Detailed Description is not to be regarded as limiting the scope of the preceding Summary of the Invention in any way. The Detailed Description will make reference to a number of drawings as follows.

[0019]

[Fig. 1]

Fig. 1 illustrates a 5G Communication system - A virtual Cloud Radio Interface.

[0020]

[Fig. 2]

Fig. 2 illustrates a method of generating scrambling codes set for use in NR-PBCH's scrambling function and NR-PBCH to SS Burst set mapping function in a 5G mobile

communication system assisting the implicit detection of radio frame number upon successful decoding of NR-PBCH(s).

[0021]

[Fig- 3]

Fig. 3 illustrates an exemplary PBCH transmission using the disclosed method in a system where the SS Burst set transmission periodicity configuration is 5ms, enabling NR-UEs in different modes (i.e. initial cell selection, CONNECTED-MODE, IDLE-MODE, INACTIVE MODE) to acquire NR-MIB.

[0022]

[Fig. 4]

Fig. 4 illustrates an exemplary PBCH transmission using the disclosed method in a system where the SS Burst set transmission periodicity configuration is 10ms, enabling NR-UEs in different modes (i.e. initial cell selection, CONNECTED-MODE, IDLE-MODE, INACTIVE MODE) to acquire NR-MIB.

[0023]

[Fig. 5]

Fig. 5 illustrates an exemplary PBCH transmission using the disclosed method in a system where the SS Burst set transmission periodicity configuration is 20ms, enabling NR-UEs in different modes to acquire NR-MIB.

[0024]

[Fig. 6]

Fig. 6 illustrates an exemplary Channel coding structure for the transmission of NR-BCH transport channel at a 5G base-station.

[0025]

[Fig- 7]

Fig. 7 illustrates an alternative method of generating scrambling codes set for use in

NR-PBCH's scrambling function and NR-PBCH to SS Burst set mapping function in a 5G mobile communication system assisting the implicit detection of radio frame number upon successful decoding of NR-PBCH(s).

[0026]

[Fig. 8]

Fig. 8 illustrates an exemplary (Macro) interference coordination in transmitting minimum system information (NR-MIB) among TRPs forming radio interface cloud in 5G system by using the novel 'SS Burst set start' configuration parameter.

[0027]

[Fig. 9]

Fig. 9 illustrates SSBs transmission method for a configured SS Burst set periodicity < ¼ PBCH TTI (i.e. 20ms, 10ms and 5ms).

[0028]

[Fig. 10]

Fig. 10 illustrates SSBs transmission method for a configured SS Burst set periodicity =

½ PBCH TTI (i.e. 40ms).

[0029]

[Fig- 11]

Fig. 11 illustrates SSBs transmission method for a configured SS Burst set periodicity > PBCH TTI (i.e. 80ms and 160ms).

[0030]

[Fig. 12]

Fig. 12 illustrates an exemplary Extended SSB structures and Extended SSB to NR-Slot mapping.

[0031]

[Fig. 13]

Fig. 13 illustrates an exemplary (Micro) interference coordination in transmitting minimum system information (i.e. NR-MIB) among TRPs forming radio interface cloud in 5G system by using the method of mapping SSBs within a SS Burst set with the assistance of hybrid signalling method in indicating SSB timing index.

[0032]

[Fig. 14]

Fig. 14 illustrates an exemplary dynamic 'SS Burst set periodicity' reconfiguration - where the 1st 5ms window is configured as 'anchored SS burst set'.

[0033]

[Fig. 15]

Fig. 15 illustrates an exemplary dynamic 'SS Burst set periodicity' reconfiguration - where the 4th 5ms window is configured as 'anchored SS burst set'.

Description of Embodiments

[0034]

Reference will now be made in detail to the preferred embodiments of the invention, examples of which are illustrated in accompanying drawings. Where possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.

[0035]

Fig. 1 exemplarily illustrates a 5G wireless communication system with radio interface cloud, method of transmitting synchronisation signal blocks (i.e. SSBs) with interference coordination, and apparatus in which the exemplary embodiment of the invention may be analysed, discussed or practices to advance. The wireless communication system (10) may be considered as an evolution beyond the traditional cellular network, where the well-defined cellular concept is no longer applicable. The wireless communication system (10) comprises a gNB (30) which is connected to and control plurality of TRPs (e.g. Transmission and reception points: 11, 12, 13, and 14) which forms a cloud radio interface, providing wireless connectivity services to plurality of NR-UEs (i.e. UEs with new radio capability e.g. 20, 21, 22, 23 and 24) in the region using sets of dedicated beams (e.g. 15, 16, 17 and 18). In this system, all TRPs forming the cloud radio interface are time-synchronised and SFN-synchronised where any UE operating in the said cloud radio interface is initially required to synchronise and then maintain the synchronisation with one or more indexed beams provided by one or more TRPs for wireless connectivity services. In this system, the network may find and locate UE for providing the requested services where a dedicated beam provided by one TRP may be used to service one UE (e.g. 21, 24) or two or more UEs (e.g. 22 & 23). For moving UE (e.g. 20), it may initially synchronise to one or more beams (15) provided by a TRP (UE at 20.1 and TRP 11). While moving in the cloud radio interface (UE path 20.0), the UE (e.g. UE 20) may concurrently synchronise to multiple beams provided by two or more TRPs (e.g. 20.2, 20.3 and 20.4).

Synchronising to multiple beams provided by multiple TRPs simultaneously may further require the network to configure its TRPs to transmit their SSBs in coordinated manner in such a way that the transmitted SSBs from neighbouring TRPs will not interfere with one another and allow a UE within a nominated period of time such as 20ms to be able to detect suitable beams for services from its surrounding TRPs. The method for interference coordination in SSBs

transmission will be further discussed in one or more subsequent embodiments of the present invention.

[0036]

According to the first embodiment of present invention, in order to minimise number of unnecessary blind decoding overhead especially for configuration of burst set periodicity being 20ms or longer due to the introduction of 8 or 16 scrambling codes, a set of four (4) predefined scrambling codes is used as input to the method that generates a sequence of 16 scrambling codes comprising multiple copies of 4-predefined scrambling codes being arranged in a unique sequences, where full set of the generated sequence or sub-sets of the generated sequence being methodologically selected for scrambling PBCH redundancy or time version at a gNB will depend on the SS Burst set periodicity configuration and SS Burst set start window configuration. In reference to Fig. 2, the aforementioned method (100) may take a set of 4 predefined

scrambling codes (110) i.e. the first scrambling code (111), the second scrambling code (112), the third scrambling code (113) and the fourth scrambling code (114) as inputs to generate a 4x4 square matrix (115) of 16 elements, where an each element in the 4x4 matrix (i.e. E.01 , E.02, E.03, ..., E.15, E.16) is a scrambling code index in the set of {the first scrambling code (111), the second scrambling code (112), the third scrambling code (113) and the fourth scrambling code (114)} . The 4x4 matrix (115) is generated by taking the first scrambling code (111), the second scrambling code (112), the third scrambling code (113) and the fourth scrambling code (114) as the 4 elements (E.01, E.05, E.09, and E.13) forming the first row (120). The first row

(120) is "cyclic-shifted" to create the next 4 elements (E.02, E.06, E.10, and E.14) of second row

(121) ; The second row (121) is then "cyclic-shifted" to create the further 4 elements (E.03, E.07, E.l l, and E.15) of third row (122); The third row (122) is "cyclic-shifted" for the last time to create the last 4 elements (E.04, E.08, E.12, and E.16) of the fourth row (123). According to the present embodiment, the first column (126) comprises the 4 scrambling code indexes for use within the 1st 20ms window (102) of a PBCH TTI (101), the second column (127) comprises the 4 scrambling code indexes for use within the 2nd 20ms window (103) of a PBCH TTI (101); the third column (128) comprises the 4 scrambling code indexes for use within the 3rd 20ms window (104) of a PBCH TTI (101); and the fourth column (129) comprises the scrambling code indexes for use within the last 20ms window (105) of a PBCH TTI (101). In any column (i.e. 126, 127, 128 and 129), each element represents the scrambling code index for use on PBCHs within 5ms of the corresponding 20ms window (i.e. pair of consecutive even and odd radio frames). Where the 1st elements represent the scrambling code index for use within the 1st 5ms (106) of the corresponding 20ms window (i.e. 102, 103, 104, or 105); the 2nd elements represent the scrambling code index for use within the 2nd 5ms (107) of the corresponding 20ms window (i.e. 102, 103, 104, or 105); the 3rd elements represent the scrambling code index for use within the 3rd 5ms (108) of the corresponding 20ms window (i.e. 102, 103, 104, or 105); and the last elements represent the scrambling code index for use within the last 5ms (109) of the corresponding 20ms window (i.e. 102, 103, 104, or 105).

[0037]

When the 5ms burst set periodicity is configured for the transmission of SS blocks, the scrambling code indexes for use on transmitted PBCHs at every 5ms intervals in a PBCH TTI of 80ms can be read out element- wise from the matrix (115), column by column (125) starting from element (E.01) in the first column (126) and finishing at element (E.16) in the last column (129). Example (130) shown in Fig. 3 further illustrates the generated sequence of scrambling codes indexes within PBCH TTI of 80ms for 5ms burst set periodicity configuration. For a UE at initial cell selection state, it may detect a SS block in the burst set within the first 5ms window of radio frame 8k (106), however it may fail to decode the associated PBCH after 4 blind decoding attempts. With the default SS burst set periodicity of 20ms assumption, the UE may attempt to combine at most 4 redundancy or time versions of PBCH in SS blocks being detected at 20ms intervals within a PBCH TTI of 80ms window which may result in successful decoding of PBCH (131) where the scrambling code sequence of { 1st; 2nd; 3rd; and 4th} enabling the successful PBCH decoding may further indicate the first detected SS block is in the first half of radio frame 8k (106). Similarly, the successful decoding of PBCH (132) using scrambling codes sequence of {2nd; 3rd; 4th; and 1st} may indicate the first detected SS block is in the second half of radio frame 8k (107); the successful decoding of PBCH (133) using scrambling codes sequence of {3rd; 4th; 1st and 2nd } may indicate the first detected SS block is in the first half of radio frame 8k+l (108); the successful decoding of PBCH (133) using scrambling codes sequence of {4th; 1st ; 2nd and 3rd } may indicate the first detected SS block is in the second half of radio frame 8k+l (109). Any consecutive successful decoding of SS blocks resulting in the same PBCH content at 5ms interval (139) further implies the network configured 5ms burst set periodicity. For a UE in IDLE-MODE, CONNECTED-MODE or INACTIVE-MODE may attempt to combine PBCHs in detected SS blocks at consecutive 5ms-intervals using the generated sequence of scrambling codes indexes (e.g. 135, 136, 137, 138) to improve the PBCH decodability as well as to detect if SS burst set periodicity has been changed.

[0038]

When the 10ms burst set periodicity is configured for the transmission of SS blocks, the scrambling code indexes for use on transmitted PBCHs at every 10ms intervals in a PBCH TTI of 80ms can be read out, from the matrix (115), at the rate of every second elements, column by column (125) starting from element (E.01) or element (E.02) in the first column (126) and finishing at element (E.15) or element (E.16) in the last column (129) depending on whether the first 5ms (106) or the 2nd 5ms (107) of the first 20ms window (i.e. first radio frame of the PBCH TTI) being selected for the SS Burst set start window. Example (140) shown in Fig. 4, further illustrates the generated sequence of scrambling codes indexes within PBCH TTI of 80ms for 10ms burst set periodicity configuration where the first 5ms (106) of the first 20ms window (102) being selected for the SS Burst set start. For a UE at initial cell selection state, it may detect a SS block in the burst set within the first 5ms window of radio frame 8k (106), however it may fail to decode the associated PBCH after 4 blind decoding attempts. With the default SS burst set periodicity of 20ms assumption, the UE may attempt to combine at most 4 redundancy versions of PBCH in SS blocks being detected at 20ms intervals within a PBCH TTI of 80ms window which may result in successful decoding of PBCH (141) where the scrambling code pattern of {1st; 2nd; 3rd; and 4th} enabling the successful PBCH decoding may further indicate the first detected SS block is in the first half of radio frame 8k (106). Similarly, the successful decoding of PBCH (143) using scrambling codes pattern {3rd; 4th; 1st and 2nd } may indicate the first detected SS block is in the first half of radio frame 8k+l (108). Consecutive successful decoding of SS blocks resulting in the same PBCH content at 10ms interval (149) further implies the network configured 10ms burst set periodicity. For a UE in IDLE-MODE,

CONNECTED-MODE or INACTIVE-MODE may attempt to combine PBCHs in detected SS blocks at consecutive lOms-intervals using the generated sequence of scrambling codes indexes (e.g. 145, 147) to improve the PBCH decodability as well as to detect if SS burst set periodicity has been changed.

[0039]

When the 20ms burst set periodicity is configured for the transmission of SS blocks, the scrambling code indexes for use on transmitted PBCHs at every 20ms intervals in a PBCH TTI of 80ms can be read out, from the matrix (115), at the rate of every fourth elements, column by column (125) starting from element (E.01), element (E.02), element (E.03), or element (E.04) in the first column (126) and finishing at element (E.13), element (E.14), element (E.15), or element (E.16) in the last column (129) depending on whether the first 5ms (106), the 2nd 5ms (107), the 3rd 5ms (108), or the 4th 5ms (109) of the first 20ms window being selected as for the SS Burst set start window. Example (150) shown in Fig. 5, further illustrates the generated sequence of scrambling codes indexes within PBCH TTI of 80ms for 20ms burst set periodicity configuration where the first 5ms (106) of the first 20ms window (102) being selected for the SS Burst set start.

[0040]

When the 40ms, 80ms or 160ms burst set periodicity is configured for the transmission of SS blocks, the scrambling code indexes for use on transmitted PBCHs in a PBCH TTI of 80ms can be read out, from the matrix (115), at the rate of every fourth elements, column by column (125) starting from element (E.01), element (E.02), element (E.03), or element (E.04) in the first column (126) and finishing at element (E.13), element (E.14), element (E.15), or element (E 16) in the last column (129) depending on whether the first 5ms (106), the 2nd 5ms (107), the 3rd 5ms (108), or the 4th 5ms (109) of the first 20ms window being selected for the SS Burst set start window. For example, if the first 5ms (106) of the first 20ms window (102) is selected or the SS Burst set start window, then the generated scrambling code indexes sequences for transmitting a PBCH and its redundancies will comprise the first scrambling code (E.01), second scrambling code (E.05), third scrambling code (E.09), and fourth scrambling code (E.13). Where the first 2 generated scrambling code indexes i.e. the first scrambling code (E.01) and second scrambling code (E.05), are used for scrambling the transmitted PBCH and its first redundancy respectively which are then mapped to the will-be-disclosed extended SS Block within the designated SS Burst set start. Furthermore, second 2 output scrambling code indexes i.e. the third scrambling code (E.09), and fourth scrambling code (E.13), are used for scrambling the transmitted PBCH's second and third redundancies respectively which are then mapped to the extended SS Block within a SS burst set being associated with the designated SS Burst set start. For 80ms or 160ms burst set periodicity, and according to the present embodiment, the said SS burst set being associated with the designated SS Burst set start is a repeated version of the SS Burst set start which is preferably transmitted within a 5ms window that immediately follows the 5 ms window.

[0041]

According to the second embodiment of the present invention, when being used at a gNB or NR TRP, the above disclosed method for generating scrambling codes at every 5ms windows within a PBCH TTI of 80ms regardless of the configured 'SS burst set periodicity', can be implemented through 2 separate functions i.e. scrambling function and SS burst set mapping function as being illustrated in the NR-PBCH channel coding structure (200) - Fig. 6. In reference to Fig. 6, the NR-PBCH channel coding structure may take at least NR-BCH transport block (201) and SSB time index (202) as inputs for CRC insertion function (210). Where the full or partial SSB time index (202) may be explicitly used for indication of the SS block in a SS Burst set and upon the successful detection and decoding of one or more repeated SSBs, OFDM symbol index, slot index in a radio frame and radio frame number can be determined. At channel coding and rate matching function (220), the NR-BCH transport block (201) and SSB time index (202) with CRC are used to generate 4 PBCH's redundancy or time versions naming PBCHRV0 (221), PBCHRV1 (222), PBCHRV2 (223), and PBCHRV3 (224) where each PBCH's

redundancy or time versions are designed for being self-decodable. At scrambling function (240), 4 predefined scrambling codes i.e. first scrambling code, second scrambling code, third scrambling code and fourth scrambling code, may be used for bit-scrambling PBCHRVO (221), PBCHRV1 (222), PBCHRV2 (223), and PBCHRV3 (224) respectively. The scrambled

PBCHRVO, PBCHRV 1 , PBCHRV2, and PBCHRV3 are then modulated such as QPSK

modulation, at the modulation function (240) to produce 4 redundantly or timely modulated PBCHs i.e. PBCHC1RV0 (251), PBCHC2RV1 (252), PBCHC3RV2 (253), and PBCHC4RV3 (254). According to the present embodiment, at the SS burst set mapping function (250), the SS burst set periodicity and SS Burst set start parameters are used to drive the mapping function (255) to output appropriate modulated PBCH version {i.e. PBCHC1RV0 (251), PBCHC2RV1 (252), PBCHC3RV2 (253), or PBCHC4RV3 (254)} On the fly' for mapping to the designated SSB within a configured SS Burst set. By applying the above disclosed algorithm, the sequence of modulated PBCH versions being output for SSB mapping shall follow the illustrated path (255.5), where the modulated PBCH version corresponding to E.01 i.e. PBCHC1RV0 (251) is output for the 1st 5ms window of a PBCH TTI, followed by modulated PBCH version corresponding to E.02 i.e. PBCHC2RV1 (252), and so on to finish with PBCH version corresponding to E.16 i.e. PBCHC3RV2 (252). For configured 5ms SS burst set periodicity, all modulated PBCH versions corresponding to element E.01, E02, E.03, E.15, and E.16 are output at every 5ms intervals within a PBCH TTI of 80ms. For configured SS burst set periodicity > 5ms, the 'SS Burst set start' parameter is firstly used to identify the starting element (i.e. 255.1, 255.2, 255.3, and 255.4) corresponding to the 5ms window in which the SSBs of the first SS burst set shall be mapped, and the configured 'SS burst set periodicity' is used for determining element skipping patterns i.e. every second elements for 10ms periodicity, and every fourth elements for 20ms, 40ms, 80ms and 160ms starting from the element corresponding to the SS Burst set start. For example (260), with the configured SS burst set periodicity of 10ms and the 1st 5ms window (255.1) being configured for SS Burst set start in the PBCH TTI of 80ms (261), the modulated PBCHC1RV0 (251) corresponding to element E.01 is output for mapping to the designated SSB within the SS Burst set in the first 5ms window (263) (i.e. first half of radio frame 8k). Subsequently, modulated PBCH version corresponding to every 2nd elements (i.e. E.03, E.05, E.07... E.13, E.15) are output at every 10ms intervals (262) for mapping to the designated SSBs within the SS Burst sets in the first 5ms windows of radio frames (8k+l), (8k+2), (8k+3), ..., (8k+7).

[0042]

An alternative to the method disclosed in the 1st and 2nd embodiments is more simplified method for use at a TRP but may result at high number of blind decoding attempts at a UE regardless SS Burst set periodicity configuration. In reference to Fig. 7, the alternative method (200b) may comprise 4 predefined scrambling codes (111, 112, 113, and 114) for use in the 1st 20ms window (102) of a PBCH TTI (101), on the first PBCH's redundancy (221), at 5ms granularity; the same 4 predefined scrambling codes for use in the 2nd 20ms window (103) of the PBCH TTI (101), on the second PBCH's redundancy (222), at 5ms granularity; the same 4 predefined scrambling codes for use in the 3rd 20ms window (104) of the PBCH TTI (101), on the third PBCH's redundancy (223), at 5ms granularity; and the same 4 predefined scrambling codes for use in the 4th 20ms window (105) of the PBCH TTI (101), on the fourth PBCH's redundancy (224), at 5ms granularity. At a UE, upon the detection of a SSB, it may perform at most 16 blind decoding attempts (i.e. 4 PBCH redundancies by 4 scrambling codes) on a PBCH to determine the 80ms timing at half of radio frame (i.e. 5ms) granularity.

[0043]

According to the third embodiment of the present invention, the introduction of "SS Burst set start" configuration parameter shall allow plurality of TRPs which together form a cloud radio interfaces for wireless connectivity services in a region, to be configured with different "SS Burst set start" values enabling interference management coordination in transmitting minimum system information in the servicing region. In reference to Fig. 8, the said plurality of TRPs, having the same system frame timing and synchronised SFN, and providing wireless connectivity services to plurality of NR-UEs in the region as being discussed in associated with the system illustrated through Fig. 1 , can be exemplarily configured or reconfigured with different "SS Burst set start" values as being illustrated per the timing diagram (270) in Fig. 8. In the illustrated example, there are 3 TRPs [i.e. TRP(l) (272), TRP(2) (274) and TRP(3) (276)], where:

TRP(l) (272) may be configured with 20ms SS burst set periodicity (279) and SS Burst set start is in 1st 5ms window (280) of the PBCH TTI (271);

TRP(2) (274) may be configured with 20ms SS burst set periodicity (279) and SS Burst set start in 2nd 5ms window (281) of the PBCH TTI (271); and

TRP(3) (276) may be configured with 40ms SS burst set periodicity (283) and SS Burst set start in 3rd 5ms window (282) of the PBCH TTI (271).

[0044]

This is to allow an NR-UE within a window of 15ms (280, 281 and 282) to detect available beams for its usage and acquire the minimum system information transmitted from TRP(l) (272), TRP(2) (274), and TRP(3) (276). Furthermore, TRP(l) (272), TRP(2) (274), and TRP(3) (276) or TRP's ID may not be visible to a NR-UE

[0045]

According to the fourth embodiment of the present invention, in order to achieve the same or similar PBCH decoding performance at a UE in initial cell selection state regardless of the configured SS burst set periodicity, the transmission of SSBs within a SS Burst set and transmission of the SS Burst sets within a PBCH TTI are described below.

[0046]

In reference to the exemplary timing diagram (300) illustrated in Fig. 9, for the case where SS Burst set periodicity is 20ms or less (i.e. 10ms and 5ms), the normal SSB is proposed for use. A transmitted normal SSB (e.g. 311) in the SS Burst set start (e.g. 310) within a PBCH TTI (e.g. 301) shall at least comprise a PSS (312), a SSSl (313) and the PBCH's 1st

transmission (314). The repetition of the said SSB (e.g. 321) in the immediately followed second SS burst set (e.g. 320) within the same PBCH TTI (e.g. 301) shall at least comprise the same PSS (312), a SSS2 (323) and PBCH's redundancy (324). The SSS l and SSS2 are generated from the same value taken from the predefined sets of 1000 possible values. The SSSl and SSS2 transmission are alternated on consecutive SS Burst sets (e.g. SSSl for SSBs in the 1st SS Burst set 311, SSS2 for SSBs in the 2nd SS Burst set 321, SSSl for SSBs in the 3rd SS Burst set 331, SSS2 for SSBs in the 4th SS Burst set 341, and so on). The alternations of SSSl and SSS2 transmission shall allow a UE to identify or detect a missed SSB(s) and/or 'SS Burst set periodicity'. A normal SSB is said to be mapped where PSS is mapped on one OFDM symbol, SSSl or SSS2 is mapped on one OFDM symbol, and PBCH or its redundancies is mapped across two OFDM symbols. The scrambling codes selection for use in scrambling the first PBCH and its redundancies shall follow the methods described in the 1 st and 2nd embodiments of the present invention. A UE is allowed to perform the soft combine of the PBCH's 1st transmission (e.g. 314) and one or more PBCH's redundancies (324, 334 and 344) to improve the PBCH decodability. The arrangement of PSS, SSS, and PBCH OFDM symbols within a normal SSB is predefined according to 3GPP RAN-WG1 's agreement, and a predefined arrangement of PSS, SSS, and PBCH OFDM symbols can be down selected from set of [PSS, SSS, PBCH, PBCH] (331. a); [PSS, PBCH, SSS, PBCH] (331.b); [PBCH, PSS, SSS, PBCH] (331.c); [PSS, PBCH, PBCH, SSS] (331.d). According to the present embodiment, for implicit indication of a normal SSB being mapped in the 1st half or 2nd half of a 14-symbols slot or alternatively for implicit indication of a normal SSB being mapped in the even slot number or odd slot number of a paired 7-symbols slots, it is proposed that 2 different arrangements of PPS, SSS, and PBCH are selected for use (i.e. in the replacement or the complement of the explicit use of c₀ ). For example, the arrangement of [PSS, PBCH, SSS, PBCH] (331.b) may be selected for mapping a normal SSB to the 1st half of a 14-symbols slot where the arrangement of [PBCH, PSS, SSS, PBCH] (33 l .c) may be selected for mapping a normal SSB to the 2nd half of a 14-symbols slot. One or more symbol spacing between detected PSS and SSS may indicate the detected SSB in the 1st half of a 14-symbols slot, where detected PSS and SSS on consecutive symbols may indicate the detected SSB in the 2nd half of a 14-symbols slot. The utilisation of implicit indication of a normal SSB being mapped in in the 1 st or 2nd half of a 14-symbols slot, may result in the same SSB time index being used at a TRP in mapping 2 normal SSBs in one slot of 14-symbols. This enables UE to perform soft combine PBCHs of 2 detected SSBs in the same slot for the PBCH

decodability improvement.

[0047]

In reference to Fig. 10 - exemplary timing diagram (350), for the case where SS Burst set periodicity is 40ms, the extended SSB is proposed for use. The proposed extended SSB (e.g. 353) comprises the aforementioned normal SSB (e.g. 358) and additional two OFDM symbols being allocated for the mapping additional PBCH's redundancy (e.g. 357). In the SS Burst set start (e.g. 352) within a PBCH TTI (e.g. 351), extended SSB(s) (e.g. 353) for transmission shall at least comprise a PSS (354), a SSS1 (355), the PBCH's 1st transmission (356), and one PBCH's redundancy (357), where the repetition of the said extended SSB (e.g. 363) in the immediately followed second SS burst set (e.g. 362) within the same PBCH TTI (e.g. 351) shall at least comprise the same PSS (364), a SSS2 (365) and other two PBCH's redundancies (366 and 367). The selection of scrambling codes for use in scrambling the first PBCH transmission and its redundancies shall follow the methods described in the 1st and 2nd embodiment of the present invention. Alternatively, two PBCH's transmissions being mapped on the same extended SSB may use the same scrambling code where scrambling code selection will follow the methods described in the 1 st embodiment of the present invention. A UE is allowed to perform the soft combine of the PBCH's 1 st transmission (356) and one or more PBCH's redundancies (357, 366 and 367) to improve the PBCH decodability.

[0048]

In reference to Fig. 11 - exemplary timing diagram (370), for the case where SS Burst set periodicity is 80ms or larger (e.g. 160ms), the extended SSB is also proposed for use. In the SS Burst set start (e.g. 372) within a PBCH TTI (e.g. 371), extended SSB(s) (e.g. 373) for transmission shall at least comprise a PSS (374), a SSS1 (375), the PBCH's 1 st transmission (376), and one PBCH's redundancy (377). The SS Burst set start is said to repeat in the immediately followed 5ms second window (382), where the repetition of the said extended SSB (e.g. 383) in the repeated SS burst set (e.g. 382) within the same PBCH TTI (e.g. 371) shall at least comprise the same PSS (374), the same SSS1 (375) and other remaining two PBCH's redundancies (386 and 387). The same SSS1 (375) being detected the same SSBs in the consecutive SS Burst sets shall allow a UE to differentiate the SS Burst set periodicity of 80ms or larger from the SS Burst set periodicity of 5ms (refer to 517 in Fig. 14 for visual illustration). The selection of scrambling codes for use in scrambling the first PBCH transmission and its redundancies shall be follow the methods described in the 1 st and 2nd embodiment of the present invention. Alternatively, two PBCH's transmissions being mapped on the same extended SSB may use the same scrambling code where scrambling code selection will follow the methods described in the 1 st embodiment of the present invention. A UE is allowed to perform the soft combine of the PBCH's 1st transmission (376) and one or more PBCH's redundancies (377, 386 and 387) to improve the PBCH decodability.

[0049] According to the present embodiment, there is at most one extended SSB being mapped to one slot of 14 symbols or a pair of two consecutive 7-symbol slots (i.e. consecutive even slot and odd slot). In reference to the exemplary mapping options (390) illustrated in Fig. 12, depending on the time locations of the existing normal SSB, the additional 2 symbols being allocated for PBCH's redundancy mapping in an extended SSB can be the 2 OFDM symbols from the end on a normal SSB (e.g. 390a) or the 2 OFDM symbols at the beginning of a normal SSB (e.g. 390b).

[0050]

For the case, where a normal SSB (392a) is within the first half of a 14-symbol slot or within the even slot of a 7-symbol slot (e.g. 394a), the first 2 symbols of the 14-symbol slot's second half or the first 2 symbols of the odd slot of the associated 7-symbol slot (395 a), are reserved for a PBCH's redundancy mapping. This mapping further mandates one OFDM symbol (i.e. symbol #2 - 396a) for DL transmission and leave three symbols (i.e. symbols #2, 3, and 4 - 397a) for flexible DL/UL configuration i.e. being used for DL transmission or UL transmission and as guard period;

[0051]

For the case, where a normal SSB (392b) is within the second half of a 14-symbol slot or within the odd slot of a 7-symbol slot (e.g. 394b), the last 2 symbols the 14-symbol slot's first half or the last 2 symbols of the even slot of the associated 7-symbol slot (395b), are reserved for PBCH's redundancy mapping. This mapping further mandates three OFDM symbols (i.e. symbol #2, 3 and 4 - 396b) for DL transmission and leave one symbol (i.e. symbols # 4 - 397b) for flexible configuration i.e. being used for DL transmission or UL transmission and as guard period.

[0052]

In comparing the extended SSB mapping options 390a and 390b, option 390a may appear more advantageous than option 390b and it is proposed as preferred option for

implementation. Furthermore, a UE may firstly attempt to detect a normal SSB and monitor the presence of PBCH's DMRS on the additional 2 symbols being allocated for PBCH's redundancy in the case that extended SSB is used.

[0053]

The final embodiment of the present invention is the method for indicating SSBs within a SS Burst set which shall enable the versatile and flexibility in scheduling and mapping SSBs within a periodic SS Burst set without introducing significant (implicit and explicit) signalling overhead where implicit signalling may require UE to perform additional blind detection/decoding. As being mentioned in the background section, 3 GPP RAN-WG1 has - identified that the contents in a NR-MIB (i.e. minimum system information) may include timing information within a radio frame having [0-7] bits for information such as SSB time index [0-6] bits (i.e. b₅b₄b₃b₂b_lb₀ ) and half radio frame timing [0-1] bit (i.e. c₀ Non Patent Literature 11). If the SSB time index [0-6] bits is used to represent indexed SSB number from 0 to 63 within a periodic SS burst set, then the SSB locations/positions has to be predefined independently for the maximum number of SS-blocks within SS burst set (L = 4), (L = 8) and (L = 64) so that upon successful detection and decoding of a SSB with SSB timing index in the valid range, a UE should be able to identify at least OFDM symbol index, slot index in a radio frame and radio frame number. The method where the SSB locations/positions has to be predefined up front for use, shall further restrict a gNB in scheduling the transmission of SS Burst sets among TPRs which form radio interface cloud for wireless connectivity services, and therefore there is a needs for new method in indicating SSBs within a periodic SS Burst set which shall enable a gNB to configure its TRPs to schedule and map a SSB to any possible position being available for use within a periodic SS burst set. The method comprises:

1. With reference to Fig. 13 for illustration, partition a 5ms burst set window (e.g. 401) into 5 consecutive lms-intervals i.e. the 1st Ims-interval (402), the 2nd Ims-interval (403), the 3rd Ims-interval (404), the 4th Ims-interval (405) and the 5th Ims-interval (406). Where 3 bits may be used to explicitly indicate which Ims-interval (i.e. 1 st, 2nd, 3rd, 4th, or 5th) that a SSB is transmitted and received. Alternatively, the 3 bits indicating the 1ms window that a SSB belong to, may be represented implicitly through PBCH DMRS sequence designs i.e. there may be 5 differentiable DMRS sequences forming a periodic sequence of 5ms in length where each is allocated for use on PBCHs in a 1ms window.

e.g. '000' for indicating a SSB in the 1st Ims-interval (402); '001 ' for indicating a SSB in the 2nd Ims-interval (403); '010' indicating a SSB in for the 3rd Ims-interval (404); 'Oi l ' for indicating a SSB in the 4th Ims-interval (405); and ' 100' for indicating a SSB in the 5th

Ims-interval (406)];

2. Depending on the numerology used in transmitting and receiving minimum system information i.e. NR-MIB, there may be 2" slots in a Ims-interval (e.g. 1 slot, 2 slots, 4 slots, 8 slots or 16 slots). Where a slot may comprise 14 OFDM symbols. Slots within a

Ims-interval are further indexed from 0 to (2" - 1 ) e.g. slot#0 (408) and slot#l (409) for ( 2" = 2 ). Thus, additional 4 bits may be used explicitly indicate which slot number in an interval of 1ms that a SSB is transmitted and received; 3. According to 3GPP RAN-WG1 agreement, there are at most two SSBs being mapped in one slot of 14 symbols. From the aforementioned fourth embodiment, SSB in the first half of a 14-symbol slot (410) and SSB in the second half of a 14-symbol (411) can be implicitly indicated using two differentiable PSS and SSS mapping arrangements. Otherwise, one more bit can be used as explicit signalling.

From the above-described method in indicating SSBs within a periodic SS Burst set, successful detecting the PSS and associated SSS of a SSB indicates (implicitly) whether the detected SSB is in the first half or second half of a slot. Full or partial 7 bits being retrieved from the decoding of the PBCH, further indicates (explicitly) the SSB time index, where the 3 bits (e.g. 3 MSB) may indicate which lms-interval that a detected SSB belongs to, and 4 bits (e.g. 4 LSB) may indicate which slot number in the said lms-interval that the SSB is received. The method of using 7-bits to explicitly or hybrid (i.e. explicit and implicit) indicate the SSB time index as being described, allows a gNB to configure its TRP to map a SSB in any possible candidate positions within a SS burst set interval. Where a transmitting SSBs pattern in a periodic SS burst set may uniquely appear distributed (e.g. TRP#0 - 420 and TRP#1 - 430), localised (e.g. TRP#2 - 440), or combination of distributed and localised (e.g. TRP#3 - 450 and TRP#4 - 460). By coordinating the TRPs (e.g. TRP#0, TRP#1, TRP#2, TRP#3 and TRP#4) which form an radio interface cloud, to share the same SS Bust set(s) in transmitting time-multiplexed beam-formed SSBs at a gNB like the example 400, shall further enable a UE in a window of 5ms to acquire minimum system information and possible servicing beams at its location/position from its surrounding servicing TRPs.

[0054]

When the disclosed scrambling code set generation and implementation method for use in the first & second embodiments, introduction of "SS Burst set start" configuration parameter for use in the third embodiment, SSBs transmission method for in the fourth embodiment, and the hybrid scheme for indicating SSBs within a SS Burst set for use in the final embodiment of the present invention, are incorporated for use at a gNB, the gNB can configure/reconfigure one or more its TRPs, on PBCH TTI basis, to change their SS burst set periodicity to facilitate fast network access or to reduce/eliminate system information overhead and save power as being exemplarily illustrated in Fig. 14 and Fig. 15.

[0055]

In reference to Fig. 14, on PBCH TTI basis (501), a gNB may reconfigure its TRP to change SS Burst set periodicity at the beginning of a new PBCH TTI, while keeping the same 'SS Burst set start' (503) i.e. 1st 5ms window is selected as anchored SS burst set window. For example, the currently configured SS burst set periodicity may be 5ms (510) and SS Burst set start in the first 5ms window (503). A gNB may reconfigure the TRP to change from 5ms SS Burst set periodicity ( 10) to other SS Burst set periodicity value which is different from 5, e.g. 10ms SS Burst set periodicity (511), 20ms SS Burst set periodicity (512), 40ms SS Burst set periodicity (513), 80 or 160ms SS Burst set periodicity (514). Where the change in periodicity may be detected through the change in SSSx (e.g. 515 for 10ms as new SS Burst set periodicity and 516 for 20ms as new SS Burst set periodicity);

[0056]

In reference to Fig. 15, on PBCH TTI basis (531), a gNB may reconfigure its TRP to change SS Burst set periodicity at the beginning of a new PBCH TTI, and also changing 'SS Burst set start' where the 2nd, 3rd, or 4th 5ms window may be selected as anchored SS burst set window. For example, the currently configured SS burst set periodicity may be 5ms (540) and SS Burst set start in the first 5ms window which certainly having an SS Burst set in the anchored SS burst set window. A gNB may reconfigure the TRP to change from 5ms SS Burst set periodicity (540) to 10ms SS Burst set periodicity (541) with the new SS Burst set start in the second 5ms window which certainly having an SS Burst set in the anchored SS burst set window. Alternatively, A gNB may reconfigure the TRP to change from 5ms SS Burst set periodicity (540) to 20ms SS Burst set periodicity (542) with the new SS Burst set start in the 4th 5ms window (533) which is the anchored SS burst set window.

[0057]

According the present embodiment, a gNB may optionally indicate 'anchored SS burst set' to assist a UE using 2-bits signalling to assist the detection of SS Burst set periodicity reconfiguration.

[0058]

The novelty of the foregoing embodiments reside in:

'SS Burst set start' configuration parameter and associated method of use to enable inter TRPs interference coordination and management in broadcasting beam-formed minimum system information at 5ms granularity;

'Anchored SS Burst set' configuration parameter and associated method of use to enable dynamic SS burst set periodicity reconfiguration on PBCH TTI basis;

Full or Partial 7-bit SSB time index and associated signalling methods (explicit or hybrid) to enable the flexible mapping of an SSB to any possible candidate SSB locations within a burst set of 5ms, realising the versatile SSB mapping patterns for use in achieving inter TRPs interference coordination in broadcasting beam formed minimum system information to be managed at SSB granularity;

Differentiable first SSB format and second SSB format through the distinguishable PSS and SSS mapping;

Extended SSB and extended SSB formats as well as the method of use in transmitting & receiving SSBs for 40ms, 80ms and 160ms SS burst set periodicities; and

Scramming codes set generation and use in transmitting SSBs for 5ms, 10ms, 20ms, 40ms, 80ms, and 160ms SS burst set periodicities, and that results at reduction in number of blind decoding attempts to be done at a UE hence to optimise processing power at a UE.

[0059]

To recap, the preferred embodiments described in this document relate to method for use in a multi-beams wireless communication system comprising one or more gNBs and multiple associated TRPs providing wireless connectivity services to plurality of user equipment (UEs). In the said system, a gNB may configure its associated TRPs to operate on the same carrier frequency, share the same carrier/operational bandwidth, and have time-synchronised in establishing a cloud radio interface providing beam-formed wireless connectivity services to multiple UEs.

[0060]

The method for use in a multi-beam environment includes the following important features:

The introduction of 'SS Burst set start' configuration parameter for use at a gNB in configuring or reconfiguring its associated TRPs for transmitting minimum system information. In establishing the aforementioned local radio interface cloud, the gNB may configure or reconfigured the TRPs with different SS Burst set starts to enable inter TRPs interference coordination in broadcasting beam-formed minimum system information at 5ms granularity;

The introduction of 'anchored SS Burst set' configuration parameter for use at a gNB and plurality of UEs to enable the dynamic reconfiguration of SS Burst set periodicity at a TRP on PBCH TTI basis. The configured 'anchored SS Burst set' for a TRP indicates the window of 5ms within a PBCH TTI or paired PBCH TTI and within that window there is always a SS burst set for mapping and transmission regardless of the configured or reconfigured SS burst set periodicity. The gNB may use 2-bits for explicit indication of 'anchored SS Burst set' configuration to a UE;

The introduction of 7-bit SSB time index and associated signalling method to enable the flexibility in mapping a SSB in any possible candidate SSB locations within in a SS burst set of 5ms and therefore allowing the inter TRPs interference coordination in broadcasting beam formed minimum system information to be managed at SSB granularity. The 3 -bits among the said 7-bits may be used to indicate implicitly or explicitly whether a SSB is within the 1st, 2nd, 3rd, 4th or 5th 1ms interval of a 5ms burst set interval, and the remaining 4-bits may be used to indicate explicitly the slot index (i.e. 0, 1, .. 15) within the 1ms interval that a SSB belongs to;

The introduction of first SSB format for mapping a normal SSB to the 1 st half of a

14-symbols slot and second SSB format for mapping a normal SSB to the 2nd half of a

14-symbols slot. The first SSB format and second SSB format are differentiable by the distinguishable mapping of PSS and SSS within a SSB i.e. consecutive PSS and SSS mapping vs separated or spacing PSS and SSS mapping, (note: normal SSB is the current 3GPP endorsed structure that has 1 PSS OFDM symbol, 1 SSS OFDM symbol and 2 PBCH OFDM symbols);

The introduction of extended SS Block (SSB) for use with SS burst set periodicity of 40ms, 80ms and 160ms. The proposed extended SSB comprise the normal SSB and additional two OFDM symbols in the same 14-symbols slot for the mapping one PBCH redundancy or time version. This may allow an extended SSB to carry two time varying PBCH redundancies. There are also the first extended SSB format for mapping an extended SSB to the 1st half of a

14-symbols slot and second extended SSB format for mapping an extended SSB to the 2nd half of a 14-symbols slot. There is almost one extended SSB being mapped to one 14-symbol slot;

Method of transmitting extended SSBs for use with SS burst set periodicity of 80ms and 160ms. When SS burst set periodicity of 80ms or 160ms, is configured or reconfigured for SSBs transmission, there is only one scheduled SS burst set per PBCH TTI or per paired PBCH TTIs. There proposes the scheduled SS burst set is retransmitted in the immediately followed window of 5ms. Where the first extended SSB format may be used for mapping of extended SSB in the scheduled SS burst set, and the second extended SSB format may be used for mapping of extended SSB in the retransmitted SS burst set or via versa;

The introduction of 2 SSSX sequences namely SSS1 and SSS2 for use alternatively at

SS Burst set level, where SSS1 may be used in every SSBs within the first burst set of a PBCH TTI to assist the missed detected SSBs at SS Burst set level or implicit indication of SS Burst set periodicity. For SS burst set periodicity of 80ms and 160ms, SSS1 may be used in every SSBs within the scheduled and retransmitted SS burst sets;

Method of generating scrambling codes for use in transmitting PBCH at a TRP, and for further use in reducing number of blind decoding at a UE. In the said method, four (4) scrambling codes may be predefined and further used in generating a unique sequence of 16 scrambling code elements being indexed from 1 to 16. Where each indexed element (i.e. 1, 2, and 3 to 16) in the said sequence is pointing to the scrambling code and the corresponding PBCH redundancy or time version for use in transmitting PBCHs in the corresponding window of 5ms within a PBCH TTI. There is a one to one association between the 4 predefined scrambling codes and the 4 time varying PBCH redundancies. With this method, a UE may perform at most 12 blind decoding attempts on a PBCH to determine the 80ms timing at 5ms granularity when 5ms SS burst set periodicity is configured for SSB transmission. When 10ms, 20ms, 40ms, 80ms or 160ms SS burst set periodicity is configured for SSB transmission, a UE may perform at most 4 blind decoding attempts on a PBCH to determine the 80ms timing at 5ms granularity; and

An alternative to the above scramming code generation is that the 4 predefined scrambling codes may be used for scrambling all four redundancy versions of a PBCH in generating 16 scrambled PBCH redundancy versions (i.e. 4 scrambling codes by 4 redundancies) where each scrambled PBCH redundancy version is associated with the 5ms window within a 80ms PBCH TTI of 5ms. This method may require a UE to perform at most 16 blind decoding attempts on a PBCH to determine the 80ms timing at 5ms granularity regardless SS Bust set periodicity.

[0061]

The foregoing embodiments provide the following advantages:

Provide framework for inter TRPs interference coordination and management in broadcasting beam-formed minimum system information at 5ms granularity and at SSB granularity through the introduction of 'SS Burst set start' configuration parameter and the design of 7-bits SSB time index;

Provide framework for enabling dynamic SS burst set periodicity reconfiguration on PBCH TTI basis through the introduction of 'anchored SS Burst set' configuration parameter;

Introduction of first and second SSB formats for use in mapping normal SSB to a 14-symbol slot enables 2 SSBs being mapped to the same slot having their PBCH carrying the same payload for soft-combine at a UE;

Introduction of extended SSB enables the same or similar minimum PBCH decoding performance being achieved across all configured SS burst set periodicities;

The introduction and usage of SSS1 and SSS2 enable the missing SSB detection and SS burst set periodicity detection; and

The method of generating scrambling codes set helps the reduction of number of blind decoding attempts to be done at a UE.

[0062]

A person skilled in the art will appreciate that many embodiments and variations can be made without departing from the ambit of the present invention. [0063]

In compliance with the statute, the invention has been described in language more or less specific to structural or methodical features. It is to be understood that the invention is not limited to specific features shown or described since the means herein described comprises preferred forms of putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims appropriately interpreted by those skilled in the art.

[0064]

Reference throughout this specification to One embodiment' or 'an embodiment' means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearance of the phrases 'in one embodiment' or 'in an embodiment' in various places throughout this

specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more combinations.

[0065]

For example, the whole or part of the exemplary embodiments disclosed above can be described as, but not limited to, the following supplementary notes.

(Supplementary note 1)

A method for use in a scalable New Radio (NR) system that comprises at least one logical access node (gNB) and a plurality of associated transmission reception points (TRPs) forming virtual radio interface cloud that provides beam formed wireless connectivity services to a plurality of new radio-user equipments (NR-UEs), the method comprising the steps of:

at the gNB, determining a number of beams and beam's configuration to be serviced at each and every associated TRP to achieve desirable radio cloud coverage;

at the gNB, configuring the associated TRPs with a synchronisation Signal (SS) Burst set periodicity, SS Burst set start, and/or anchored SS Burst set;

at the gNB, further configuring the associated TRPs, that can have the same configured SS Burst set start or anchored SS Burst set, with non-overlapping SS Blocks (SSBs) mapping patterns;

at a configured TRP, in a periodically scheduled SS Burst set window within a physical broadcast channel (PBCH) transmission time interval (TTI), transmitting beam-formed SSBs following the determined SSBs mapping patterns, where a SSB can at least comprise PSS, SSSX and PBCH or PBCHs; and at a NR-UE in a local radio interface cloud, performing SSBs detection and associated PBCHs decoding to identify at least available beams for wireless connectivity services at its location, slot boundary, Virtual Cell's identities (IDs) or Virtual cloud radio interface IDs, orthogonal frequency-division multiplexing (OFDM) symbol index, slot index in a radio frame, radio frame number and/or any other minimum system information.

(Supplementary note 2)

The method according to Supplementary note 1, wherein the SS Burst set start value, whether configured or reconfigured, indicates whether the first SS Burst set in a PBCH TTI starts in the 1st, 2nd, 3rd or 4th window of 5ms within the PBCH TTI; or the 1st half of the first radio frame within the PBCH TTI, 2nd half of the first radio frame within the PBCH TTI, 1 st half of the second radio frame within the PBCH TTI, or 2nd half of the second radio frame within the PBCH TTI.

(Supplementary note 3)

The method of Supplementary note 2, wherein a configured SS Burst set start has a default value indicating that the first SS Burst set in a PBCH TTI starts in the 1st 5ms- window of the PBCH TTI or the 1st half of the first radio frame with the PBCH TTI.

(Supplementary note 4)

The method of Supplementary note 3, wherein an initially configured SS Burst set start at a TPvP can change corresponding to the reconfiguration of the SS Burst set periodicity of that TRP.

(Supplementary note 5)

The method according to Supplementary note 1 or 2, wherein in establishing the local radio interface cloud, the plurality of TRPs are configured to: operate on the same carrier frequency, share the same carrier/operational bandwidth, and have a synchronised SFN; and/or are further configured or reconfigured with different SS Burst set starts to enable inter TRPs interference coordination in broadcasting beam-formed minimum system information at 5ms granularity.

(Supplementary note 6)

The method according to Supplementary note 1, where a configured anchored SS Burst set value indicates whether the anchored SS Burst set occurs in the 1st , 2nd , 3rd or 4th window of 5ms in a PBCH TTI.

(Supplementary note 7)

The method of Supplementary note 6, wherein in a configured anchored SS Burst set window of 5ms at a TRP, there is always a SS burst set being scheduled for transmission regardless of the configured or reconfigured SS Burst set periodicity at that TRP.

(Supplementary note 8)

The method of Supplementary note 6, wherein a configured anchored SS Burst set of a TRP has the same value as the value of the initially configured SS Burst set start or the corresponded SS Burst set start resulting from reconfiguration of SS Burst set periodicity of that TRP.

(Supplementary note 9)

The method of Supplementary note 8, wherein a TRP uses 2-bits to explicitly indicate the configured anchored SS Burst set to UEs.

(Supplementary note 10)

The method according to Supplementary note 1 , wherein a TRP is configured or reconfigured with the SS Burst set periodicity of 20ms or less for periodic SS Burst set transmission, and the TRP transmits at most 2 normal SSBs per 14-symbols slot using normal SSB formats.

(Supplementary note 11)

The method of Supplementary note 10, wherein a first normal SSB format for mapping a normal SSB in the first half of a 14-symbol slot and a second normal SSB format for mapping a normal SSB in the second half of a 14-symbol slot are predefined for common use with subcarrier spacing (SCS) including 15kHz, 30kHz, 60kHz and 120kHz.

(Supplementary note 12)

The method of Supplementary note 11, where the first normal SSB format and the second normal SSB format are differentiated by the different arrangement of PSS OFDM and the associated SSSX OFDM symbols of a SSB, or PSS OFDM and associated SSS OFDM symbols are consecutive compared with PSS OFDM and the associated SSS OFDM symbols being separated by one or two PBCH OFDM symbols.

(Supplementary note 13)

The method of Supplementary note 12, wherein two normal SSBs are mapped in 1 slot of 14-symbols and share the same SSB timing index which further leads to their associated PBCHs carrying identical PBCH's payload.

(Supplementary note 14)

The method according to Supplementary note 1, wherein a TRP is configured or reconfigured with the SS Burst set periodicity of 40ms or larger for periodic SS Burst set transmission, and the TRP maps at most one extended SSB to a slot of 14 symbols using the extended SSB formats. (Supplementary note 15)

The method of Supplementary note 14, wherein a first extended SSB format comprises a first normal SSB format with additional 2 OFDM symbols and preferably the first 2 OFDM symbols in the second half of the same 14-symbol slot being reserved for the mapping of a PBCH's retransmission or time version, and a second extended SSB format comprises the second normal SSB format with additional 2 OFDM symbols and preferably the last 2 OFDM symbols in the first half of the same 14-symbol slot being reserved for the mapping of a PBCH's retransmission or time version.

(Supplementary note 16)

The method of Supplementary note 15, wherein a TRP is configured or reconfigured with SS Burst set periodicity of 80ms or larger for periodic SS Burst set transmission within a PBCH TTI of 80ms, the TRP transmitting only one scheduled SS Burst set in a window indicated by the configured SS Burst set start, and further retransmits that SS Burst set in the immediately followed window of 5ms.

(Supplementary note 17)

The method of Supplementary note 15, wherein a TRP uses the first extended SSB format for mapping and transmitting extended SSBs within the scheduled SS Burst set, and uses the second extended SSB format for mapping and transmitting extended SSBs within the retransmitted SS Burst set.

(Supplementary note 18)

The method of Supplementary note 17, wherein PBCHs of an extended SSB being transmitted within the scheduled SS Burst set and PBCHs of the associated extended SSB being transmitted within the retransmitted SS Burst set, carry the same payload assisting a soft combine.

(Supplementary note 19)

The method according to Supplementary note 1, wherein in a periodically scheduled SS burst set window, a determined SSBs mapping pattern for beam-formed SSBs transmission at a TRP appears distributed, localised, or a combination of localised and distributed, and the TRP uses explicit signaling method or hybrid signaling method to indicate a timing position of a SSB within a periodically scheduled burst set.

(Supplementary note 20)

The method of Supplementary note 19, wherein 3-bits are used to indicate whether a SSB is within the 1st , 2nd , 3rd, 4th or 5th window of 1ms within a periodically scheduled SS burst set of 5ms, and a TRP explicitly signals the 3-bits information to UEs or implicitly indicates through predefined signatures for detection at UEs.

(Supplementary note 21)

The method of Supplementary note 20, wherein the TRP uses another 4-bits for explicit indication of the slot indexes within the 1ms window on which a S SB is mapped.

(Supplementary note 22)

The method of Supplementary note 19, wherein the utilisation of distributed pattern, localised pattern, or the combination of localised and distributed pattern in creating a

non-overlapping SSBs pattern, allowing a plurality of TRPs to share one or more 5ms window within a PBCH TTI in transmitting their beam-formed SSBs, is said to enable inter TRPs interference coordination in broadcasting beam formed minimum system information at SSB granularity.

(Supplementary note 23)

The method according to Supplementary note 1, wherein two differentiable SSSX sequences namely SSSl and SSS2 are alternatively used at a periodic SS Burst set level within a PBCH TTI, and SSS 1 is selected for use in every SSB within the first SS Burst set of a PBCH TTI.

(Supplementary note 24)

The method of Supplementary note 23, wherein SSSl and SSS2 are generated from the same value taken from predefined sets of 1000 possible values.

(Supplementary note 25)

The method of Supplementary note 24, wherein the set of values applicable for SSS2 is different from the set of value applicable for SSS l to allow for consecutive burst set detection, or burst set periodicity, or half of radio frame timing detection in the case of 5ms burst set periodicity from the reception of single SSS.

(Supplementary note 26)

The method of Supplementary note 25, wherein SSSl is selected for use in every SSBs within the scheduled SS Burst set and within the repeated SS Burst set in a PBCH TTI to allow for repeated burst set detection.

(Supplementary note 27)

The method according to Supplementary note 1 , wherein a set of four (4) differentiable scrambling codes for use on PBCH's scrambling are predefined to implicitly indicate 80ms timing at 5ms granularity or the 3 least significant bits (LSB) of SFN at half radio frame timing. (Supplementary note 28)

The method of Supplementary note 27, wherein the 4 predefined scrambling codes are used as input to a first method that generates a unique sequence of 16 scrambling code elements being indexed from 1 to 16.

(Supplementary note 29)

The method of Supplementary note 28, wherein each indexed element in the said sequence points to the scrambling code and the corresponding PBCH redundancy or time version for use in transmitting PBCHs in the corresponding window of 5ms within a PBCH TTI.

(Supplementary note 30)

The method of Supplementary note 29, wherein the first, second, third and fourth predefined scrambling code correspond to first, second, third and fourth redundancy or time versions of a PBCH respectively.

(Supplementary note 31)

The method of Supplementary note 30, except the case of 5ms burst set periodicity configuration, wherein a UE performs at most 4 blind decoding attempts on a PBCH and further uses detected SSSX to determine the 80ms timing at 5ms granularity.

(Supplementary note 32)

The method of Supplementary note 31 , for the case of 5ms burst set periodicity configuration, wherein a UE performs at most 4 blind decoding attempts on a PBCH and further performs blind decoding attempts on the same SSB in at most 2 neighbouring SS Bust sets to determine the 80ms timing at 5ms granularity.

(Supplementary note 33)

The method according to Supplementary note 27, wherein in a second method, the 4 predefined scrambling codes are used for scrambling all four redundancy versions of a PBCH in generating 16 scrambled PBCH redundancy or time versions.

(Supplementary note 34)

The method of Supplementary note 33, wherein the first redundancy version of a PBCH being scrambled with the first, second, third and fourth predefined scrambling codes is for a first

20ms window of a PBCH TTI at 5ms window granularity.

(Supplementary note 35)

The method of Supplementary note 34, wherein the second redundancy version of a PBCH being scrambled with the first, second, third and fourth predefined scrambling codes is for the second 20ms window of a PBCH TTI at 5ms window granularity.

(Supplementary note 36)

The method of Supplementary note 35, wherein the third redundancy version of a

PBCH being scrambled with the first, second, third and fourth predefined scrambling codes is for the third 20ms window of a PBCH TTI at 5ms window granularity.

(Supplementary note 37)

The method of Supplementary note 36, wherein the fourth redundancy version of a PBCH being scrambled with the first, second, third and fourth predefined scrambling codes is for the fourth 20ms window of a PBCH TTI at 5ms window granularity.

(Supplementary note 38)

The method of Supplementary note 1, regardless of the configured SS Burst set periodicity, wherein a UE performs at most 16 blind decoding attempts on a PBCH to determine 80ms timing at 5ms granularity.

[0066]

This application is based upon and claims the benefit of priority from Australian provisional patent application No. 2017902847, filed on July 20, 2017, the disclosure of which is incorporated herein in its entirety by reference.

Reference Signs List

[0067]

10 wireless communication system

11, 12, 13, 14 TRP

20, 21, 22, 23 UE

30 gNB

Claims

[Claim 1]

at a configured TRP, in a periodically scheduled SS Burst set window within a physical broadcast channel (PBCH) transmission time interval (TTI), transmitting beam-formed SSBs following the determined SSBs mapping patterns, where a SSB can at least comprise PSS, SSSX and PBCH or PBCHs; and

at a NR-UE in a local radio interface cloud, performing SSBs detection and associated PBCHs decoding to identify at least available beams for wireless connectivity services at its location, slot boundary, Virtual Cell's identities (IDs) or Virtual cloud radio interface IDs, orthogonal frequency-division multiplexing (OFDM) symbol index, slot index in a radio frame, radio frame number and/or any other minimum system information.

[Claim 2]

The method according to claim 1, wherein the SS Burst set start value, whether configured or reconfigured, indicates whether the first SS Burst set in a PBCH TTI starts in the 1st, 2nd, 3rd or 4th window of 5ms within the PBCH TTI; or the 1st half of the first radio frame within the PBCH TTI, 2nd half of the first radio frame within the PBCH TTI, 1st half of the second radio frame within the PBCH TTI, or 2nd half of the second radio frame within the PBCH TTI.

[Claim 3]

The method of claim 2, wherein a configured SS Burst set start has a default value indicating that the first SS Burst set in a PBCH TTI starts in the 1st 5ms-window of the PBCH TTI or the 1 st half of the first radio frame with the PBCH TTI.

[Claim 4]

The method of claim 3, wherein an initially configured SS Burst set start at a TRP can change corresponding to the reconfiguration of the SS Burst set periodicity of that TRP.

[Claim 5]

The method according to claim 1 or 2, wherein in establishing the local radio interface cloud, the plurality of TRPs are configured to: operate on the same carrier frequency, share the same carrier/operational bandwidth, and have a synchronised SFN; and/or are further configured or reconfigured with different SS Burst set starts to enable inter TRPs interference coordination in broadcasting beam-formed minimum system information at 5 ms granularity.

[Claim 6]

The method according to claim 1, where a configured anchored SS Burst set value indicates whether the anchored SS Burst set occurs in the 1st , 2nd , 3rd or 4th window of 5ms in a PBCH TTI.

[Claim 7]

The method of claim 6, wherein in a configured anchored SS Burst set window of 5ms at a TRP, there is always a SS burst set being scheduled for transmission regardless of the configured or reconfigured SS Burst set periodicity at that TRP.

[Claim 8]

The method of claim 6, wherein a configured anchored SS Burst set of a TRP has the same value as the value of the initially configured SS Burst set start or the corresponded SS Burst set start resulting from reconfiguration of SS Burst set periodicity of that TRP.

[Claim 9]

The method of claim 8, wherein a TRP uses 2-bits to explicitly indicate the configured anchored SS Burst set to UEs.

[Claim 10] The method according to claim 1 , wherein a TRP is configured or reconfigured with the SS Burst set periodicity of 20ms or less for periodic SS Burst set transmission, and the TRP transmits at most 2 normal SSBs per 14-symbols slot using normal SSB formats.

[Claim 11]

The method of claim 10, wherein a first normal SSB format for mapping a normal SSB in the first half of a 14-symbol slot and a second normal SSB format for mapping a normal SSB in the second half of a 14-symbol slot are predefined for common use with subcarrier spacing (SCS) including 15kHz, 30kHz, 60kHz and 120kHz.

[Claim 12]

The method of claim 11 , where the first normal SSB format and the second normal SSB format are differentiated by the different arrangement of PSS OFDM and the associated SSSX OFDM symbols of a SSB, or PSS OFDM and associated SSS OFDM symbols are consecutive compared with PSS OFDM and the associated SSS OFDM symbols being separated by one or two PBCH OFDM symbols.

[Claim 13]

The method of claim 12, wherein two normal SSBs are mapped in 1 slot of 14-symbols and share the same SSB timing index which further leads to their associated PBCHs carrying identical PBCH's payload.

[Claim 14]

The method according to claim 1, wherein a TRP is configured or reconfigured with the SS Burst set periodicity of 40ms or larger for periodic SS Burst set transmission, and the TRP maps at most one extended SSB to a slot of 14 symbols using the extended SSB formats.

[Claim 15]

The method of claim 14, wherein a first extended SSB format comprises a first normal SSB format with additional 2 OFDM symbols and preferably the first 2 OFDM symbols in the second half of the same 14-symbol slot being reserved for the mapping of a PBCH's

retransmission or time version, and a second extended SSB format comprises the second normal SSB format with additional 2 OFDM symbols and preferably the last 2 OFDM symbols in the first half of the same 14-symbol slot being reserved for the mapping of a PBCH's retransmission or time version.

[Claim 16]

The method of claim 15, wherein a TRP is configured or reconfigured with SS Burst set periodicity of 80ms or larger for periodic SS Burst set transmission within a PBCH TTI of 80ms, the TRP transmitting only one scheduled SS Burst set in a window indicated by the configured SS Burst set start, and further retransmits that SS Burst set in the immediately followed window of 5ms.

[Claim 17]

The method of claim 15, wherein a TRP uses the first extended SSB format for mapping and transmitting extended SSBs within the scheduled SS Burst set, and uses the second extended SSB format for mapping and transmitting extended SSBs within the retransmitted SS Burst set.

[Claim 18]

The method of claim 17, wherein PBCHs of an extended SSB being transmitted within the scheduled SS Burst set and PBCHs of the associated extended SSB being transmitted within the retransmitted SS Burst set, carry the same payload assisting a soft combine.

[Claim 19]

The method according to claim 1, wherein in a periodically scheduled SS burst set window, a determined SSBs mapping pattern for beam-formed SSBs transmission at a TRP appears distributed, localised, or a combination of localised and distributed, and the TRP uses explicit signaling method or hybrid signaling method to indicate a timing position of a SSB within a periodically scheduled burst set.

[Claim 20]

The method of claim 19, wherein 3 -bits are used to indicate whether a SSB is within the 1st , 2nd , 3rd, 4th or 5th window of 1ms within a periodically scheduled SS burst set of 5ms, and a TRP explicitly signals the 3 -bits information to UEs or implicitly indicates through predefined signatures for detection at UEs.

[Claim 21]

The method of claim 20, wherein the TRP uses another 4-bits for explicit indication of the slot indexes within the 1ms window on which a SSB is mapped.

[Claim 22]

The method of claim 19, wherein the utilisation of distributed pattern, localised pattern, or the combination of localised and distributed pattern in creating a non-overlapping SSBs pattern, allowing a plurality of TRPs to share one or more 5ms window within a PBCH TTI in transmitting their beam- formed SSBs, is said to enable inter TRPs interference coordination in broadcasting beam formed minimum system information at SSB granularity.

[Claim 23]

The method according to claim 1, wherein two differentiable SSSX sequences namely SSSl and SSS2 are alternatively used at a periodic SS Burst set level within a PBCH TTI, and SSSl is selected for use in every SSB within the first SS Burst set of a PBCH TTI.

[Claim 24]

The method of claim 23, wherein SSSl and SSS2 are generated from the same value taken from predefined sets of 1000 possible values.

[Claim 25]

The method of claim 24, wherein the set of values applicable for SSS2 is different from the set of value applicable for SSS l to allow for consecutive burst set detection, or burst set periodicity, or half of radio frame timing detection in the case of 5ms burst set periodicity from the reception of single SSS.

[Claim 26]

The method of claim 25, wherein SSSl is selected for use in every SSBs within the scheduled SS Burst set and within the repeated SS Burst set in a PBCH TTI to allow for repeated burst set detection.

[Claim 27]

The method according to claim 1 , wherein a set of four (4) differentiable scrambling codes for use on PBCH's scrambling are predefined to implicitly indicate 80ms timing at 5ms granularity or the 3 least significant bits (LSB) of SFN at half radio frame timing.

[Claim 28]

The method of claim 27, wherein the 4 predefined scrambling codes are used as input to a first method that generates a unique sequence of 16 scrambling code elements being indexed from 1 to 16.

[Claim 29]

The method of claim 28, wherein each indexed element in the said sequence points to the scrambling code and the corresponding PBCH redundancy or time version for use in transmitting PBCHs in the corresponding window of 5ms within a PBCH TTI.

[Claim 30]

The method of claim 29, wherein the first, second, third and fourth predefined scrambling code correspond to first, second, third and fourth redundancy or time versions of a PBCH respectively.

[Claim 31]

The method of claim 30, except the case of 5ms burst set periodicity configuration, wherein a UE performs at most 4 blind decoding attempts on a PBCH and further uses detected SSSX to determine the 80ms timing at 5ms granularity.

[Claim 32]

The method of claim 31 , for the case of 5ms burst set periodicity configuration, wherein a UE performs at most 4 blind decoding attempts on a PBCH and further performs blind decoding attempts on the same SSB in at most 2 neighbouring SS Bust sets to determine the 80ms timing at 5ms granularity.

[Claim 33]

The method according to claim 27, wherein in a second method, the 4 predefined scrambling codes are used for scrambling all four redundancy versions of a PBCH in generating 16 scrambled PBCH redundancy or time versions.

[Claim 34]

The method of claim 33, wherein the first redundancy version of a PBCH being scrambled with the first, second, third and fourth predefined scrambling codes is for a first 20ms window of a PBCH TTI at 5ms window granularity.

[Claim 35]

The method of claim 34, wherein the second redundancy version of a PBCH being scrambled with the first, second, third and fourth predefined scrambling codes is for the second 20ms window of a PBCH TTI at 5ms window granularity.

[Claim 36]

The method of claim 35, wherein the third redundancy version of a PBCH being scrambled with the first, second, third and fourth predefined scrambling codes is for the third 20ms window of a PBCH TTI at 5ms window granularity.

[Claim 37]

The method of claim 36, wherein the fourth redundancy version of a PBCH being scrambled with the first, second, third and fourth predefined scrambling codes is for the fourth 20ms window of a PBCH TTI at 5ms window granularity.

[Claim 38]

The method of claim 1, regardless of the configured SS Burst set periodicity, wherein a UE performs at most 16 blind decoding attempts on a PBCH to determine 80ms timing at 5ms granularity.