WO2025166473A1

WO2025166473A1 - Systems and methods for performing common channel monitoring

Info

Publication number: WO2025166473A1
Application number: PCT/CN2024/075906
Authority: WO
Inventors: Wei Cao; Nan Zhang; Ziyang Li; Linxi HU; Junli Li
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2024-02-05
Filing date: 2024-02-05
Publication date: 2025-08-14
Anticipated expiration: 2026-08-05

Abstract

Presented are systems and methods for performing common channel monitoring. A wireless communication device can determine a resource for monitoring a downlink common channel. The wireless communication device can perform monitoring of the DL common channel according to the determination.

Description

SYSTEMS AND METHODS FOR PERFORMING COMMON CHANNEL MONITORING

TECHNICAL FIELD

The disclosure relates generally to wireless communications, including but not limited to systems and methods for performing common channel monitoring.

BACKGROUND

Coverage is a key consideration in cellular network deployments. With the rise of interconnected devices, there is a growing focus on effective device communication. The current 3GPP standards, spanning from 3G to 5G and beyond, focus on the importance of seamless communication among various devices, from smart home devices to wearable devices. Communication via satellite is one of the typical scenarios of non-terrestrial networks in 3GPP 5G standardization. In 6G, satellites will play an increasingly key role in providing coverage and resilience. In industrial settings, the complexity of tasks often requires collaboration. This calls for several cooperative operational management systems, with the aim of creating workgroups and managing different types of devices to complete the required tasks.

SUMMARY

The example embodiments disclosed herein are directed to solving the issues relating to one or multiple of the problems presented in the prior art, as well as providing additional features that will become readily apparent by reference to the following detailed description when taken in conjunction with the accompany drawings. In accordance with various embodiments, example systems, methods, devices and computer program products are disclosed herein. It is understood, however, that these embodiments are presented by way of example and are not limiting, and it will be apparent to those of ordinary skill in the art who read the present disclosure that various modifications to the disclosed embodiments can be made while remaining within the scope of this disclosure.

At least one aspect is directed to a system, method, apparatus, or a computer-readable medium. A wireless communication device (e.g., UE) can determine a resource (e.g., time domain resource, which corresponds to periodicity, for instance) for monitoring a downlink (DL) common channel. In some implementations, the wireless communication device can perform the monitoring of the DL common channel according to the determination. In certain implementations, the resource for monitoring the DL common channel can be a periodicity (e.g., periodic time domain resource (s) ) determined according to a periodicity for monitoring a synchronization signal block (SSB) . In some implementations, the DL common channel can exclude the SSB (e.g., in time domain and/or frequency domain) .

In certain implementations, the resource (e.g., time domain resource, which corresponds to periodicity, for instance) for monitoring the DL common channel resource can be determined by at least one of the following: one or more periodicities for monitoring the DL common channel that are indicated by a radio resource control (RRC) signaling received by the wireless communication device; or one or more periodicities for monitoring the DL common channel that are determined by detection of the wireless communication device, where the detection can be performed by the wireless communication device according to a candidate periodicity value in a set of candidate periodicity values. In certain implementations, the wireless communication device that is in radio resource control (RRC) connected state in a cell can receive/obtain/acquire a periodicity for monitoring the DL common channel in another cell via an RRC signaling (in some implementations, the RRC signal may also include the handover signal) .

In certain implementations, the wireless communication device can determine at least one of the following: a frame (e.g., corresponding to SFN_c) or a periodicity for monitoring the DL common channel according to a value of a synchronization signal block (SSB) offset (k_ssb) . In certain implementations, the wireless communication device can determine a frame with a system frame number (SFN_c) satisfying:

ifor

if

where Index_periodicity is determined according to the value of k_ssb; μ is a subcarrier spacing (SCS) scaling factor based on a reference SCS; is a number of slots in a frame based on an SCS defined by μ; O and M are determined by configuration; and i is a corresponding SSB index.

In certain implementations, the wireless communication device can determine at least one of the following: a frame or a periodicity for monitoring the DL common channel according to a value of a defined field (e.g., bit flag is 1) in a master information block (MIB) . In certain implementations, the wireless communication device can determine whether a resource for monitoring the DL common channel (e.g., SIB1) is invalid. In some implementations, the DL common channel may include a system information block 1 (SIB1) . In some implementations, the resource may include a frequency resource, a time resource, or a time and frequency resource.

In certain implementations, the wireless communication device can determine that the resource is invalid when all bits in a bitmap of the frequency domain resource assignment field in DCI format 1_0 are set to zeros. In certain implementations, the wireless communication device can determine that the resource is invalid when the resource at least partially overlaps with a resource of a corresponding synchronization signal block (SSB) or a corresponding type0 physical downlink control channel (PDCCH) common search space (CSS) set. In certain implementations, the DL common channel may include at least one of the following: a synchronization signal block (SSB) ; a type0 physical downlink control channel (PDCCH) common search space (CSS) set; or system information block 1 (SIB1) .

In some implementations, the system of the technical solution disclosed herein can support performing common channel monitoring, according to at least one of the following example configurations (e.g., features or solutions) :

● Example configuration: Monitoring Common Channel Indication/Configuration.

BRIEF DESCRIPTION OF THE DRAWINGS

Various example embodiments of the present solution are described in detail below with reference to the following figures or drawings. The drawings are provided for purposes of illustration only and merely depict example embodiments of the present solution to facilitate the reader’s understanding of the present solution. Therefore, the drawings should not be considered limiting of the breadth, scope, or applicability of the present solution. It should be noted that for clarity and ease of illustration, these drawings are not necessarily drawn to scale.

FIG. 1 illustrates an example cellular communication network in which techniques disclosed herein may be implemented, in accordance with an embodiment of the present disclosure;

FIG. 2 illustrates a block diagram of an example base station and a user equipment device, in accordance with some embodiments of the present disclosure;

FIG. 3 illustrates an example arrangement/configuration of a satellite footprint, in accordance with some embodiments of the present disclosure;

FIG. 4 illustrates an example implementation of SSBs and Type0-PDCCH CSS sets within the time domain, in accordance with some embodiments of the present disclosure;

FIG. 5 illustrates an example feature of common channel monitoring, in accordance with some embodiments of the present disclosure;

FIG. 6 illustrates an example implementation of SSB, CORESET0, and SIB1 across time-frequency resource (s) , in accordance with some embodiments of the present disclosure; and

FIG. 7 illustrates a flow diagram of an example method for performing common channel monitoring, in accordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION

1. Mobile Communication Technology and Environment

FIG. 1 illustrates an example wireless communication network, and/or system, 100 in which techniques disclosed herein may be implemented, in accordance with an embodiment of the present disclosure. In the following discussion, the wireless communication network 100 may be any wireless network, such as a cellular network or a narrowband Internet of things (NB-IoT) network, and is herein referred to as “network 100. ” Such an example network 100 includes a base station 102 (hereinafter “BS 102” ; also referred to as wireless communication node) and a user equipment device 104 (hereinafter “UE 104” ; also referred to as wireless communication device) that can communicate with each other via a communication link 110 (e.g., a wireless communication channel) , and a cluster of cells 126, 130, 132, 134, 136, 138 and 140 overlaying a geographical area 101. In FIG. 1, the BS 102 and UE 104 are contained within a respective geographic boundary of cell 126. Each of the other cells 130, 132, 134, 136, 138 and 140 may include at least one base station operating at its allocated bandwidth to provide adequate radio coverage to its intended users.

For example, the BS 102 may operate at an allocated channel transmission bandwidth to provide adequate coverage to the UE 104. The BS 102 and the UE 104 may communicate via a downlink radio frame 118, and an uplink radio frame 124 respectively. Each radio frame 118/124 may be further divided into sub-frames 120/127 which may include data symbols 122/128. In the present disclosure, the BS 102 and UE 104 are described herein as non-limiting examples of “communication nodes, ” generally, which can practice the methods disclosed herein. Such communication nodes may be capable of wireless and/or wired communications, in accordance with various embodiments of the present solution.

FIG. 2 illustrates a block diagram of an example wireless communication system 200 for transmitting and receiving wireless communication signals (e.g., OFDM/OFDMA signals) in accordance with some embodiments of the present solution. The system 200 may include components and elements configured to support known or conventional operating features that need not be described in detail herein. In one illustrative embodiment, system 200 can be used to communicate (e.g., transmit and receive) data symbols in a wireless communication environment such as the wireless communication environment 100 of FIG. 1, as described above.

System 200 generally includes a base station 202 (hereinafter “BS 202” ) and a user equipment device 204 (hereinafter “UE 204” ) . The BS 202 includes a BS (base station) transceiver module 210, a BS antenna 212, a BS processor module 214, a BS memory module 216, and a network communication module 218, each module being coupled and interconnected with one another as necessary via a data communication bus 220. The UE 204 includes a UE (user equipment) transceiver module 230, a UE antenna 232, a UE memory module 234, and a UE processor module 236, each module being coupled and interconnected with one another as necessary via a data communication bus 240. The BS 202 communicates with the UE 204 via a communication channel 250, which can be any wireless channel or other medium suitable for transmission of data as described herein.

As would be understood by persons of ordinary skill in the art, system 200 may further include any number of modules other than the modules shown in FIG. 2. Those skilled in the art will understand that the various illustrative blocks, modules, circuits, and processing logic described in connection with the embodiments disclosed herein may be implemented in hardware, computer-readable software, firmware, or any practical combination thereof. To clearly illustrate this interchangeability and compatibility of hardware, firmware, and software, various illustrative components, blocks, modules, circuits, and steps are described generally in terms of their functionality. Whether such functionality is implemented as hardware, firmware, or software can depend upon the particular application and design constraints imposed on the overall system. Those familiar with the concepts described herein may implement such functionality in a suitable manner for each particular application, but such implementation decisions should not be interpreted as limiting the scope of the present disclosure.

In accordance with some embodiments, the UE transceiver 230 may be referred to herein as an “uplink” transceiver 230 that includes a radio frequency (RF) transmitter and a RF receiver each comprising circuitry that is coupled to the antenna 232. A duplex switch (not shown) may alternatively couple the uplink transmitter or receiver to the uplink antenna in time duplex fashion. Similarly, in accordance with some embodiments, the BS transceiver 210 may be referred to herein as a “downlink” transceiver 210 that includes a RF transmitter and a RF receiver each comprising circuity that is coupled to the antenna 212. A downlink duplex switch may alternatively couple the downlink transmitter or receiver to the downlink antenna 212 in time duplex fashion. The operations of the two transceiver modules 210 and 230 may be coordinated in time such that the uplink receiver circuitry is coupled to the uplink antenna 232 for reception of transmissions over the wireless transmission link 250 at the same time that the downlink transmitter is coupled to the downlink antenna 212. Conversely, the operations of the two transceivers 210 and 230 may be coordinated in time such that the downlink receiver is coupled to the downlink antenna 212 for reception of transmissions over the wireless transmission link 250 at the same time that the uplink transmitter is coupled to the uplink antenna 232. In some embodiments, there is close time synchronization with a minimal guard time between changes in duplex direction.

The UE transceiver 230 and the base station transceiver 210 are configured to communicate via the wireless data communication link 250, and cooperate with a suitably configured RF antenna arrangement 212/232 that can support a particular wireless communication protocol and modulation scheme. In some illustrative embodiments, the UE transceiver 210 and the base station transceiver 210 are configured to support industry standards such as the Long Term Evolution (LTE) and emerging 5G standards, and the like. It is understood, however, that the present disclosure is not necessarily limited in application to a particular standard and associated protocols. Rather, the UE transceiver 230 and the base station transceiver 210 may be configured to support alternate, or additional, wireless data communication protocols, including future standards or variations thereof.

In accordance with various embodiments, the BS 202 may be an evolved node B (eNB) , a serving eNB, a target eNB, a femto station, or a pico station, for example. In some embodiments, the UE 204 may be embodied in various types of user devices such as a mobile phone, a smart phone, a personal digital assistant (PDA) , tablet, laptop computer, wearable computing device, etc. The processor modules 214 and 236 may be implemented, or realized, with a general purpose processor, a content addressable memory, a digital signal processor, an application specific integrated circuit, a field programmable gate array, any suitable programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof, designed to perform the functions described herein. In this manner, a processor may be realized as a microprocessor, a controller, a microcontroller, a state machine, or the like. A processor may also be implemented as a combination of computing devices, e.g., a combination of a digital signal processor and a microprocessor, a plurality of microprocessors, one or multiple microprocessors in conjunction with a digital signal processor core, or any other such configuration.

Furthermore, the steps of a method or algorithm described in connection with the embodiments disclosed herein may be embodied directly in hardware, in firmware, in a software module executed by processor modules 214 and 236, respectively, or in any practical combination thereof. The memory modules 216 and 234 may be realized as RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. In this regard, memory modules 216 and 234 may be coupled to the processor modules 210 and 230, respectively, such that the processors modules 210 and 230 can read information from, and write information to, memory modules 216 and 234, respectively. The memory modules 216 and 234 may also be integrated into their respective processor modules 210 and 230. In some embodiments, the memory modules 216 and 234 may each include a cache memory for storing temporary variables or other intermediate information during execution of instructions to be executed by processor modules 210 and 230, respectively. Memory modules 216 and 234 may also each include non-volatile memory for storing instructions to be executed by the processor modules 210 and 230, respectively.

The network communication module 218 generally represents the hardware, software, firmware, processing logic, and/or other components of the base station 202 that enable bi-directional communication between base station transceiver 210 and other network components and communication nodes configured to communicate with the base station 202. For example, network communication module 218 may be configured to support internet or WiMAX traffic. In a typical deployment, without limitation, network communication module 218 provides an 802.3 Ethernet interface such that base station transceiver 210 can communicate with a conventional Ethernet based computer network. In this manner, the network communication module 218 may include a physical interface for connection to the computer network (e.g., Mobile Switching Center (MSC) ) . The terms “configured for, ” “configured to” and conjugations thereof, as used herein with respect to a specified operation or function, refer to a device, component, circuit, structure, machine, signal, etc., that is physically constructed, programmed, formatted and/or arranged to perform the specified operation or function.

The Open Systems Interconnection (OSI) Model (referred to herein as, “open system interconnection model” ) is a conceptual and logical layout that defines network communication used by systems (e.g., wireless communication device, wireless communication node) open to interconnection and communication with other systems. The model is broken into seven subcomponents, or layers, each of which represents a conceptual collection of services provided to the layers above and below it. The OSI Model also defines a logical network and effectively describes computer packet transfer by using different layer protocols. The OSI Model may also be referred to as the seven-layer OSI Model or the seven-layer model. In some embodiments, a first layer may be a physical layer. In some embodiments, a second layer may be a Medium Access Control (MAC) layer. In some embodiments, a third layer may be a Radio Link Control (RLC) layer. In some embodiments, a fourth layer may be a Packet Data Convergence Protocol (PDCP) layer. In some embodiments, a fifth layer may be a Radio Resource Control (RRC) layer. In some embodiments, a sixth layer may be a Non-Access Stratum (NAS) layer or an Internet Protocol (IP) layer, and the seventh layer being the other layer.

Various example embodiments of the present solution are described below with reference to the accompanying figures to enable a person of ordinary skill in the art to make and use the present solution. As would be apparent to those of ordinary skill in the art, after reading the present disclosure, various changes or modifications to the examples described herein can be made without departing from the scope of the present solution. Thus, the present solution is not limited to the example embodiments and applications described and illustrated herein. Additionally, the specific order or hierarchy of steps in the methods disclosed herein are merely example approaches. Based upon design preferences, the specific order or hierarchy of steps of the disclosed methods or processes can be re-arranged while remaining within the scope of the present solution. Thus, those of ordinary skill in the art will understand that the methods and techniques disclosed herein present various steps or acts in a sample order, and the present solution is not limited to the specific order or hierarchy presented unless expressly stated otherwise.

2. Systems and Methods for Performing Common Channel Monitoring

As the new radio (NR) system transitions to higher frequencies, propagation conditions may deteriorate compared to those at lower frequencies, exacerbating coverage challenges. In certain implementations, beamforming can be extensively/widely applied through the use of directional antennas. Additionally, in certain implementations, beam sweeping can bring enhanced flexibility and efficiency to network coverage. For example, in non-terrestrial networks, beam hopping can be used to facilitate coverage over a vast area with a limited number of simultaneous beams. In certain implementations, coverage availability, based on the periodicity of beam sweeping, can be adapted to the traffic load in different areas.

In certain implementations, as illustrated in FIG. 3, the entire/whole footprint of a satellite can be exceedingly large. For example, a typical low-earth orbit (LEO) satellite at a 600km orbital height can cover a circular area with a radius of approximately 1000km, given a minimum elevation angle of 30 degrees. However, the footprint of a single beam can be constrained/limited by the legacy physical random-access channel (PRACH) design for terrestrial networks. In certain implementations, the maximum radius of a beam can be limited to 100km due to the PRACH Cyclic Prefix (CP) length limitation. As a result, a satellite may require a large number of beams (potentially hundreds or even thousands) to cover its entire/whole footprint. In certain implementations, the effective isotropic radiated power (EIRP) density (measured in dBW/MHz) can be used for downlink (DL) coverage system-level evaluation, which may mean/indicate that the total transmission power is proportional to the system bandwidth. However, in certain implementations, the total transmission power can be limited by the payload hardware capability instead of the system bandwidth. Due to the limitation on the total transmission power of a satellite, a portion/part of the beams can be activated simultaneously to ensure a satisfactory link budget.

In certain implementations, within terrestrial networks, network energy savings (NES) can be achieved by using longer beam sweeping periodicity at the base station (BS) side in areas with low traffic or during off-peak hours. Additionally, in certain implementations, a repeater or reconfigurable intelligent surface (RIS) with beam-sweeping capability can be used to address coverage holes. In certain implementations, the common channel (or common signal) from the BS can be forwarded by the repeater or RIS using beam sweeping.

In certain implementations, from the viewpoint of a BS, the DL common channels (e.g., common signals/transmissions) for initial access may include at least one of the following: SSB, which is used for cell search and/or DL synchronization; Type0-PDCCH CSS set, which is used to indicate the time-frequency resource for SIB1; or SIB1, which includes the remaining important system information of a cell. In some implementations, the SIB1 may include the time-frequency resource for Type0A-PDCCH.

In certain implementations, the DL common channels can occupy a considerable amount of time-frequency domain resources. For example, as illustrated in FIG. 4, four synchronization signal blocks (SSBs) and their corresponding Type0-PDCCH CSS sets for SIB1 (e.g., SSB Case C with SCS of 30kHz) can be shown/observed in the time domain. As a result, the BS’s scheduling can be restricted due to periodic beam sweeping for the transmission of DL common channels. In certain implementations, a BS may opt to skip some DL common channel transmission to mitigate the scheduling restriction. Additionally, reducing the transmission of DL common channels can be desirable for network energy savings. In certain implementations, extra/additional indications may be conveyed to the UE by the BS to assist in efficient DL channel signal monitoring on the UE side (e.g., to coordinate with respect to skipping or reducing the downlink common signal/channel transmissions) . In certain implementations, as illustrated in FIG. 5, a method for DL common channel monitoring indication/configuration may be employed/utilized to assist efficient DL common channel monitoring on the UE side.

In certain implementations, a UE may assume that half-frames with SSBs occur with a periodicity of 20ms for initial cell selection. In some implementations, where a BS’s coverage is divided into N_footprint footprints, the BS can use a beam to sequentially sweep across the N_footprint footprints over time. Each footprint can be revisited by the BS’s beam per/every 20ms to transmit the DL common channels. For each footprint, the active time (referred to as T_active) per 20ms is to be at least equal to the overall/total time domain resource length of all transmitted DL common channels. This may mean/indicate that N_footprint is not to exceed 20ms/T_active. In certain implementations, a BS’s beam may be at least one of the following: a spatial filter, an associated RS with QCL relationship, a beam index, or an associated time/frequency/polarization/spatial resource.

An example of the time domain resource consumption by SSBs and/or Type0-PDCCH CSS sets is provided as follows:

In certain implementations, where the BS is to serve more footprints, there can be several possible approaches/ways, which include, but are not limited to, employing/using a longer periodicity (i.e., > 20ms) for DL common channel transmission; and/or using simultaneous beams at the BS to serve different footprints at the same time, which generally leads to higher hardware complexity/cost for analogous beamforming. In addition, the network’s energy consumption may be proportional to the number of simultaneous beams.

In certain implementations, in terrestrial networks, a UE can monitor the DL common channels with a given periodicity. In certain implementations, a UE can be provided/configured per serving cell with ssb-periodicityServingCell, which determines the periodicity of the half frames for receiving SSBs for the serving cell. In some implementations, where the UE is not configured with the periodicity of the half frames for the receptions of the SSBs, the UE can assume the periodicity of a half frame. In certain implementations, a UE can assume that the periodicity is the same for all SSBs in the serving cell. For initial cell selection, a UE may assume that half frames with SS/PBCH blocks occur with a periodicity of 20ms. The candidate SSB index of the SSB can correspond to the SSB index provided by ssb-PositionsInBurst in SIB1 or in ServingCellConfigCommon. In certain implementations, a UE can monitor the PDCCH in the Type0-PDCCH CSS set with a fixed periodicity of 20ms when using the SSB and/or CORESET multiplexing pattern 1. For SSB and CORESET multiplexing patterns 2 and 3, a UE can monitor the PDCCH in the Type0-PDCCH CSS set with a periodicity equal to the periodicity of SSB. In certain implementations, the time-frequency resource of SIB1 can be indicated in the PDCCH in the Type0-PDCCH CSS set. In some implementations, a UE can monitor SIB1 according to the time-frequency resource indicated in the PDCCH.

In certain implementations, to support/facilitate more flexible scheduling for the BS and/or to support more footprints, the BS may opt to skip some DL common channel transmissions. For a non RRC_CONNECTED UE, the UE may lack information about the cell it intends to access. As a result, an extra indication is to be informed/provided/sent to the UE by the BS to assist in efficient DL common channel monitoring on the UE side.

In certain implementations, the periodicity for monitoring DL common channels can follow an extended SSB’s periodicity. In some implementations, the SSB can be the first DL common channel to be blindly detected by a UE for initial access. In certain implementations, a longer periodicity in the SSB transmission can be used. For example, a set of extended SSB transmission periodicities may include {20ms, 40ms, 80ms, 160ms} . A UE may use/select one of these periodicities for its blind SSB scan. After successfully detecting an SSB, the UE can detect other DL common channels using the periodicity of the used/selected SSB. In certain implementations, the resource allocated for monitoring other DL common channels can be determined based on a periodicity that is set/determined according to the periodicity for monitoring one of the synchronization signal blocks (SSB) . In some implementations, the UE can determine the actual SSB transmission periodicity, as indicated by ssb-periodicityServingCell, after successfully receiving SIB1.

In certain implementations, a UE can determine one or more periodicities for DL common channel monitoring using a candidate periodicity in/from a set of candidate periodicity values. As a result, for some implementers, no explicit signaling is needed. However, the cost/trade-off is the requirement that the UE try/attempt blind detection with more than one candidate periodicity. For example, in certain implementations, a set of candidate periodicity values {20, 40, 80, 160} ms can be predefined, and/or a UE can use one of them to blindly monitor the DL common channels. In certain implementations, more than one set of candidate periodicity values can be predefined for different DL common channels, and a UE can use the values from the different sets to blindly monitor different DL common channels. For example, a set of candidate periodicity values {20, 40} ms can be predefined for SSB, and/or a set of candidate periodicity values {80, 160} ms can be predefined for the Type0-PDCCH CSS set and/or SIB1. In certain implementations, more than one set of candidate periodicity values can be predefined for different DL common channels, and a UE can use the values from the different sets to blindly monitor different DL common channels with a predefined association. For example, a set of candidate periodicity values {20, 40} ms can be predefined for SSB, and/or a set of candidate periodicity values {80, 160} ms can be predefined for the Type0-PDCCH CSS set and/or SIB1. The set of candidate periodicity values {20, 40} ms for SSB and the set of candidate periodicity values {80, 160} ms for the Type0-PDCCH CSS set and/or SIB1 can be associated using a one-to-one mapping. In certain implementations, where a UE determines the SSB’s periodicity is 20ms, the UE can use 80ms to detect the Type0-PDCCH CSS set and/or SIB1.

In certain implementations, after initial access, a UE can be provided with one or more periodicities for DL common channel monitoring via RRC signaling. For example, a UE can be provided with an ssb-periodicityServingCell of 40ms for SSB monitoring or a periodicity of 80ms for Type0-PDCCH CSS set and SIB1 monitoring. In certain implementations, the BS can save/conserve time-frequency resources and/or energy for some of the DL common channel transmissions, and/or the UE can efficiently monitor the corresponding DL common channels. However, the cost/trade-off is the requirement for more RRC signaling, such as the inclusion of a new field in the RRCReconfiguration message.

In certain implementations, for an RRC_CONNECTED UE, the UE can be provided with a periodicity of DL common channel monitoring for another cell (e.g., a neighboring cell, a secondary cell) via RRC signaling, which can be used for measurement of another cell or handover to another cell. For example, the RRC signaling may include at least one of the following:

A. {cell id, periodicity} , where the periodicity is applicable to the DL common channels of the cell (cell_id) ;

B. {cell_id, SSB_index, periodicity} , where the periodicity is applicable to the cell (cell_id) and/or its SSB (SSB_index) ;

C. {cell_id, SSB_index_list, periodicity} , where the periodicity is applicable to the cell (cell_id) and/or its SSBs (SSB_index_list) ; or

D. {cell_id, SSB_index, periodicity1, periodicity2} , where the periodicity1 is applicable to the cell (cell_id) and/or its SSB (SSB_index) , and the periodicity2 is applicable to the cell (cell_id) and/or its Type0-PDCCH CSS set and/or SIB1.

In certain implementations, a new indication or a predefined rule can determine the DL common channel monitoring occasion in a time domain. For example, in certain implementations, where a UE detects an SSB and determines that a CORESET for the Type0-PDCCH CSS set is present according to k_ssb, the UE may monitor the Type0-PDCCH CSS set according to PDCCH-ConfigSIB1 in MIB. In some implementations, the UE can monitor SIB1 using the time-frequency resource indication obtained in the Type0-PDCCH CSS set. In certain implementations, a BS may opt to skip some of the Type0-PDCCH CSS set and SIB1 transmissions, which indicates that the transmission periodicity of Type0-PDCCH CSS set and SIB1 may be longer than that of the SSB. In this case, a UE is to receive an indication regarding the monitoring periodicity for the Type0-PDCCH CSS set and/or SIB1. For example, one or more periodicities for the Type0-PDCCH CSS set and/or SIB1 can be predefined. In certain implementations, the UE can determine its monitoring periodicity for the Type0-PDCCH CSS set and SIB1 using one of the provided indications.

In certain implementations, an indication can be implicitly carried by k_ssb, as illustrated in the table below. For example, a UE can determine that a CORESET for the Type0-PDCCH CSS set is present if k_ssb<24 for FR1 or k_ssb<12 for FR2. In some implementations, a rule can be used to map different k_ssb values to the predefined periodicities of the Type0-PDCCH CSS set and/or SIB1. In certain implementations, a UE can directly determine the periodicity of the Type0-PDCCH CSS set and/or SIB1 after successfully decoding MIB. However, the cost is that the BS may have some restrictions on SSB frequency domain resource allocation. In certain implementations, a UE can monitor PDCCH in the Type0-PDCCH CSS set in a frame with a system frame number (SFN_C) satisfying:

ifor

if

Here, the values for O, M, and the index of the first symbol of the CORESET in monitoring slots can be found/provided. Additionally, μ represents the SCS scaling factor based on a reference SCS of 15kHz, and the represents the number of slots in a frame based on an SCS defined by μ. Additionally, the Index_periodicity can be represented by Index_periodicity = log₂ (candidate periodicity/reference periodicity) . For example, if the reference periodicity is 20ms (the default SSB periodicity) and the candidate periodicity is 160ms, the Index_periodicity = log₂ (candidate periodicity/reference periodicity) = log₂ (160/20) = 3.

In certain implementations, an indication can be added to the MIB. In some implementations, the indication can be a new/defined field, e.g., a bit flag. In some implementations, where the bit flag is set to 1, the UE can determine that the periodicity for the Type0-PDCCH CSS set and/or SIB1 is a predefined value other than the periodicity of the used SSB. For example, the UE can monitor the SSBs using a default SSB’s periodicity of 20ms before initial access. In some implementations, the UE can monitor the Type0-PDCCH CSS set and/or SIB1 using a predefined periodicity (e.g., 40ms) , where the bit flag in MIB is 1. In certain implementations, where the bit flag in MIB is 0 (or not presented) , the UE can monitor the Type0-PDCCH CSS set and/or SIB1 using a periodicity of 20ms. In certain implementations, there may be no impact on legacy SSB generation on the BS side. However, the cost is the requirement for an additional/extra bit in the MIB.

In certain implementations, where the bit flag in MIB is 1, a UE can monitor PDCCH in the Type0-PDCCH CSS set in a frame with a system frame number (SFN_C) satisfying:

SFN_cmod (4) =0 ifor

SFN_cmod (4) =1 if

Here, 4 corresponds to the example, predefined periodicity of 40ms.

In certain implementations, where the bit flag in MIB is 0 (or not presented) , a UE can monitor PDCCH in the Type0-PDCCH CSS set in a frame with a system frame number (SFN_C) satisfying:

SFN_cmod (2) =0 ifor

SFN_cmod (2) =1 if

Here, the values for O, M, and the index of the first symbol of the CORESET in monitoring slots can be found/provided/configured. Additionally, μ represents the SCS scaling factor based on a reference SCS of 15kHz, and therepresents the number of slots in a frame based on an SCS defined by μ. Additionally, i is the corresponding SSB index.

In certain implementations, the DL common channel monitoring occasion can be determined by the validity of the corresponding resource. For example, the time-frequency resource for SIB1 can be indicated in the Type0-PDCCH using format 1_0. The frequency domain resource information can be directly encoded in the DCI using the “Frequency domain resource assignment” field. In certain implementations, as illustrated in FIG. 6, the time domain resource can be predefined and determined by the multiplexing pattern of SSB and/or CORESET. For example, a default setting of A for normal CP can be predefined for the multiplexing pattern 1. In some implementations, as shown in FIG. 6, the PDSCH carrying SIB1 occupies 4～13 symbols, which follow the slot of the corresponding CORESET0.

In certain implementations, where an SIB1 is to be skipped in a BS’s DL common channel transmission, an invalid time-frequency resource of SIB1 can be provided/applied/allocated/used in the Type0-PDCCH. In some implementations, SIB1 can be skipped per SSB, which can be desirable if different SSBs are used to serve footprints with different traffic loads. However, the cost is that the Type0-PDCCH, which indicates an invalid time-frequency resource of SIB1, can be wasted, including the time-frequency resource and the transmission power of the Type0-PDCCH. In certain implementations, there can be several methods to inform the UE about how to determine an invalid time-frequency resource of SIB1.

In certain implementations, the “Frequency domain resource assignment” in DCI format 1_0 with CRC scrambled by SI-RNTI can use downlink resource allocation of type 0. The resource block assignment information may include a bitmap indicating the resource block groups (RBGs) that are allocated. In certain implementations, where all bits in the bitmap are zero, the UE can determine that the time-frequency resource for SIB1 is invalid and/or can skip it.

In certain implementations, a time-frequency resource that partially or completely overlaps with (the corresponding) SSB or Type0-PDCCH can be considered/regarded as invalid. In some implementations, a UE can determine whether the time-frequency resource of SIB1 is valid and/or can monitor SIB1 accordingly. In certain implementations, where a UE determines that the time-frequency resource for SIB1 is invalid, the UE can opt to skip it.

Referring now to FIG. 7, which illustrates a flow diagram of a method 700 for performing common channel monitoring. The method 700 may be implemented using any of the components and devices detailed herein in conjunction with FIGS. 1–6. In an overview, the method 700 may include a wireless communication device determining a resource for monitoring a downlink (DL) common channel (STEP 702) . The method may include the wireless communication device performing the monitoring of the DL common channel according to the determination (STEP 704) .

In certain configurations, a wireless communication device (e.g., UE) can determine a resource (e.g., time domain resource, which corresponds to periodicity, for instance) for monitoring a downlink (DL) common channel (STEP 702) . In certain configurations, the resource for monitoring the DL common channel can be a periodicity (e.g., periodic time domain resource (s) ) determined according to a periodicity for monitoring a synchronization signal block (SSB) . In some implementations, the DL common channel can exclude the SSB.

In certain configurations, the resource (e.g., time domain resource, which corresponds to periodicity, for instance) for monitoring the DL common channel resource can be determined by at least one of the following: one or more periodicities for monitoring the DL common channel that are indicated by a radio resource control (RRC) signaling received by the wireless communication device; or one or more periodicities for monitoring the DL common channel that are determined by detection of the wireless communication device, where the detection can be performed by the wireless communication device according to a candidate periodicity value in/from a set/list/plurality of candidate periodicity values. In certain configurations, the wireless communication device that is in radio resource control (RRC) connected state in a cell can receive/obtain/acquire a periodicity for monitoring the DL common channel in another cell via an RRC signaling (in some implementations, the RRC signal may also include the handover signal) .

In certain configurations, the wireless communication device can determine at least one of the following: a frame (e.g., corresponding to SFN_c) or a periodicity for monitoring the DL common channel according to a value of a synchronization signal block (SSB) offset (k_ssb) . In certain configurations, the wireless communication device can determine a frame with a system frame number (SFN_c) satisfying:

ifor

if

In certain configurations, the wireless communication device can determine at least one of the following: a frame or a periodicity for monitoring the DL common channel according to a value of a defined field (e.g., bit flag is 1) in a master information block (MIB) . In certain configurations, the wireless communication device can determine whether a resource for monitoring the DL common channel (e.g., SIB1) is invalid. In some implementations, the DL common channel may include a system information block 1 (SIB1) . In some implementations, the resource may include a frequency resource, a time resource, or a time and frequency resource.

In certain configurations, the wireless communication device can determine that the resource is invalid when all bits in a bitmap of the frequency domain resource assignment field in DCI format 1_0 are set to zeros. In certain configurations, the wireless communication device can determine that the resource is invalid when the resource at least partially overlaps with a resource of a corresponding synchronization signal block (SSB) or a corresponding type0 physical downlink control channel (PDCCH) common search space (CSS) set. In certain configurations, the DL common channel may include at least one of the following: a synchronization signal block (SSB) ; a type0 physical downlink control channel (PDCCH) common search space (CSS) set; or system information block 1 (SIB1) .

At least one aspect is directed to a system, method, apparatus, or a computer-readable medium. In certain configurations, the wireless communication device can perform the monitoring of the DL common channel according to the determination (STEP 704) .

While various embodiments/implementations of the present solution have been described above, it should be understood that they have been presented by way of example only, and not by way of limitation. Likewise, the various diagrams may depict an example architecture or configuration, which are provided to enable persons of ordinary skill in the art to understand example features and functions of the present solution. Such persons would understand, however, that the solution is not restricted to the illustrated example architectures or configurations but can be implemented using a variety of alternative architectures and configurations. Additionally, as would be understood by persons of ordinary skill in the art, one or multiple features of one embodiment/implementation can be combined with one or multiple features of another embodiment/implementation described herein. Thus, the breadth and scope of the present disclosure should not be limited by any of the above-described illustrative embodiments.

It is also understood that any reference to an element herein using a designation such as “first, ” “second, ” and so forth does not generally limit the quantity or order of those elements. Rather, these designations can be used herein as a convenient means of distinguishing between two or more elements or instances of an element. Thus, a reference to first and second elements does not mean that only two elements can be employed, or that the first element must precede the second element in some manner.

Additionally, a person having ordinary skill in the art would understand that information and signals can be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, and symbols, which may be referenced in the above description, can be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

A person of ordinary skill in the art would further appreciate that any of the various illustrative logical blocks, modules, processors, means, circuits, methods and functions described in connection with the aspects disclosed herein can be implemented by electronic hardware (e.g., a digital implementation, an analog implementation, or a combination of the two) , firmware, various forms of program or design code incorporating instructions (which can be referred to herein, for convenience, as “software” or a “software module) , or any combination of these techniques. To clearly illustrate this interchangeability of hardware, firmware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware, firmware or software, or a combination of these techniques, depends upon the particular application and design constraints imposed on the overall system. Skilled artisans can implement the described functionality in various ways for each particular application, but such implementation decisions do not cause a departure from the scope of the present disclosure.

Furthermore, a person of ordinary skill in the art would understand that various illustrative logical blocks, modules, devices, components, and circuits described herein can be implemented within or performed by an integrated circuit (IC) that can include a general purpose processor, a digital signal processor (DSP) , an application specific integrated circuit (ASIC) , a field programmable gate array (FPGA) or other programmable logic device, or any combination thereof. The logical blocks, modules, and circuits can further include antennas and/or transceivers to communicate with various components within the network or within the device. A general purpose processor can be a microprocessor, but in the alternative, the processor can be any conventional processor, controller, or state machine. A processor can also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or multiple microprocessors in conjunction with a DSP core, or any other suitable configuration to perform the functions described herein.

If implemented in software, the functions can be stored as one or multiple instructions or code on a computer-readable medium. Thus, the steps of a method or algorithm disclosed herein can be implemented as software stored on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that can be enabled to transfer a computer program or code from one place to another. A storage media can be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer.

In this document, the term “module” as used herein, refers to software, firmware, hardware, and any combination of these elements for performing the associated functions described herein. Additionally, for purpose of discussion, the various modules are described as discrete modules; however, as would be apparent to one of ordinary skill in the art, two or more modules may be combined to form a single module that performs the associated functions according to embodiments of the present solution.

Additionally, memory or other storage, as well as communication components, may be employed in embodiments of the present solution. It will be appreciated that, for clarity purposes, the above description has described embodiments of the present solution with reference to different functional units and processors. However, it will be apparent that any suitable distribution of functionality between different functional units, processing logic elements or domains may be used without detracting from the present solution. For example, functionality illustrated to be performed by separate processing logic elements, or controllers, may be performed by the same processing logic element, or controller. Hence, references to specific functional units are only references to a suitable means for providing the described functionality, rather than indicative of a strict logical or physical structure or organization.

Various modifications to the embodiments described in this disclosure will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other embodiments without departing from the scope of this disclosure. Thus, the disclosure is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the novel features and principles disclosed herein, as recited in the claims below.

Claims

A method comprising:

determining, by a wireless communication device, a resource for monitoring downlink (DL) common channel and

performing, by the wireless communication device, the monitoring of the DL common channel, according to the determination.
The method of claim 1, wherein the resource for monitoring the DL common channel is a periodicity determined according to a periodicity for monitoring a synchronization signal block (SSB) ,

wherein the DL common channel excludes the SSB.
The method of claim 1, wherein the resource for monitoring the DL common channel resource is determined by at least one of:

one or more periodicities for monitoring the DL common channel that are indicated by a radio resource control (RRC) signaling received by the wireless communication device; or

one or more periodicities for monitoring the DL common channel that are determined by detection of the wireless communication device, wherein the detection is performed by the wireless communication device according to a candidate periodicity value in a set of candidate periodicity values.
The method of claim 1, comprising:

receiving, by the wireless communication device that is in radio resource control (RRC) connected state in a cell, a periodicity for monitoring DL common channel in another cell, via a RRC signaling.
The method of claim 1, wherein the determining comprises:

determining, by the wireless communication device, at least one of: a frame or a periodicity for monitoring the DL common channel, according to a value of a synchronization signal block (SSB) offset (k_ssb) .
The method of claim 5, wherein determining the frame comprises:

determining, by the wireless communication device, a frame with a system frame number (SFN_c) satisfying:

ifor

if

wherein:

Index_periodicity is determined according to the value of k_ssb,

μ is a subcarrier spacing (SCS) scaling factor based on a reference SCS,

is a number of slots in a frame based on an SCS defined by μ,

O and M are determined by configuration, and

i is a corresponding SSB index.
The method of claim 1, wherein the determining comprises:

determining, by the wireless communication device, at least one of: a frame or a periodicity for monitoring DL common channel, according to a value of a defined field in a master information block (MIB) .
The method of claim 1, wherein the determining comprises:

determining, by the wireless communication device, whether a resource for monitoring DL common channel is invalid,

wherein at least one of:

the DL common channel comprises a system information block 1 (SIB1) ; or

the resource comprises a frequency resource, a time resource, or a time and frequency resource.
The method of claim 8, comprising:

determining, by the wireless communication device, that the resource is invalid when all bits in a bitmap of frequency domain resource assignment field in DCI format 1_0, are set to zeros.
The method of claim 8, comprising:

determining, by the wireless communication device, that the resource is invalid when the resource at least partially overlaps with a resource of a corresponding synchronization signal block (SSB) or a corresponding type0 physical downlink control channel (PDCCH) common search space (CSS) set.
The method of any one of claims 1-10, wherein the DL common channel comprises at least one of:

a synchronization signal block (SSB) ;

a type0 physical downlink control channel (PDCCH) common search space (CSS) set; or

system information block 1 (SIB1) .
A non-transitory computer readable medium storing instructions, which when executed by at least one processor, cause the at least one processor to perform the method of any one of claims 1-11.
An apparatus comprising:

at least one processor configured to perform the method of any one of claims 1-11.