WO2021003661A1

WO2021003661A1 - Systems and methods for performing random access procedure

Info

Publication number: WO2021003661A1
Application number: PCT/CN2019/095213
Authority: WO
Inventors: Junfeng Zhang; Xing Liu; Haigang HE; Li Tian
Original assignee: Zte Corporation
Priority date: 2019-07-09
Filing date: 2019-07-09
Publication date: 2021-01-14
Also published as: CN113785652A

Abstract

A method performed by a wireless communication device includes receiving, by a wireless communication device from a wireless communication node, a message indicating a relationship between a first plurality of parameters and a second plurality of parameters. The method includes determining, by the wireless communication device based on the first plurality of parameters, a first search space to obtain a first control channel from the wireless communication node. The method includes determining, by the wireless communication device based on the relationship between the first plurality of parameters and second plurality of parameters, a second search space to obtain a second control channel.

Description

SYSTEMS AND METHODS FOR PERFORMING RANDOM ACCESS PROCEDURE

TECHNICAL FIELD

The disclosure relates generally to wireless communications and, more particularly, to systems and methods for performing random access procedure in wireless communication systems.

BACKGROUND

In the 5th Generation (5G) New Radio (NR) mobile networks, before a user equipment (UE) can send data to a base station (BS) , the UE is required to obtain uplink timing synchronization and downlink timing synchronization with the BS. The uplink timing synchronization can be achieved by performing a random access procedure. To meet the demand for faster and efficient communications, the random access procedure is to be provided.

SUMMARY

The example embodiments disclosed herein are directed to solving the issues relating to one or more of the existing problems, 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.

In one embodiment, a wireless communication method performed by a wireless communication device includes: receiving, by a wireless communication device from a wireless communication node, a message indicating a relationship between a first plurality of parameters and a second plurality of parameters; determining, by the wireless communication device based on the first plurality of parameters, a first search space to obtain a first control channel from the wireless communication node; and determining, by the wireless communication device based on the relationship between the first plurality of parameters and second plurality of parameters, a second search space to obtain a second control channel.

In another embodiment, a wireless communication apparatus includes a processor and a memory. The processor is configured to read code from the memory and implement a method. The method includes: receiving, by a wireless communication device from a wireless communication node, a message indicating a relationship between a first plurality of parameters and a second plurality of parameters; determining, by the wireless communication device based on the first plurality of parameters, a first search space to obtain a first control channel from the wireless communication node; and determining, by the wireless communication device based on the relationship between the first plurality of parameters and second plurality of parameters, a second search space to obtain a second control channel.

In yet another embodiment, a computer program product includes a computer-readable program medium code stored thereupon. The code, when executed by a processor, causes the processor to implement a method. The method includes: receiving, by a wireless communication device from a wireless communication node, a message indicating a relationship between a first plurality of parameters and a second plurality of parameters; determining, by the wireless communication device based on the first plurality of parameters, a first search space to obtain a first control channel from the wireless communication node; and determining, by the wireless communication device based on the relationship between the first plurality of parameters and second plurality of parameters, a second search space to obtain a second control channel.

In one embodiment, a wireless communication method performed by a wireless communication node includes: determining, by a wireless communication node, a first plurality of parameters, the first plurality of parameters configured for a wireless communication device to obtain, from the wireless communication node, a first control channel in a first search space; determining, by the wireless communication node, a relationship between the first plurality of parameters and a second plurality of parameters, the second plurality of parameters configured for the wireless communication device to obtain, from the wireless communication node, a second control channel in a second search space; and transmitting, by the wireless communication node to the wireless communication device, a message indicating the relationship between the first plurality of parameters and the second plurality of parameters.

In another embodiment, a wireless communication apparatus includes a processor and a memory. The processor is configured to read code from the memory and implement a method. The method includes: determining, by a wireless communication node, a first plurality of parameters, the first plurality of parameters configured for a wireless communication device to obtain, from the wireless communication node, a first control channel in a first search space; determining, by the wireless communication node, a relationship between the first plurality of parameters and a second plurality of parameters, the second plurality of parameters configured for the wireless communication device to obtain, from the wireless communication node, a second control channel in a second search space; and transmitting, by the wireless communication node to the wireless communication device, a message indicating the relationship between the first plurality of parameters and the second plurality of parameters.

In yet another embodiment, a computer program product includes a computer-readable program medium code stored thereupon. The code, when executed by a processor, causes the processor to implement a method. The method includes: determining, by a wireless communication node, a first plurality of parameters, the first plurality of parameters configured for a wireless communication device to obtain, from the wireless communication node, a first control channel in a first search space; determining, by the wireless communication node, a relationship between the first plurality of parameters and a second plurality of parameters, the second plurality of parameters configured for the wireless communication device to obtain, from the wireless communication node, a second control channel in a second search space; and transmitting, by the wireless communication node to the wireless communication device, a message indicating the relationship between the first plurality of parameters and the second plurality of parameters.

The above and other aspects and their implementations are described in greater detail in the drawings, the descriptions, and the claims.

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.

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

Figure 2 illustrates block diagrams of an example base station and an example user equipment device, in accordance with some embodiments of the present disclosure.

Figure 3 illustrates a flow diagram of an example process for performing a random access procedure, in accordance with some embodiments of the present disclosure.

Figure 4 illustrates a search space configuration, in accordance with some embodiments of the present disclosure.

Figure 5 illustrates symbol locations for monitoring PDCCH CORESET, in accordance with some embodiments of the present disclosure.

Figure 6 illustrates a relationship between a search space for a msgB and a search space for msg2/msg4, in accordance with some embodiments of the present disclosure.

Figure 7 illustrates a relationship between one or more predefined msgB monitoring symbols and one or more predefined msg2/msg4 monitoring symbols, in accordance with some embodiments of the present disclosure.

Figure 8 a flow diagram of an example process for configuring a random access procedure for a wireless communication device, in accordance with some embodiments of the present disclosure.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

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.

A. Network Environment and Computing Environment

Figure 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” ) and a user equipment device 104 (hereinafter “UE 104” ) 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 Figure 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 respectively described herein as non-limiting examples of “communication node” (or “wireless communication node” ) and “communication device” (or “wireless communication device” ) generally, which can practice the methods disclosed herein. Such communication nodes and devices may be capable of wireless and/or wired communications, in accordance with various embodiments of the present solution.

Figure 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 Figure 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 Figure 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 can 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. 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 a next generation nodeB (gNodeB or gNB) , an evolved node B (eNB) , a serving eNB, a target eNB, a femto station, a pico station, or a Transmission Reception Point (TRP) , 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 more microprocessors in conjunction with a digital signal processor core, or any other such configuration.

Furthermore, the steps of a process, 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 communication 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.

B. Example Random Access Procedures

In NR systems, a two-step random access procedure is introduced according to some embodiments. The two-step random access procedure includes a message B (msgB) physical downlink control channel (PDCCH) according to some embodiments. The msgB PDCCH is a PDCCH that is associated with a msgB according to some embodiments. The msgB PDCCH is indicated using a msgB radio network temporary identifier (msgB-RNTI) according to some embodiments. The msgB-RNTI may be a random access RNTI (RA-RNTI) or a new RNTI (New RNTI which is separated from the traditional message 2 RA-RNTI) according to some embodiments. The msgB includes SuccessRAR, FallbackRAR, or Backoff indicator (BI) according to some embodiments. The SuccessRAR is the preamble sequence in the two-step random access msgA and the random access response after the PUSCH is successfully received and demodulated by the base station according to some embodiments. The FallbackRAR is a random access response after the preamble sequence in the msgA is successfully received by the base station when the PUSCH is unsuccessfully demodulated by the base station according to some embodiments. The BI is a general back-off indication according to some embodiments.

For the msgB PDCCH, if the resource set and the search space are controlled by the same control resource set (CORESET) as the messages 2 or 4 (msg2/4) in the four-step random access procedure, it is difficult to distinguish between the msgB and the msg2/4 by time-frequency resources according to some embodiments. If the msgB PDCCH uses the traditional RA-RNTI, it is still difficult to distinguish between the msgB and the msg2 according to some embodiments. If the msgB uses the New RNTI, and the New RNTI and the RA-RNTI do not overlap, the msgB and the msg2 can be distinguished according to some embodiments. However, due to the limited space of the entire RNTI , the design of a New RNTI that does not overlap the RA-RNTI may not be feasible according to some embodiments. Thus, it is important to provide a new method to distinguish between the msgB and the msg2/4 according to some embodiments.

The present disclosure provides systems and methods for performing random access procedure that can distinguish between the msgB PDCCH and other control channels according to some embodiments.

The physical resources of a control channel may be expressed by control resource set (CORESET) definition or configuration according to some embodiments. The CORESET in the frequency domain contains a set of PRBs according to some embodiments. The minimum particle size of the set of PRBs is 6 RBs according to some embodiments. The length of the set of PRBs in the time domain is between 1 and 3 symbols according to some embodiments. The CORESET includes Resource Element Groups (REGs) and Control Channel Elements (CCEs) according to some embodiments. The CCE includes a set of REGs according to some embodiments. Control channel (e.g., PDCCH) is aggregated by the CCEs according to some embodiments. Each control channel is associated with a search space according to some embodiments. Each search space is associated with a CORESET ID according to some embodiments. UE uses the information of search space to search and demodulated PDCCH according to some embodiments.

A CORESET for a control channel of random access is configured using parameters ra-ControlResourceSet according to some embodiments. If a CORESET for a control channel of random access is not configured, the CORESET is set as a default CORESET that is same as a CORESET for the remaining system information (RMSI) according to some embodiments.

For random access triggering event, the difference between 2-step RACH and 4-step RACH is not significant according to some embodiments. Especially for the random access initiated by the initial access, using a default CORESET#0 reduces the overhead of system information according to some embodiments.

In some embodiments, the search space of a random access control channel is configured using the parameter ra-SearchSpace in the PDCCH Config Common signaling. The type1 search space in Rel-15 is provided solely for search spaces that are associated with the RACH msg2 or msg4 according to some embodiments. The type1 search space is configured separately in a system information according to some embodiments.

For 2-step RACH, the msgB is separately configured using the type1A search space according to some embodiments. The msgB is separately configured from other messages in the signaling according to some embodiments. In this way, the msgB is distinguished from other messages (e.g., msg2/4) according to some embodiments.

Figure 3 is a flow diagram of an example process 300 for performing a random access procedure according to some embodiments. The process 300 can be performed by a wireless communication device (e.g., UE 104 or 204) according to some embodiments.

At operation 302, the wireless communication device can receive a message indicating a relationship between a first plurality of parameters and a second plurality of parameters from a wireless communication node according to some embodiments. The wireless communication device can receive the message from a wireless communication node (e.g., BS 102 or 202) . The message can be included in at least one of: a high-layer signal (e.g., radio resource control (RRC) signal) , a broadcast signal, or a multi-cast signal. Alternatively, the relationship can be predefined, according to some embodiments. As such, the wireless communication device can use the relationship to determine the second parameters without receiving the message. The first plurality of parameters can include at least one of: a first monitoring slot period, a first monitoring slot offset, a first duration of slots occupied by the first control channel, or a first monitoring symbol pattern every slot according to some embodiments. The second plurality of parameters include at least one of: a second monitoring slot period, a second monitoring slot offset, a second duration of slots occupied by the second control channel, or a second monitoring symbol pattern every slot according to some embodiments. The first or second monitoring symbol pattern may be sometimes referred to as a parameter, MonitoringSymbolWithinSlot, which shall be discussed in further detail below.

The message indicates the relationship as the second monitoring slot offset being equal to a combination of the first monitoring slot offset and the first duration of slots occupied by the first control channel according to some embodiments. The message indicates the relationship as the second monitoring slot offset being equal to a combination of the first monitoring slot offset, the first duration of slots occupied by the first control channel, and a predefined number of slot offset according to some embodiments. The message indicates the relationship as the second duration of slots occupied by the second control channel being equal to or less than the first duration of slots occupied by the first control channel according to some embodiments. The message indicates the relationship as the second monitoring symbol pattern every slot being offset from the first monitoring symbol pattern every slot by a predefined number of symbol offset according to some embodiments.

At operation 304, the wireless communication device can determine a first search space to obtain a first control channel from the wireless communication node according to some embodiments. The wireless communication device can determine the first search space based on the first plurality of parameters. The first search space is configured for the wireless communication device to monitor the first control channel in a 4-step random access procedure according to some embodiments. The first search space is associated with a msg2/msg4 in a 4-step random access procedure according to some embodiments.

At operation 306, the wireless communication device can determine a second search space to obtain a second control channel according to some embodiments. The wireless communication device can determine the second search space based on the relationship between the first plurality of parameters and second plurality of parameters. The second search space is configured for the wireless communication device to monitor the second control channel in a 2-step random access procedure. The second search space is associated with a msgB in a 2-step random access procedure according to some embodiments.

Figure 4 illustrates a search space configuration 400 according to an example embodiment. The search space 400 is configured over a period of time according to some embodiments. The search space 400 includes one or more sets of slots according to some embodiments. Each slot 402 is used for monitor a PDCCH CORESET according to some embodiments. Continuous slots indicates a continuous monitoring duration according to some embodiments. For example, as shown in Figure 4, there are three continuous slots 408, which indicates the duration for the search space is 3 according to some embodiments.

A PDCCH monitoring offset 404 is defined as a time difference between a frame boundary 406 (e.g., the boundary of the PDCCH CORESET) and the first slot that is used for monitoring the PDCCH CORESET according to some embodiments. A monitor periodicity 408 is defined as a time period from a first set of monitoring slots to a second continuous set of monitoring slots according to some embodiments. A frame index n _f and a slot index

can be calculated using the following equation:

The

is a total number of slots in a frame. The k _p, sis a monitoring periodicity. The o _p, sis a monitoring offset.

The frame index n _f , the slot index

and a parameter MonitoringSymbolWithinSlot can be used to determine a symbol location of a PDCCH monitoring occasion within the slots according to some embodiments. The parameter MonitoringSymbolWithinSlot indicates a PDCCH monitoring pattern for the PDCCH search space according to some embodiments.

Figure 5 illustrates symbol locations for monitoring PDCCH CORESET according to an example embodiment. Each slot (e.g., slot 0, slot 1) includes multiple symbol locations according to some embodiments. The symbol locations 502 and 504 are used for monitoring PDCCH CORESET according to some embodiments. In this example, the MonitoringSlotPeriodicity is 2 slots (e.g., slots between the first symbol location 502 and the first symbol location 504) according to some embodiments. The offset is 1 slot (e.g., slot 0 is before the first symbol location 502) according to some embodiments. The duration is 1 slot according to some embodiments. The MonitoringSymbolWithinSlot parameter is 10001000100000 according to some embodiments. A time period for monitoring a CORESET is 2 symbol locations (e.g., 502 and 504) according to some embodiments.

Figure 6 illustrates a relationship 600 between a search space 604 for a msgB and a search space 602 for msg2/msg4 according to an example embodiment. The msgB search space 604 is predefined as being located at one slot behind the msg2/msg4 search space 602 within the time domain according to some embodiments. In other words, the msgB search space 604 is located adjacent to and right after the msg2/msg4 search space according to some embodiments. The time difference between the msgB search space and the msg2/msg4 search space is 1 slot. In this way, the predetermined offset for the msgB search space can be calculated using the parameters of the msg2/msg4 according to some embodiments. For example, the offset of the msgB search space = offset of the msg2/msg4 + duration of the msg2/msg4 + time difference according to some embodiments and the time difference is not limited to 1 slot.

In some embodiments, it is predefined that the duration of the msgB search space is equal to or less than the duration of the msg2/msg4 search space according to some embodiments. The duration of the msgB can be determined using the following equation:

msgB Duration = min {msg2/4 duration , msg2/4 MonitoringSlotPeriodicity -msg2/4 offset -msg2/4 duration} .

In the equation above, the MonitoringSlotPeriodicity -offset -msg2/4 duration is associated with situations when the msgB duration is located at the end of the slots and cannot be extended out of the monitoring slot period according to some embodiments.

The msgB search space has the same monitoring period as the msg2, and within each monitoring period, msgB is right behind the msg2 according to some embodiments. In this way, no additional message is needed to locate the msgB search space according to some embodiments.

Figure 7 illustrates a relationship 700 between one or more predefined msgB monitoring symbols 704 and one or more predefined msg2/msg4 monitoring symbols 702 according to an example embodiment. In some embodiments, a time difference between a msgB monitoring symbol and a msg2/msg4 monitoring symbol is predefined or configured according to some embodiments. For example, as shown in Figure 7, within one of a number of slots, the msgB monitoring symbol 704 is two symbols locations behind the msg2/msg4 symbol 702 according to some embodiments. This time difference can be used to determine a location of the msgB PDCCH according to some embodiments.

In some embodiments, the msgB and the msg2/msg4 is distinguished using a location of a PDCCH candidate within a search space. In the NR system, the maximum number of search spaces within a serving cell is 40 according to some embodiments. Within these search spaces, there are multiple public search spaces and user specific search spaces according to some embodiments. Each search space (s) may include multiple aggregation level (L) according to some embodiments. Each aggregation level L represents a search space indicated as {s, L} according to some embodiments. Within each search space {s, L} , a CCE index for a candidate PDCCH is calculated using the following equation:

In the equation above, i=0, …, L-1. p is an index of a corresponding CORESET to a search space s. n _CI is a carrier indicator field of a serving cell.

is an index of a PDCCH candidate within the serving celln _CI.

is an index within a slot

N _CCE, pis the number of CCE within the CORESET p.

is defined as

is a number of PDCCH candidates within a search space {S, L} of a corresponding message n _CI.

A serving cell is configured with a n _CI value only when the cross-carrier scheduling is configured according to some embodiments. Otherwise, n _CI is equal to 0 according to some embodiments.

For a common search space (CSS) ,

which represents a starting point of a candidate PDCCH within the search space.

For a user specific searching space (USS) ,

Y _p, -1=n _RNTI≠0. A first CORESET is indicated as A ₀=39827. A second CORESET is indicated as A ₁=39829. A third CORESET is indicated as A ₂=39839. D is 65537. For USS,

is a maximum value within all PDCCH candidates in CORESET p of a search space {s, L} . In some embodiments, it may be predefined that the msgB and msg2/4 uses different PDCCH candidate. For example, a PDCCH candidate for a msgB can be set as a non-zero value

but msg2/4 has a

In this way, the msgB and the msg2/4 can be distinguished.

In some embodiments, the wireless communication device can differentiate the msgB and msg2/msg4 based on the different formats of downlink control information (DCI) . For example, via predefinition, the wireless communication device can be configured to receive the msg2/msg4 in response to receiving the DCI in DCI format 1_0; and to receive the msgB in response to receiving the DCI in DCI format 1_1 or an otherwise defined format alternative to the DCI format 1_0.

In some embodiments, the wireless communication device can differentiate the msgB and msg2/msg4 based on the different configurations of PDCCH demodulation reference signal (DMRS) . For example, via predefinition, the wireless communication device can be configured to receive the msg2/msg4 in response to receiving a first configuration of the PDCCH DMRS (e.g., a first configuration of antenna ports, sequences, etc. ) ; and to receive the msgB in response to receiving a second configuration of the PDCCH DMRS (e.g., a second configuration of antenna ports, sequences, etc. ) . In such embodiments, the msgB and msg2/msg4 may be monitored by the wireless communication device in the same CORESET and search space.

Figure 8 is a flow diagram of an example process 800 for configuring a random access procedure for a UE according to some embodiments. The process 800 can be performed by a wireless communication node according to some embodiments. The wireless communication node can be a BS (e.g., BS 102 or 202) .

At operation 802, the wireless communication node can determine a first plurality of parameters. The first plurality of parameters are configured for a wireless communication device (e.g., UE 104 or 204) to obtain a first control channel in a first search space. The first plurality of parameters can include at least one of: a first monitoring slot period, a first monitoring slot offset, a first duration of slots occupied by the first control channel, or a first monitoring symbol pattern every slot according to some embodiments. The wireless communication device can determine the first search space based on the first plurality of parameters. The first search space is configured for the wireless communication device to monitor the first control channel in a 4-step random access procedure according to some embodiments. The first search space is associated with a msg2/msg4 in a 4-step random access procedure according to some embodiments.

At operation 804, the wireless communication node can determine a relationship between the first plurality of parameters and a second plurality of parameters according to some embodiments. The second plurality of parameters are configured for the wireless communication device (e.g., UE 104 or 204) to obtain a second control channel in a second search space. The second plurality of parameters can include at least one of: a second monitoring slot period, a second monitoring slot offset, a second duration of slots occupied by the second control channel, or a second monitoring symbol pattern every slot according to some embodiments.

Instead of explicitly indicating the plurality of second parameters, the wireless communication node can implicitly indicate the plurality of second parameters via indicating the relationship between the first parameters and second parameters. As such, upon receiving the relationship, the wireless communication device can determine the second search space based on the relationship. The second search space is configured for the wireless communication device to monitor the second control channel in a 2-step random access procedure. The second search space is associated with a msgB in a 2-step random access procedure according to some embodiments. The relationship can be indicative of the second monitoring slot offset being equal to a combination of the first monitoring slot offset and the first duration of slots occupied by the first control channel according to some embodiments. The relationship can be indicative of the second monitoring slot offset being equal to a combination of the first monitoring slot offset, the first duration of slots occupied by the first control channel, and a predefined number of slot offset according to some embodiments. The relationship can be indicative of the second duration of slots occupied by the second control channel being equal to or less than the first duration of slots occupied by the first control channel according to some embodiments. The relationship can be indicative of the second monitoring symbol pattern every slot being offset from the first monitoring symbol pattern every slot by a predefined number of symbol offset according to some embodiments.

At operation 806, the wireless communication node can transmit a message indicating the relationship between the first plurality of parameters and the second plurality of parameters. The message can be included in at least one of: a high-layer signal (e.g., radio resource control (RRC) signal) , a broadcast signal, or a multi-cast signal. Alternatively, the relationship can be predefined, in some embodiments. As such, the wireless communication node may optionally transmit the message.

It should be understood that the value used for each case listed above is an example, and the mapping between the value and the case is not limited to the examples above. They are provided for illustrative purpose only and should not be regarded as limiting.

While various embodiments 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 architectural 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 more features of one embodiment can be combined with one or more features of another embodiment 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, for example, 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 more 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 more 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 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 implementations 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 implementations without departing from the scope of this disclosure. Thus, the disclosure is not intended to be limited to the implementations 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 wireless communication method, comprising:

receiving, by a wireless communication device from a wireless communication node, a message indicating a relationship between a first plurality of parameters and a second plurality of parameters;

determining, by the wireless communication device based on the first plurality of parameters, a first search space to obtain a first control channel from the wireless communication node; and

determining, by the wireless communication device based on the relationship between the first plurality of parameters and second plurality of parameters, a second search space to obtain a second control channel.
The method of claim 1, wherein the first search space is configured for the wireless communication device to monitor the first control channel in a 4-step random access procedure, and the second search space is configured for the wireless communication device to monitor the second control channel in a 2-step random access procedure.
The method of claim 1, wherein the first plurality of parameters include at least one of: a first monitoring slot period, a first monitoring slot offset, a first duration of slots occupied by the first control channel, or a first monitoring symbol pattern every slot, and the second plurality of parameters include at least one of: a second monitoring slot period, a second monitoring slot offset, a second duration of slots occupied by the second control channel, or a second monitoring symbol pattern every slot.
The method of claim 3, wherein the message indicates the relationship as the second monitoring slot offset being equal to a combination of the first monitoring slot offset and the first duration of slots occupied by the first control channel.
The method of claim 3, wherein the message indicates the relationship as the second monitoring slot offset being equal to a combination of the first monitoring slot offset, the first duration of slots occupied by the first control channel, and a predefined number of slot offset.
The method of claim 3, wherein the message indicates the relationship as the second duration of slots occupied by the second control channel being equal to or less than the first duration of slots occupied by the first control channel.
The method of claim 3, wherein the message indicates the relationship as the second monitoring symbol pattern every slot being offset from the first monitoring symbol pattern every slot by a predefined number of symbol offset.
A wireless communication apparatus comprising a processor and a memory, wherein the processor is configured to read code from the memory and implement a method recited in any of claims 1 to 7.
A computer program product comprising a computer-readable program medium code stored thereupon, the code, when executed by a processor, causing the processor to implement a method recited in any of claims 1 to 7.
A wireless communication method, comprising:

determining, by a wireless communication node, a first plurality of parameters, the first plurality of parameters configured for a wireless communication device to obtain, from the wireless communication node, a first control channel in a first search space;

determining, by the wireless communication node, a relationship between the first plurality of parameters and a second plurality of parameters, the second plurality of parameters configured for the wireless communication device to obtain, from the wireless communication node, a second control channel in a second search space; and

transmitting, by the wireless communication node to the wireless communication device, a message indicating the relationship between the first plurality of parameters and the second plurality of parameters.
The method of claim 10, wherein the first search space is configured for the wireless communication device to monitor the first control channel in a 4-step random access procedure, and the second search space is configured for the wireless communication device to monitor the second control channel in a 2-step random access procedure.
The method of claim 11, wherein the first plurality of parameters include at least one of: a first monitoring slot period, a first monitoring slot offset, a first duration of slots occupied by the first control channel, or a first monitoring symbol pattern every slot, and the second plurality of parameters include at least one of: a second monitoring slot period, a second monitoring slot offset, a second duration of slots occupied by the second control channel, or a second monitoring symbol pattern every slot.
The method of claim 11, wherein the message indicates the relationship as the second monitoring slot offset being equal to a combination of the first monitoring slot offset and the first duration of slots occupied by the first control channel.
The method of claim 11, wherein the message indicates the relationship as the second monitoring slot offset being equal to a combination of the first monitoring slot offset, the first duration of slots occupied by the first control channel, and a predefined number of slot offset.
The method of claim 11, wherein the message indicates the relationship as the second duration of slots occupied by the second control channel being equal to or less than the first duration of slots occupied by the first control channel.
The method of claim 11, wherein the message indicates the relationship as the second monitoring symbol pattern every slot being offset from the first monitoring symbol pattern every slot by a predefined number of symbol offset.
A wireless communication apparatus comprising a processor and a memory, wherein the processor is configured to read code from the memory and implement a method recited in any of claims 10 to 16.
A computer program product comprising a computer-readable program medium code stored thereupon, the code, when executed by a processor, causing the processor to implement a method recited in any of claims 10 to 16.