CN114390715A

CN114390715A - User equipment and base station in wireless communication system and method performed by the same

Info

Publication number: CN114390715A
Application number: CN202110523269.8A
Authority: CN
Inventors: 吴敏; 孙霏菲; 王轶; 熊琦; 喻斌
Original assignee: Samsung Electronics Co Ltd
Current assignee: Samsung Electronics Co Ltd
Priority date: 2020-10-21
Filing date: 2021-05-13
Publication date: 2022-04-22

Abstract

The present disclosure provides a user equipment and a base station in a wireless communication system and a method performed thereby. The method performed by the user equipment comprises: determining a third timing advance based on the first timing advance configured by the base station and/or a second timing advance estimated by the user equipment, wherein the third timing advance is used for Physical Random Access Channel (PRACH) transmission of an initial random access procedure; receiving a timing advance control instruction indicated by a base station through a Random Access Response (RAR); and obtaining a fourth timing advance according to the timing advance indicated by the timing advance control instruction and the third timing advance.

Description

User equipment and base station in wireless communication system and method performed by the same

Technical Field

The present disclosure relates to the field of communications technologies, and in particular, to a user equipment and a base station in a wireless communication system and a method performed by the user equipment and the base station.

Background

In order to meet the increasing demand for wireless data communication services since the deployment of 4G communication systems, efforts have been made to develop improved 5G or quasi-5G communication systems. Accordingly, the 5G or quasi-5G communication system is also referred to as a "super 4G network" or a "post-LTE system".

The 5G communication system is implemented in a higher frequency (millimeter wave) band, for example, a 60GHz band, to achieve a higher data rate. In order to reduce propagation loss of radio waves and increase transmission distance, beamforming, massive Multiple Input Multiple Output (MIMO), full-dimensional MIMO (FD-MIMO), array antenna, analog beamforming, massive antenna technology are discussed in the 5G communication system.

Further, in the 5G communication system, development of improvement of the system network is ongoing based on advanced small cells, cloud Radio Access Network (RAN), ultra dense network, device-to-device (D2D) communication, wireless backhaul, mobile network, cooperative communication, coordinated multipoint (CoMP), reception side interference cancellation, and the like.

In 5G systems, hybrid FSK and QAM modulation (FQAM) and Sliding Window Superposition Coding (SWSC) have been developed as Advanced Coding Modulation (ACM), and filter bank multi-carrier (FBMC), non-orthogonal multiple access (NOMA), and Sparse Code Multiple Access (SCMA) as advanced access techniques.

Disclosure of Invention

In order to overcome the above technical problems or at least partially solve the above technical problems, the following technical solutions are proposed:

according to an aspect of the present disclosure, there is provided a method performed by a user equipment in a wireless communication system, the method may include: determining a third timing advance based on the first timing advance configured by the base station and/or a second timing advance estimated by the user equipment, wherein the third timing advance is used for Physical Random Access Channel (PRACH) transmission of an initial random access procedure; receiving a timing advance control instruction indicated by a base station through a Random Access Response (RAR); and obtaining a fourth timing advance according to the timing advance indicated by the timing advance control instruction and the third timing advance.

According to another aspect of the present disclosure, there is provided a method performed by a base station in a wireless communication system, the method may include: receiving a PRACH transmission from a user equipment, wherein the PRACH transmission is based on a third timing advance determined from a first timing advance configured by a base station and/or a second timing advance estimated by the user equipment; and sending a timing advance control instruction indicated by the RAR to the user equipment, wherein the timing advance indicated by the timing advance control instruction and the third timing advance are used to obtain a fourth timing advance.

According to another aspect of the present disclosure, there is provided a user equipment and a base station in a wireless communication system performing the above method.

According to another aspect of the present disclosure, there is provided a method for channel transmission in a wireless communication network, including: determining a first time domain resource offset associated with the channel, wherein the first time domain resource offset is associated with a transmission delay; determining each of a plurality of time domain resource locations for transmitting the channel based on the first time domain resource offset; and transmitting the channel based on at least one of the plurality of time domain resource locations.

According to another aspect of the present disclosure, there is provided an apparatus for channel transmission in a wireless communication network, comprising: an offset determination module configured to determine a first time domain resource offset associated with the channel, wherein the first time domain resource offset is associated with a transmission latency; a location determination module configured to determine each of a plurality of time domain resource locations for transmitting the channel based on the first time domain resource offset; and a transmitting module configured to transmit the channel based on at least one of the plurality of time domain resource locations.

According to another aspect of the present disclosure, there is provided an apparatus for channel transmission in a wireless communication network, comprising: a transceiver configured to transmit and receive signals to and from the outside; and a processor configured to control the transceiver to perform a method according to an embodiment of the present disclosure.

According to another aspect of the present disclosure, there is provided a computer readable medium having stored thereon computer readable instructions, which when executed by a processor, are for implementing a method according to embodiments of the present disclosure.

Drawings

The above and/or additional aspects and advantages of the present disclosure will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

fig. 1 illustrates an example wireless network in accordance with embodiments of the present disclosure;

fig. 2a and 2b illustrate example wireless transmit and receive paths according to embodiments of the present disclosure;

fig. 3a illustrates an example UE according to an embodiment of the present disclosure;

fig. 3b illustrates an example base station gNB in accordance with an embodiment of the present disclosure;

FIG. 4 illustrates a diagram of an example timing advance in a wireless communication system;

fig. 5 shows a flowchart of an example method performed by a UE in a wireless communication system according to an embodiment of the present disclosure;

fig. 6a-6e show schematic diagrams of an example common TA indicated by a base station, according to an embodiment of the present disclosure;

figure 7 shows a schematic diagram of an example MAC RAR composition, according to an embodiment of the present disclosure;

FIG. 8 shows a schematic diagram of an example TA Command MAC CE composition, according to embodiments of the present disclosure;

FIG. 9 shows a schematic diagram of an example TA Command MAC CE composition, according to embodiments of the present disclosure;

fig. 10 shows a flowchart of an example method performed by a UE in a wireless communication system according to an embodiment of the present disclosure;

FIG. 11 shows a schematic diagram of an example timing offset, according to an embodiment of the present disclosure;

fig. 12 shows a block diagram of an example UE in accordance with an embodiment of the present disclosure;

fig. 13 shows a block diagram of an example base station in accordance with an embodiment of the disclosure;

fig. 14 shows a schematic flow diagram of a method for channel transmission in a wireless communication network according to an embodiment of the present disclosure;

fig. 15 shows a schematic diagram of uplink scheduling according to an embodiment of the present disclosure;

FIG. 16 shows a schematic diagram of extending the range of values of a timer, according to an embodiment of the disclosure;

FIG. 17 shows a schematic diagram of changing the start time of a timer according to an embodiment of the present disclosure;

fig. 18 shows a schematic diagram of transmission and reception with multiple HARQ processes according to an embodiment of the present disclosure;

fig. 19 shows a schematic diagram of configuring multiple cycles for channel transmission according to an embodiment of the present disclosure;

fig. 20 shows a block diagram of an apparatus for channel transmission in a wireless communication network according to an embodiment of the present disclosure; and

fig. 21 shows a schematic diagram of an apparatus for channel transmission in a wireless communication network according to an embodiment of the present disclosure.

Detailed Description

Reference will now be made in detail to the embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary only for the purpose of illustrating the present disclosure and should not be construed as limiting the same.

As used herein, the singular forms "a", "an", "the" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. It will be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element or intervening elements may also be present. Further, "connected" or "coupled" as used herein may include wirelessly connected or wirelessly coupled. As used herein, the term "and/or" includes all or any element and all combinations of one or more of the associated listed items.

Although ordinal terms such as "first," "second," etc., are used to describe various elements, these elements are not limited herein. These terms are only used to distinguish one element from another element, regardless of chronological order or importance. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

It will be understood by those within the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

As will be appreciated by those skilled in the art, a "terminal" as used herein includes both devices having a wireless signal receiver, which are devices having only a wireless signal receiver without transmit capability, and devices having receive and transmit hardware, which have devices having receive and transmit hardware capable of two-way communication over a two-way communication link. Such a device may include: a cellular or other communication device having a single line display or a multi-line display or a cellular or other communication device without a multi-line display; personal Communications Systems (PCS), which may combine voice, data processing, facsimile and/or data Communications capabilities; personal Digital Assistants (PDAs), which may include radio frequency receivers, pagers, internet/intranet access, web browsers, notepads, calendars, and/or Global Positioning System (GPS) receivers; a conventional laptop and/or palmtop computer or other device having and/or including a radio frequency receiver. As used herein, a "terminal" or "terminal device" may be portable, transportable, installed in a vehicle (aeronautical, maritime, and/or land-based), or situated and/or configured to operate locally and/or in a distributed fashion at any other location(s) on earth and/or in space. As used herein, a "terminal Device" may also be a communication terminal, a web terminal, a music/video playing terminal, such as a PDA, a Mobile Internet Device (MID) and/or a Mobile phone with music/video playing function, or a smart tv, a set-top box, etc.

The description and drawings are provided by way of example only to assist the reader in understanding the present disclosure. They are not intended, nor should they be construed, as limiting the scope of the disclosure in any way. While certain embodiments and examples have been provided, it will be apparent to those skilled in the art, based on the disclosure herein, that changes can be made in the embodiments and examples shown without departing from the scope of the disclosure.

Fig. 1 illustrates an example wireless network 100 in accordance with various embodiments of the present disclosure. The embodiment of the wireless network 100 shown in fig. 1 is for illustration only. Other embodiments of wireless network 100 can be used without departing from the scope of this disclosure.

Wireless network 100 includes a gandeb (gNB)101, a gNB 102, and a gNB 103. gNB 101 communicates with gNB 102 and gNB 103. The gNB 101 also communicates with at least one Internet Protocol (IP) network 130, such as the internet, a proprietary IP network, or other data network.

Depending on the network type, other well-known terms can be used instead of "gnnodeb" or "gNB", such as "base station" or "access point". For convenience, the terms "gNodeB" and "gNB" are used in this patent document to refer to network infrastructure components that provide wireless access for remote terminals. Also, other well-known terms, such as "mobile station", "subscriber station", "remote terminal", "wireless terminal", or "user equipment", can be used instead of "user equipment" or "UE", depending on the network type. For convenience, the terms "user equipment" and "UE" are used in this patent document to refer to a remote wireless device that wirelessly accesses the gNB, whether the UE is a mobile device (such as a mobile phone or smartphone) or what is commonly considered a stationary device (such as a desktop computer or vending machine).

gNB 102 provides wireless broadband access to network 130 for a first plurality of User Equipments (UEs) within coverage area 120 of gNB 102. The first plurality of UEs includes: a UE 111, which may be located in a Small Enterprise (SB); a UE 112, which may be located in an enterprise (E); UE 113, which may be located in a WiFi Hotspot (HS); a UE 114, which may be located in a first residence (R); a UE 115, which may be located in a second residence (R); the UE116, may be a mobile device (M) such as a cellular phone, wireless laptop, wireless PDA, etc. gNB 103 provides wireless broadband access to network 130 for a second plurality of UEs within coverage area 125 of gNB 103. The second plurality of UEs includes UE 115 and UE 116. In some embodiments, one or more of the gnbs 101-103 are capable of communicating with each other and with the UEs 111-116 using 5G, Long Term Evolution (LTE), LTE-A, WiMAX, or other advanced wireless communication technologies.

The dashed lines illustrate the approximate extent of

coverage areas

120 and 125, which are shown as approximately circular for purposes of illustration and explanation only. It should be clearly understood that coverage areas associated with the gNB, such as

coverage areas

120 and 125, can have other shapes, including irregular shapes, depending on the configuration of the gNB and variations in the radio environment associated with natural and artificial obstructions.

As described in more detail below, one or more of gNB 101, gNB 102, and gNB 103 include a 2D antenna array as described in embodiments of the present disclosure. In some embodiments, one or more of gNB 101, gNB 102, and gNB 103 support codebook design and structure for systems with 2D antenna arrays.

Although fig. 1 shows one example of a wireless network 100, various changes can be made to fig. 1. For example, wireless network 100 can include any number of gnbs and any number of UEs in any suitable arrangement. Also, the gNB 101 can communicate directly with any number of UEs and provide those UEs with wireless broadband access to the network 130. Similarly, each gNB 102-103 is capable of communicating directly with network 130 and providing UEs with direct wireless broadband access to network 130. Further, the

gnbs

101, 102, and/or 103 can provide access to other or additional external networks, such as external telephone networks or other types of data networks.

Fig. 2a and 2b illustrate example wireless transmit and receive paths according to the present disclosure. In the following description, transmit path 200 can be described as being implemented in a gNB (such as gNB 102), while receive path 250 can be described as being implemented in a UE (such as UE 116). However, it should be understood that the receive path 250 can be implemented in the gNB and the transmit path 200 can be implemented in the UE. In some embodiments, receive path 250 is configured to support codebook design and structure for systems with 2D antenna arrays as described in embodiments of the present disclosure.

The transmit path 200 includes a channel coding and modulation block 205, a serial-to-parallel (S-to-P) block 210, an N-point Inverse Fast Fourier Transform (IFFT) block 215, a parallel-to-serial (P-to-S) block 220, an add cyclic prefix block 225, and an up-converter (UC) 230. Receive path 250 includes a down-converter (DC)255, a remove cyclic prefix block 260, a serial-to-parallel (S-to-P) block 265, an N-point Fast Fourier Transform (FFT) block 270, a parallel-to-serial (P-to-S) block 275, and a channel decode and demodulation block 280.

In transmit path 200, a channel coding and modulation block 205 receives a set of information bits, applies coding, such as Low Density Parity Check (LDPC) coding, and modulates the input bits, such as with Quadrature Phase Shift Keying (QPSK) or Quadrature Amplitude Modulation (QAM), to generate a sequence of frequency domain modulation symbols. A serial-to-parallel (S-to-P) block 210 converts (such as demultiplexes) the serial modulation symbols into parallel data in order to generate N parallel symbol streams, where N is the number of IFFT/FFT points used in the gNB 102 and the UE 116. N-point IFFT block 215 performs IFFT operations on the N parallel symbol streams to generate a time-domain output signal. Parallel-to-serial block 220 converts (such as multiplexes) the parallel time-domain output symbols from N-point IFFT block 215 to generate a serial time-domain signal. Add cyclic prefix block 225 inserts a cyclic prefix into the time domain signal. Upconverter 230 modulates (such as upconverts) the output of add cyclic prefix block 225 to an RF frequency for transmission over a wireless channel. The signal can also be filtered at baseband before being converted to RF frequency.

The RF signal transmitted from the gNB 102 reaches the UE116 after passing through the radio channel, and the reverse operation to that at the gNB 102 is performed at the UE 116. Downconverter 255 downconverts the received signal to baseband frequency and remove cyclic prefix block 260 removes the cyclic prefix to generate a serial time-domain baseband signal. Serial-to-parallel block 265 converts the time-domain baseband signal to parallel time-domain signals. The N-point FFT block 270 performs an FFT algorithm to generate N parallel frequency domain signals. The parallel-to-serial block 275 converts the parallel frequency domain signals to a sequence of modulated data symbols. Channel decode and demodulation block 280 demodulates and decodes the modulated symbols to recover the original input data stream.

Each of the gnbs 101-103 may implement a transmit path 200 similar to transmitting to the UE 111-116 in the downlink and may implement a receive path 250 similar to receiving from the UE 111-116 in the uplink. Similarly, each of UEs 111-116 may implement a transmit path 200 for transmitting in the uplink to gNB 101-103 and may implement a receive path 250 for receiving in the downlink from gNB 101-103.

Each of the components in fig. 2a and 2b can be implemented using hardware only, or using a combination of hardware and software/firmware. As a specific example, at least some of the components in fig. 2a and 2b may be implemented in software, while other components may be implemented in configurable hardware or a mixture of software and configurable hardware. For example, FFT block 270 and IFFT block 215 may be implemented as configurable software algorithms, where the value of the number of points N may be modified depending on the implementation.

Further, although described as using an FFT and IFFT, this is merely illustrative and should not be construed as limiting the scope of the disclosure. Other types of transforms can be used, such as Discrete Fourier Transform (DFT) and Inverse Discrete Fourier Transform (IDFT) functions. It should be understood that the value of the variable N may be any integer (such as 1,2,3,4, etc.) for DFT and IDFT functions, and any integer that is a power of 2 (such as 1,2, 4, 8, 16, etc.) for FFT and IFFT functions.

Although fig. 2a and 2b show examples of wireless transmission and reception paths, various changes may be made to fig. 2a and 2 b. For example, the various components in fig. 2a and 2b can be combined, further subdivided, or omitted, and additional components can be added according to particular needs. Also, fig. 2a and 2b are intended to illustrate examples of the types of transmit and receive paths that can be used in a wireless network. Any other suitable architecture can be used to support wireless communications in a wireless network.

Fig. 3a illustrates an example UE116 according to the present disclosure. The embodiment of the UE116 shown in fig. 3a is for illustration only, and the

UE

111 and 115 of fig. 1 can have the same or similar configuration. However, UEs have a wide variety of configurations, and fig. 3a does not limit the scope of the present disclosure to any particular implementation of a UE.

The UE116 includes an antenna 305, a Radio Frequency (RF) transceiver 310, Transmit (TX) processing circuitry 315, a microphone 320, and Receive (RX) processing circuitry 325. The UE116 also includes a speaker 330, a processor/controller 340, an input/output (I/O) interface 345, input device(s) 350, a display 355, and a memory 360. Memory 360 includes an Operating System (OS)361 and one or more applications 362.

RF transceiver 310 receives incoming RF signals from antenna 305 that are transmitted by the gNB of wireless network 100. The RF transceiver 310 down-converts an incoming RF signal to generate an Intermediate Frequency (IF) or baseband signal. The IF or baseband signal is sent to RX processing circuitry 325, where RX processing circuitry 325 generates a processed baseband signal by filtering, decoding, and/or digitizing the baseband or IF signal. RX processing circuit 325 sends the processed baseband signals to speaker 330 (such as for voice data) or to processor/controller 340 (such as for web browsing data) for further processing.

TX processing circuitry 315 receives analog or digital voice data from microphone 320 or other outgoing baseband data (such as network data, e-mail, or interactive video game data) from processor/controller 340. TX processing circuitry 315 encodes, multiplexes, and/or digitizes the outgoing baseband data to generate a processed baseband or IF signal. RF transceiver 310 receives the outgoing processed baseband or IF signals from TX processing circuitry 315 and upconverts the baseband or IF signals to RF signals, which are transmitted via antenna 305.

The processor/controller 340 can include one or more processors or other processing devices and executes the OS 361 stored in the memory 360 in order to control overall operation of the UE 116. For example, processor/controller 340 may be capable of controlling the reception of forward channel signals and the transmission of reverse channel signals by RF transceiver 310, RX processing circuitry 325, and TX processing circuitry 315 in accordance with well-known principles. In some embodiments, processor/controller 340 includes at least one microprocessor or microcontroller.

The processor/controller 340 can also execute other processes and programs resident in the memory 360, such as operations for channel quality measurement and reporting for systems having 2D antenna arrays as described in embodiments of the present disclosure. Processor/controller 340 is capable of moving data into and out of memory 360 as needed to perform a process. In some embodiments, processor/controller 340 is configured to execute applications 362 based on OS 361 or in response to signals received from the gNB or the operator. The processor/controller 340 is also coupled to an I/O interface 345, where the I/O interface 345 provides the UE116 with the ability to connect to other devices, such as laptop computers and handheld computers. I/O interface 345 is the communication path between these accessories and processor/controller 340.

The processor/controller 340 is also coupled to input device(s) 350 and a display 355. The operator of the UE116 can input data into the UE116 using the input device(s) 350. Display 355 may be a liquid crystal display or other display capable of presenting text and/or at least limited graphics (such as from a website). A memory 360 is coupled to the processor/controller 340. A portion of memory 360 can include Random Access Memory (RAM) while another portion of memory 360 can include flash memory or other Read Only Memory (ROM).

Although fig. 3a shows one example of the UE116, various changes can be made to fig. 3 a. For example, the various components in FIG. 3a can be combined, further subdivided, or omitted, and additional components can be added according to particular needs. As a particular example, the processor/controller 340 can be divided into multiple processors, such as one or more Central Processing Units (CPUs) and one or more Graphics Processing Units (GPUs). Also, while fig. 3a shows the UE116 configured as a mobile phone or smart phone, the UE can be configured to operate as other types of mobile or fixed devices.

Fig. 3b illustrates an example gNB 102 according to the present disclosure. The embodiment of the gNB 102 shown in fig. 3b is for illustration only, and the other gnbs of fig. 1 can have the same or similar configuration. However, the gNB has a wide variety of configurations, and fig. 3b does not limit the scope of the present disclosure to any particular implementation of the gNB. Note that gNB 101 and gNB 103 can include the same or similar structure as gNB 102.

As shown in fig. 3b, the gNB 102 includes a plurality of antennas 370a-370n, a plurality of RF transceivers 372a-372n, Transmit (TX) processing circuitry 374, and Receive (RX) processing circuitry 376. In some embodiments, one or more of the plurality of antennas 370a-370n comprises a 2D antenna array. The gNB 102 also includes a controller/processor 378, a memory 380, and a backhaul or network interface 382.

The RF transceivers 372a-372n receive incoming RF signals, such as signals transmitted by UEs or other gnbs, from the antennas 370a-370 n. RF transceivers 372a-372n down-convert the incoming RF signals to generate IF or baseband signals. The IF or baseband signal is sent to RX processing circuitry 376, where RX processing circuitry 376 generates a processed baseband signal by filtering, decoding, and/or digitizing the baseband or IF signal. The RX processing circuit 376 sends the processed baseband signals to the controller/processor 378 for further processing.

TX processing circuitry 374 receives analog or digital data (such as voice data, network data, e-mail, or interactive video game data) from controller/processor 378. TX processing circuitry 374 encodes, multiplexes, and/or digitizes the outgoing baseband data to generate a processed baseband or IF signal. RF transceivers 372a-372n receive outgoing processed baseband or IF signals from TX processing circuitry 374 and upconvert the baseband or IF signals into RF signals for transmission via antennas 370a-370 n.

Controller/processor 378 can include one or more processors or other processing devices that control the overall operation of gNB 102. For example, the controller/processor 378 can control the reception of forward channel signals and the transmission of reverse channel signals through the RF transceivers 372a-372n, RX processing circuitry 376, and TX processing circuitry 374 according to well-known principles. The controller/processor 378 can also support additional functions, such as higher-level wireless communication functions. For example, the controller/processor 378 can perform a Blind Interference Sensing (BIS) process, such as by performing a BIS algorithm, and decode the received signal with the interference signal subtracted. Controller/processor 378 may support any of a wide variety of other functions in the gNB 102. In some embodiments, controller/processor 378 includes at least one microprocessor or microcontroller.

Controller/processor 378 is also capable of executing programs and other processes resident in memory 380, such as a base OS. The controller/processor 378 can also support channel quality measurement and reporting for systems with 2D antenna arrays as described in embodiments of the present disclosure. In some embodiments, controller/processor 378 supports communication between entities such as a web RTC. Controller/processor 378 can move data into and out of memory 380 as needed to perform a process.

Controller/processor 378 is also coupled to a backhaul or network interface 382. Backhaul or network interface 382 allows gNB 102 to communicate with other devices or systems over a backhaul connection or over a network. Backhaul or network interface 382 can support communication via any suitable wired or wireless connection(s). For example, when the gNB 102 is implemented as part of a cellular communication system (such as one supporting 5G or new radio access technologies or NR, LTE or LTE-a), the backhaul or network interface 382 can allow the gNB 102 to communicate with other gnbs over wired or wireless backhaul connections. When gNB 102 is implemented as an access point, backhaul or network interface 382 can allow gNB 102 to communicate with a larger network (such as the internet) via a wired or wireless local area network or via a wired or wireless connection. Backhaul or network interface 382 includes any suitable structure that supports communication over a wired or wireless connection, such as an ethernet or RF transceiver.

A memory 380 is coupled to the controller/processor 378. A portion of memory 380 can include RAM and another portion of memory 380 can include flash memory or other ROM. In some embodiments, a plurality of instructions, such as a BIS algorithm, are stored in memory. The plurality of instructions are configured to cause the controller/processor 378 to perform a BIS process and decode the received signal after subtracting at least one interfering signal determined by a BIS algorithm.

As described in more detail below, the transmit and receive paths of gNB 102 (implemented using RF transceivers 372a-372n, TX processing circuitry 374, and/or RX processing circuitry 376) support aggregated communication with FDD and TDD cells.

Although fig. 3b shows one example of a gNB 102, various changes may be made to fig. 3 b. For example, the gNB 102 can include any number of each of the components shown in fig. 3 a. As a particular example, the access point can include a number of backhauls or network interfaces 382 and the controller/processor 378 can support routing functions to route data between different network addresses. As another particular example, although shown as including a single instance of TX processing circuitry 374 and a single instance of RX processing circuitry 376, gNB 102 can include multiple instances of each (such as one for each RF transceiver).

Exemplary embodiments of the present disclosure are further described below in conjunction with the appended drawings.

The text and drawings are provided as examples only to assist the reader in understanding the disclosure. They are not intended, nor should they be construed, as limiting the scope of the disclosure in any way. While certain embodiments and examples have been provided, it will be apparent to those skilled in the art, based on the disclosure herein, that changes can be made in the embodiments and examples shown without departing from the scope of the disclosure.

In the 5G Rel-16 standard of 3GPP, a related research of Non-terrestrial networks (NTN) was conducted. With the wide area coverage capability of the satellite, the NTN enables an operator to provide 5G commercial services in areas where ground network infrastructure is not available, realizes 5G service continuity, and particularly plays a role in emergency communication, maritime communication, aviation communication, communication along a railway, and other scenes.

In NTN, two scenarios can be classified according to whether the satellite has the capability of decoding 5G signals: transparent payload (transparent payload) based scenes; and a scenario based on a regenerative load (regenerative load). In the transparent load-based scenario, the satellite does not have the capability of decoding the 5G signal, and the satellite directly passes through the received 5G signal sent by the ground terminal to the ground NTN gateway. In a scene based on a regenerative load, a satellite has the capability of decoding a 5G signal, decodes the received 5G signal transmitted by a ground terminal, re-encodes the decoded data and transmits the data to a ground NTN gateway, and the data can be directly transmitted to the ground NTN gateway or transmitted to other satellites and then transferred to the ground NTN gateway by the other satellites.

Due to the fact that the satellite is very high from the ground (for example, the height of a low-orbit satellite is 600km or 1200km, and the height of a synchronous satellite is close to 36000km), the transmission delay of a communication signal between a ground terminal and the satellite is very large, even can reach dozens or hundreds of milliseconds, while in a traditional ground cellular network, the transmission delay is only dozens of microseconds, and the great difference causes that NTN needs to use a physical layer technology different from that of the ground network, such as physical layer technologies of time frequency synchronization/tracking, Timing Advance (TA) of uplink transmission, physical layer processes, HARQ retransmission sensitive to delay transmission, and the like.

One effect of the large transmission delay is that the TA of the UE transmitting the uplink signal is increased, which may make the existing PRACH pilot sequence for estimating the maximum 2ms TA unusable because the TA is approximately twice the transmission delay.

Therefore, the UE needs to adopt a new method for acquiring the TA, for example, the UE calculates the distance between the satellite and the UE according to the satellite ephemeris to estimate the TA; or, the UE estimates the TA according to a time difference between the received timestamp and the local reference time; alternatively, the base station indicates a common TA or a reference TA, etc. through a system information block. Furthermore, as the TA increases, the scheduling delay for uplink transmission also needs to be correspondingly enlarged, i.e. additional timing offset is introduced. The present disclosure proposes solutions mainly for TA acquisition and related technical details of timing offset.

For simplicity of description herein, a satellite with decoding capability, a satellite without decoding capability, an air-borne transmitting platform with decoding capability, an air-borne transmitting platform without decoding capability, and other types of air transmitters in a non-terrestrial network may all be referred to as a base station. The techniques of the present disclosure are primarily for non-terrestrial networks, and may also be used for terrestrial networks.

In order to ensure time synchronization on the base station side, both Long Term Evolution (LTE) and New Radio (NR) systems use an Uplink Timing Advance (UL TA) mechanism. From the UE side, the timing advance is essentially a negative offset (negative offset) between the start time of the received downlink subframe and the time of the transmitted uplink subframe. The base station can control the arrival time of uplink signals from different UEs at the base station by appropriately controlling the offset of each UE. For a UE farther from the base station, due to a larger transmission delay, uplink data is transmitted earlier than for a UE closer to the base station.

Fig. 4 shows a schematic diagram of timing advance in a wireless communication system.

As shown in fig. 4, the UE may transmit a data packet ahead of a time indicated by the TA by compensating for a transmission delay caused by the distance by the TA so that the uplink data packet arrives at the base station (e.g., the gNB) at a desired time. As can be seen from fig. 4, the timings of the uplink subframe and the downlink subframe on the base station side are the same, and the timings of the uplink subframe and the downlink subframe on the UE side are offset from each other.

The base station may determine the TA value for each UE by measuring the uplink transmissions of the UE. Thus, the base station can be used to estimate the TA value as long as the UE has uplink transmissions. In theory, any Signal transmitted by the UE (e.g., Sounding Reference Signal (SRS), Demodulation Reference Signal (DMRS), Channel Quality Indicator (CQI), Acknowledgement (ACK), Negative Acknowledgement (NACK), Physical Uplink Shared Channel (PUSCH), etc.) may be used to measure TA. In the Random Access procedure, the base station determines a TA value by measuring a received Physical Random Access Channel (PRACH) pilot, sends the TA to the UE through a timing advance command field of the RAR, and the UE uses the received TA for subsequent uplink transmission, for example, for Msg3 transmission, until receiving an updated TA adjustment amount.

In the NTN system, since the distance between the satellite base station and the UE is much greater than the distance between the ground base station and the UE in a Terrestrial Network (TN) system, the corresponding transmission delay and TA are also greater, and the conventional PRACH pilot design is not sufficient to support TA measurement in a wider range. Therefore, the UE needs to use a new method to acquire TA, for example, the UE may estimate TA by estimating transmission distance/delay between a non-terrestrial base station (e.g., satellite), and/or the satellite base station indicates TA to the UE through SIB, then the UE may determine TA for PRACH transmission based on the self-estimated TA and/or the TA indicated by the satellite base station to reuse the existing PRACH pilot without affecting PRACH detection performance on the base station side.

According to an embodiment of the present disclosure, at least the following solutions are provided:

scheme 1. a method performed by a user equipment in a wireless communication system, comprising:

determining a third timing advance based on a first timing advance configured by a base station and/or a second timing advance estimated by the user equipment, wherein the third timing advance is used for a physical random access channel, PRACH, transmission of an initial random access procedure;

receiving a timing advance control instruction indicated by a base station through a Random Access Response (RAR); and

and obtaining a fourth timing advance according to the timing advance indicated by the timing advance control instruction and the third timing advance.

Scheme 2. the method of scheme 1, further comprising:

the fourth timing advance is updated based on drift information of the timing advance.

Scheme 3. the method of scheme 2, further comprising:

determining an update period; and

the fourth timing advance is periodically updated according to an update period.

Scheme 4. the method of scheme 3, wherein the update period is determined by one of:

receiving an update period transmitted by a base station; and

and obtaining an updating period according to the drift information of the timing advance.

Scheme 5. the method of scheme 2, wherein the drift information of the timing advance comprises:

common timing advance drift information configured by the base station through a system information block SIB, UE-specific radio resource control RRC signaling, or media access control MAC control element CE; and/or

The timing advance drift information dedicated to the user equipment is configured by the base station through radio resource control RRC signaling dedicated to the user equipment or media access control MAC control element CE, or estimated by the user equipment.

Scheme 6. the method of scheme 5, further comprising:

determining a first update period and a second update period;

updating a fourth timing advance according to the common timing advance drift information based on the first update period; and

updating, based on a second update period, a fourth timing advance according to the user equipment-specific timing advance drift information.

Scheme 7. the method of any of schemes 1-6, further comprising:

receiving an absolute timing advance control instruction indicated by a base station through a Media Access Control (MAC) control unit (CE); and

and obtaining a latest fourth timing advance according to the timing advance indicated by the received absolute timing advance control instruction and a latest third timing advance, wherein the latest third timing advance is determined based on the first timing advance newly configured by the base station and/or the second timing advance newly estimated by the user equipment.

Scheme 8. the method of scheme 7, wherein,

and determining the indicated timing advance according to the field and the reserved bit of the absolute timing advance control instruction in the MAC CE.

Scheme 9. the method of scheme 1, wherein the first timing advance is configured by one of:

configuring by a base station through a System Information Block (SIB); and

configuring, by the base station through the SIB, after the user equipment enters a radio resource control RRC connected state, by the base station through user equipment-specific RRC signaling or media access control MAC control element CE, wherein a value configured through the user equipment-specific RRC signaling or MAC CE is used to replace a value configured through the SIB.

Scheme 10. the method of scheme 9, wherein the first timing advance configured by the user equipment specific RRC signaling or MAC CE has a different indication granularity than the first timing advance configured by the SIB.

Scheme 11. the method of scheme 1, 9 or 10, wherein the first timing advance is associated with a particular time instant, the method further comprising:

when an interval between the time using the first timing advance and the associated specific time exceeds a preset range, the user equipment updates the first timing advance based on drift information of the first timing advance configured by the base station and uses the updated first timing advance.

Scheme 12. the method of scheme 11, wherein the specific time associated with the first timing advance is indicated by the base station, or defaults to a starting position of a modification period in which system information indicating the first timing advance is located, or defaults to a starting position of a radio frame with a system frame number of 0, or defaults to a time for receiving the first timing advance.

Scheme 13. the method of scheme 1, wherein the first timing advance is one of the following configurations:

a cell-specific first timing advance;

a first timing advance specific to a beam footprint;

a first timing advance specific to the beam footprint group; and

a first timing advance specific to the carrier bandwidth part.

Scheme 14. the method of scheme 1, wherein estimating the second timing advance uses one of the following estimation approaches:

estimating a second timing advance based on a geographical location difference between the user equipment and the base station;

estimating a second timing advance based on a reference time difference between the user equipment and the base station; and

estimating a second timing advance based on a geographical location difference and a reference time difference between the user equipment and the base station,

wherein the geographical location of the base station is determined based on information related to satellite ephemeris indicated by the base station, and the reference time of the base station is indicated by the SIB.

Scheme 15. the method of scheme 1, wherein whether the third timing advance comprises the first timing advance configured by the base station is related to how the user equipment estimates the second timing advance:

the third timing advance comprises the first timing advance if the manner of estimation of the second timing advance is based on a geographical difference between the user equipment and the base station; and

the third timing advance does not include the first timing advance if the second timing advance is estimated based on a reference time difference between the user equipment and the base station.

Scheme 16. the method of scheme 15, further comprising: and the user equipment reports the user equipment capability corresponding to the second timing advance estimation mode to the base station.

Scheme 17. the method according to scheme 16, wherein the ue reports the second timing advance estimation to the base station by one of:

reporting the second timing advance estimation mode to a base station through a user equipment dedicated RRC signaling or an MAC CE; and

and implicitly reporting the second timing advance estimation mode to a base station through the PRACH resource.

Scheme 18. the method of scheme 1, further comprising: reporting the second timing advance to the base station.

Scheme 19. the method of scheme 18, further comprising: and reporting the variation of the second timing advance relative to the second timing advance reported last time to the base station.

Scheme 20. the method of scheme 18 or 19, wherein reporting the second timing advance to the base station is triggered by one of:

if receiving the command of triggering the timing advance report indicated by the base station, triggering the report of the second timing advance;

if the second timing advance estimated latest is more than the second timing advance reported last time and exceeds the preset range, triggering the report of the second timing advance; and

and if the timer for controlling the reporting of the timing advance expires, triggering the reporting of the second timing advance, wherein the timer for controlling the reporting of the timing advance is started or restarted after the second timing advance is reported each time.

Scheme 21. the method according to scheme 20, wherein the receiving of the instruction to trigger the timing advance report, which is indicated by the base station, includes one of:

receiving a trigger timing advance reporting instruction indicated by Downlink Control Information (DCI) by a base station; and

and receiving a command which is indicated by the base station through the MAC CE and triggers the timing advance report.

Scheme 22. the method of scheme 18, wherein the reporting of the second timing advance to the base station comprises one of:

reporting the second timing advance to the base station through a Physical Uplink Control Channel (PUCCH); and

and reporting the second timing advance to the base station through the MAC CE.

Scheme 23, according to the method of scheme 18, reporting the second timing advance to the base station includes: reporting the second timing advance within a predefined or preconfigured time after the time at which the second timing advance estimation is performed.

Scheme 24. the method of scheme 1, further comprising receiving an offset of a second timing advance from a base station to correct the second timing advance using the offset of the second timing advance.

Scheme 25. according to the method of scheme 24, the offset of the second timing advance uses at least one of the following configurations:

the second timing advance offsets are configured for different timing advance estimation modes respectively; and

the offsets of the second timing advance are configured separately for different timing advance estimation accuracies.

The method of claim 1, further comprising determining that the fourth timing advance is invalid when at least one of the following conditions is met:

a timer configured by the base station for maintaining the timing advance expires, wherein the timer for maintaining the timing advance is started or restarted after each update of the fourth timing advance;

expiration of a validity period for the second timing advance;

changing the beam footprint of the user equipment;

the change of the geographical position of the user equipment exceeds a preset range;

the distance between the user equipment and the base station is changed beyond a preset range; and

the time interval since the last update of the fourth timing advance exceeds the preset range.

Scheme 27. the method of scheme 26, further comprising: at or before the occurrence of the fourth timing advance failure,

re-estimating a second timing advance, determining a third timing advance based on the newly estimated second timing advance, and using the third timing advance for uplink transmission, or initiating a random access procedure and using the third timing advance for PRACH transmission, or adjusting the fourth timing advance determined to be invalid based on a variation of the newly estimated second timing advance and a last estimated second timing advance, and using the adjusted fourth timing advance for uplink transmission; and/or the presence of a gas in the gas,

receiving a first timing advance newly configured by a base station, determining a third timing advance based on the first timing advance newly configured by the base station, and using the third timing advance for uplink transmission, or initiating a random access procedure and using the third timing advance for PRACH transmission, or adjusting a fourth timing advance determined to be invalid based on a variation of the first timing advance newly configured and the first timing advance configured last time, and using the adjusted fourth timing advance for uplink transmission.

Scheme 28. the method of scheme 1, further comprising:

a timing offset for uplink scheduling is calculated based on the fourth timing advance and the calculated timing offset is used for determining the time delay for uplink scheduling.

Scheme 29. according to the method of scheme 28, the calculating the timing offset for uplink scheduling based on the fourth timing advance is obtained by calculating a round of a ratio of the fourth timing advance to a duration of one uplink slot.

Scheme 30. the method of scheme 1, further comprising:

receiving a timing offset configured by a base station, wherein the received timing offset is calculated based on a fourth timing advance reported by the user equipment to the base station.

Scheme 31. the method of scheme 30, further comprising:

the received timing offset is configured by the base station through the SIB and after the user equipment enters the RRC connected state, through user equipment-specific RRC signaling or MAC CE.

Scheme 32. the method of any of schemes 1-31, wherein the method is performed by the user equipment by communicating with a non-terrestrial base station in a non-terrestrial network.

Scheme 33. a method performed by a base station in a wireless communication system, the method comprising:

receiving a physical random access channel, PRACH, transmission of an initial random access procedure from a user equipment, wherein the PRACH transmission is sent based on a third timing advance determined by the user equipment based on a first timing advance configured by the base station, and/or a second timing advance estimated by the user equipment; and

sending a timing advance control instruction indicated by a Random Access Response (RAR) to the user equipment,

wherein the timing advance indicated by the timing advance control instruction and the third timing advance are used for the user equipment to determine a fourth timing advance.

Scheme 34 the method of scheme 33, further comprising indicating drift information of timing advance to the user equipment for the user equipment to update a fourth timing advance.

Scheme 35. the method of scheme 33 or 34, further comprising transmitting an absolute timing advance control instruction indicated by a media access control, MAC, control element, CE, to the user equipment,

wherein the absolute timing advance control instruction indicates a timing advance and a latest third timing advance used by the user equipment to determine a latest fourth timing advance, the latest third timing advance being determined by the user equipment based on a first timing advance newly configured by the base station and/or a second timing advance newly estimated by the user equipment.

A user equipment in a wireless communication system, comprising:

a memory storing instructions; and

a controller configured to execute the instructions to implement the method of any of aspects 1-32.

Scheme 37. a base station in a wireless communication system, comprising:

a memory storing instructions; and

a controller configured to execute the instructions to implement the method of any of aspects 33-35.

Fig. 5 shows a flowchart of an example method performed by a UE in a wireless communication system according to an embodiment of the present disclosure. The method may comprise the steps of:

s501: determining a third timing advance based on the first timing advance configured by the base station and/or a second timing advance estimated by the UE, wherein the third timing advance is used for PRACH transmission of an initial random access procedure;

s502: receiving a timing advance control instruction indicated by a base station through RAR; and

s503: and obtaining a fourth timing advance according to the timing advance indicated by the timing advance control instruction and the third timing advance.

According to an embodiment of the present disclosure, the first timing advance may be one of the following configurations:

a cell-specific first timing advance;

a first timing advance specific to a beam footprint;

a first timing advance specific to the beam footprint group; and

a first timing advance specific to the carrier bandwidth part.

The first timing advance dedicated for the beam footprint is a first timing advance configured for each beam footprint, the first timing advance dedicated for the beam footprint group is a first timing advance configured for each beam footprint group, and the first timing advance dedicated for the carrier bandwidth part is a first timing advance configured for each initial uplink carrier bandwidth part.

In this description, a first Timing Advance (TA) may be configured by the base station through an SIB, or configured by the base station through UE-specific RRC signaling or MAC CE with finer granularity after the UE enters an RRC connected state, and may also be referred to as a common TA (common TA), a reference TA (reference TA), or a TA offset (TA offset), where the first TA may be a part of a complete TA, that is, a partial TA, and cannot be directly used for uplink transmission other than PRACH; the second TA is estimated by the UE based on the location or the reference time, and may also be referred to as an estimated TA, where the second TA may be a part of a complete TA, that is, a partial TA, and cannot be directly used for uplink transmission other than PRACH; the third TA is determined by the UE based on the first TA and/or the second TA, and may be the first TA, the second TA, or a sum of the first TA and the second TA, where the third TA may also be referred to as an initial TA and may be used for PRACH transmission, and the third TA may be a part of a complete TA, that is, a partial TA; the fourth TA may be determined by the UE based on the timing advance control directive indicated by the RAR and the third TA, the fourth TA may be for uplink transmissions subsequent to the PRACH transmission, the fourth TA is a full TA, and may be for uplink transmissions other than the PRACH.

The method for determining the third TA (initial TA) is described in detail below with reference to specific embodiments.

Example 1: determination of initial TA in initial random Access procedure

For a UE in an RRC Idle Mode (Idle Mode), an Inactive Mode (Inactive Mode), or just starting up (e.g., power-on, restart), during an initial random access procedure, the UE may acquire an initial TA by at least one of the following manners, and use the acquired initial TA for PRACH transmission, i.e., send the PRACH in advance by a corresponding amount of time.

Example 1-1: UE uses the common TA indicated by the base station as the initial TA

In the initial random access procedure, the common TA may be configured by the base station through a system information block SIB.

For example, the base station may indicate and transmit the common TA to the UE through the broadcasted SIB, and the UE determines an initial TA for PRACH transmission based on the received common TA.

In some embodiments, the configuration of the common TA may be Cell specific (Cell specific), i.e. all UEs of the same Cell use the same common TA. The scheme has the advantages that the signaling overhead is low, the method is suitable for cells with small range, and the difference value between the maximum TA and the minimum TA in the cells can be covered by the existing PRACH, namely, the difference value does not exceed 2 ms.

In some embodiments, the configuration of the common TA may be Beam-focused Specific (Beam-focused Specific), where the Beam footprint refers to the coverage area of the channel on the ground for one Beam transmitted by the base station. Beam footprint Specific, also referred to as Beam Specific, and may also be referred to as Synchronization Signal Block (SSB) Specific, i.e., SSB Specific. The public TA dedicated to the Beam footprint means that all UEs in the same Beam footprint (Beam footprint) use the same public TA, the UE determines the best Beam for downlink transmission according to SSB measurement, and further determines the public TA corresponding to the best Beam, and the base station indicates the corresponding public TA for each Beam in the SIB, that is, each public TA configured by the base station is associated with an index (index) of an SSB. The scheme is suitable for cells with large range, the difference value between the maximum TA and the minimum TA in the cells is large, and the cells cannot be covered by the existing PRACH, but the difference value between the maximum TA and the minimum TA in the coverage range of one beam can be covered by the existing PRACH, namely, the difference value does not exceed 2 ms.

In some embodiments, the configuration of the common TA may be Beam-fotopprint group Specific (Beam-fotopprint group Specific), which may also be referred to as SSB group Specific (SSB group Specific), that is, all UEs within a same group of Beam footprints use a same common TA, all beams sent by the base station side are divided into a plurality of Beam groups, each of the plurality of Beam groups includes a plurality of beams, the UE determines an optimal Beam for downlink transmission according to SSB measurement, and further determines a Beam group to which the optimal Beam belongs and a corresponding common TA thereof, and the base station indicates the corresponding common TA for each Beam group in the SIB, that is, each common TA of the base station configuration may be associated with an index (index) of one SSB group (SSB group). The scheme is suitable for the cells with moderate range, the difference value between the maximum TA and the minimum TA in the cells is large, and the cells cannot be covered by the existing PRACH, but the difference value between the maximum TA and the minimum TA in the coverage range of a plurality of adjacent beams of the cells can be covered by the existing PRACH, namely, the difference value does not exceed 2 ms.

In particular, in the above method for configuring a common TA based on beam group dedication, the number of beams included in each beam group is configurable, for example, the base station may configure each beam group to include 1, 3, or 5 beams, etc., and default that SSBs with consecutive index numbers belong to the same beam group. In some embodiments, assuming that the total number of beams in a cell is configured to be 12 and 3 beams are included in one beam group, there are 4 beam groups in total, the SSBs corresponding to the first beam group have indices #0, #1, #2, the SSBs corresponding to the second beam group have indices #3, #4, #5, and so on. The base station may configure a corresponding common TA value for each beam group.

In some embodiments, the configuration of the common TA may be carrier Bandwidth Part Specific (BWP Specific). For example, assuming that a cell has multiple initial DL (Downlink) BWPs or multiple initial UL (Uplink) BWPs, each initial UL BWP has a configuration of a corresponding common TA, and the common TAs corresponding to different initial UL BWPs may be the same or different; alternatively, each initial DL BWP has a configuration of a corresponding common TA, and the common TAs corresponding to different initial DL BWPs may be the same or different.

In some embodiments, the common TA may be configured by UE-Specific RRC signaling or MAC CE after the UE enters the RRC connected state, in addition to being configured by the SIB in one of the above manners, i.e. the configuration of the common TA may be UE-Specific (UE Specific).

Optionally, the system supports multiple configurations of the TA, which may be multiple of the above configurations, i.e., cell-specific, beam footprint group-specific, carrier bandwidth portion-specific, and/or UE-specific, and which configuration is specifically used may depend on the configuration of the base station.

In order to save signaling overhead, the granularity of the common TA indicated by the base station as described above may be much larger than the granularity of a TA Command (TA Command). In some embodiments, for example, the granularity of the common TA indicated by the base station may be 1ms, and then the residual TA within 1ms may be estimated by the existing PRACH. Whereas the granularity of the existing TA instruction is T_c*64*16/2^uWherein T is_cIs the duration of one sampling interval, is T_c＝1/(480*10³4096) seconds and u is related to the Subcarrier Spacing (SCS), where u-0, 1,2,3,4 corresponds to SCS 15,30,60,120,240kHz, respectively.

Fig. 6a-6e show schematic diagrams of an example common TA indicated by a base station, according to embodiments of the present disclosure. In fig. 6a-6e, D01 indicates the transmission delay between reference point 1Ref _1 and satellite 101, D02 indicates the transmission delay between satellite 101 and ground base station 102, D03 indicates the transmission delay between satellite 101 and reference point 2Ref _2, D11 indicates the transmission delay between user equipment UE1 and satellite 101, and D12 indicates the transmission delay between user equipment UE2 and satellite 101.

As shown in fig. 6a, the common TA is 2 × D01. The physical meaning of the common TA described above is 2 times the propagation delay between reference point 1Ref _1 within the cell or beam footprint and satellite 101 (i.e., D01). Wherein the reference point may be at a central location of a cell or beam footprint; alternatively, the reference point may be anywhere within the cell or beam footprint, and may even be anywhere between the terrestrial UE and the satellite, the location of the reference point depending on the implementation of the satellite. The satellite here may have the decoding capability of the base station.

As shown in fig. 6b, the common TA is 2 × (D01+ D02). The physical meaning of the common TA described above is 2 times the sum of the transmission delay between reference point 1Ref _1 within the cell or beam footprint and satellite 101 (i.e., D01), and the transmission delay between satellite 101 and ground base station 102 (i.e., D02). As above, reference point 1Ref _1 may be at the center of the cell or beam footprint; alternatively, reference point 1Ref _1 may be anywhere within the cell or beam footprint, and may even be anywhere between the terrestrial UE and the satellite, the location of the reference point depending on the implementation of the satellite. The satellite may not have the base station capability of the base station and may act as a relay (relay) for the signals transmitted between the UE and the terrestrial base station.

As shown in fig. 6c, the common TA is 2 × D02. The physical meaning of the common TA mentioned above is 2 times the transmission delay (i.e., D02) between the satellite 101 and the terrestrial base station 102. The satellite may not have the base station capability of the base station and may act as a relay (relay) for the signals transmitted between the UE and the terrestrial base station.

As shown in fig. 6D, the common TA is 2 × D03. The physical meaning of the common TA described above is 2 times the propagation delay between satellite 101 and reference point 2Ref _2 (i.e., D03). The reference point may be anywhere between the satellite and the ground base station, depending on the implementation of the satellite. The satellite may not have the base station capability of the base station and may act as a relay (relay) for the signals transmitted between the UE and the terrestrial base station.

As shown in fig. 6e, the common TA is 2 × (D01+ D03). The physical meaning of the common TA described above is 2 times the sum of the transmission delay between reference point 1Ref _1 and satellite 101 (i.e., D01), and the transmission delay between satellite 101 and reference point 2Ref _2 (i.e., D03) within the cell or beam footprint. As above, reference point 1Ref _1 may be at the center of the cell or beam footprint; or may be anywhere within the cell or beam footprint, or even anywhere between the terrestrial UE and the satellite, the location of the reference point depending on the implementation of the satellite. Reference point 2Ref _2 may be anywhere between the satellite and the terrestrial base station, depending on the satellite implementation. The satellite may not have the base station capability of the base station and may act as a relay (relay) for the signals transmitted between the UE and the terrestrial base station.

Examples 1 to 2: the UE uses the estimated TA estimated by itself as the initial TA

In the initial random access procedure, the UE may estimate a timing advance by itself and determine an initial TA for PRACH transmission based on the estimated timing advance.

According to an embodiment of the disclosure, the UE may estimate the second timing advance using one of the following estimation approaches: estimating a second timing advance based on a geographical location difference between the UE and the base station; estimating a second timing advance based on a reference time difference between the UE and the base station; and estimating a second timing advance based on a geographical location difference and a reference time difference between the UE and the base station. In some embodiments, the geographic location of the base station may be determined based on information related to satellite ephemeris indicated by the base station, and the reference time of the base station may be indicated by the base station through a SIB.

In some embodiments, the UE may calculate a transmission distance between the UE and the satellite according to its own geographic location and the geographic location of the satellite, so as to obtain a corresponding transmission delay between the UE and the satellite, where 2 times of the transmission delay is an estimated TA value. The geographical position of the UE is determined by a Global Navigation Satellite System (GNSS) module of the UE, that is, the scheme may be applied to a UE with GNSS capability; the geographic location of the satellite may be determined by the base station through satellite ephemeris (satellite ephemeris) indicated by the SIB.

In some embodiments, the UE may calculate a transmission delay between the UE and the base station based on a local reference time and a received timestamp (timestamp) sent by the base station, where a time difference between the received timestamp of the UE and a time when the timestamp is received is the transmission delay, and 2 times the transmission delay is an estimated TA value. The local reference time of the UE may be determined by the GNSS module, that is, the scheme may be applicable to the UE with GNSS capability; the received time stamp may be transmitted by the base station through the SIB.

According to the embodiment of the disclosure, the UE may report the UE capability corresponding to the estimation mode of the second timing advance to the base station.

According to an embodiment of the disclosure, the UE may report the estimation manner of the second timing advance to the base station by one of the following manners: reporting the second timing advance estimation mode to the base station through UE special RRC signaling or MAC CE; and implicitly reporting the second timing advance estimation mode to the base station through the PRACH resource.

In some embodiments, the system may support both TA estimation methods, which TA estimation method is adopted by the UE depends on the UE capability, and the UE may report the capability of the corresponding TA estimation method to the base station, that is, inform the base station whether the estimated TA of the UE is based on the satellite ephemeris or the timestamp. In addition, different UE capabilities may have different TA estimation accuracies, for example, a UE with high positioning capability may estimate a more accurate TA, and the UE may report the capability corresponding to the TA estimation accuracy to the base station, i.e., inform the base station of the corresponding level of the estimated TA accuracy. The UE may report the capability of the corresponding TA estimation mode and/or the capability of the corresponding TA estimation accuracy through RRC signaling or MAC CE.

In some embodiments, in the four-step random access process, the UE may report, at the Msg3, the capability of the corresponding TA estimation method and/or the capability of the corresponding TA estimation accuracy through RRC signaling or MAC CE; or, in the two-step random access process, the UE may report the capability corresponding to the TA estimation mode and/or the capability corresponding to the TA estimation accuracy in the PUSCH of the MsgA through RRC signaling or MAC CE.

In some embodiments, the UE may implicitly report the capability of the corresponding TA estimation method and/or the capability of the corresponding TA estimation accuracy through the used PRACH resource, that is, the UE using different TA estimation methods uses different PRACH resources, that is, the base station may know the TA estimation method used by the UE according to the detected PRACH resource; or, the UEs with different TA estimation capabilities use different PRACH resources, that is, the base station may know the TA estimation accuracy of the UE according to the detected PRACH resource.

In particular, since the satellite moves faster relative to the terrestrial UE, the transmission distance between the two may change rapidly, and the corresponding TA may also change rapidly, and if the TA is estimated too early before the PRACH is transmitted, the TA used in transmitting the PRACH may have failed. To guarantee timeliness of TA estimation, the UE should perform TA estimation within a certain time interval no later than before PRACH transmission, which may be predefined or configured by the base station through the SIB.

Examples 1 to 3: UE determines initial TA according to public TA indicated by base station and estimated TA estimated by UE

In the initial random access procedure, the UE may receive the base station indicated common TA and may estimate the TA itself, and determine an initial TA for PRACH transmission based on the base station indicated common TA and the estimated TA.

For example, as shown in fig. 6b to 6e, the satellite may not have the decoding capability of the base station, but relay the transmission signal between the terrestrial base station and the UE, and the transmission delay between the base station and the UE may include two parts: one part is transmission delay between the ground base station and the satellite, the corresponding part of the TA can be called as a public TA, the base station can indicate the public TA through SIB, and the specific configuration method is the same as the configuration method of the initial TA; the other part is the transmission delay between the UE and the satellite, the corresponding part of the TA can be called UE-dedicated TA, and the UE can estimate the transmission distance between the UE and the base station according to the own geographical position and the geographical position of the satellite so as to obtain the transmission delay and further estimate to obtain the UE-dedicated TA. As described above, the geographic location of the UE may be determined by the GNSS module and the geographic location of the satellites may be determined by the satellite ephemeris. The UE may use a sum of the common TA indicated by the SIB by the base station and the TA estimated by the UE itself for PRACH transmission.

That is, the UE may determine the initial TA, i.e., TA _ initial, by the following equation (1):

TA_initial＝TA_common+TA_est (1)

the TA _ common is a common TA indicated in the SIB by the base station, and the specific configuration method is the same as the common TA configuration method described above, that is, the common TA may be cell-specific, beam footprint group-specific, or BWP-specific; TA _ est is a TA value that the UE estimates based on the distance between the satellite and the UE. TA _ initial may be used for transmission of Msg1 (i.e., PRACH) for a four-step random access procedure or MsgA (i.e., PRACH and PUSCH) for a two-step random access procedure.

In some embodiments, whether the initial timing advance TA _ initial described above contains a common timing advance TA _ common configured by the base station is related to the way the UE estimates the second timing advance:

if the UE estimates the timing advance in a manner based on the geographical location difference between the user equipment and the base station, the initial timing advance comprises a common timing advance, and the estimated timing advance is TA _ initial-TA _ common + TA _ est;

if the UE estimates the timing advance in a way that is based on the reference time difference between the user equipment and the base station, the initial timing advance does not include the common timing advance, only the estimated timing advance, i.e. TA _ initial-TA _ est.

For example, as described with respect to fig. 5, examples 1-1, 1-2, and 1-3 above for determining an initial TA are used here for a UE in an initial random access procedure, e.g., in an RRC idle/inactive mode, or just powered on (e.g., powered on, restarted), after the UE sends a PRACH in advance by a corresponding amount of time, the UE may receive a monitored timing advance control Command (e.g., a Command field) in the RAR and superimpose an indication value of the received timing advance control Command on the initial TA, and use the superimposed TA for Msg3 and all subsequent uplink transmissions until an updated TA Command is received. That is, the UE may adjust the initial TA using a TA Command.

For example, the UE may determine a TA value TA _ Msg3 for the Msg3 and subsequent uplink transmissions by equation (2) as follows:

TA_msg3＝TA_prach+TA_cmd (2)

the TA _ PRACH is an initial TA value used for PRACH transmission, and the TA _ cmd is an indication value of a TA Command field in the RAR.

Figure 7 shows a schematic diagram of a MAC RAR composition according to an embodiment of the disclosure. The MAC RAR is configured to include a Timing Advance Command (Timing Advance Command), an UL Grant (UL Grant), a Temporary C-RNTI (temporal C-RNTI) field, and an R field.

As shown in fig. 7, the timing advance instruction indication field in the RAR contains 12 bits. Optionally, the indicator value is not an Absolute (Absolute) TA value, but is an adjustment amount (adjustment) of an initial TA used for PRACH transmission, and the indicator value may be a positive number or a negative number. Optionally, the indicated value is a partial TA, and needs to be superimposed on an initial TA used for PRACH transmission, where the superimposed TA is a complete TA, and the indicated value can only be a positive number.

According to embodiments of the present disclosure, the TA for uplink transmission may be maintained in real time using TA Drift (e.g., TA Drift) and/or TA control commands (e.g., TA Command) indicated by the MAC CE.

The method for maintaining a TA is described in detail below with reference to specific embodiments.

Example 2: maintenance of TA in RRC connected state

After the UE enters the RRC Connected Mode, the UE may maintain the TA by at least one of the following manners, and use the updated TA for uplink transmission of PUSCH, Physical Uplink Control Channel (PUCCH), SRS, and the like.

Example 2-1: UE updates TA based on relative TA Command sent by base station

After the UE enters the RRC connected state, the base station may measure the remaining TA according to the uplink signal or channel sent by the UE, and continuously adjust the TA value with respect to the TA Command, so that the uplink transmission sent by the UE reaches the base station side at a specified time. Here, the TA Command indication value is an adjustment amount with respect to the TA of the previous uplink transmission.

That is, the UE updates the TA value by the following equation (3):

TA(j+1)＝TA(j)+TA_cmd (3)

TA (j +1) and TA (j) are TA values used by the j +1 th uplink transmission and the j th uplink transmission, respectively, TA _ cmd is an indication value of a relative TA Command sent by the base station, and the j +1 th uplink transmission is an uplink transmission corresponding to the TA Command received by the UE and performing TA adjustment.

Alternatively, the base station may adjust the TA by sending a TA Command through the MAC CE, e.g., the base station may reuse an existing TA Command MAC CE, which includes a TAG ID (Timing Advance group identifier) and a Timing Advance Command (Timing Advance Command) field. As shown in fig. 8, the timing advance command indication field contains 6 bits; alternatively, a two byte MAC CE is used to indicate a larger range of relative TA Command.

Optionally, since the satellite moves fast relative to the UE, the TA may also change fast, and in order to ensure timeliness of the TA, the base station may dynamically indicate the TA Command through the downlink control information DCI, for example, add a new TA Command indication field to the existing DCI, or re-interpret the existing DCI indication field as the TA Command, for example, re-interpret an indication field (such as a PUCCH resource indication field, etc.) related to HARQ-ACK feedback as the TA Command.

Example 2-2: UE updates TA based on absolute TA Command sent by base station

According to embodiments of the present disclosure, a UE may receive an absolute timing advance control instruction indicated by a base station through a MAC CE; and obtaining a latest fourth timing advance according to the timing advance indicated by the received absolute timing advance control instruction and a latest third timing advance, wherein the latest third timing advance is determined based on a first timing advance newly configured by the base station and/or a second timing advance newly estimated by the UE.

In some embodiments, the base station may update the TA value of the RRC connected UE through an absolute TA Command MAC CE. As shown in fig. 9, the absolute TA Command MAC CE includes a Timing Advance Command (Timing Advance Command) field and an R field, wherein the absolute TA Command indication field includes 12 bits, and the indication value of the absolute TA Command is an adjustment amount with respect to the initial TA, i.e. has a similar meaning to the TA Command indicated in the MAC RAR, unlike the physical meaning of the existing absolute TA Command.

That is, the UE updates the TA value by the following equation (4):

TA＝TA_initial+TA_cmd (4)

the TA _ initial is referred to as an initial TA, and the determination method is the same as the method for determining the initial TA for PRACH transmission by the UE in the RRC idle/inactive state, that is, TA _ initial is TA _ common, or TA _ initial is TA _ est, or TA _ initial is TA _ common + TA _ est; TA _ cmd is the indication value of the absolute TA Command MAC CE.

As described above, if the initial TA is determined based on the TA estimated by the UE, for the UE in the RRC connected state, the initial TA should be determined using the estimated TA reported to the base station most recently, and the full TA should be determined based on the initial TA and the absolute TA Command indication value.

According to an embodiment of the present disclosure, the common TA may be configured by the base station through SIB, and configured by the base station through UE-specific RRC signaling or MAC CE after the UE enters the RRC connected state, wherein a value configured through the UE-specific RRC signaling or MAC CE is used to replace a value configured through SIB.

In some embodiments, if the initial TA is determined based on the common TA indicated by the base station, then for the UE in the RRC connected state, the initial TA may be determined using the common TA indicated by the base station through a SIB, or the initial TA may be determined using the common TA indicated by the base station through UE-specific RRC signaling or MAC CE, and the full TA may be determined based on the initial TA and the absolute TA Command indication value. According to an embodiment of the present disclosure, the common timing advance configured by UE-specific RRC signaling or MAC CE and the common timing advance configured by SIB have different indication granularities. For example, the common TA indicated by the base station through UE-specific RRC signaling or MAC CE may have finer granularity than the common TA indicated through SIB. That is, before entering the RRC connected state, the UE determines the initial TA based on the coarser common TA indicated by the SIB by the base station; the UE may determine the initial TA based on a more accurate common TA indicated by the base station through UE-specific RRC signaling or MAC CE after entering the RRC connected state.

If the common TA is indicated by the base station by UE-specific RRC signaling, an explicit time for the UE to use the common TA after receiving the signaling indication of the common TA needs to be specified, e.g., the base station indicates the explicit time for using the common TA together with the indication of the TA, or the default UE starts to enable the common TA at a predefined or preconfigured interval after receiving the signaling indication of the common TA.

According to embodiments of the present disclosure, the indicated timing advance may be determined according to a field of an absolute timing advance control instruction and reserved bits in the MAC CE.

In some embodiments, to extend the indication range of the absolute TA Command and reuse the existing absolute TA Command MAC CE as much as possible, the TA Command may be indicated using the reserved bit "R" in the MAC CE, for example, the number of indicating bits of the TA Command may be extended from 12 bits to 15 bits using the remaining three "R" bits, except for the first "R" bit in the MAC CE.

Fig. 10 shows a flowchart of an example method performed by a UE in a wireless communication system according to an embodiment of the present disclosure. The method may comprise the steps of:

s1001: determining a third timing advance based on the first timing advance configured by the base station and/or a second timing advance estimated by the UE, wherein the third timing advance is used for PRACH transmission of an initial random access procedure;

s1002: receiving a timing advance control instruction indicated by a base station through RAR;

s1003: obtaining a fourth timing advance according to the timing advance indicated by the timing advance control instruction and the third timing advance; and

s1004: the fourth timing advance is updated based on drift information of the timing advance.

In the embodiment shown in fig. 10, the operations of steps S1001 to S1003 are substantially the same as steps S501 to S503 in fig. 5, and thus the description thereof is omitted here for the sake of brevity.

According to an embodiment of the present disclosure, the drift information of the timing advance may include:

common timing advance drift information, configured by the base station through SIB, UE-specific RRC signaling, or MAC CE; and/or

UE-specific timing advance drift information is configured by the base station through UE-specific RRC signaling, or MAC CE, or estimated by the UE.

The following is described in detail with reference to specific examples 2-3 (for updating TA based on TA Drift estimated by the UE) and examples 2-4 (for updating TA based on TA Drift indicated by the base station).

Examples 2 to 3: UE updates TA based on estimated TA Drift

For example, since the moving speed of the satellite relative to the UE is relatively constant, the UE may estimate the relative moving speed through the GNSS module and the satellite ephemeris, and further estimate the change in the distance between the UE and the satellite per unit time, so as to obtain the change amount of the TA per unit time, that is, the Drift rate (TA Drift) of the TA over time, and the UE may continuously update the TA based on the estimated TA Drift. This method has at least the following advantages: the base station does not need to send TA Command frequently, thereby saving a large amount of signaling overhead and being capable of quickly and dynamically adjusting TA. This method can also be used in combination with examples 2-1 and 2-2 described above.

That is, the UE updates the TA value by the following equation (5):

TA(j+1)＝TA(j)+TA_drift*Time_delta (5)

wherein TA (j +1) and TA (j) are respectively TA update of j +1 time and j time; TA _ Drift is TA Drift estimated by the UE, that is, the Drift of TA in unit time, and the unit is the Drift of TA in each ms time, and the value of TA _ Drift may be positive or negative; time delta is the Time interval between the jth TA update and the j +1 th TA update.

According to embodiments of the present disclosure, a UE may determine an update period; and periodically updating the fourth timing advance according to the update period. For example, the UE may derive the update period from drift information of the timing advance. In some embodiments, the UE may periodically adjust the TA according to the estimated TA Drift, the periodic interval (i.e., Time delta) may be predefined or preconfigured, e.g., the period of TA adjustment may be configured by the base station through SIB, or UE-specific RRC signaling, or MAC CE. In some embodiments, the base station may trigger the UE to update the TA based on the estimated TA Drift, e.g., the base station may trigger the UE to update the TA through DCI or MAC CE, and the UE enables the updated TA at a time after receiving the DCI or MAC CE for a certain time interval, which may be predefined or preconfigured.

Because the UE can only estimate the TA Drift corresponding to the transmission delay between the satellite and the UE, but cannot estimate the TA Drift corresponding to the transmission delay between the satellite and the ground base station, the method can be applied to a scenario where the satellite has a base station decoding capability, that is, the complete TA can be formed by the transmission delay between the satellite and the UE, and does not include the transmission delay between the satellite and the ground base station.

Examples 2 to 4: UE updates TA based on TA Drift indicated by base station

Examples 2-4 are substantially the same as examples 2-3, except that the TA Drift corresponding to the transmission delay between the UE and the satellite described above can be estimated and indicated to the UE by the base station, i.e., the UE updates the TA based on the TA Drift indicated by the base station.

In addition, in a scenario where the satellite does not have a base station decoding capability but only plays a role in signal relay, the satellite has a relatively constant moving speed with respect to the ground base station, similar to the satellite having a relatively constant moving speed with respect to the ground UE, so that the transmission delay between the satellite and the ground base station may also have a corresponding TA Drift. For convenience of description, in an embodiment of the present disclosure, the TA Drift corresponding to the transmission delay between the UE and the satellite may be referred to as UE-specific timing advance Drift (UE-specific TA Drift), and the TA Drift corresponding to the transmission delay between the satellite and the terrestrial base station may be referred to as Common TA Drift (Common TA Drift). The UE-specific TA Drift may be configured to the UE by the base station or estimated by the UE, and the common TA Drift may be configured to the UE by the base station.

The UE may update the TA according to the common TA Drift indicated by the base station, and the UE-specific TA Drift indicated by the base station or the UE-estimated TA Drift.

For example, the UE may adjust TA according to equation (6) as follows:

TA(j+1)＝TA(j)+(TA_common_drift+TA_uespecific_drift)*Time_delta (6)

alternatively, the first and second electrodes may be,

the UE may adjust TA according to equations (7) - (8) as follows:

TA(j+1)＝TA(j)+TA_common_drift*Time_delta (7)，

TA(j+1)＝TA(j)+TA_uespecific_drift*Time_delta (8)。

TA (j +1) and TA (j) are respectively TA update of j +1 th Time and j th Time, TA _ common _ Drift is TA Drift corresponding to transmission delay between the UE and the satellite, TA _ UE specific _ Drift is TA Drift corresponding to transmission delay between the satellite and the ground base station, and Time _ delta is a Time interval between the TA update of j th Time and the TA update of j +1 th Time.

According to embodiments of the present disclosure, a UE may determine an update period; and periodically updating the fourth timing advance according to the update period. For example, the UE may receive an update period transmitted by the base station to determine the update period. According to embodiments of the present disclosure, the UE may determine a first update period and a second update period, and update the fourth timing advance according to the common timing advance drift information based on the first update period, and update the fourth timing advance according to the UE-specific timing advance drift information based on the second update period.

In some embodiments, the adjustment period for the common TA Drift may be different from the adjustment period for the UE-specific TA Drift, e.g., the base station may configure corresponding adjustment periods for the common TA Drift and the UE-specific TA Drift, respectively. That is, the UE may adjust the TAs based on the common TA Drift or the UE-dedicated TA Drift at different times, respectively, instead of having to adjust the TAs at the same time.

In some embodiments, the base station may configure the UE-specific TA Drift and the common TA Drift to the UE separately, for example, the base station may configure the UE-specific TA Drift through UE-specific RRC signaling or MAC CE, and the common TA Drift is configured through SIB, similar to the common TA described above, and may be cell-specific, beam group-specific, or carrier bandwidth part-specific; or, the base station may configure the UE-specific TA Drift and the common TA Drift through UE-specific RRC signaling or MAC CE, respectively; alternatively, the base station may configure the UE-specific TA Drift and the common TA Drift through the SIB, respectively, and may be cell-specific, beam group-specific, or carrier bandwidth part-specific.

In some embodiments, the base station configures the UE with the sum of the UE-specific TA Drift and the common TA Drift, that is, for the UE, the UE does not need to distinguish the UE-specific TA Drift from the common TA Drift, as long as the TA is updated according to the TA Drift configured by the base station. As above, the base station may configure the sum of the UE-specific TA Drift and the common TA Drift through UE-specific RRC signaling, MAC CE, or SIB.

In some embodiments, the base station may configure a common TA Drift to the UE, while the UE-specific TA Drift is estimated by the UE itself. The base station may configure the common TA Drift through UE-specific RRC signaling, MAC CE, or SIB.

In some embodiments, the UE periodically updates the TA according to the TA driffrift configured by the base station and/or the TA driffrift estimated by the UE, and a period (time interval) for updating the TA may be predefined, preconfigured or predetermined, for example, the period for adjusting the TA may be configured by the base station through SIB or UE-specific RRC signaling; alternatively, the period for updating TA may be calculated by the UE based on TA drift, and the period for updating TA may be a time interval when the TA drift amount reaches a preset size.

In some embodiments, the UE needs to update the TA based on the TA Drift for each uplink timeslot, and use the updated TA for uplink transmission. In other words, the period (time interval) for updating TA is one uplink timeslot.

In some embodiments, the base station may trigger the UE to update the TA based on the TA Drift configured by the base station and/or the TA Drift estimated by the UE, for example, the base station may trigger the UE to update the TA through DCI or MAC CE, and the UE activates the updated TA at a time after receiving the DCI or MAC CE for a certain time interval, which may be predefined or preconfigured.

As described above, the base station may indicate the common TA through the SIB, and the base station needs to continuously indicate the latest common TA since the common TA is continuously changed, but considering that the change time of the system information is limited by a minimum modification period (modification period), the common TA indicated through the SIB may not be applicable to the entire modification period, and when the UE determines the initial TA based on the common TA indicated by the SIB, the common TA indicated by the SIB may also need to be adjusted, which may also be adjusted based on a drift of the common TA, similar to the TA adjustment of the RRC connection state.

According to embodiments of the present disclosure, a common timing advance may be associated with a particular time instant. When an interval between a time using the common timing advance and an associated specific time exceeds a preset range, the UE may update the common timing advance based on drift information of the common timing advance configured by the base station and use the updated common timing advance.

According to an embodiment of the present disclosure, the specific time associated with the common timing advance may be indicated by the base station, or defaulted to a starting position of a modification period in which system information for indicating the common timing advance is located, or defaulted to a starting position of a radio frame with a system frame number of 0, or defaulted to a time for receiving the common timing advance.

In some embodiments, the common TA indicated by the SIB by the base station is associated with an absolute time, and if an interval between a time when the UE applies the common TA and the associated time exceeds a predefined or preconfigured range, the UE needs to adjust the common TA, for example, the common TA may be adjusted based on the TA Drift indicated by the base station, and when the common TA is indicated by the SIB by the base station, the corresponding TA Drift may be indicated together.

For a UE in RRC Connected Mode, when initiating some specific random access procedure, the sending PRACH may use the same TA as sending other uplink physical channels/signals, e.g., when the initiated random access procedure is non-contention based; for other specific random access procedures, the sending PRACH may use a different TA than the sending of other uplink physical channels/signals, for example, when the initiated random access procedure is contention-based, the TA determination method may use the foregoing determination method for the initial TA for PRACH transmission of the RRC idle/inactive UE.

As described in the foregoing method for determining an initial TA, when determining an initial TA for PRACH transmission based on a common TA, an RRC connected UE may use a common TA different from an RRC idle/inactive UE, and the RRC connected UE may determine the initial TA based on a UE-specific common TA, that is, a common TA configured by a base station through UE-specific RRC signaling or MAC CE; while the RRC idle/inactive UE can only determine the initial TA, i.e., the common TA configured by the base station through the SIB, based on the common TA dedicated to the cell, the beam group, or the carrier bandwidth part.

In some embodiments, which of the above-mentioned common TAs is used by the RRC connected UE to determine the initial TA for PRACH transmission may be determined by the type of random access procedure it initiates, e.g., when the purpose of initiating the random access procedure is to correct out-of-synchronization, the common TA configured by the SIB may be used to determine the initial TA for PRACH transmission; when initiating a random access procedure for requesting uplink resources, the initial TA for PRACH transmission may be determined using a common TA configured through UE-specific signaling.

Example 3: reporting of TA estimates

According to an embodiment of the disclosure, the UE may report the second timing advance estimated by the UE to the base station.

In the above method for determining and updating TA, it is an important method that the UE estimates the TA according to the location information or the reference time, and in order to make the base station have complete knowledge of the TA compensated by the UE, the UE may report the estimated TA to the base station, so as to achieve the purpose of reporting the estimated TA to the base stationThe base station is enabled to configure Timing Offset (Timing Offset) of uplink transmission based on TA compensated by the UE side, and the Timing Offset is used for determining a transmission slot of the uplink transmission, and specifically, the Timing Offset is additionally superimposed on a scheduling delay indicated in DCI (such as scheduling delay K2 of PUSCH, scheduling delay K1 of PUCCH, and the like) to determine a slot number for the uplink transmission. The TA granularity reported to the base station by the UE can be the same as the TA granularity configured to the UE by the existing base station, namely T_c*64*16/2^uWherein T is_cIs the duration of one sampling interval, is T_c＝1/(480*10³4096) seconds, u is related to the Subcarrier Spacing (SCS), with u being 0,1,2,3,4 corresponding to SCS 15,30,60,120,240kHz, respectively.

In some embodiments, in a Four-Step (Four-Step) random access procedure, the UE may send PRACH based on the estimated TA and always report the estimated TA or the TA for PRACH backoff to the base station in Msg3 through MAC CE or RRC signaling.

In some embodiments, in the four-step random access process, the UE may send PRACH based on the estimated TA, and whether to report the estimated TA in Msg3 or the TA used for PRACH compensation may be configured by the base station through an SIB; alternatively, whether to report the estimated TA or the TA for PRACH compensation in Msg3 may be indicated by the base station in the RAR.

In some embodiments, in a Two-Step (Two-Step) random access procedure, the UE may send MsgA based on the estimated TA and report the estimated TA or the TA for MsgA compensation to the base station in the PUSCH of MsgA through MAC CE or RRC signaling.

In some embodiments, in a two-step random access procedure, the UE may send MsgA based on the estimated TA, whether the estimated TA is reported in the PUSCH of MsgA or the TA for MsgA compensation may be configured by the base station through the SIB.

In some embodiments, after the UE enters the RRC connected state, the base station may trigger the UE to report the estimated TA or the compensated total TA value through explicit signaling. The base station triggers TA report through MAC CE, correspondingly, the UE reports TA through MAC CE, for example, the base station triggers TA report through reserved bit in the existing MAC CE for indicating TA Command, reserved bit in the existing MAC CE for indicating absolute TA value, or newly defined special MAC CE; or, the base station triggers TA reporting through DCI, and correspondingly, the UE reports the TA through PUCCH, for example, the TA reporting is sent through a newly added 1 bit in DCI, a redefinition of an existing bit field in DCI, or an existing reserved bit or reserved state in DCI.

According to an embodiment of the disclosure, reporting the second timing advance to the base station may be triggered by one of the following ways:

According to an embodiment of the present disclosure, receiving the instruction to trigger the timing advance report, where the instruction is indicated by the base station, may include one of:

receiving a trigger timing advance reporting instruction indicated by DCI by a base station; and

In some embodiments, after the UE enters the RRC connected state, the UE reports the estimated TAs to the base station through the MAC CE or RRC signaling, and the UE needs to report each estimated TA.

In some embodiments, after the UE enters the RRC connected state, the UE may trigger TA reporting based on a predefined event, e.g., if the difference between the UE's latest estimated TA and the estimated TA reported to the base station before exceeds a predefined or preconfigured threshold, the UE triggers TA reporting.

In some embodiments, after the UE enters the RRC connected state, the UE may trigger TA Reporting based on a preconfigured Timer (Timer), for example, the base station configures a TA _ Reporting _ Timer for the UE through RRC signaling, and after the UE estimates a TA each time of Reporting, the UE starts or restarts the TA _ Reporting _ Timer (Timer Reporting in advance), and in the TA _ Reporting _ Timer running process, the UE does not need to initiate TA estimation and Reporting; when TA _ Reporting _ Timer expires, the UE shall initiate TA estimation and Reporting.

According to the embodiment of the disclosure, the UE may report, to the base station, a variation of the second timing advance relative to a second timing advance reported last time.

In some embodiments, in order to save signaling overhead of TA estimation reporting, the UE may report a variation amount relative to a TA estimation reported last time, that is, it is not necessary to report a complete TA estimation amount, but the UE needs to report the complete TA estimation amount when reporting the TA estimation for the first time, and specifically, all the methods described above may be used. The base station can also trigger the UE to report the TA estimation variation and the complete TA estimation through different signaling.

According to an embodiment of the present disclosure, reporting, by the UE, the second timing advance to the base station may include one of:

reporting the second timing advance to the base station through a PUCCH; and

and reporting the second timing advance to the base station through the MAC CE.

According to embodiments of the present disclosure, the UE may report the second timing advance within a predefined or preconfigured time after the time at which the second timing advance estimation is performed.

The TA estimation and TA reporting both need to consume the power Of the UE, and in order to reduce the power consumption Of the UE as much as possible, especially for an Internet Of Things (IOT) UE with a high power consumption requirement, the number Of times Of TA estimation and reporting may be limited.

In some embodiments, the UE estimates the TA only when initiating the random access in the RRC non-connected state, sends Msg1 (four-step random access procedure) or MsgA (two-step random access procedure) with the estimated TA as the initial TA, and reports the estimated TA only in the random access procedure, where the initiation purpose of the random access procedure is to establish the RRC connection. For the four-step random access process, the UE sends PRACH based on the estimated TA and reports the estimated TA to the base station in Msg 3; for the two-step random access process, the UE sends MsgA based on the estimated TA, that is, sends PRACH and associated PUSCH based on the estimated TA, and reports the estimated TA to the base station in the PUSCH of MsgA. For example, the UE may report the estimated TA in the PUSCH of Msg3 or MsgA through a dedicated MAC CE.

The UE will not estimate the TA any more after entering the RRC connected state, and even if uplink desynchronization occurs (i.e., TA failure), the UE can still transmit random access triggered by the uplink desynchronization based on the TA estimated when the RRC connection is established, that is, send Msg1 or MsgA based on the TA estimated before, and need not report the estimated TA that has been reported again. Since the network cannot identify whether the random access procedure initiated by the UE is triggered by uplink desynchronization, all the random access procedures of the UE after entering the RRC connected state can be based on the TA estimated when the RRC connection is established. That is, the UE estimates the TA only once when the RRC connection is established, and reports the TA only once during the RRC connection establishment, and does not estimate the TA and report the TA after entering the RRC connected state.

From the perspective of the base station, the base station may determine whether the purpose of the random access process is used for establishing an RRC connection according to whether the estimated TA reported by the UE is received in the random access process, and if the estimated TA reported by the UE is received, the purpose of the random access process is used for establishing an RRC connection, and Msg1 or MsgA of the random access process is sent based on the received estimated TA; if the estimated TA reported by the UE is not received, the random access process is started in an RRC connection state, the base station already receives the estimated TA reported by the UE in the RRC establishment process, and the Msg1 or the MsgA of the random access process is sent based on the previously reported estimated TA. That is, the base station should store the estimated TA reported by the UE in the RRC establishment procedure.

In some embodiments, the UE estimates TA when initiating random access in RRC non-connected state, and sends Msg1 or MsgA with the estimated TA as initial TA, and reports the estimated TA in the course of this random access, as described above, the UE may report the estimated TA in the PUSCH of Msg3 (four-step random access procedure) or MsgA (two-step random access procedure). After entering the RRC connected state, the UE may estimate and report the TA when a specific condition is satisfied, for example, the UE may estimate and report the TA when one of the following conditions is satisfied:

the first condition is as follows: after entering an RRC connected state, the UE re-estimates the TA only when uplink desynchronization occurs (namely, the TA fails), sends the Msg1 or the MsgA based on the re-estimated TA and reports the latest estimated TA to the base station in a random access process triggered by the desynchronization. The UE will not estimate and report the TA in other cases. For random access procedures triggered by other reasons in RRC connected state, the UE may send Msg1 or MsgA based on the valid TA since the TA is still valid.

And a second condition: after entering an RRC connected state, the UE re-estimates the TA only when uplink desynchronization occurs (namely TA failure) and the time from the last estimated TA exceeds a preset range, sends Msg1 or MsgA based on the re-estimated TA, and reports the latest estimated TA to the base station in a random access process triggered by desynchronization. The UE will not estimate and report the TA in other cases. For random access procedures triggered by other reasons in RRC connected state, the UE may send Msg1 or MsgA based on the valid TA since the TA is still valid. If the random access procedure is triggered by out-of-sync and the time since the last estimated TA is not outside the preset range, the UE may send Msg1 or MsgA based on the last estimated TA. The preset range for determining whether the time since the last estimated TA is exceeded may be predefined, or pre-configured.

And (3) carrying out a third condition: after entering the RRC connected state, the UE re-estimates the TA only when initiating a random access, sends Msg1 or MsgA based on the re-estimated TA, and reports the newly estimated TA to the base station during the random access, regardless of whether the random access is triggered by out-of-sync. The UE will not estimate and report the TA in other cases.

Example 4: TA offset

According to an embodiment of the present disclosure, the UE may receive an offset of the second timing advance from the base station to correct the second timing advance using the offset of the second timing advance.

In the method of determining TA by UE estimation, there is a certain offset between the TA estimated by the UE and the actual TA, i.e. TA offset, which may also be referred to as TA margin (TA margin). For example, the reference time of the UE and the reference time of the base station may be from different time synchronization sources with a fixed time difference between them, then the UE estimates the TA based on the timestamp to produce TA offset/margin; and/or the position of the satellite estimated by the UE based on the reference time and the satellite ephemeris may also be offset, i.e., the UE may also make TA offset/margin based on the distance estimation TA between the satellite and the UE. In order to control the error between the estimated TA of the UE and the actual TA within a certain range, the base station may indicate TA offset/margin to the UE, and the UE superimposes the TA offset/margin indicated by the base station on the estimated TA of the UE to reduce the estimation error, i.e., TA _ offset/margin + TA _ est. In the above method for determining an initial TA by the RRC idle/inactive UE and the method for updating the TA by the RRC connected UE, if the UE determines the TA according to the estimated TA, the TA _ offset/margin indicated by the base station may be superimposed on the estimated TA.

In some embodiments, the base station configures the above TA offset/margin through SIB, that is, the UE of one cell may use the same TA offset/margin; alternatively, the base station configures the above TA offset/margin through UE-specific RRC signaling or MAC CE, i.e., each UE has its own TA offset/margin.

According to an embodiment of the present disclosure, the offset of the second timing advance may use at least one of the following configurations:

In some embodiments, the configuration of TA offset/margin is related to the estimation method of TA and/or the estimation accuracy of TA of the UE. For example, the base station configures corresponding TA offsets/margin according to different TA estimation methods (based on satellite ephemeris or based on time stamp); and/or respectively configuring corresponding TA offset/margin according to different TA estimation precisions.

Example 5: effectiveness of TA

After the UE acquires the TA through the above method, the TA may be maintained based on a predefined mechanism, that is, whether the TA is valid is determined according to a predefined rule, if the TA is determined to be valid, the TA may be continuously used to transmit the uplink physical signal/channel, and if the TA is determined to be invalid, the TA needs to be updated or reacquired.

According to an embodiment of the present disclosure, it may be determined that the fourth timing advance is invalid when at least one of the following conditions is satisfied:

expiration of a validity period for the second timing advance;

changing the beam footprint of the UE;

the change of the geographical position of the UE exceeds a preset range;

the distance between the UE and the base station is changed beyond a preset range; and

For example, the UE may determine that the TA is invalid by at least one of the following events:

if a timer TimeAlignimentTimer configured by the base station to maintain the TA expires, the UE determines that the TA is invalid. Here, the UE starts or restarts the TimeAlignmentTimer every time the TA is updated.

If the beam of the downlink transmission of the UE is changed, the UE judges that the TA fails.

The UE determines that the TA is invalid if the change in the geographical location of the UE exceeds a predefined or preconfigured threshold. Here, the UE needs to estimate its own geographical location periodically based on the GNSS module.

The UE determines that the TA is invalid if the change in distance between the UE and the satellite exceeds a predefined or preconfigured threshold. Here, the UE needs to periodically estimate the distance between itself and the satellite based on the GNSS module and the satellite ephemeris.

And if the UE calculates that the TA Drift exceeds a predefined or preconfigured threshold value after the TA is updated last time according to the TA Drift configured by the base station or estimated by the UE, the UE judges that the TA is invalid.

If the time interval since the last TA update exceeds a predefined or preconfigured threshold, the UE determines that the TA is invalid.

If the validity period (validity Time) or validity Timer (validity Timer) configured by the base station for estimating the TA expires, the UE determines that the TA is invalid. Here, the UE starts the validity period or timer after each estimation of TA.

According to embodiments of the present disclosure, at or before the occurrence of the fourth timing advance failure, the UE may perform the following operations:

If the TA is determined to be invalid in the above event, the UE needs to perform at least one of the following procedures:

the UE needs to re-initiate a random access procedure to acquire the TA, and similarly to the above RRC idle/inactive UE initiating the random access procedure, it needs to acquire an initial TA for PRACH transmission. The UE may determine the initial TA based on the re-estimated TA and/or the common TA newly indicated by the base station. Unlike RRC idle/inactive state UEs, the UE may determine an initial TA based on a common TA configured by the base station through UE-specific RRC signaling or MAC CE;

the UE needs to update the TA based on the TA Drift described above;

the UE needs to re-estimate the TA and/or receive the public TA newly indicated by the base station, and determine the initial TA based on the re-estimated TA and/or the public TA newly indicated by the base station, unlike the RRC idle/inactive UE, the UE may determine the initial TA using the public TA configured through UE-specific RRC signaling or MAC CE, and directly use the initial TA for uplink transmission;

the UE needs to re-estimate the TA and/or receive the common TA newly indicated by the base station, adjust the timing advance determined to be invalid based on the amount of change of the newly estimated timing advance from the last estimated timing advance, and/or adjust the timing advance determined to be invalid based on the amount of change of the newly configured common timing advance from the last configured common timing advance, and use the adjusted timing advance for uplink transmission.

In some embodiments, in order not to affect uplink transmission, the UE estimates the TA in advance and/or receives the common TA newly indicated by the base station before the TA failure is expected to ensure TA usage consistency, i.e. there is no gap period for TA failure, resulting in no uplink transmission being sent during the gap period, except PRACH. For example, the UE re-estimates the good TA and/or receives the common TA newly indicated by the base station before the beam switch occurs; or, before the validity period of the estimated TA expires, the UE re-estimates the good TA and/or receives the public TA newly indicated by the base station; alternatively, the UE may re-estimate the good TA and/or receive the common TA newly indicated by the base station before the expected change in geographic location is outside of a certain range.

Example 6: timing Offset (Timing Offset)

According to an embodiment of the present disclosure, the UE may calculate a timing offset for uplink scheduling based on the fourth timing advance and use the calculated timing offset for determining the time delay for uplink scheduling.

In the LTE system, a fixed time interval is provided between a PDCCH and a PUSCH/PUCCH scheduled by the PDCCH, taking into account a decoding time of the PDCCH and a transmission preparation time of the PUSCH/PUCCH. In the NR system, in addition to considering the decoding time of the PDCCH and the transmission preparation time of the PUSCH/PUCCH, in order to allocate resources within a certain period of time to a plurality of UEs at one time point to improve scheduling efficiency, the base station may dynamically indicate a delay of uplink scheduling through the DCI, such as the scheduling delay K2 of the PUSCH, the scheduling delay K1 of the PUCCH, and the like. In the NTN system, as the transmission delay increases, the TA for uplink transmission increases, and a timing offset is added to the existing K2 and K1 values to determine the timeslot number of uplink transmission, wherein the timing offset is related to the TA value compensated by the UE side, as shown in fig. 7, the timing offset is substantially equal to the TA value compensated by the UE side, the UE scheduled uplink timeslot and the downlink timeslot indicated for scheduling have a certain time interval, and the time interval is equal to about 2 times of the transmission delay, i.e. equal to about TA, but the granularity of the timing offset and the TA is the same, the granularity (i.e. unit) of the timing offset is the number of timeslots, and the granularity (i.e. unit) of the TA adjustment is T_c*64*16/2^u。

According to an embodiment of the present disclosure, the UE calculates the timing offset for uplink scheduling based on the fourth timing advance, which may be obtained by calculating a round of a ratio of the fourth timing advance to a duration of one uplink slot.

In some embodiments, the UE may derive timing offsets for various timing relationships based on the compensated total TA value. For example, the UE derives the timing offset from the TA value according to the following equation (9):

TTA is time corresponding to total TA value compensated by UE side, and the unit is milliThe number of seconds is, in turn,

the time contained in a time slot is related to the subcarrier spacing, for example, when SCS is 15,30,60,120,240kHz, i.e., u is 0,1,2,3,4, and correspondingly

That is, the UE converts the compensated total TA time into the corresponding number of slots by rounding down, and uses the number as the timing offset, that is, the unit of the timing offset is the uplink slot.

In some embodiments, in the four-step random access process, the UE reports the estimated TA at Msg3, and then the timing offset of the PUCCH carrying the ACK feedback corresponding to Msg4 may be calculated by the TA reported by the UE, instead of the timing offset broadcasted by the SIB; in the two-step random access process, the UE reports the estimated TA on the PUSCH of the MsgA, and then the timing offset of the PUCCH carrying the ACK feedback corresponding to the MsgB can be calculated from the TA reported by the UE, instead of the timing offset broadcasted through the SIB.

According to an embodiment of the present disclosure, a UE may receive a timing offset configured by a base station, wherein the received timing offset is calculated based on a timing advance reported by the UE to the base station. The received timing offset may be configured by the base station through the SIB and after the UE enters the RRC connected state, through UE-specific RRC signaling or MAC CE.

In the following, the common timing offset and the UE-specific timing offset are described in detail.

In some embodiments, the common timing offset is configured by the base station through SIB, similar to the configuration of the common TA described above, the base station may configure the cell-specific, beam footprint group-specific, or carrier bandwidth portion-specific common timing offset through SIB, and the common timing offset may be used for RRC connection state establishment of a PUSCH, etc. scheduled by RAR, of a previous uplink transmission, and a timing relationship of a broadcast channel.

In some embodiments, after the UE is in the RRC connected state, the base station may configure the UE-specific timing offset through UE-specific RRC signaling or MAC CE, which is only used for timing relationships of unicast channels.

According to embodiments of the present disclosure, the method described in connection with the above embodiments may be performed by a UE by communicating with a non-terrestrial base station in a non-terrestrial network. However, the present disclosure is not limited thereto, and may also be performed by the UE by communicating with other base stations than the non-terrestrial base station.

According to an embodiment of the present disclosure, there is provided a method performed by a base station in a wireless communication system, the method may include:

receiving a PRACH transmission of an initial random access procedure from a UE, wherein the PRACH transmission is transmitted based on a third timing advance determined by the UE based on a first timing advance configured by a base station and/or a second timing advance estimated by the UE; and

sending a timing advance control instruction indicated by the RAR to the UE,

wherein the timing advance indicated by the timing advance control instruction and the third timing advance are used by the UE to determine a fourth timing advance.

In some embodiments, the method may further include indicating drift information of the timing advance to the UE for the UE to update the fourth timing advance.

In some embodiments, the method may further include transmitting an absolute timing advance control instruction indicated by the MAC CE to the UE, wherein the absolute timing advance control instruction indicates a timing advance to be used by the UE to determine a latest fourth timing advance with a latest third timing advance determined by the UE based on the first timing advance newly configured by the base station and/or the second timing advance newly estimated by the UE.

Fig. 12 shows a block diagram of an example UE in accordance with an embodiment of the disclosure.

Referring to fig. 12, a UE 1200 includes a transceiver 1201, a controller 1202, and a memory 1203. Under control of the controller 1202 (which may be implemented as one or more processors), the UE 1200 may be configured to perform the relevant operations performed by the UE in the above-described methods. Although the transceiver 1201, the controller 1202 and the memory 1203 are shown as separate entities, they may be implemented as a single entity, such as a single chip. The transceiver 1201, the controller 1202, and the memory 1203 may be electrically connected or coupled to each other. The transceiver 1201 may transmit and receive signals to and from other network entities, such as a node (which may be, for example, a base station, a relay node, etc.) and/or another UE, etc. In some embodiments, transceiver 1201 may be omitted. In this case, the controller 1202 may be configured to execute instructions (including computer programs) stored in the memory 1203 to control the overall operation of the UE 1200, thereby implementing the operations in the flow of the above-described method.

Fig. 13 shows a block diagram of an example base station in accordance with an embodiment of the disclosure.

Referring to fig. 13, a base station 1300 includes a transceiver 1301, a controller 1302, and a memory 1303. Under control of a controller 1302 (which may be implemented as one or more processors), the base station 1300 may be configured to perform the relevant operations performed by the base station in the methods described above. Although the transceiver 1301, the controller 1302 and the memory 1303 are illustrated as separate entities, they may be implemented as a single entity, such as a single chip. The transceiver 1301, the controller 1302, and the memory 1303 may be electrically connected or coupled to each other. The transceiver 1301 may transmit and receive signals to and from other network entities, such as another node (which may be, for example, a base station, a relay node, etc.) and/or a UE, etc. In some embodiments, transceiver 1301 may be omitted. In this case, the controller 1302 may be configured to execute instructions (including computer programs) stored in the memory 1303 to control the overall operation of the base station 1300, thereby implementing the operations in the flow of the above-described method.

According to an embodiment of the present disclosure, at least the following aspects are also provided.

According to an aspect of the present disclosure, there is provided a method for channel transmission in a wireless communication network, including: determining a first time domain resource offset associated with the channel, wherein the first time domain resource offset is associated with a transmission delay; determining each of a plurality of time domain resource locations for transmitting the channel based on the first time domain resource offset; and transmitting the channel based on at least one of the plurality of time domain resource locations.

Optionally, determining a first time domain resource offset associated with the channel comprises: determining the first time domain resource offset based on an additional delay offset associated with the transmission delay; and/or determining the first time domain resource offset based on a scheduling time domain offset indication associated with the channel and the additional delay offset.

Optionally, the extra delay offset is configured or predefined in a unit of a downlink timeslot length or an uplink timeslot length.

Optionally, the method further comprises: starting and/or stopping a timer associated with the channel based on a transmission delay of the channel.

Optionally, starting and/or stopping a timer associated with the channel based on a transmission delay of the channel, further comprising at least one of: determining a value range of a timer associated with the channel based on the transmission delay, and starting and/or stopping the timer based on the value range; and determining a start time and/or a stop time of a timer associated with the channel based on the transmission delay, and starting and/or stopping the timer based on the start time and/or the stop time.

Optionally, determining, based on the transmission delay, a value range of a timer associated with the channel includes at least one of: taking a first value range of the timer configured by a system as a value range of the timer, wherein the first value range is determined based on the transmission delay of the channel; and determining a timing delay associated with the transmission delay based on the transmission delay of the channel, and determining the sum of a first value range of the timer configured by the system and the timing delay as the value range of the timer.

Optionally, the timing delay associated with the transmission delay comprises at least one of: an additional delay offset associated with the transmission delay; a current timing advance value associated with the channel; a common timing advance value associated with the channel; a first additional delay configured by the system for autonomous retransmission of the channel; and a second extra delay employed by the timer for hybrid automatic repeat request retransmissions.

Optionally, the method further comprises: determining a hybrid automatic repeat request process number associated with a starting time domain resource for transmitting the channel based on a transmission delay of the channel.

Optionally, determining a hybrid automatic repeat request process number associated with a starting time domain resource for transmitting the channel based on a transmission delay of the channel comprises: and determining a hybrid automatic repeat request process number associated with the starting time domain resource for transmitting the channel according to the transmission delay of the channel and the actual transmission position of the channel.

Optionally, determining a hybrid automatic repeat request process number associated with a starting time domain resource for transmitting the channel based on a transmission delay of the channel comprises: determining an additional offset associated with the transmission delay based on the transmission delay; determining a current time domain location associated with the starting time domain resource based on the additional offset; and determining a hybrid automatic repeat request process number associated with a starting time domain resource for transmitting the channel based on the current time domain location.

Optionally, transmitting the channel based on at least one of the plurality of time domain resource locations comprises: determining a time domain resource location for transmitting the channel based on one or more time periods associated with the channel, wherein at least one of the one or more time periods is associated with the transmission delay.

Optionally, at least one of the one or more time periods is a system-configured hybrid automatic repeat request round trip time.

Optionally, the starting location associated with at least one of the one or more time periods is determined based on at least one of: determining a starting position of a time domain resource for the channel scheduled based on a system; determining based on a time location of the system configuration corresponding to at least one of the one or more time periods; and determining based on a starting position of a time domain resource actually used to transmit the channel or a position where a received signal associated with the channel is detected.

Optionally, the method further comprises: determining a hybrid automatic repeat request type for each of a plurality of hybrid automatic repeat request processes associated with time domain resources for transmitting the channel, wherein the hybrid automatic repeat request type is determined based on at least one of: determining a hybrid automatic repeat request process type of a channel corresponding to a hybrid automatic repeat request process based on indication information in configuration information of each channel; determining a hybrid automatic repeat request process type of each hybrid automatic repeat request process based on the process number of the hybrid automatic repeat request process; determining a hybrid automatic repeat request process type of the hybrid automatic repeat request process based on indication information in Downlink Control Information (DCI); determining a hybrid automatic repeat request process type for the hybrid automatic repeat request process based on a configuration of a timer related to a retransmission of the channel; and determining a hybrid automatic repeat request process type for the hybrid automatic repeat request process based on a number of retransmissions or a retransmission time associated with the channel.

According to yet another aspect of the present disclosure, there is provided an apparatus for channel transmission in a wireless communication network, comprising: a transceiver configured to transmit and receive signals to and from the outside; and a processor configured to control the transceiver to perform a method according to an embodiment of the present disclosure.

According to yet another aspect of the present disclosure, there is provided a computer readable medium having stored thereon computer readable instructions, which when executed by a processor, are for implementing a method according to embodiments of the present disclosure.

The time domain resource position used for channel sending is determined based on the transmission delay in the wireless communication network, so that the time domain influence and the performance degradation caused by the large transmission delay to the communication system can be effectively eliminated when the channel sending is carried out in the wireless communication network with the large transmission delay.

Exemplary embodiments of the present disclosure are described below with continued reference to the accompanying drawings.

The 3GPP is developing related research on Non-terrestrial networks (NTN). With the wide area coverage capability of the satellite, the NTN enables an operator to provide 5G commercial services in areas where ground network infrastructure is not available, realizes 5G service continuity, and particularly plays a role in emergency communication, maritime communication, aviation communication, communication along a railway, and other scenes. Meanwhile, research on narrowband internet of things (NB-IoT) and enhanced machine communication (eMTC) carried by a non-terrestrial network is also being developed by 3 GPP.

Compared with a terrestrial wireless communication network, due to the extremely high distance between the satellite and the ground (for example, the height of a low-orbit satellite is 600km or 1200km, and the height of a synchronous satellite is close to 36000km), the transmission delay of communication signals between the ground terminal and the satellite is extremely large, and can even reach tens or hundreds of milliseconds. This makes NTN require the use of different physical layer techniques than terrestrial networks, such as Timing Advance (TA) for uplink transmissions. The present disclosure mainly provides a solution applicable to the case of a very large transmission delay, by taking uplink and downlink channel transmissions such as a Configured Grant (CG), a semi-persistent scheduling (SPS), and the like as examples.

Due to the large distance between the terrestrial UE (e.g., mobile terminal) and the satellite, there is a large transmission delay. In order to enable a base station to observe the same downlink time when receiving signals transmitted by different UEs, an additional delay offset is introduced for Uplink scheduling, such as Physical Uplink Shared Channel (PUSCH), Physical Uplink Control Channel (PUCCH), Sounding Reference Signal (SRS), and other channels or signals, for example, the additional delay K is an additional delay_offset. In general K_offsetEqual to or approximately equal to the transmission delay. For uplink transmission before Radio Resource Control (RRC) connection establishment, a common delay K may be broadcasted in the system information_offset. After the UE establishes the RRC connection, the base station may further update the K through UE-specific RRC signaling, or the RRC signaling may be combined with Media Access Control (MAC) or Downlink Control Information (DCI) dynamic indication_offsetThe value of (c). In particular, different channels, signals can be configured with different K_offset。K_offsetAnd may be generally any one or a combination of cell-specific, beam-specific, bandwidth part (BWP) -specific, UE-specific, and channel/signal-specific.

Since the different intervals of the uplink and downlink subcarriers result in different time lengths of symbols and time slots, K_offsetConfigured or predefined in units of downlink slot length or uplink slot length. Can be K_offsetA reference slot length (or corresponding subcarrier spacing) is configured or defined. For example, the reference slot length may be a slot length corresponding to a CORESET 0 subcarrier interval or a slot length corresponding to an interval of an initial Synchronization Signal Block (SSB), or a slot length of a specific downlink BWP.

More specifically, K_offsetCan be added in the following way:

● PUSC for DCI schedulingH, the time slot scheduled by the PUSCH can be

● for RAR scheduled PUSCH transmission, the UE may be in slot n + K₂+Δ+K_offsetAnd uploading the PUSCH. And delta is an extra offset used for scheduling PUSCH transmission by RAR, and is mainly used for reserving enough time for UE to decode PDSCH and analyze uplink authorization in RAR.

● for a slot transmitting HARQ-ACK on PUCCH, the UE may be in slot n + K₁+K_offsetAnd uploading the PUCCH.

● for the activation time of the MAC CE, the UE assumes that the downlink configuration can be in the time slot

The first slot thereafter takes effect. Wherein

X is the number of slots in each subframe for the subcarrier spacing μ, depending on the capability of the UE.

● for Channel State Information (CSI) reference resource timing, CSI reference resource can be in downlink time slot

The above.

● for aperiodic SRS timing, the UE may be in a slot

Is transmitted on each triggered SRS resource. And k is a time slot where the PDCCH triggering the SRS is located.

Wherein, mu_PUSCH、μ_PDCCH、μ_SRSThe sub-carrier intervals of the slots in which the PUSCH, the PDCCH (Physical Downlink Control Channel), and the SRS are located are respectively indicated. K₁And K₂The slot offset of the PUSCH is scheduled for PDSCH to PUCCH and DCI, respectively. n is the position of the respective reference signal.

A time offset for CSI reference resources to DCI.

Next, fig. 14 shows a schematic flow diagram of a method for channel transmission in a wireless communication network according to an embodiment of the present disclosure. As shown in fig. 14, in step S1401, a first time domain resource offset associated with a channel may be determined, wherein the first time domain resource offset may be associated with a transmission delay; in step S1402, each of a plurality of time domain resource locations for a transmission channel may be determined based on a first time domain resource offset; and in step S1403, the channel may be transmitted based on at least one of the plurality of time domain resource locations. The method shown in fig. 14 will be further described with reference to examples.

According to an embodiment of the disclosure, determining a first time domain resource offset associated with a channel may include: determining a first time domain resource offset based on an additional delay offset associated with a transmission delay; and/or determining a first time domain resource offset based on a scheduling time domain offset indication associated with the channel and the additional delay offset. In some embodiments, the scheduling time domain offset indication may be K as described above₁Or K₂The slot offset may be other symbol offsets or time offsets indicated in DCI or system signaling, or may be a combination of the slot offset and the symbol offset. The method can accurately schedule the system with large transmission delay, so that the positions of signals when different UE (user equipment) reach the base station can be aligned, and the complexity of the base station is simplified.

Fig. 15 shows a schematic diagram of uplink scheduling according to an embodiment of the present disclosure. As shown in FIG. 15, the base station (e.g., gNB) transmits an uplink schedule at time slot n (time t 1) due to transmissionAnd delaying, the UE receives the uplink scheduling at time t2, and the UE considers that time t2 is time slot n. Received uplink scheduling indication is at n + K₂+K_offsetAnd carrying out uplink transmission on the time slot. On the UE side, Timing Advance (TA) may be performed on the actual transmission so that the UE may perform the actual uplink transmission at time t 3. Thus, the uplink transmission can be at n + K of the base station time₂+K_offsetThe base station arrives at the time slot (time t 4). Thus, when scheduling multiple UEs, the base station need not compensate for the delay for each UE.

The above description assumes K_offsetIs one or more time slots. Theoretically, K_offsetShould be approximately equal to 2 times the transmission delay. Wherein, the transmission delay can be determined by the distance from the base station to the UE. The actual transmission delay may not necessarily be an integer multiple of the time slot. K_offsetThe expression may be calculated in other time units such as absolute time (e.g., milliseconds ms) or the number of symbols. In particular, it is possible to use, for example,

or

Or the number of slot times may be selected that is closest to the TA value. The time slot time length may be an uplink time slot time length or a downlink time slot time length. The TA may be a common (common) TA or a TA indicated in a TA command or a TA in which the UE transmits an actual application (app) uplink at this time or the last time.

Furthermore, for dynamic scheduling, the scheduling of the base station should be required to satisfy that the UE still satisfies the UE processing delay (e.g. the actual time interval between PDCCH and actual PUSCH transmission) after the TA is applied. Otherwise, the UE may be considered to be in erroneous scheduling.

Time domain location of CG PUSCH

There are two types of Configuration Granted (CG) PUSCHs in NR: type 1 and Type 2. Wherein the authorization of Type 1 CG PUSCH is configured through RRC, and the authorization of Type 2 CG PUSCH is activated by DCI.

For Type 2 CG PUSCH, the time domain resource location of PUSCH on each period of the configuration grant may be calculated in accordance with the dynamically scheduled PUSCH.

In the current NR, for Type 2 configuration grant (Type 2 CG), the MAC entity should consider that the sequential (sequential) nth uplink grant starts at a symbol position calculated according to the following formula a:

[ (SFN × number of OfSlotsPerFrame × number of OfSymbolsPerSlot) + (number of slots in frame (number) × number of OfSymbolsPerSlot) + number of symbols of slot (number)]＝[(SFN_{start time}×numberOfSlotsPerFrame×numberOfSymbolsPerSlot+slot_{start time}×numberOfSymbolsPerSlot+symbol_{start time})+N×periodicity]modulo (1024 × numberOfSlotsPerFrame × numberOfSymbolsPerSlot) (equation A)

The number of the continuous slots (slots) in each frame (frame) and the number of the continuous symbols in each slot are respectively the number of the continuous slots (slots) in each frame (frame). The period is a period of uplink configuration authorization. SFN is the System frame number, SFN_{start time}、slot_{start time}And symbol_{start time}SFN, timeslot, and symbol sequence number corresponding to the (re-) initialized PUSCH first transmission opportunity of the uplink configuration grant, respectively.

For a Type 2 CG PUSCH with a large TA, a slot position corresponding to a first transmission opportunity of the PUSCH can be obtained by at least one of the following methods:

the method comprises the following steps: can be combined with K₂The slot offset is determined as a first time domain resource offset associated with a channel (e.g., an uplink grant), and each time domain resource location for transmitting the channel is determined based on the first time domain resource offset. E.g. slot_{start time}May be based only on K indicated in DCI₂The slot offset is obtained, and K_offsetIs irrelevant. Wherein K indicated in DCI₂The slot offset may be based on the networkIs determined. The implementation is simple, and the implementation complexity of the UE and the base station can be reduced. Wherein slot_{start time}The UE side may receive downlink time slots as reference (e.g. the downlink time slots of the UE in fig. 15). Or may use the uplink timeslot of the UE after the UE applies the TA as a reference (e.g. the uplink timeslot of the UE in fig. 15).

The second method comprises the following steps: can be according to K₂Slot offset and extra delay offset K_offsetA first time domain resource offset associated with the uplink grant is determined and each time domain resource location for the transmit channel is determined based on the first time domain resource offset. E.g. slot_{start time}Can be according to K_offsetAnd K indicated in DCI₂The slot offset is obtained. In particular slot_{start time}Can pass through

And (4) obtaining. This can make the processing of Type 2 CG PUSCH the same as the processing of dynamically scheduled PUSCH. At this time, slot_{start time}Reference may be made to downlink time slots received by the UE side (e.g. downlink time slots of the UE in fig. 15). Or may use the uplink timeslot of the UE after the UE applies the TA as a reference (e.g. the uplink timeslot of the UE in fig. 15).

Then, the starting symbol position of the nth uplink grant can be obtained according to formula a, so that each of a plurality of time domain resource positions for transmitting the uplink grant can be further determined.

In addition, for the second method, the calculation method equivalent to the symbol position for maintaining the uplink configuration grant is the same as the calculation method of the first method, and the formula a is directly modified into the formula B:

[ (SFN × NumberOfSlotsPerFrame × NumberOfSymbolsPerSlot) + (number of slots in frame × NumberOfSymbolsPerSlot) + number of symbols of slot]＝[(SFN_{start time}×numberOfSlotsPerFrame×numberOfSymbolsPerSlot+(slot_{start time}+K_offset)×numberOfSymbolsPerSlot+symbol_{start time})+N×periodicity]modulo (1024 × numberOfSlotsPerFrame × numberOfSymbolsPerSlot) (formula B)

Wherein, K_offsetCan be configured in system messages or UE specific RRC signaling, and K_offsetIn units of time slots. In particular, K for PUSCH may be obtained in configuration information of PUSCH_offsetAnd can also be obtained in the RRC signaling of CG PUSCH configuration. Obtaining in RRC signaling that the same or different K is configured for each CG PUSCH configuring a plurality of CG PUSCHs_offsetValue, a more flexible effect can be achieved.

For K_offsetIn the case of symbol unit, the starting symbol position of the nth uplink grant can be calculated by using formula B':

[ (SFN × NumberOfSlotsPerFrame × NumberOfSymbolsPerSlot) + (number of slots in frame × NumberOfSymbolsPerSlot) + number of symbols of slot]＝[(SFN_{start time}×numberOfSlotsPerFrame×numberOfSymbolsPerSlot+slot_{start time}×numberOfSymbolsPerSlot+symbol_{start time}+K_offset)+N×periodicity]modulo (1024 × number of SlotsPerFrame × number of SymbolsPerSlot) (formula B')

For K_offsetIn the case of absolute time units, it can be based on K_offsetAnd obtaining parameters taking time slots or symbols as units, and respectively substituting the parameters into the formula B or the formula B' to obtain the initial symbol position of the Nth uplink configuration authorization. Wherein, according to K_offsetThe method for obtaining the parameters in time slots or symbols can be K_offsetDivided by the slot length or symbol length and rounded or the most recent value. The timeslot length may be a downlink timeslot length or an uplink timeslot length.

The grant for Type 1 CG PUSCH is RRC configured. In the current NR system, for the Type 1 configuration grant (Type 1 CG), the MAC entity should decide the starting symbol position according to the following formula C in consideration of the sequential (sequential) nth uplink grant:

[ (SFN × numberofslotspersFrame × numberofSymbolsPerSlot) + (number of slots in frame × numberOfSymbolsPerSlot) + number of symbols of slot ] (timeReferenceSFN × numberOfSlotsPerFrame × numberSymbolsPerSlot + timeDomainOffset × numberSymbolsPerSlot + S + N × periodicity) module (1024 × numberOfSlotsPerFrame × numberOfSymbolsPerSlot) (formula C)

Wherein, the timeReferenceSFN is a reference SFN, the timeDomainOffset is a slot offset to the reference SFN, and S is a position of an initial symbol in time domain resource allocation.

For a Type 1 CG PUSCH with a large TA, the symbol position of the nth uplink grant may be obtained by at least one of the following methods:

the method comprises the following steps: the actual timing advance can be taken into account when configuring the timeDomainOffset. The actual timing advance value may be determined based on the transmission delay in the network. Then, the UE may obtain the symbol position of the nth uplink grant along the above formula C. The time domain offset may be referred to a downlink timeslot received by the UE side (e.g., a downlink timeslot of the UE in fig. 15). Or the timeDomainOffset may be referred to as an uplink timeslot of the UE after the TA is applied by the UE (e.g. the uplink timeslot of the UE in fig. 15). In method 1, when an uplink grant arrives at the UE, it is necessary to determine a time domain position where uplink PUSCH transmission can be performed, based on the time domain position of the CG PUSCH resource and the TA. That is, the UE needs to find the uplink timeslot position corresponding to the time domain resource position of the first CG PUSCH to transmit. Wherein, the uplink time slot position is obtained after applying (Apply) Timing Advance (TA) to the downlink time slot position. As shown in fig. 15, if the uplink traffic arrives at time t2, the nearest CG PUSCH position is time t3, and at this time, the corresponding downlink resource is the resource at time t 5. At this time, the UE may calculate the HARQ process number according to the downlink timeslot corresponding to time t 5. This method is relatively simple to implement.

The method 2 comprises the following steps: can be shifted by K according to the extra delay_offsetDetermine a first time domain resource offset associated with the uplink grant and based on the first time domain resource offsetThe quantity determines each time domain resource location for the transmit channel. For example, may be according to K_offsetAnd calculating to obtain the symbol position of the Nth uplink authorization. The method has the same processing as dynamic scheduling and is simpler. Specifically, for the configuration in units of time slots, the nth uplink grant symbol position can be inferred according to the following formula D:

[ (SFN × NumberOfSlotsPerFrame × NumberOfSymbolsPerSlot) + (number of slots in frame × NumberOfSymbolsPerSlot) + number of symbols of slot]＝(timeReferenceSFN×numberOfSlotsPerFrame×numberOfSymbolsPerSlot+(timeDomainOffset+K_offset) X number of symbol OfSymbolsPerSlot + S + N number of period) module (1024 number of symbol OfSlotsPerFrame number of symbol sPerSlot)

Wherein, K_offsetMay be configured in system messages or UE-specific RRC signaling. In particular, K for PUSCH may be obtained in configuration information of PUSCH_offsetThe configuration information may also be obtained in RRC signaling configured in Type 1 CG PUSCH, for example:

configuring the same or different K for each CG PUSCH of a plurality of CG PUSCHs_offsetValue, a more flexible effect can be achieved.

For K_offsetIn the case of symbol unit, the starting symbol position of the nth uplink grant can be calculated by using formula D':

[ (SFN × NumberOfSlotsPerFrame × NumberOfSymbolsPerSlot) + (number of slots in frame × NumberOfSymbolsPerSlot) + number of symbols of slot]＝(timeReferenceSFN×numberOfSlotsPerFrame×numberOfSymbolsPerSlot+timeDomainOffset×numberOfSymbolsPerSlot+S+K_offset+ N × periodicity) module (1024 × numberOfSlotsPerFrame × numberOfSymbolsPerSlot) (formula D')

For K_offsetIn units of absolute timeCan be according to K_offsetAnd obtaining parameters taking time slots or symbols as units, and respectively substituting the parameters into the formula D or the formula D' to deduce the position of the Nth uplink authorization symbol. Wherein, according to K_offsetThe method for obtaining the parameters in time slots or symbols can be K_offsetDivided by the slot length or symbol length and rounded or the most recent value. The timeslot length may be a downlink timeslot length or an uplink timeslot length.

Retransmission timer

For the CG PUSCH, the base station may configure a scheduled grant timer through an RRC configuration Information Element (IE), where the IE indicates a timer (timer), and if the timer is considered to be stopped, it indicates that data uploaded by the corresponding HARQ process is successfully received by the base station. In addition, the base station may further configure a message element (IE) cg-retransmission timer through RRC, where the IE indicates a timer for indicating a time when the UE cannot perform an autonomous retransmission related HARQ process. Due to the large transmission delay between the base station and the UE, at least one of the two timers needs to be modified to accommodate the transmission delay. According to embodiments of the present disclosure, a timer associated with a channel may be started and/or stopped based on a transmission delay of the channel. In some embodiments, a range of values for a timer associated with transmission of a channel may be determined based on a transmission delay of the channel, and the timer may be started and/or stopped based on the range of values. For example, a first value range of a timer configured by the system may be used as the value range of the timer, where the first value range may be determined based on the transmission delay of the channel; and/or determining a timing delay associated with the transmission delay based on the transmission delay of the channel, and determining the sum of a first value range of the timer configured by the system and the timing delay as the value range of the timer. The method can be suitable for a system with large transmission delay, so that the timer can cover the transmission delay and ensure the normal work of the system. Specifically, at least one of the two timers may be calculated by at least one of the following methods:

the method comprises the following steps: an additional delay (or timing delay) may be added based on the first range of values of the system-configured timer (e.g., configured by the base station).

The method 2 comprises the following steps: the range of the timer can be directly extended (e.g., by the system or base station). For example, the system may directly determine a first value range of the timer based on the transmission delay of the channel and use it as the timing range of the timer.

The method 3 comprises the following steps: the value range of the timer can be expanded and extra delay can be added. I.e., a combination of method 1 and method 2.

Fig. 16 shows a schematic diagram of extending the value range of a timer according to an embodiment of the disclosure. As shown in fig. 16, the UE transmits an uplink grant on slot n, and starts or restarts the timer. Then, the value range of the timer needs to be large enough. This allows the base station to reserve enough time for potential retransmission scheduling. As shown in fig. 16, this timer needs to add at least twice the transmission delay. For example, the extra delay may be a TA value or K used in the preamble to determine the PUSCH time domain time resource_offsetValue, or TA/2 value, etc. Wherein the TA may be a common TA or a TA actually applied by the UE. This extra delay can also be configured separately by specific signaling.

Additionally or alternatively, a start time and/or a stop time of a timer associated with a channel may be determined based on a transmission delay of the channel, and the timer may be started and/or stopped based on the start time and/or the stop time. Significant transmission delays can be accommodated by modifying the start and/or stop times of the timer. In particular, the timer may be started after an additional delay. Fig. 17 shows a schematic diagram of changing the start time of a timer according to an embodiment of the present disclosure. As shown in fig. 17, the UE may send an uplink grant on slot n and may start or restart the timer after an additional delay. In particular, this timer may be configuredGrantTimer.

Specifically, the turning on and/or off of the configuredGrantTimer and/or the cg-retransmission timer may be performed by at least one of the following methods:

● if an uplink grant of a CG PUSCH is received in the RAR, or an uplink grant is received in the PDCCH and a New Data Indicator (NDI) corresponding to the HARQ process is 1 (retransmission), then a configurable grant timer is turned on (or turned back on) for the corresponding HARQ process after an extra delay. At this time, if the cg-Retransmission Timer is configured, the cg-Retransmission Timer may be stopped directly for the corresponding HARQ process or after an additional delay.

●, an uplink grant is received in the PDCCH, and NDI corresponding to the HARQ process is 0, and the DCI is an active DCI of Type 2 CG PUSCH, if configurable grant timer and/or CG-retransmission timer is running, at least one of the two timers is stopped directly or after an extra delay.

● if an uplink grant is received in the PDCCH and the corresponding transmission is an initial transmission, then the configuredGrantTimer and/or the cg-retransmission Timer are turned on or turned back on after an extra delay.

● if the HARQ process receives downlink feedback, the HARQ process may stop either directly or after an additional delay to configure GrantTimer and/or cg-retransmission Timer.

Preferably, the UE may start a timer after the additional delay, but may not stop a timer after the additional delay.

The additional delay (i.e., timing delay) described in the above method may be at least one of: k corresponding to CG PUSCH_offset(configured by the methods described previously); or a current TA associated with the channel transmission; or a common (common) TA associated with channel transmission; or a first extra delay additionally configured by a base station (or a system) for CG PUSCH autonomous retransmission; or the same configuration as the second additional delay employed by the timer for calculating HARQ retransmissions. Wherein, the common TA may be configured through system information or UE-specific RRC signaling. The UE current TA may be the sum of the common TA and the UE specific TA transmitted by the base station to the UE. Wherein the UE-specific TA may include: TA in RAR and TA in subsequent TA commands.

Calculation of HARQ-ID

In the NR system, for configuring uplink grants (configured uplink grants), if neither HARQ-ProcID-Offset2 nor cg-retransmission timer is configured, the HARQ process ID associated with the first symbol for uplink transmission can be deduced according to the following formula:

HARQ Process ID＝[floor(CURRENT_symbol/periodicity)]modulo nrofHARQ-Processes。

wherein, the period is the period of system configuration, and the nrofHARQ-Processes are the number of hybrid automatic repeat request (HARQ) Processes in the configured uplink grant.

For the configured uplink grant configured with the HARQ process ID Offset HARQ-ProcID-Offset2, the hybrid automatic repeat request process number (HARQ process ID) associated with the first symbol for uplink transmission can be inferred according to the following formula:

HARQ Process ID＝[floor(CURRENT_symbol/periodicity)]modulo nrofHARQ-Processes+harq-ProcID-Offset2。

wherein, the position of the current symbol is:

CURRENT _ symbol ═ (SFN × number of slot spotsperframe × number of symbol symbospersslot + slot in frame where CURRENT symbol is located × number of symbol spotsperslot + symbol in slot where CURRENT symbol is located) (formula E)

The number of the continuous slots (slots) in each frame (frame) and the number of the continuous symbols in each slot are respectively the number of the continuous slots (slots) in each frame (frame).

According to an embodiment of the present disclosure, a hybrid automatic repeat request process number associated with a starting time domain resource for transmitting a channel may be determined based on a transmission delay of the channel. Wherein the starting time domain resource may be, for example, the first symbol for uplink transmission as described above. For systems with large TA or large transmission delay, the position of the current symbol used to decide the HARQ ID number in CG PUSCH can be defined by one of two methods:

the method comprises the following steps: the number of the hybrid automatic repeat request process associated with the starting time domain resource for transmitting the channel can be determined according to the transmission delay of the channel and the actual transmission position of the channel. For example, the position of the current symbol may be defined as the position of the downlink symbol corresponding to the grant received by the UE, and calculated by using formula E. Note that this position may not be the position of actual upstream transmission. For example, referring to fig. 15, the actual uplink transmission position of the UE is the time slot corresponding to time t3, and the downlink symbol position corresponding to the grant received by the UE may be the time slot corresponding to time t 5. Wherein t5 is the time after TA is applied at t 3. And the UE determines the corresponding downlink time slot position according to the actual sending position and the applied TA (or transmission delay), and determines the HARQ process number corresponding to the PUSCH according to the determined downlink time slot position. The base station can calculate according to the actual sending and receiving time slot positions, and the complexity of the base station is reduced.

The second method comprises the following steps: an additional offset associated with the transmission delay may be determined based on the transmission delay; determining a current time domain location associated with the starting time domain resource based on the additional offset; and determining a hybrid automatic repeat request process number associated with a starting time domain resource for transmitting the channel based on the current time domain location. For example, the current symbol position may be obtained according to the following formula F:

CURRENT _ symbol ═ (SFN × number of slot spotsperframe × number of symbol in frame + X) × number of symbol sporspot + symbol of symbol in slot where CURRENT symbol is located) (formula F)

Where X may be an additional offset in units of slots. The offset may be obtained based on a transmission delay of a channel, e.g., may be K used to obtain a PUSCH time domain transmission position_offsetOr is-K_offsetOr sending the TA applied by the PUSCH, or the common TA, or parameters configured for additional signaling.

Similarly, if X is a number in symbols, the current symbol position can be obtained with the following formula:

CURRENT _ symbol ═ (SFN × number of slot spotsperframe × number of symbol symbospersslot + (slot in frame where previous symbol is located × number of symbol spotslot + symbol of slot where CURRENT symbol is located + X) (formula F')

For the case where X is in absolute time units, the current symbol position can be obtained by substituting the above formula F or formula F' with the parameter in time slots or symbols obtained from X, respectively. The method of obtaining the parameter in units of slots or symbols according to X may be obtained by dividing X by the slot length or symbol length and then rounding up or taking the most recent value. The timeslot length may be a downlink timeslot length or an uplink timeslot length.

The method can avoid the base station from calculating the HARQ process for each UE, and can reuse the existing method for calculating the number of the HARQ process.

Configuration for multiple CG PUSCH or DL SPS

Due to the existence of large transmission delay, the design of the system needs to avoid sending a plurality of DCIs to activate CG PUSCH or DL SPS as much as possible. Especially for the case of multiple CG PUSCH or multiple DL SPS configurations. In Rel-16, joint deactivation is introduced for multiple CG PUSCHs or multiple DL SPSs. Then, multiple joint activations may be further introduced. Further, one or more CG PUSCHs and a plurality of DL SPSs may be simultaneously activated for one DCI.

In addition, due to the long transmission delay, since the CG PUSCH and DL SPS are both configured with equal periods, for a limited number of HARQ processes, one HARQ Round Trip Time (RTT) may span multiple periods of the same HARQ process. In particular, fig. 18 shows a schematic diagram of transmission and reception in which there are a plurality of HARQ processes according to an embodiment of the present disclosure. As shown in fig. 18, terminal a (which may be a base station or a UE) transmits on the resource where HARQ 0 is located, and receives the transmission at terminal B (UE or base station) after a certain transmission delay and then performs feedback. Similarly, after a certain transmission delay, terminal a receives HARQ feedback sent by terminal B. Generally, the base station or system configures or pre-defines HARQ RTT times for uplink and downlink to the UE, for example:

drx-HARQ-RTT-TimerDL (every downlink HARQ process except the broadcast process): a minimum period (duration) of downlink grant for the HARQ retransmission that is expected (expected) by the MAC entity (entity);

drx-HARQ-RTT-timerll (per uplink HARQ process): the minimum time period before the MAC entity expects a grant for one uplink HARQ retransmission.

For the case where the actual HARQ RTT time at terminal a spans multiple time domain resources of HARQ 0, due to the limitations of the base station and UE capabilities or system design, the UE or the base station may not be able to transmit or receive on the HARQ 0 resource within the HARQ RTT time. For this case, it can be solved by one of the following methods:

the method A comprises the following steps: PDSCH reception and/or PUSCH transmission for the same HARQ process may not be performed at the actual HARQ RTT time.

Further, this method is only applicable to HARQ processes supporting HARQ feedback, and is not applicable to processes not performing HARQ feedback. Alternatively, this method is applicable to whether there is HARQ feedback. Whether the process transmits and/or receives within the actual HARQ RTT time may be determined according to the configuration of the base station. For example, whether to transmit or receive the same HARQ process may be determined by the configuration in the HARQ ID number and/or the configuration grant to which the resource belongs.

As in the example of fig. 18, terminal a may not transmit on the HARQ 0 resource within the HARQ RTT time. And/or if the signal is detected on the resource of a certain HARQ, the signal is not received on the resource of the same HARQ process number within the time of HARQ RTT. In particular, the starting times at which terminal a and terminal B calculate the HARQ RTT time may be the times at which transmission and reception start, respectively. In particular, for the PDSCH, if reception of HARQ on the corresponding HARQ process is not required, a power saving effect can be achieved.

In addition, the protocol may provide or the system may configure the UE, and if the UE detects a downlink signal on a resource of a certain HARQ process and performs feedback, ACK may be fed back for a PDSCH resource corresponding to the HARQ process within an RTT time corresponding to the HARQ process, or no feedback may be performed. The specific decision may be based on whether the HARQ feedback is single HARQ feedback, and/or the HARQ codebook type. For example, for Type 1 HARQ codebooks are occupied with NACKs. As another example, if there is only DL SPS feedback, no feedback is done, otherwise it is occupied with NACK.

The method B comprises the following steps: a time domain resource location for transmitting a channel may be determined based on one or more time periods associated with the channel, wherein at least one of the one or more time periods is associated with a transmission delay of the channel. For example, a time period may be a period or an offset, or the length of a timer. For example, a number of parameters (e.g., time period, periodicity, or offset) may be configured to determine DL SPS and/or UL CG time domain resource locations.

Specifically, a period (or time period) P2 for deciding the starting position of each set of PUSCH and/or PDSCH resources may be configured. And a period (or time period) P1 for determining the time domain location of each resource in a set of PUSCH and/or PDSCH. In one example, the period P1 may be defined as an offset between multiple PDSCH or PUSCH resources. The period (or time period) or the offset may be configured by the base station (e.g., RRC configuration and/or DCI indication) or predefined. In one example, if one DCI schedules multiple PUSCHs and/or multiple PDSCHs, the time domain locations of the multiple PUSCHs and/or multiple PDSCHs may be decided according to the indication in the DCI. For example, an offset of each time domain resource may be indicated in DCI, or each time domain resource location may be inferred from a predefined or configured offset and the number of PUSCHs and/or PDSCHs, or a Time Domain Resource Allocation (TDRA) table or the like may be configured that may indicate multiple time domain resource locations. In particular, the period P1 may be predefined to be 0, and then multiple PUSCH and/or PDSCH transmissions are nominally continuous. In practice, it may also be a continuous transmission, or a continuous transmission in the name of a symbol or slot, which may correspond to uplink or downlink.

In one specific implementation, the period P1 may be an existing period of CG PUSCH and/or DL SPS configured in the present NR system. And the period P2 is an additional period for defining whether the available resource is valid (valid). For example, fig. 19 shows a schematic diagram that configures multiple cycles for channel transmission according to an embodiment of the present disclosure. As shown in fig. 19, only the first set of resources for each HARQ process starting with period P2 is valid. In particular, the period P2 may be a configuration related to transmission delay. For example, the period P2 is a HARQ RTT time, or a Koffset is added on the basis of the HARQ RTT time, or a configuredgranttimer, or TA, etc.

Further, the start position (or start time) for the above time period, or offset amount may be determined according to at least one of the following methods:

method 1) may be determined based on a starting position of a time domain resource for a channel scheduled by a system. For example, the decision may be based on the first PUSCH and/or PDSCH activated by DCI.

Method 2) may be determined based on a time location of the system configuration corresponding to at least one of the one or more time periods. For example, the relative time position of a specific time period configured by the system may be determined, for example, one or more of SFN, timeslot, and symbol sequence number of the start position of the time period. This method is equally applicable to Type 1 CG PUSCH.

Method 3) may be decided according to a start position of a time domain resource of an actually transmitted or detected received signal. For example, the determination may be made based on the actually transmitted PUSCH position and/or the detected PDSCH position. This approach may support more flexible CG PUSCH transmissions. This method may be another expression or configuration implementation of method a described above. That is, at least one of the one or more time periods may be a system-configured hybrid automatic repeat request round trip time, HARQ RTT.

The method C comprises the following steps: defining or configuring the base station to transmit or receive and/or feed back resources corresponding to each DL SPS and/or ULCG. At this time, a specific feedback method needs to be defined for the case of the repeated HARQ process. For example, the HARQ-ACK codebook may be defined according to the slot number. Alternatively, the position of the actually transmitted PDSCH corresponding to the feedback may be determined according to the timing relationship of the PDSCH of HARQ-ACK. Specifically, the position of the PDSCH corresponding to actual transmission may be determined by pushing forward t times according to the HARQ-ACK transmission time n. And the t times are the time offset from the PDSCH indicated in the DCI corresponding to the PDSCH scheduling to the PUCCH carrying the HARQ-ACK.

Handling for HARQ-less

Due to the large RTT, multiple HARQ processes are required to fill up the time gap caused by the transmission delay, or transmission without HARQ feedback (HARQ-less) is required. This method is also referred to as blind retransmission. Then for CG PUSCH and/or DL SPS, the hybrid automatic repeat request type for each of the multiple hybrid automatic repeat request processes associated with the time domain resources used to transmit the channel may be determined according to at least one of the following methods, e.g., whether a transmission without HARQ feedback may be determined according to at least one of the following methods:

●, the type of the hybrid automatic repeat request process of the channel corresponding to the hybrid automatic repeat request process can be determined based on the indication information in the configuration information of each channel. For example, whether to introduce HARQ feedback-free transmission may be configured separately for each CG PUSCH and/or DL SPS. Since there may be multiple HARQ processes in each configuration, if configured, the multiple HARQ processes are all with or without HARQ feedback transmission.

● may determine the hybrid automatic repeat request process type of each hybrid automatic repeat request process based on the process number of the hybrid automatic repeat request process. For example, whether there is HARQ feedback may be decided according to the HARQ process ID of each CG PUSCH and/or DL SPS. Specifically, whether one or more HARQ processes have HARQ feedback may be predefined or configured by the base station. For example, the base station configures HARQ process ID 0 to HARQ process ID 3 as HARQ processes without feedback. Process ID for the case where there are multiple HARQ processes, determining whether each HARQ process has HARQ feedback further according to at least one of the following methods:

■, determining whether all HARQ processes in the CG PUSCH and/or DL SPS configuration have HARQ feedback according to the HARQ ID corresponding configuration of a specific one (e.g. the smallest (first) HARQ ID) in the CG PUSCH and/or DL SPS configuration. This has the advantage that the processing of the UE and the base station is relatively simple.

■, determining whether HARQ feedback exists in the HARQ process according to each HARQ ID in the configuration. This has the advantage of being relatively flexible.

● may determine the hybrid automatic repeat request process type of the hybrid automatic repeat request process based on the indication information in the downlink control information DCI. For example, whether the corresponding HARQ process or processes have no HARQ feedback transmission may be decided according to the indication of activating DCI. Specifically, the indication field additionally added in the DCI, or the DCI format, or a Radio Network Temporary Identity (RNTI) scrambled by the DCI, or a configuration corresponding to the DCI format, and the like may be used. This approach is the most flexible and can be shared with dynamic scheduling.

● may determine the hybrid automatic repeat request process type of the hybrid automatic repeat request process based on a configuration of a timer associated with a retransmission of the channel. For example, the decision may be based on whether a retransmission related timer is configured. For example, for CG PUSCH, retransmission is deemed unnecessary if configuredGrantTimer is not configured or the value is 0. Autonomous retransmission of the UE after expiration of the timer may be achieved if only the cg-retransmission timer is configured. For another example, whether HARQ feedback is not needed for uplink or downlink is determined according to whether a Discontinuous Reception (DRX) retransmission timer is configured. For example, HARQ feedback is not needed if not configured. This approach may save signaling overhead.

● may determine the hybrid automatic repeat request process type of the hybrid automatic repeat request process based on the number of retransmissions or the retransmission time associated with the channel. For example, the number of repetitions or the time may be determined. HARQ feedback is not needed if the corresponding PUSCH or PDSCH repetition number or time is greater than a threshold. The method is more flexible, can support one HARQ process to dynamically change whether HARQ feedback is needed or not, and does not need DCI overhead.

Next, fig. 20 shows a block diagram of an apparatus 2000 for channel transmission in a wireless communication network according to an embodiment of the present disclosure.

As shown in fig. 20, the apparatus 2000 may include an offset determination module 2010, a location determination module 2020, and a transmitting module 2030. The apparatus 2000 may implement the method for channel transmission according to the above-described embodiment of the present disclosure. For example, the offset determination module 2010 may be configured to determine a first time domain resource offset associated with a channel, wherein the first time domain resource offset is associated with a transmission latency; the position determination module 2020 can be configured to determine each of a plurality of time domain resource positions for a transmit channel based on a first time domain resource offset; and the transmitting module 2030 may be configured to transmit the channel based on the plurality of time domain resource locations.

Fig. 21 shows a schematic diagram of an apparatus 2100 for channel transmission in a wireless communication network, according to an embodiment of the disclosure. As shown in fig. 21, the apparatus 2100 may include a transceiver 2110 and a processor 2120. The transceiver 2110 may be configured to transmit and receive signals to and from the outside. The processor 2120 may be configured to control the transceiver 2110 to perform a method for channel transmission in a wireless communication network according to an embodiment of the present disclosure.

Various embodiments of the present disclosure may be implemented as computer readable code embodied on a computer readable recording medium from a particular perspective. The computer readable recording medium is any data storage device that can store data readable by a computer system. Examples of the computer readable recording medium may include read-only memory (ROM), random-access memory (RAM), compact disc read-only memory (CD-ROM), magnetic tapes, floppy disks, optical data storage devices, carrier waves (e.g., data transmission via the internet), and the like. The computer-readable recording medium can be distributed over network-connected computer systems and thus the computer-readable code can be stored and executed in a distributed fashion. Also, functional programs, codes, and code segments for implementing various embodiments of the present disclosure may be easily construed by those skilled in the art to which the embodiments of the present disclosure are applied.

It will be understood that embodiments of the present disclosure may be implemented in hardware, software, or a combination of hardware and software. The software may be stored as program instructions or computer readable code executable on a processor on a non-transitory computer readable medium. Examples of the non-transitory computer readable recording medium include magnetic storage media (e.g., ROM, floppy disks, hard disks, etc.) and optical recording media (e.g., CD-ROMs, Digital Video Disks (DVDs), etc.). The non-transitory computer-readable recording medium can also be distributed over network-coupled computer systems so that the computer-readable code is stored and executed in a distributed fashion. The medium may be read by a computer, stored in a memory, and executed by a processor. The various embodiments may be implemented by a computer or a portable terminal including a controller and a memory, and the memory may be an example of a non-transitory computer-readable recording medium adapted to store program(s) having instructions to implement the embodiments of the present disclosure. The present disclosure may be realized by a program having codes for embodying the apparatus and method described in the claims, the program being stored in a machine (or computer) readable storage medium. The program may be electronically carried on any medium, such as a communication signal conveyed via a wired or wireless connection, and the disclosure suitably includes equivalents thereof.

Those skilled in the art will appreciate that the present disclosure includes apparatus relating to performing one or more of the operations described in the present application. These devices may be specially designed and manufactured for the required purposes, or they may comprise known devices in general-purpose computers. These devices have stored therein computer programs that are selectively activated or reconfigured. Such a computer program may be stored in a device (e.g., computer) readable medium or in any type of medium suitable for storing electronic instructions and respectively coupled to a bus.

It will be understood by those within the art that each block of the block diagrams and/or flowchart illustrations, and combinations of blocks in the block diagrams and/or flowchart illustrations, can be implemented by computer program instructions. Those skilled in the art will appreciate that the computer program instructions may be implemented by a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, implement the aspects specified in the block or blocks of the block diagrams and/or flowchart illustrations of the present disclosure.

Those of skill in the art will appreciate that the various operations, methods, steps in the processes, acts, or solutions discussed in the present disclosure may be interchanged, modified, combined, or eliminated. Further, other steps, measures, schemes in various operations, methods, flows that have been discussed in this disclosure may also be alternated, altered, rearranged, broken down, combined, or deleted. Further, steps, measures, schemes in the prior art having various operations, methods, procedures disclosed in the present disclosure may also be alternated, modified, rearranged, decomposed, combined, or deleted.

The foregoing is only a partial embodiment of the present disclosure, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present disclosure, and these modifications and decorations should also be regarded as the protection scope of the present disclosure.

Claims

1. A method performed by a user equipment in a wireless communication system, comprising:

2. The method of claim 1, further comprising:

3. The method of claim 2, wherein the drift information of the timing advance comprises:

4. The method of any of claims 1-3, further comprising:

5. The method of claim 1, wherein the first timing advance is configured by one of:

configuring by a base station through a System Information Block (SIB); and

6. The method of claim 1 or 5, wherein the first timing advance is associated with a particular time instant, the method further comprising:

7. The method of claim 1, wherein the first timing advance is one of the following configurations:

a cell-specific first timing advance;

a first timing advance specific to a beam footprint;

a first timing advance specific to the beam footprint group; and

a first timing advance specific to the carrier bandwidth part.

8. The method of claim 1, wherein estimating the second timing advance uses one of the following estimation approaches:

9. The method of claim 1, wherein whether the third timing advance comprises the first timing advance configured by the base station relates to a manner in which the user equipment estimates a second timing advance:

10. The method of claim 9, further comprising: and the user equipment reports the user equipment capability corresponding to the second timing advance estimation mode to the base station.

11. The method of claim 10, wherein the ue reports the estimate of the second timing advance to a base station by one of:

12. The method of claim 1, further comprising: reporting the second timing advance to the base station.

13. The method of claim 12, further comprising: and reporting the variation of the second timing advance relative to the second timing advance reported last time to the base station.

14. The method of claim 12 or 13, wherein reporting the second timing advance to the base station is triggered by one of:

15. The method of claim 1, further comprising receiving an offset of a second timing advance from a base station to correct the second timing advance using the offset of the second timing advance.