Configuration of Random Access Preamble

Abstract

A wireless communication method for use in a wireless terminal is disclosed. The wireless communication method includes transmitting a random access preamble selected from a plurality of predetermined preambles for random access to a wireless network node.

Description

Technical Field

[0001] This document generally relates to wireless communication. Background Art

[0002] In some cases, Internet-of-thing (IoT) devices may be distributed in remote areas. In these cases, it is challenging to provide ubiquitous coverage for IoT services. To ensure ubiquitous coverage and service continuity, narrowband IoT (NB-IoT) on low-Earth-orbit (LEO) satellites becomes an attractive architecture. However, the LEO channel may be accompanied by a large Doppler frequency shift and a long round-trip time (RTT), which will have a significant impact on the random access process in NB-IoT (e.g., the physical random access channel (PRACH) process). Therefore, how to design the PRACH to support the initial access of IoT devices served by LEO satellites becomes a topic to be discussed. Summary of the Invention

[0003] This document relates to methods, systems, and devices for configuring random access preambles, and more particularly, to methods, systems, and devices for configuring random access preambles in NB-IoT.

[0004] Specifically, the present disclosure relates to a wireless communication method for use in a wireless terminal. The wireless communication method includes transmitting a random access preamble selected from a plurality of predetermined preambles for random access to a wireless network node.

[0005] Various embodiments may preferably implement the following features:

[0006] Preferably, a plurality of predetermined preambles are determined by disabling at least one symbol group of a plurality of reference preambles.

[0007] Preferably, there is frequency hopping between symbol groups of each of the plurality of predetermined preambles, and the frequency hopping is greater than 1 subcarrier spacing.

[0008] Preferably, the frequency hopping is 6 subcarrier spacings.

[0009] Preferably, the length of the cyclic prefix in the plurality of predetermined preambles is adjusted based on the maximum time offset associated with the wireless terminal.

[0010] Preferably, the subcarrier spacing of the plurality of predetermined preambles is greater than twice the maximum frequency offset.

[0011] Preferably, the subcarrier spacing of the plurality of predetermined preambles is less than the reciprocal of the maximum time offset.

[0012] Preferably, the subcarrier spacing of the plurality of predetermined preambles is adjusted by at least one scaling factor.

[0013] Preferably, the subcarrier spacing of the plurality of predetermined preambles is adjusted by different scaling factors in different frames.

[0014] Preferably, the plurality of predetermined preambles are determined by disabling at least one resource occasion among the plurality of reference preambles.

[0015] Preferably, there is a resource occasion gap between every two adjacent symbol groups of the plurality of predetermined preambles in the frequency domain.

[0016] Preferably, the resource occasion gaps have different numbers of subcarrier spacings.

[0017] Preferably, the symbols in each symbol group of the plurality of predetermined preambles form one of a Zadoff–Chu sequence or a pseudo-noise sequence.

[0018] Preferably, the cyclic prefix in the plurality of predetermined preambles includes at least one symbol in the tail of the symbol group of the cyclic prefix.

[0019] Preferably, the wireless communication method further includes receiving, from a wireless network node, a configuration associated with the plurality of predetermined preambles.

[0020] Preferably, the configuration includes at least one of the following: disabling information for disabling at least one symbol group or at least one resource occasion of the plurality of reference preambles, the subcarrier spacing of the plurality of predetermined preambles, at least one scaling factor for adjusting the subcarrier spacing of the plurality of predetermined preambles, or a sequence of at least one scaling factor.

[0021] The present disclosure relates to a wireless communication method for use in a wireless network node. The wireless communication method includes receiving, from a wireless terminal, a random access preamble selected from a plurality of predetermined preambles for random access.

[0022] Various embodiments may preferably implement the following features:

[0023] Preferably, the plurality of predetermined preambles are determined by disabling at least one symbol group of the plurality of reference preambles.

[0024] Preferably, there is a frequency hopping between the symbol groups of each of the plurality of predetermined preambles, and the frequency hopping is greater than 1 subcarrier spacing.

[0025] Preferably, the frequency hopping is 6 subcarrier spacings.

[0026] Preferably, the length of the cyclic prefix in the plurality of predetermined preambles is adjusted based on the maximum time offset associated with the wireless terminal.

[0027] Preferably, the subcarrier spacing of the plurality of predetermined preambles is greater than twice the maximum frequency offset.

[0028] Preferably, the subcarrier spacing of the plurality of predetermined preambles is less than the reciprocal of the maximum time offset.

[0029] Preferably, the subcarrier spacing of the plurality of predetermined preambles is adjusted by at least one scaling factor.

[0030] Preferably, the subcarrier spacing of the plurality of predetermined preambles is adjusted by different scaling factors in different frames.

[0031] Preferably, the plurality of predetermined preambles are obtained by disabling at least one resource occasion among a plurality of reference preambles.

[0032] Preferably, the plurality of predetermined preambles have a resource occasion gap between every two adjacent symbol groups in the frequency domain.

[0033] Preferably, the resource occasion gap has different numbers of subcarrier spacings.

[0034] Preferably, the symbols in each symbol group of the plurality of predetermined preambles form one of a Zadoff–Chu sequence or a pseudo-noise sequence.

[0035] Preferably, the cyclic prefix in the plurality of predetermined preambles includes at least one symbol in the tail of the symbol group of the cyclic prefix.

[0036] Preferably, the wireless communication method further includes transmitting a configuration associated with the plurality of predetermined preambles to the wireless terminal.

[0037] Preferably, the configuration includes at least one of the following: disabling information for disabling at least one symbol group or at least one resource occasion of a plurality of reference preambles, the subcarrier spacing of the plurality of predetermined preambles, at least one scaling factor for adjusting the subcarrier spacing of the plurality of predetermined preambles, or a sequence of at least one scaling factor.

[0038] The present disclosure relates to a wireless terminal including a communication unit configured to transmit a random access preamble selected from a plurality of predetermined preambles for random access to a wireless network node.

[0039] Various embodiments may preferably implement the following features:

[0040] Preferably, the wireless terminal further includes a processor configured to execute the wireless communication method of any one of the foregoing methods.

[0041] The present disclosure relates to a wireless network node, including a communication unit configured to receive a random access preamble selected from a plurality of predetermined preambles for random access from a wireless terminal.

[0042] Various embodiments may preferably implement the following features:

[0043] Preferably, the wireless network node further includes a processor configured to perform a wireless communication method of any one of the foregoing methods.

[0044] The present disclosure relates to a computer program product including computer-readable program medium code stored thereon, which when executed by a processor causes the processor to perform the wireless communication method of any one of the foregoing methods.

[0045] Exemplary embodiments disclosed herein relate to features that will become apparent from the following description taken in conjunction with the accompanying drawings. According to various embodiments, exemplary systems, methods, devices, and computer program products are disclosed herein. However, it should be understood that these embodiments are presented by way of example and not limitation, and it will be apparent to those of ordinary skill in the art who have read the present disclosure that various modifications can be made to the disclosed embodiments while remaining within the scope of the present disclosure.

[0046] Therefore, the present disclosure is not limited to the exemplary embodiments and applications described and illustrated herein. Additionally, the specific order and / or hierarchy of steps in the methods disclosed herein are merely exemplary methods. Based on design preferences, the specific order or hierarchy of steps of the disclosed methods or processes can be rearranged while remaining within the scope of the present disclosure. Thus, those of ordinary skill in the art will understand that the methods and techniques disclosed herein present various steps or acts in a sample order, and the present disclosure is not limited to the specific order or hierarchy presented unless otherwise expressly stated. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The above and other aspects and their implementations are described in more detail in the drawings, the detailed description, and the claims.

[0048] Figure 1 An example of a schematic diagram of a wireless terminal according to an embodiment of the present disclosure is shown.

[0049] Figure 2 An example of a schematic diagram of a wireless network node according to an embodiment of the present disclosure is shown.

[0050] Figure 3 An example of a schematic diagram of a preamble according to an embodiment of the present disclosure is shown.

[0051] Figure 4Shows a schematic diagram of a preamble according to an embodiment of the present disclosure.

[0052] Figure 5 Shows a schematic diagram of a preamble according to an embodiment of the present disclosure.

[0053] Figure 6 Shows a schematic diagram of a preamble according to an embodiment of the present disclosure.

[0054] Figure 7 Shows a schematic diagram of a preamble according to an embodiment of the present disclosure.

[0055] Figure 8 Shows a schematic diagram of a preamble according to an embodiment of the present disclosure.

[0056] Figure 9 Shows a schematic diagram of a preamble according to an embodiment of the present disclosure.

[0057] Figure 10 Shows a schematic diagram of a preamble according to an embodiment of the present disclosure.

[0058] Figure 11 Shows a schematic diagram of a preamble according to an embodiment of the present disclosure.

[0059] Figure 12 Shows a schematic diagram of a preamble according to an embodiment of the present disclosure.

[0060] Figure 13 Shows a schematic diagram of a preamble according to an embodiment of the present disclosure.

[0061] Figure 14 Shows a schematic diagram of a preamble according to an embodiment of the present disclosure.

[0062] Figure 15 Shows a flowchart of a process according to an embodiment of the present disclosure.

[0063] Figure 16 Shows a flowchart of a process according to an embodiment of the present disclosure. Detailed Description

[0064] Figure 1Schematic diagram of a wireless terminal 10 according to an embodiment of the present disclosure. The wireless terminal 10 may be a user equipment (UE), a mobile phone, a laptop computer, a tablet computer, an e-book, or a portable computer system, and is not limited thereto. The wireless terminal 10 may include a processor 100 (such as a microprocessor or an application specific integrated circuit (ASIC)), a storage unit 110, and a communication unit 120. The storage unit 110 may be any data storage device that stores program code 112 accessed and executed by the processor 100. Embodiments of the storage unit 112 include, but are not limited to, a subscriber identity module (SIM), a read-only memory (ROM), a flash memory, a random-access memory (RAM), a hard disk, and an optical data storage device. The communication unit 120 may be a transceiver and is used to transmit and receive signals (e.g., messages or packets) according to the processing result of the processor 100. In an embodiment, the communication unit 120 transmits and receives signals through Figure 1 at least one antenna 122 shown in

[0065] In an embodiment, the storage unit 110 and the program code 112 may be omitted, and the processor 100 may include a storage unit having the stored program code.

[0066] The processor 100 may implement any of the steps in the exemplary embodiments on the wireless terminal 10, for example, by executing the program code 112.

[0067] The communication unit 120 may be a transceiver. As an alternative or in addition, the communication unit 120 may combine a transmitting unit and a receiving unit, and the transmitting unit and the receiving unit are configured to transmit signals to and receive signals from a wireless network node (e.g., a base station), respectively.

[0068] Figure 2Schematic diagram of a wireless network node 20 according to an embodiment of the present disclosure. The wireless network node 20 may be a satellite, a base station (BS), a network entity, a mobility management entity (MME), a serving gateway (S-GW), a packet data network (PDN) gateway (P-GW), a radio access network (RAN), a next-generation RAN (NG-RAN), a data network, a core network, or a radio network controller (RNC), and is not limited thereto. In addition, the wireless network node 20 may include (perform) at least one network function, such as an access and mobility management function (AMF), a session management function (SMF), a user plane function (UPF), a policy control function (PCF), an application function (AF), etc. The wireless network node 20 may include a processor 200 such as a microprocessor or an ASIC, a storage unit 210, and a communication unit 220. The storage unit 210 may be any data storage device that stores program code 212 accessed and executed by the processor 200. Examples of the storage unit 210 include, but are not limited to, SIM, ROM, flash memory, RAM, hard disk, and optical data storage devices. The communication unit 220 may be a transceiver and is used to send and receive signals (e.g., messages or packets) according to the processing result of the processor 200. In an example, the communication unit 220 sends and receives signals through Figure 2 at least one antenna 222 shown in

[0069] In an embodiment, the storage unit 210 and the program code 212 may be omitted. The processor 200 may include a storage unit having the stored program code.

[0070] The processor 200 may implement any of the steps described in the exemplary embodiments on the wireless network node 20, for example, by executing the program code 212.

[0071] The communication unit 220 may be a transceiver. As an alternative or in addition, the communication unit 220 may combine a sending unit and a receiving unit, and the sending unit and the receiving unit are configured to send signals to and receive signals from a wireless terminal (e.g., a UE), respectively.

[0072] In the present disclosure, a preamble may be a Physical Random Access Channel (PRACH) preamble, a random access preamble, a Random Access Channel (RACH) preamble, or a preamble for random access (procedure).

[0073] In an embodiment, a random access preamble (e.g., a PRACH preamble) is used in wireless communication to achieve uplink (UL) synchronization at the initialization of access. In NB-IoT, the signals of each UE are concentrated on a narrow band of 180 KHz. In addition, the PRACH preamble is transmitted in a single subcarrier and hops within the narrow band.

[0074] In an embodiment, a symbol group is a concatenation of a cyclic prefix and several identical Orthogonal Frequency-Division Multiplexing (OFDM) symbols. For example, each of the OFDM symbols occupies only one subcarrier and has a value of "1" in the frequency domain. The PRACH preamble in NB-IoT consists of several symbol groups (e.g., repeating units) with frequency hopping. Figure 3 A schematic diagram showing predetermined PRACH preambles PRACH#0 to PRACH#11 is shown. Note that Figure 3 The timing and frequency relationship between PRACH#0 to PRACH#11 is shown, which does not limit the actual timing and / or frequency of each preamble. As Figure 3 shown, each of PRACH#0 to PRACH#11 is located in a PRACH opportunity of each subcarrier, and the frequency hopping of each of PRACH#0 to PRACH#11 is determined by the frequency position of the corresponding first symbol group. In addition, Figure 3 the symbol group shown in includes 6 symbols (e.g., a cyclic prefix and 5 OFDM symbols with a value of "1"). During the initialization process, the UE selects (e.g., chooses) a PRACH opportunity and transmits the corresponding random access preamble. The BS can identify the UE based on the position of the PRACH opportunity where the random access preamble is located. In Figure 3 the subcarrier spacing (SCS) is 3.75 KHz, and the frequency hopping between the symbol groups of each of PRACH#0 to PRACH#11 is a single SCS or 6 SCSs. In an embodiment, the SCS may be 1.25 KHz.

[0075] In the LEO scenario, due to the high speed and altitude of the satellite, the Doppler frequency shift and RTT of the channel become larger than those in the terrestrial network scenario. Even after compensating for the common Doppler frequency shift and RTT of each beam, the residual time offset (TO) and frequency offset (FO) may still be greater than the symbol length and SCS, respectively. In an embodiment, if the UE has the global navigation satellite system (GNSS) capability, the residual TO and FO can be further compensated based on the UE location and ephemeris. However, when the position estimation is inaccurate or when the UE cannot compensate for the residual TO and FO, the TO and FO may still be large.

[0076] According to the accuracy of the GNSS estimation and the compensation capability of the UE, the residual TO and FO can be divided into four cases as follows.

[0077] (1) Small TO and small FO

[0078] In an embodiment, the UE can obtain an accurate estimate of its own position and the position of the satellite, and the compensated residual TO and FO are small. In this case, the cyclic prefix (CP) of the symbol group in the PRACH preamble can be designed to be shorter. For example, the CP length can be determined (e.g., adjusted or reduced) according to the maximum (e.g., the largest) residual TO. In addition, small frequency hopping (e.g., frequency hopping with 1 SCS) would be unnecessary. In an embodiment, the frequency hopping between the symbol groups of the PRACH preamble is enhanced by designing a new frequency hopping pattern for the repetition unit of the PRACH preamble, or by disabling some symbol groups in the reference preamble (e.g., the preamble of the existing PRACH preamble format). For example, the new frequency hopping pattern can only include frequency hopping greater than 1 SCS. In an embodiment, the frequency hopping can be 6 SCS. As an alternative or in addition, the PRACH preamble configured for the UE can be determined by disabling the symbol groups corresponding to the reference preamble and having a 1 SCS frequency hopping.

[0079] (2) Small TO and large FO

[0080] In an embodiment, due to errors in GNSS and / or because the UE cannot perform frequency compensation, the UE may have a small residual TO and a large residual FO. In NB-IoT, 12 or 36 consecutive subcarriers are used for the PRACH, and each subcarrier can be regarded as a resource occasion (e.g., a RACH occasion (RO)). When the FO is greater than half of the SCS, the BS cannot determine the correct RO corresponding to the preamble. To overcome a large FO (e.g., FO greater than half of the SCS), the SCS can be enlarged. In an embodiment, the SCS is determined (e.g., magnified, adjusted) by a scaling factor selected (e.g., configured) by the BS. In an embodiment, the SCS is determined (e.g., magnified, adjusted) by a list of scaling factors selected (e.g., configured) by the BS. In an embodiment with a large FO, for PRACH preambles, some ROs can be disabled. For example, to insert RO gaps between every two symbol groups of different PRACH preambles, some ROs can be removed. In an embodiment, to avoid conflicts, the symbols in each symbol group can have different values to enlarge the size of the preamble pool (i.e., increase the preamble capacity). For example, the symbols in each symbol group can form a Zadoff–Chu sequence or a pseudo-noise sequence. In an embodiment, the CP length can also be reduced (e.g., adjusted) according to the maximum residual TO.

[0081] (3) Large TO and small FO

[0082] In an embodiment with a large TO and a small FO, the product of the residual TO and FO can be less than 0.5 (i.e., TO*FO < 0.5). In this embodiment, the SCS can be reduced to compensate for the large TO. As an alternative or in addition, the large TO can be covered by setting different values for the symbols in each symbol group. Additionally, the CP length can be extended up to the entire symbol group at most to overcome the large TO.

[0083] (4) Large TO and large FO

[0084] In an embodiment, when the UE does not have GNSS capabilities, both the residual TO and FO will be large. As discussed in cases (2) and (3), the large TO and large FO can be compensated by setting different values for the symbols in each symbol group and / or inserting RO gaps between the symbol groups of different PRACH preambles.

[0085] The following embodiments provide more details of the (multiple) configurations and / or (multiple) formats proposed in the present disclosure. Note that those skilled in the art should recognize that the embodiments disclosed in the present disclosure can be implemented individually or in any possible combination.

[0086] Embodiment 1:

[0087] In this embodiment, a new frequency hopping pattern is disclosed, for example, for a scenario with a small TO and a small FO. In the case of a small TO, small frequency hopping (e.g., frequency hopping with one SCS) would be unnecessary. Therefore, a new frequency hopping pattern for the repetition unit of each preamble can be redefined. In an embodiment where the frame structure type is 1 (which refers to the frequency hopping pattern of preamble formats 0 and 1 in NB-IoT), the frequency position of the I-th symbol group can be described as follows:

[0088]

[0089] When i mod 4 = 0, all are the same as the NB-IoT preamble.

[0090] Figure 4 A schematic diagram of preambles PRACH#0 to PRACH#11 according to an embodiment of the present disclosure is shown. In Figure 4 , each symbol group consists of 5 symbols and a CP. In the embodiment, the length of the CP is the same as the maximum TO. In addition, each of PRACH#0 to PRACH#11 is a concatenation of several repetition units. For each repetition unit, the frequency position of the first symbol group is randomly generated. As Figure 4 shown, for each of PRACH#0 to PRACH#11, the (frequency) jump between symbol groups in the repetition unit is 6 SCS.

[0091] Embodiment 2:

[0092] In this embodiment, a new frequency hopping pattern is disclosed, for example, for a scenario with a small TO and a small FO. In addition, the new frequency hopping pattern is determined (e.g., obtained or acquired) based on the frequency hopping pattern of a reference preamble. For example, the reference preamble can be a preamble of an existing preamble format in NB-IoT. In the embodiment, the frequency hopping pattern of the reference preamble can be represented as follows:

[0093]

[0094] where is the frequency position of the i-th symbol group.

[0095] In the embodiment, for example, the new frequency hopping pattern can be determined by disabling some members of the reference preamble. For example, the new frequency hopping pattern can be constructed as follows:

[0096]

[0097] where is the frequency position of the i-th symbol group.

[0098] Embodiment 3:

[0099] In this embodiment, for the scenarios of small TO and small RO, certain symbol groups in the reference preamble can be disabled. In Figure 3 , each in the preamble has two cases of small frequency hopping and large frequency hopping between its adjacent symbol groups. When both TO and FO are small, Figure 3 certain symbol groups shown in

[0100] Figure 5 FIG. shows a schematic diagram of preambles PRACH#1 to PRACH#11 according to an embodiment of the present disclosure. Compared with the symbol groups shown in Figure 3 , the 1st and 4th symbol groups in the repeating unit of each of PRACH#0 to PRACH#11 shown in Figure 5 are disabled. Therefore, each of PRACH#0 to PRACH#11 only has large frequency hopping between symbol groups in its repeating unit. As shown in Figure 5 , each of PRACH#0 to PRACH#11 only has a frequency hopping of 6 SCS. In the embodiment, for example, when considering the link budget, the number of repeating units in each of PRACH#0 to PRACH#11 can be increased.

[0101] In the embodiment, the generated space-time-frequency resources can be used for new ROs of additional PRACH preambles by means of disabling.

[0102] In the embodiment, the CP has the same length as the maximum residual TO.

[0103] In the embodiment, Figure 5 the patterns (such as preambles) shown in

[0104]

[0105] where is the frequency position of the i-th symbol group.

[0106] Embodiment 4:

[0107] In this embodiment, the SCS of the preamble is magnified to compensate for large FO.

[0108] In the embodiment, the SCS is magnified to twice the maximum (largest) FO to overcome large FO.

[0109] Figure 6A schematic diagram of preambles PRACH#0 to PRACH#11 according to an embodiment of the present disclosure is shown. In Figure 6 , FO is greater than half of the original SCS (i.e., 0.5*SCS), and the carrier-to-noise ratio (CNR) is sufficient to support an SCS twice that of the maximum FO (2*FO). In this case, the SCS can be adjusted to 7.5 KHz, which is twice the maximum FO (i.e., the maximum FO is 3.75 KHz).

[0110] Embodiment 5:

[0111] In this embodiment, the BS can configure at least one scaling factor for adjusting the SCS of a predetermined preamble.

[0112] In the embodiment, after the UE compensates based on the GNSS-based positioning result, the residual FO has various values. In this embodiment, the BS can configure a scaling factor for adjusting (e.g., determining) the SCS of the PRACH preamble. In addition, the BS can configure different scaling factors for different radio frames. For example, the BS can configure a list of scaling factors, and the scaling factors correspond to consecutive radio frames in the sequence of the list of scaling factors. In this embodiment, the UE can select the RO (i.e., different scaling factors) in different radio frames according to its own (coarse) FO estimate.

[0113] Figure 7 A schematic diagram of preambles PRACH#0 to PRACH#11 according to an embodiment of the present disclosure is shown. In Figure 7 , the BS configures two scaling factors with values 1 and 2 and broadcasts the scaling factors to the UE in the system information block (SIB). After receiving the scaling factors, the UE applies the scaling factors to different frames. As Figure 7 shown, in the first frame, the SCS of each of PRACH#0 to PRACH#11 is 3.75 KHz (e.g., applying the scaling factor with value 1). After the first frame, in the second frame, the SCS of each of PRACH#0 to PRACH#11 becomes 7.5 KHz (e.g., applying the scaling factor with value 2). Note that the first frame and the second frame can be repeated in the time domain, and the UE can estimate its own FO and select a suitable frame to send the PRACH preamble.

[0114] Embodiment 6:

[0115] In this embodiment, the number of symbols in a single symbol group is reduced, for example, in the case of small TO. In the embodiment, the symbol group is a concatenation of N OFDM symbols, where N is a positive integer. When N is large, the overhead caused by the CP is relatively reduced. In the embodiment with small TO, the CP can be designed to have a short length, and N can also be configured as a smaller number. In the embodiment where N is reduced to a smaller number, the channel coefficient of the symbol group can remain unchanged to reduce the TO estimation error.

[0116] Figure 8 A schematic diagram of preambles PRACH#0 to PRACH#11 according to an embodiment of the present disclosure is shown. In Figure 8 it, the number N of symbols in each symbol group is reduced to 2.

[0117] Embodiment 7:

[0118] In this embodiment, for example, when the FO is large, an RO gap is inserted between the symbol groups of the PRACH preamble. As a result, the influence caused by the FO can be eliminated.

[0119] Figure 9 A schematic diagram of preambles PRACH#0 to PRACH#3 according to an embodiment of the present disclosure is shown. In this embodiment, the maximum FO is 5KHz, and the SCS is 3.5KHz. In Figure 9 it, the ROs with SCS indices 0, 2, 3, 5, 6, 8, 9, and 11 are disabled. In other words, an RO gap with 2 SCSs is inserted between every two adjacent symbol groups in the frequency domain. In this embodiment, the BS detects 3 subcarriers of a single RO of each symbol group (i.e., Figure 9 each symbol group in it includes 3 subcarriers for the RO). Since the maximum FO is less than 1.5 times the SCS, the influence of the FO can be eliminated through the Figure 9 preamble configuration / format shown in it.

[0120] Embodiment 8:

[0121] In this embodiment, the symbols of the preamble group of each preamble can be set to different values to form a sequence (e.g., ZC sequence or PN sequence).

[0122] In the embodiment, when the maximum FO is very large, the number of ROs of the preamble can be reduced because the SCS can be greatly increased to compensate for the FO. In this embodiment, the symbols of each symbol group can form a ZC sequence or a PN sequence to increase the PRACH preamble capacity.

[0123] Figure 10A schematic diagram of a preamble according to an embodiment of the present disclosure is shown. In this embodiment, the maximum FO is 60 KHz, and the SCS is set to 30 KHz to mitigate the influence of FO. In Figure 10 , each symbol group has a CP and symbols S1 to S N , where N is a positive integer greater than 1. Note that, for illustration in Figure 10 , only two symbol groups with a CP and symbols S1 to S N are shown. In this embodiment, the symbols S1 to S N of each symbol group can be set to different values (e.g., to form a ZC sequence or a PN sequence). With different selections of the symbols S1 to S N , each RO can support the simultaneous transmission of more than one preamble. Therefore, the conflicts in the PRACH procedure are greatly reduced.

[0124] Embodiment 9:

[0125] In this embodiment, RO gaps with different numbers of SCS are inserted between the symbol groups of the preamble.

[0126] In the embodiment, UEs within a beam may have different FOs. Therefore, the RO gaps between ROs can be set to have different numbers of SCS. In the embodiment, the UE determines a rough estimate of its FO and accordingly selects an appropriate RO based on the RO gaps between ROs.

[0127] Figure 11 A schematic diagram of preambles PRACH#0 to PRACH#3 according to an embodiment of the present disclosure is shown. In Figure 11 , for PRACH#0 to PRACH#3 respectively, four ROs at the same time are separated by gaps with different numbers of SCS. For example, in the first symbol group of PRACH#0 to PRACH#3, the interval between the ROs of PRACH#0 and PRACH#1 is 1, the interval between the ROs of PRACH#1 and PRACH#2 is 2, and the interval between the ROs of PRACH#2 and PRACH#3 is 3. Therefore, the ROs of RACH#0 to PRACH#3 can support maximum FOs that are 2.5, 1.5, 1.5, and 0.5 times the SCS respectively.

[0128] In the embodiment, Figure 11 the gaps between the ROs shown in

[0129] Embodiment 10:

[0130] In this embodiment, for example, for the case with a large TO and a small FO, the SCS can be reduced.

[0131] In an embodiment, FO can be less than 0.5 / maximum TO. In this embodiment, TO can be overcome by adjusting (e.g., selecting) an SCS that is greater than 2 * maximum FO and / or less than 1 / maximum TO.

[0132] Figure 12 A schematic diagram of preambles PRACH#0 to PRACH#11 according to an embodiment of the present disclosure is shown. In this embodiment, the maximum TO is 3 ms and the maximum FO is 100 Hz. In this case, the SCS is set to 312.5 Hz to compensate for TO and FO.

[0133] Embodiment 11:

[0134] In an embodiment, the CP can be extended, for example, for scenarios with a large TO.

[0135] In an embodiment, the length of a single symbol group can be greater than the maximum TO, and the symbols in each of the symbol groups have different values (e.g., form a sequence). In this embodiment, the CP can be extended to estimate TO.

[0136] Figure 13 A schematic diagram of preambles PRACH#0 to PRACH#11 according to an embodiment of the present disclosure is shown, where the SCS is 3.75 KHz. In Figure 13 which, each preamble group consists of a CP and N symbols S1 to S N consisting. In this embodiment, the CP is extended by including M symbols at the tail of its symbol group, where M is a positive integer less than N. For example, M can be 12, and the extended CP includes the CP and the symbols S N-11 、S N-10 、…S N (N > 12). Based on the extended CP with 12 added symbols, the BS can estimate a TO of up to 3.2 ms.

[0137] Embodiment 12:

[0138] In this embodiment with a large TO and a large FO, the symbols in each symbol group can have different values (e.g., form a sequence) and / or RO gaps can be inserted between the symbol groups of different preambles. In other words, Embodiment 7 and 11 can be combined.

[0139] Figure 14 A schematic diagram of a preamble according to an embodiment of the present disclosure is shown, where the SCS is 3.75 KHz. In Figure 14Among them, RO in the subcarriers with indices 0, 2, 3, 5, 6, 8, 9, and 11 is disabled. Additionally, each symbol group includes a CP and N symbols S1 to S N , and symbols S1 to S N form a sequence (e.g., ZC sequence or PN sequence). Thus, each enabled subcarrier (e.g., RO) can include multiple symbol groups for multiple preambles (e.g., preamble groups). For example, the first symbol group in subcarrier #1 can correspond to preamble group PG#0, the first symbol group in subcarrier #4 can correspond to preamble group PG#1, and so on. In Figure 14 , each preamble in preamble groups PG#0 to PG#3 has a frequency hop greater than 1 SCS (i.e., 6 SCS) from the first symbol group to the second symbol group. In an embodiment, the frequency hop of each preamble in preamble groups PG#0 to PG#3 can be changed to 1 SCS.

[0140] Figure 15 Shows a flowchart of a process according to an embodiment of the present disclosure. Figure 15 The process shown in can be used in a wireless terminal (e.g., UE) and includes the following steps:

[0141] Step 1500: Receive a configuration (optional) associated with multiple predetermined preambles from a wireless network node (e.g., BS).

[0142] Step 1502: Transmit a random access preamble selected from multiple predetermined preambles for random access to the wireless network node.

[0143] In Figure 15 , the wireless terminal can receive a configuration (step 1500) associated with multiple predetermined preambles from the wireless network node (optional). Additionally, the wireless terminal transmits a random access preamble for random access (procedure), where the random access preamble is selected from multiple predetermined preambles (step 1502).

[0144] More specifically, in an embodiment, multiple predetermined preambles are determined by disabling at least one symbol group of multiple reference preambles.

[0145] In an embodiment, multiple predetermined preambles have a frequency hop between symbol groups of each of the multiple predetermined preambles, and the frequency hop is greater than 1 subcarrier interval.

[0146] In an embodiment, the frequency hop is 6 subcarrier intervals.

[0147] In an embodiment, the length of the cyclic prefix in multiple predetermined preambles is adjusted based on the maximum time offset related to the wireless terminal.

[0148] In an embodiment, the subcarrier spacing of multiple predetermined preambles is greater than twice the maximum frequency offset.

[0149] In an embodiment, the subcarrier spacing of multiple predetermined preambles is less than the reciprocal of the maximum time offset.

[0150] In an embodiment, the subcarrier spacing of multiple predetermined preambles is adjusted by at least one scaling factor.

[0151] In an embodiment, the subcarrier spacing of multiple predetermined preambles is adjusted by different scaling factors in different frames.

[0152] In an embodiment, multiple predetermined preambles are determined by disabling at least one resource occasion among multiple reference preambles.

[0153] In an embodiment, multiple predetermined preambles have resource occasion gaps between every two adjacent symbol groups in the frequency domain.

[0154] In an embodiment, the resource occasion gaps have different numbers of subcarrier spacings.

[0155] In an embodiment, the symbols in each symbol group of multiple predetermined preambles form one of a Zadoff–Chu sequence or a pseudo-noise sequence.

[0156] In an embodiment, the cyclic prefix among multiple predetermined preambles includes at least one symbol in the tail of the symbol group of the cyclic prefix.

[0157] In an embodiment of receiving a configuration associated with multiple predetermined preambles from a radio network node, the configuration includes at least one of the following: disabling information for disabling at least one symbol group or at least one resource occasion of multiple reference preambles, the subcarrier spacing of multiple predetermined preambles, at least one scaling factor for adjusting the subcarrier spacing of multiple predetermined preambles, or a sequence of at least one scaling factor.

[0158] Figure 16 A flowchart of a process according to an embodiment of the present disclosure is shown. Figure 16 The process shown in can be used in a radio network node (e.g., a BS) and includes the following steps:

[0159] Step 1600: Transmit (optionally) a configuration associated with multiple predetermined preambles to a wireless terminal (e.g., a UE).

[0160] Step 1602: Receive a random access preamble selected from multiple predetermined preambles for random access from the wireless terminal.

[0161] In Figure 16In this case, the wireless network node may transmit a configuration associated with a plurality of predetermined preambles to the wireless terminal (step 1600) (optional). In addition, the wireless network node may receive a random access preamble for random access (procedure) from the wireless terminal, where the random access preamble is selected from the plurality of predetermined preambles (step 1602).

[0162] More specifically, in an embodiment, a plurality of predetermined preambles are determined by disabling at least one symbol group of a plurality of reference preambles.

[0163] In an embodiment, the plurality of predetermined preambles have frequency hopping between symbol groups of each of the plurality of predetermined preambles, and the frequency hopping is greater than 1 subcarrier spacing.

[0164] In an embodiment, the frequency hopping is 6 subcarrier spacings.

[0165] In an embodiment, the length of the cyclic prefix in the plurality of predetermined preambles is adjusted based on the maximum time offset associated with the wireless terminal.

[0166] In an embodiment, the subcarrier spacing of the plurality of predetermined preambles is greater than twice the maximum frequency offset.

[0167] In an embodiment, the subcarrier spacing of the plurality of predetermined preambles is less than the reciprocal of the maximum time offset.

[0168] In an embodiment, the subcarrier spacing of the plurality of predetermined preambles is adjusted by at least one scaling factor.

[0169] In an embodiment, the subcarrier spacing of the plurality of predetermined preambles is adjusted by different scaling factors in different frames.

[0170] In an embodiment, a plurality of predetermined preambles are determined by disabling at least one resource occasion among a plurality of reference preambles.

[0171] In an embodiment, the plurality of predetermined preambles have a resource occasion gap between every two adjacent symbol groups in the frequency domain.

[0172] In an embodiment, the resource occasion gap has different numbers of subcarrier spacings.

[0173] In an embodiment, the symbols in each symbol group of the plurality of predetermined preambles form one of a Zadoff–Chu sequence or a pseudo-noise sequence.

[0174] In an embodiment, the cyclic prefix in the plurality of predetermined preambles includes at least one symbol in the tail of the symbol group of the cyclic prefix.

[0175] In an embodiment of transmitting a configuration associated with a plurality of predetermined preambles to a wireless terminal, the configuration includes at least one of the following: disabling information for disabling at least one symbol group or at least one resource occasion of the plurality of reference preambles, a subcarrier spacing of the plurality of predetermined preambles, at least one scaling factor or a sequence of at least one scaling factor for adjusting the subcarrier spacing of the plurality of predetermined preambles.

[0176] Although various embodiments of the present disclosure have been described above, it should be understood that they are presented by way of example only and not as limitations. Similarly, the various figures may depict example architectures or configurations, which are provided to enable those of ordinary skill in the art to understand the exemplary features and functions of the present disclosure. However, such persons will understand that the present disclosure is not limited to the example architectures or configurations shown, but may be implemented using various alternative architectures and configurations. Additionally, as will be understood by those of ordinary skill in the art, one or more features of one embodiment may be combined with one or more features of another embodiment described herein. Therefore, the breadth and scope of the present disclosure should not be limited by any of the above exemplary embodiments.

[0177] It should also be understood that any reference to elements using designations such as "first", "second", etc. generally does not limit the number or order of these elements. Instead, these designations may be used herein as a convenient means of distinguishing between two or more elements or instances of an element. Thus, the reference to a first element and a second element does not mean that only two elements can be used, or that the first element must precede the second element in some manner.

[0178] Additionally, those of ordinary skill in the art will understand that any of a variety of different technologies and processes may be used to represent information and signals. For example, data, instructions, commands, information, signals, bits, and symbols (e.g., which may be referenced in the above description) may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0179] Those skilled in the art will further understand that any of the various illustrative logical blocks, units, processors, devices, circuits, methods, and functions described in connection with the aspects disclosed herein may be implemented by electronic hardware (e.g., digital implementations, analog implementations, or a combination of both), firmware, various forms of programs or design code incorporating instructions (for convenience, which may be referred to herein as "software" or "software units"), or any combination of these techniques.

[0180] To clearly illustrate this interchangeability of hardware, firmware, and software, the various illustrative components, blocks, units, circuits, and steps have been described above generally in terms of their functionality. Whether this functionality is implemented as hardware, firmware, software, or a combination of these techniques depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in various ways for each particular application, but such implementation decisions do not result in a departure from the scope of the present disclosure. In accordance with various embodiments, a processor, device, component, circuit, structure, machine, unit, etc. may be configured to perform one or more of the functions described herein. As used herein, the terms “configured to” or “configured for” with respect to a particular operation or function refer to a processor, device, component, circuit, structure, machine, unit, etc. that is physically constructed, programmed, and / or arranged to perform the particular operation or function.

[0181] Additionally, those skilled in the art will understand that the various illustrative logical blocks, units, devices, components, and circuits described herein may be implemented within or performed by an integrated circuit (IC) that may include a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic device, or any combination thereof. The logical blocks, units, and circuits may further include an antenna and / or transceiver to communicate with various components within a network or within a device. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, or state machine. The processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a combination of multiple microprocessors, a combination of one or more microprocessors and a digital signal processor core, or any other suitable configuration to perform the functions described herein. If implemented in software, the functionality may be stored as one or more instructions or code on a computer-readable medium. Accordingly, the steps of the methods or algorithms disclosed herein may be implemented as software stored on a computer-readable medium.

[0182] Computer-readable media includes both computer storage media and communication media, which communication media includes any medium that can be enabled to transfer a computer program or code from one place to another. The storage media may be any available media that can be accessed by a computer. By way of example and not limitation, such computer-readable media may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired program code in the form of instructions or data structures and that can be accessed by a computer.

[0183] In this document, the term "unit" as used herein refers to software, firmware, hardware, and any combination of these elements for performing the associated functions described herein. Additionally, for purposes of discussion, the various units are described as discrete modules; however, as will be apparent to one of ordinary skill in the art, in accordance with embodiments of the present disclosure, two or more units may be combined to form a single unit that performs the associated functions.

[0184] Additionally, in embodiments of the present disclosure, a memory or other storage device and communication components may be employed. It should be understood that, for clarity, the above description has described embodiments of the present disclosure with reference to different functional units and processors. However, it is apparent that any suitable functional distribution between different functional units, processing logic elements, or domains may be used without departing from the present disclosure. For example, functions shown to be performed by separate processing logic elements or controllers may be performed by the same processing logic element or controller. Thus, the reference to specific functional units is merely a reference to the appropriate means for providing the described functionality, rather than indicating a strict logical or physical structure or organization.

[0185] Various modifications to the embodiments described in this disclosure will be apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments without departing from the scope of the disclosure. Thus, the disclosure is not intended to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the novel features and principles disclosed herein, as set forth in the following claims.

Claims

1. A wireless communication method for use in a wireless terminal, the wireless communication method comprising: Receiving, from a wireless network node, a configuration associated with a plurality of predetermined preambles, wherein the configuration includes disabling information for disabling at least one symbol group or at least one resource occasion of a plurality of reference preambles, and the configuration further includes at least one of the following: a subcarrier spacing of the plurality of predetermined preambles, at least one scaling factor for adjusting the subcarrier spacing of the plurality of predetermined preambles, or a sequence of the at least one scaling factor; And Transmitting, to the wireless network node, a random access preamble selected from the plurality of predetermined preambles for random access, Wherein the plurality of predetermined preambles are determined by disabling at least one symbol group of a plurality of reference preambles, Wherein the plurality of predetermined preambles have frequency hopping between symbol groups of each of the plurality of predetermined preambles, and the frequency hopping is greater than 1 subcarrier spacing, Wherein the frequency hopping is 6 subcarrier spacings.

2. The wireless communication method according to claim 1, wherein a length of a cyclic prefix in the plurality of predetermined preambles is adjusted based on a maximum time offset associated with the wireless terminal.

3. The wireless communication method according to claim 1 or 2, wherein The subcarrier spacing of the plurality of predetermined preambles is greater than twice the maximum frequency offset.

4. The wireless communication method according to claim 1 or 2, wherein the subcarrier spacing of the plurality of predetermined preambles is less than the reciprocal of the maximum time offset.

5. The wireless communication method according to claim 1 or 2, wherein the subcarrier spacing of the plurality of predetermined preambles is adjusted by at least one scaling factor.

6. The wireless communication method according to claim 5, wherein the subcarrier spacing of the plurality of predetermined preambles is adjusted by different scaling factors in different frames.

7. The wireless communication method according to any one of claims 1, 2, and 6, wherein the plurality of predetermined preambles are determined by disabling at least one resource occasion among a plurality of reference preambles.

8. The wireless communication method according to claim 7, wherein the plurality of predetermined preambles have a resource occasion gap between every two adjacent symbol groups in the frequency domain.

9. The wireless communication method according to claim 8, wherein the resource occasion gap has different numbers of subcarrier spacings.

10. The wireless communication method according to any one of claims 1, 2, 6, 8, and 9, wherein symbols in each symbol group of the plurality of predetermined preambles form one of a Zadoff–Chu sequence or a pseudo-noise sequence.

11. The wireless communication method according to any one of claims 1, 2, 6, 8, and 9, wherein the cyclic prefix in the plurality of predetermined preambles includes at least one symbol in a tail of a symbol group of the cyclic prefix.

12. A wireless communication method for use in a wireless network node, the wireless communication method comprising: Transmit a configuration associated with a plurality of predetermined preambles to a wireless terminal, where the configuration includes disabling information for disabling at least one symbol group or at least one resource occasion of a plurality of reference preambles, and the configuration further includes at least one of the following: a subcarrier spacing of the plurality of predetermined preambles, at least one scaling factor for adjusting the subcarrier spacing of the plurality of predetermined preambles, or a sequence of the at least one scaling factor, Receive a random access preamble selected from the plurality of predetermined preambles for random access from the wireless terminal, where the plurality of predetermined preambles are determined by disabling at least one symbol group of a plurality of reference preambles, where the plurality of predetermined preambles have frequency hopping between symbol groups of each of the plurality of predetermined preambles, and the frequency hopping is greater than 1 subcarrier spacing, where the frequency hopping is 6 subcarrier spacings.

13. The wireless communication method according to claim 12, wherein a length of a cyclic prefix in the plurality of predetermined preambles is adjusted based on a maximum time offset associated with the wireless terminal.

14. The wireless communication method according to claim 12 or 13, wherein The subcarrier spacing of the plurality of predetermined preambles is greater than twice the maximum frequency offset.

15. The wireless communication method according to claim 12 or 13, wherein the subcarrier spacing of the plurality of predetermined preambles is less than the reciprocal of the maximum time offset.

16. The wireless communication method according to claim 12 or 13, wherein the subcarrier spacing of the plurality of predetermined preambles is adjusted by at least one scaling factor.

17. The wireless communication method according to claim 16, wherein the subcarrier spacing of the plurality of predetermined preambles is adjusted by different scaling factors in different frames.

18. The wireless communication method according to any one of claims 12, 13, and 17, wherein the plurality of predetermined preambles are obtained by disabling at least one resource occasion among a plurality of reference preambles.

19. The wireless communication method according to claim 18, wherein there is a resource occasion gap between every two adjacent symbol groups of the plurality of predetermined preambles in the frequency domain.

20. The wireless communication method according to claim 19, wherein the resource occasion gap has different numbers of subcarrier spacings.

21. The wireless communication method according to any one of claims 12, 13, 17, 19, and 20, wherein symbols in each symbol group of the plurality of predetermined preambles form one of a Zadoff–Chu sequence or a pseudo-noise sequence.

22. The wireless communication method according to any one of claims 12, 13, 17, 19, and 20, wherein the cyclic prefix in the plurality of predetermined preambles includes at least one symbol in a tail of a symbol group of the cyclic prefix.

23. A wireless terminal, comprising: A communication unit, the communication unit being configured to receive, from a wireless network node, a configuration associated with a plurality of predetermined preambles, wherein the configuration includes disabling information for disabling at least one symbol group or at least one resource occasion of a plurality of reference preambles, and the configuration further includes at least one of the following: a subcarrier spacing of the plurality of predetermined preambles, at least one scaling factor for adjusting the subcarrier spacing of the plurality of predetermined preambles, or a sequence of the at least one scaling factor; and transmit to the wireless network node a random access preamble selected from the plurality of predetermined preambles for random access, wherein the plurality of predetermined preambles are determined by disabling at least one symbol group of the plurality of reference preambles, wherein the plurality of predetermined preambles have frequency hopping between symbol groups of each of the plurality of predetermined preambles, and the frequency hopping is greater than 1 subcarrier spacing, wherein the frequency hopping is 6 subcarrier spacings.

24. The wireless terminal according to claim 23, further comprising a processor configured to execute the wireless communication method according to any one of claims 2 to 11.

25. A wireless network node, comprising: A communication unit, the communication unit being configured to transmit to a wireless terminal a configuration associated with a plurality of predetermined preambles, wherein the configuration includes disabling information for disabling at least one symbol group or at least one resource occasion of a plurality of reference preambles, and the configuration further includes at least one of the following: a subcarrier spacing of the plurality of predetermined preambles, at least one scaling factor for adjusting the subcarrier spacing of the plurality of predetermined preambles, or a sequence of the at least one scaling factor; and receive from the wireless terminal a random access preamble selected from the plurality of predetermined preambles for random access, wherein the plurality of predetermined preambles are determined by disabling at least one symbol group of the plurality of reference preambles, wherein the plurality of predetermined preambles have frequency hopping between symbol groups of each of the plurality of predetermined preambles, and the frequency hopping is greater than 1 subcarrier spacing, wherein the frequency hopping is 6 subcarrier spacings.

26. The wireless network node according to claim 25, further comprising a processor configured to execute the wireless communication method according to any one of claims 13 to 22.

27. A computer program product, the computer program product comprising computer-readable program media code stored thereon, the code causing a processor to implement the wireless communication method according to any one of claims 1 to 22 when executed by the processor.

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