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JP-7855632-B2 - Method for a two-step random access procedure, base station and terminal device

JP7855632B2JP 7855632 B2JP7855632 B2JP 7855632B2JP-7855632-B2

Inventors

  • リン， ジペン
  • ハリソン， ロバート マーク
  • グロヴレン， アスビヨルン

Assignees

  • テレフオンアクチーボラゲット エルエム エリクソン（パブル）

Dates

Publication Date
20260508
Application Date
20240509
Priority Date
20181229

Claims (12)

  1. A method in a base station (700, 3320), (302) Transmitting an RRC (Radio Resource Control) signaling message that indicates the waveform of PUSCH (Physical Uplink Shared Channel) used to transmit message A from the terminal device in a two-step random access procedure, using a converted precoder field, while timing advance information has not yet been transmitted to the terminal device in message B, In the two-step random access procedure described above, the message A is received using the waveform of the PUSCH (304), Methods that include...
  2. The method according to claim 1, The method by which message A is received based on a preamble waveform that is predetermined to be fixed or is the same as the waveform used for message 3 in a four-step random access procedure.
  3. A method according to claim 1 or 2, wherein a DFT-S-OFDM (Discrete Fourier Transform Spreading Orthogonal Frequency Division Multiplexing) waveform is used when the transform precoder is activated by the transform precoder field.
  4. A method in terminal devices (700, 3330), Receiving an RRC (Radio Resource Control) signaling message from the base station (402), which indicates the waveform of the PUSCH (Physical Uplink Shared Channel) used to transmit message A in a two-step random access procedure, via a converted precoder field, while timing advance information has not yet been received from the base station in message B, In the two-step random access procedure described above, the message A is transmitted using the waveform of PUSCH (404), Methods that include...
  5. The method according to claim 4, The method by which message A is received based on a preamble waveform that is predetermined to be fixed or is the same as the waveform used for message 3 in a four-step random access procedure.
  6. A method according to claim 4 or 5, wherein message A is transmitted by using a DFT-S-OFDM (Discrete Fourier Transform Spreading Orthogonal Frequency Division Multiplexing) waveform in the PUSCH when the conversion precoder is enabled by the conversion precoder field.
  7. Base stations (700, 3320), At least one processor (710), The base station (700) comprises at least one memory (720), the at least one memory (720) includes instructions that can be executed by the at least one processor (710), and thereby the base station (700) Sending an RRC (Radio Resource Control) signaling message that , while timing advance information has not yet been sent to the terminal device in message B, indicates the waveform of PUSCH (Physical Uplink Shared Channel) used for sending message A from the terminal device in a two-step random access procedure, using a converted precoder field; In the two-step random access procedure described above, the message A is received using the waveform of the PUSCH, A base station that operates to perform the following actions.
  8. A base station (700, 3320) according to claim 7, wherein the base station (700) operates to perform the method described in claim 2 or 3.
  9. Terminal devices (700, 3320), At least one processor (710), The terminal device (700) comprises at least one memory (720), the at least one memory (720) includes instructions that can be executed by the at least one processor (710), and thereby the terminal device (700) Receiving an RRC (Radio Resource Control) signaling message from the base station, which indicates the waveform of the PUSCH (Physical Uplink Shared Channel) used to transmit message A in a two-step random access procedure, using a converted precoder field, while timing advance information has not been received from the base station in message B, In the two-step random access procedure described above, the message A is transmitted using the waveform of PUSCH, A terminal device that operates to perform the following actions.
  10. A terminal device (700, 3330) according to claim 9, wherein the terminal device (700) operates to perform the method described in claim 5 or 6.
  11. A computer program, which, when executed by at least one processor (710), includes instructions that cause the at least one processor to perform the method described in any one of claims 1 to 3.
  12. A computer program, which, when executed by at least one processor (710), includes instructions that cause the at least one processor to perform the method described in any one of claims 4 to 6.

Description

The embodiments of this disclosure relate, in whole, to wireless communication, and more particularly to a method, base station, and terminal device for a two-step random access procedure. This section presents aspects that may facilitate a better understanding of this disclosure. Therefore, the statements in this section should be read in this context and should not be understood as acceptances of prior art or non-prior art. In the New Radio (NR) system, a four-step approach, as shown in Figure 1, can be used for the random access procedure. In this approach, the user equipment (UE) detects the synchronization signal (SS), decodes the system information broadcast in the Radio Resource Control (RRC) message, and then transmits a physical random access channel (PRACH) preamble (message 1) over the uplink. The next-generation node B (gNB) responds with a random access response (RAR, message 2). Next, the UE transmits UE identification information (message 3) over the physical uplink shared channel (PUSCH). The UE, after receiving a timing advance command in the RAR, sends a PUSCH (message 3), enabling the reception of the PUSCH with timing accuracy within the cyclic prefix (CP). Without this timing advance, a very large CP would be required to demodulate and detect the PUSCH, unless the system is applied to cells with very short distances between the UE and the gNB. Since the NR further supports larger cells, requiring the UE to provide a timing advance, a four-step approach is needed for the random access procedure. In the four-step Random Access Channel (RACH) procedure, the waveform configuration of message 3 PUSCH is carried by the RACH-ConfigCommon information element (IE), as defined in NR release 15 as follows: msg3-transformPrecoder Enables the conversion precoder for Msg3 transmission. If the field does not exist, the UE disables the conversion precoder (see Third Generation Partnership Project (3GPP®) Technical Specification (TS) 38.213 V15.3.0, Section 8.3). This summary of the invention is provided to introduce, in a simplified form, a selection of concepts that will be further described in the detailed description below. This summary is not intended to identify any important or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. One of the purposes of this disclosure is to provide an improved solution for a two-step random access procedure. According to a first aspect of this disclosure, a method at a base station is provided. This method may include transmitting a signaling message via a radio interface, indicating at least one waveform of a preamble and a PUSCH used in a request message in a two-step random access procedure. The method may further include receiving a request message via a radio interface based on at least one waveform of a preamble and a PUSCH in a two-step random access procedure. In one embodiment of this disclosure, the signaling message may include at least one of a first parameter representing the waveform of the preamble and a second parameter representing the waveform of the PUSCH. In one embodiment of this disclosure, the signaling message may be an RRC message. In one embodiment of this disclosure, at least one of the first and second parameters may be a parameter within a RACH-ConfigCommon information element (IE). In one embodiment of this disclosure, the first parameter may be configured such that the presence of the first parameter in the signaling message results in a Discrete Fourier Transform Spreading Orthogonal Frequency Division Multiplexing (DFT-S-OFDM) waveform. In one embodiment of this disclosure, the second parameter may be configured such that the presence of the second parameter in the signaling message results in a DFT-S-OFDM waveform. In one embodiment of this disclosure, the first parameter may be configured to have the same value as the second parameter. In one embodiment of this disclosure, the signaling message may represent the waveform of the preamble. The request message may be received based on the waveform of PUSCH, which is predetermined to be fixed, or is the same as the waveform used for message 3 in a four-step random access procedure, or is related to the PRACH setting used in a two-step or four-step random access procedure. In one embodiment of this disclosure, the signaling message may represent a PUSCH waveform. The request message may be received based on a preamble waveform that is predetermined to be fixed, or the same waveform used for message 1 in a four-step random access procedure. A second aspect of this disclosure provides a method for performing actions in a communication system including a host computer, a base station, and a terminal device. The method may include providing user data from the host computer. The method may further include initiating a transmission from the host computer to a terminal device carrying user data over a cellular netw