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EP-3469729-B1 - INFORMING BASE STATION REGARDING USER EQUIPMENT'S RECEPTION OF BEAM CHANGE INSTRUCTION

EP3469729B1EP 3469729 B1EP3469729 B1EP 3469729B1EP-3469729-B1

Inventors

  • ISLAM, Muhammad Nazmul
  • LUO, TAO
  • AKKARAKARAN, SONY
  • SADIQ, Bilal
  • LI, JUNYI

Dates

Publication Date
20260513
Application Date
20170515

Claims (12)

  1. A method (900) of wireless communication by a base station (1102), comprising: determining (902) to change from a first beam to a second beam; generating (904) a beam change instruction to indicate the determination to change from the first beam to the second beam; transmitting (906), to a user equipment, UE (1402), the beam change instruction in a downlink control information, DCI; and determining (910) whether or not the beam change instruction is detected by the UE; wherein the determining whether or not the beam change instruction is detected further comprises: receiving an uplink transmission including a physical uplink control channel, PUCCH, from the UE, wherein the uplink transmission further comprises at least one of: the PUCCH scrambled with a beam change scrambling code indicating that the beam change instruction is detected by the UE, a beam change demodulation reference signal, DMRS, sequence indicating that the beam change instruction is detected by the UE, or a tri-state indicator indicating one of: successful decoding of the DCI and failure of a cyclic redundancy check, CRC, for a PDSCH as a first indication when the DCI is successfully decoded and the CRC for the PDSCH fails, successful decoding of the DCI and a pass of the CRC for the PDSCH as a second indication when the DCI is successfully decoded and the CRC for the PDSCH passes, and unsuccessful decoding of the DCI as a third indication when the DCI is not successfully decoded.
  2. The method of claim 1, wherein the DCI is transmitted for an uplink, UL, grant.
  3. The method of claim 1, wherein the determining whether or not the beam change instruction is detected further comprises: decoding the uplink transmission to determine whether or not the beam change instruction is detected.
  4. The method of claim 1, wherein the determining whether or not the beam change instruction is detected further comprises: detecting an energy of the uplink transmission to determine whether or not the beam change instruction is detected.
  5. A method (1300) of wireless communication by a user equipment, UE (1402), comprising: receiving (1302) a downlink control information, DCI, from a base station (1102); determining (1304) whether a beam change instruction is detected in the DCI; indicating (1306) via an uplink transmission which is associated with the DCI whether the beam change instruction is detected, the uplink transmission including a physical uplink control channel, PUCCH, wherein the uplink transmission comprises at least one of: the PUCCH scrambled with a beam change scrambling code indicating that the beam change instruction is detected by the UE, a beam change demodulation reference signal, DMRS, sequence indicating that the beam change instruction is detected by the UE, or a tri-state indicator indicating one of: successful decoding of the DCI and failure of a cyclic redundancy check, CRC, for a PDSCH as a first indication when the DCI is successfully decoded and the CRC for the PDSCH fails, successful decoding of the DCI and a pass of the CRC for the PDSCH as a second indication when the DCI is successfully decoded and the CRC for the PDSCH passes, and unsuccessful decoding of the DCI as a third indication when the DCI is not successfully decoded; and transmitting (1308) the uplink transmission to the base station.
  6. The method of claim 5, wherein the beam change scrambling code is different from a scrambling sequence used by the UE to transmit a PUCCH if the beam change instruction is not detected in the DCI.
  7. A base station (1102) for wireless communication, comprising: means for determining (1108) to change from a first beam to a second beam; means for generating (1110) a beam change instruction to indicate the determination to change from the first beam to the second beam; means for transmitting (1110), to a user equipment, UE (1402), the beam change instruction in a downlink control information, DCI; and means for determining (1110) whether or not the beam change instruction is detected by the UE; wherein the means for determining (1110) whether or not the beam change instruction is detected by the UE is further configured to receive an uplink transmission including a physical uplink control channel, PUCCH, from the UE, wherein the uplink transmission further comprises at least one of: the PUCCH scrambled with a beam change scrambling code indicating that the beam change instruction is detected by the UE, a beam change demodulation reference signal, DMRS, sequence, indicating that the beam change instruction is detected by the UE, or a tri-state indicator indicating one of: successful decoding of the DCI and failure of a cyclic redundancy check, CRC, for a PDSCH as a first indication when the DCI is successfully decoded and the CRC for the PDSCH fails, successful decoding of the DCI and a pass of the CRC for the PDSCH as a second indication when the DCI is successfully decoded and the CRC for the PDSCH passes, and unsuccessful decoding of the DCI as a third indication when the DCI is not successfully decoded.
  8. The base station (1102) of claim 7, wherein the DCI is transmitted for an uplink, UL, grant.
  9. The base station (1102) of claim 7, wherein the means for determining whether or not the beam change instruction is detected is further configured to: decode the uplink transmission to determine whether or not the beam change instruction is detected.
  10. A user equipment, UE (1402), for wireless communication, comprising: means for receiving (1404) a downlink control information, DCI, from a base station (1102); means for determining (1408) whether a beam change instruction is detected in the DCI; means for indicating (1414) via an uplink transmission which is associated with the DCI whether the beam change instruction is detected, the uplink transmission including a physical uplink control channel, PUCCH, wherein the uplink transmission further comprises at least one of: the PUCCH scrambled with a beam change scrambling code indicating that the beam change instruction is detected by the UE, a beam change demodulation reference signal, DMRS, sequence, indicating that the beam change instruction is detected by the UE, or a tri-state indicator indicating one of: successful decoding of the DCI and failure of a cyclic redundancy check, CRC, for a PDSCH as a first indication when the DCI is successfully decoded and the CRC for the PDSCH fails, successful decoding of the DCI and a pass of the CRC for the PDSCH as a second indication when the DCI is successfully decoded and the CRC for the PDSCH passes, and unsuccessful decoding of the DCI as a third indication when the DCI is not successfully decoded; and means for transmitting (1412) the uplink transmission to the base station.
  11. The UE (1402) of claim 10, wherein the beam change scrambling code is different from a scrambling sequence used by the UE to transmit a PUCCH if the beam change instruction is not detected in the DCI.
  12. A computer program product comprising instructions causing a computer to perform all steps of one of the methods according to claims 1 - 4 or 5 - 6, when executed thereon.

Description

BACKGROUND Field The present disclosure relates generally to communication systems, and more particularly, to a beam change in wireless communication between a user equipment and a base station. Background Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. Typical wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources. Examples of such multiple-access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single-carrier frequency division multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems. These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate on a municipal, national, regional, and even global level. An example telecommunication standard is Long Term Evolution (LTE). LTE is a set of enhancements to the Universal Mobile Telecommunications System (UMTS) mobile standard promulgated by Third Generation Partnership Project (3GPP). LTE is designed to support mobile broadband access through improved spectral efficiency, lowered costs, and improved services using OFDMA on the downlink, SC-FDMA on the uplink, and multiple-input multiple-output (MIMO) antenna technology. However, as the demand for mobile broadband access continues to increase, there exists a need for further improvements in LTE technology. These improvements may also be applicable to other multi-access technologies and the telecommunication standards that employ these technologies. US 2013/0286960 A1 discloses a base station (BS) configured to perform a coordinated transmission to at least one user equipment (UE). The BS includes a plurality of antenna configured to communicate with the UE. The BS also includes processing circuitry coupled to the plurality of antennas and configured to transmit physical downlink control channel (PDCCH) to the at least one user equipment. The UE includes a plurality of antennas configured to communicate with the BS. The UE also includes a processing circuitry coupled to the plurality of antennas and configured to receive PDCCH from the BS. The PDCCH is included in one or more transmit (Tx) beams. Further prior art is disclosed in US 2013/0051364 A1, US 2015/0049824 A1 and US 2015/0341095 A1. SUMMARY The underlying problem of the present invention is solved by the subject matter of the independent claims. The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later. With a beam-forming technique, a base station may select one of beams pointing to different directions to communicate the selected beam. After selection of the beam, an optimal beam may change, and thus the base station may determine to change from a current beam to another beam. In a process of beam change, the base station transmits a beam change instruction to a user equipment to confirm a change from a current beam to another beam. However, an indication about a user equipment (UE) successfully detecting the beam change instruction may be interfered by a process involving a CRC. To the accomplishment of the foregoing and related ends, the one or more aspects comprise the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative features of the one or more aspects. These features are indicative, however, of but a few of the various ways in which the principles of various aspects may be employed, and this description is intended to include all such aspects and their equivalents. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram illustrating an example of a wireless communications system and an access network.FIGs. 2A, 2B, 2C, and 2D are diagrams illustrating LTE examples of a DL frame structure, DL channels within the DL frame structure, an UL frame structure, and UL channels within the UL frame structure, respectively.FIG. 3 is a diagram illustrating an example of an evolved Node B (eNB) and user equipment (UE) in an access network.FIGs. 4A and 4B are diagrams illustrating an example of the transmission of beamformed signals between a base station and a UE.FIG. 5A th