# US 12,010,721 B2 · Initial signal detection method and apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,010,721 B2 - Document ID: US12010721B2 - Status: Granted - Kind: B2 - Application number: 17/403,264 - Filed: 2021-08-16 - Published: 2021-12-02 - Granted: 2024-06-11 - Earliest claimed: 2019-02-15 - Assignees: Huawei Technologies Co., Ltd. - Applicants: Huawei Technologies Co., Ltd. - Inventors: Ji Wu; Jiayin Zhang; Qiong Jia - Web page: https://patentgrep.com/patent/US12010721B2 ## CPC - H04W 74/0808: using carrier sensing, e.g. carrier sense multiple access [CSMA] - H04L 5/0051: {of dedicated pilots, i.e. pilots destined for a single user or terminal} - H04L 5/0053: {Allocation of signalling, i.e. of overhead other than pilot signals} - H04W 16/14: Spectrum sharing arrangements {between different networks} - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract An initial signal detection method includes performing, by a user equipment, detection on one or more sub-channels on an unlicensed spectrum, and determining, based on a combination of a group common-demodulation reference signal and a group common-physical downlink control channel that is detected by the user equipment a first time, that downlink transmission has started or that a channel occupancy time has started. ## Claims ### Claim 1 An initial signal detection method, comprising: performing, by a user equipment (UE), detection on one or more sub-channels on an unlicensed spectrum; and determining, based on a combination of a group common-demodulation reference signal (GC-DMRS) and a GC-physical downlink control channel (GC-PDCCH) that is detected by the UE a first time that downlink transmission has started or that a channel occupancy time (COT) has started. ### Claim 2 (depends on 1) The method according to claim 1, wherein a configuration of a search space of an initial signal of the UE satisfies at least one of the following: an aggregation level of the GC-PDCCH in the initial signal is set to a fixed value; or a maximum quantity of blind detection times of the GC-PDCCH in the initial signal is one or two times in each slot. ### Claim 3 (depends on 2) The method according to claim 2, further comprising: receiving configuration information of the search space of the initial signal of the UE, wherein the configuration information includes the configuration of the search space of the initial signal of the UE. ### Claim 4 (depends on 2) The method according to claim 2, wherein a first UE-specific PDCCH uses a new radio (NR) downlink control information (DCI) 1_0 format. ### Claim 5 (depends on 1) The method according to claim 1, wherein the combination of the GC-DMRS and the GC-PDCCH, and that is detected by the UE the first time is located at a symbol 1, 3, or 7 in a slot, and the method further comprises: continuing, by the UE, to search a search space of the GC-PDCCH for a first UE-specific PDCCH of the UE. ### Claim 6 (depends on 1) The method according to claim 1, wherein the combination of the GC-DMRS and the GC-PDCCH, and that is detected by the UE the first time is located at a symbol 0 in a slot, and the method further comprises: searching, by the UE, a search space of a UE-specific PDCCH outside of a search space of the GC-PDCCH for the UE-specific PDCCH of the UE. ### Claim 7 An initial signal transmission method, comprising: performing, by a network side, listen before talk (LBT) on one or more sub-channels on an unlicensed spectrum; and sending, by the network side, one or more combinations of a group common-demodulation reference signal (GC-DMRS) and a GC-physical downlink control channel (GC-PDCCH) on one or more sub-channels on which the LBT succeeds, wherein one of the one or more combinations of the GC-DMRS and the GC-PDCCH is used as an initial signal for downlink transmission. ### Claim 8 (depends on 7) The method according to claim 7, a configuration of a search space of an initial signal of one or more user equipment (UEs) satisfies at least the following: an aggregation level of the GC-PDCCH in the initial signal is set to a fixed value; or a maximum quantity of blind detection times of the GC-PDCCH in the initial signal is one or two times for each symbol on which detection is performed. ### Claim 9 (depends on 7) The method according to claim 7, further comprising: sending, by the network side, configuration information of the search space of the initial signal of the one or more UEs, wherein the configuration information includes the configuration of the search space of the initial signal of the UE. ### Claim 10 (depends on 7) The method according to claim 7, wherein a first sent combination of the GC-DMRS and the GC-PDCCH is located at a start location of a channel occupancy time (COT). ### Claim 11 (depends on 7) The method according to claim 7, wherein one of the sent one or more combinations of the GC-DMRS and the GC-PDCCH is located at a symbol 1, 3, or 7 in a slot, wherein a search space of the GC-PDCCH comprises a first UE-specific PDCCH of the one or more UEs. ### Claim 12 (depends on 11) The method according to claim 11, wherein the first UE-specific PDCCH uses a new radio (NR) downlink control information (DCI) 1_0 format. ### Claim 13 (depends on 7) The method according to claim 7, wherein one of the one or more combinations of the GC-DMRS and the GC-PDCCH is located at a symbol 0 in a slot, wherein outside of a search space of the GC-PDCCH, a search space of a UE-specific PDCCH comprises one or more UE-specific PDCCHs. ### Claim 14 A communication apparatus, comprising: a non-transitory memory configured to store non-transitory instructions; and one or more processors coupled with the non-transitory memory, wherein the one or more processors are configured to execute the non-transitory instructions to cause the apparatus to: perform detection on one or more sub-channels on an unlicensed spectrum; and determine, based on a combination of a group common-demodulation reference signal GC-DMRS) and a GC-physical downlink control channel (GC-PDCCH) that is detected for a first time, that downlink transmission has started or that a channel occupancy time (COT) has started. ### Claim 15 (depends on 14) The apparatus according to claim 14, wherein a configuration of a search space of an initial signal of a user equipment (UE) satisfies at least one of the following: an aggregation level of the GC-PDCCH in the initial signal is set to a fixed value; or a maximum quantity of blind detection times of the GC-PDCCH in the initial signal is one or two times in each slot. ### Claim 16 (depends on 15) The apparatus according to claim 15, wherein the one or more processors are configured to execute the non-transitory instructions to further cause the apparatus to receive configuration information of the search space of the initial signal of the apparatus, wherein the configuration information includes the configuration of the search space of the initial signal of the apparatus. ### Claim 17 (depends on 16) The apparatus according to claim 16, wherein a first UE-specific PDCCH uses a new radio (NR) downlink control information (DCI) 1_0 format. ### Claim 18 (depends on 15) The apparatus according to claim 15, wherein the combination of the GC-DMRS and the and that is detected by the apparatus the first time is located at a symbol 1, 3, or 7 in a slot, and the one or more processors are configured to execute the non-transitory instructions to further cause the apparatus to continue to search a search space of the GC-PDCCH for a first UE-specific PDCCH of the UE. ### Claim 19 (depends on 15) The apparatus according to claim 15, wherein the combination of the GC-DMRS and the and that is detected by the apparatus for the first time is located at a symbol 0 in a slot, and the one or more processors are configured to execute the non-transitory instructions to further cause the apparatus to search a search space of a UE-specific PDCCH outside of a search space of the GC-PDCCH for the UE-specific PDCCH of the apparatus.