# US 12,184,579 B2 · Method and apparatus for transmitting DMRS > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,184,579 B2 - Document ID: US12184579B2 - Status: Granted - Kind: B2 - Application number: 18/464,886 - Filed: 2023-09-11 - Published: 2023-12-28 - Granted: 2024-12-31 - Earliest claimed: 2017-04-01 - Assignees: Huawei Technologies Co., Ltd. - Applicants: Huawei Technologies Co., Ltd. - Inventors: Xiang Ren; Yong Liu; Shibin Ge; Xiaoyan Bi - Web page: https://patentgrep.com/patent/US12184579B2 ## CPC - H04L 5/0051: {of dedicated pilots, i.e. pilots destined for a single user or terminal} - H04L 5/0092: {Indication of how the channel is divided} - H04L 5/023: {Multiplexing of multicarrier modulation signals, e.g. multi-user orthogonal frequency division multiple access [OFDMA] (multicarrier modulation H04L27/2601)} - H04W 72/04: Wireless resource allocation - H04L 5/10: with dynamo-electric generation of carriers; with mechanical filters or demodulators - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract Embodiments of this application disclose a method and an apparatus for transmitting a DMRS, and relate to the field of communications technologies. The method and the apparatus are applicable to an NR system. The method for transmitting a DMRS may include: determining a time-frequency resource used to carry a DMRS; and then sending the DMRS by using the time-frequency resource. ## Claims ### Claim 1 A method for sending a demodulation reference signal (DMRS), comprising: sending the DMRS mapped on a time-frequency resource in at least one resource unit, wherein: in each resource unit of the at least one resource unit, time-frequency resources that can be used for the DMRS correspond to three DMRS port groups, the three DMRS port groups comprise a first DMRS port group, a second DMRS port group, and a third DMRS port group; each DMRS port group comprises two DMRS ports, and a same time-frequency resource is multiplexed for the DMRS ports in each DMRS port group in a code division multiplexing (CDM) manner; and in each resource unit, a time-frequency resource corresponding to the first DMRS port group is subcarrier 0, subcarrier 1, subcarrier 6, and subcarrier 7 on a first symbol in time domain, a time-frequency resource corresponding to the second DMRS port group is subcarrier 2, subcarrier 3, subcarrier 8, and subcarrier 9 on the first symbol in time domain, a time-frequency resource corresponding to the third DMRS port group is subcarrier 4, subcarrier 5, subcarrier 10, and subcarrier 11 on the first symbol in time domain; or in each resource unit of the at least one resource unit, time-frequency resources that can be used for the DMRS corresponds to three DMRS port groups, the three DMRS port groups comprise a first DMRS port group, a second DMRS port group, and a third DMRS port group; each DMRS port group comprises two DMRS ports, and a same time-frequency resource is multiplexed for the DMRS ports in each DMRS port group in a code division multiplexing (CDM) manner; and in each resource unit, a time-frequency resource corresponding to the first DMRS port group is subcarrier 0, subcarrier 1, subcarrier 6, and subcarrier 7 on a first symbol and a second symbol in time domain, a time-frequency resource corresponding to the second DMRS port group is subcarrier 2, subcarrier 3, subcarrier 8, and subcarrier 9 on the first symbol and the second symbol in time domain, a time-frequency resource corresponding to the third DMRS port group is subcarrier 4, subcarrier 5, subcarrier 10, and subcarrier 11 on the first symbol and the second symbol in time domain. ### Claim 2 (depends on 1) The method according to claim 1, wherein the resource unit is a resource block (RB). ### Claim 3 (depends on 1) The method according to claim 1, wherein the first symbol and the second symbol are continuous in time domain. ### Claim 4 (depends on 1) The method according to claim 1, wherein the DMRS is for a downlink transmission or an uplink transmission. ### Claim 5 A method for receiving a demodulation reference signal (DMRS), comprising: receiving the DMRS by using a time-frequency resource in at least one resource unit, wherein: in each resource unit of the at least one resource unit, time-frequency resources that can be used for the DMRS correspond to three DMRS port groups, the three DMRS port groups comprise a first DMRS port group, a second DMRS port group, and a third DMRS port group; each DMRS port group comprises two DMRS ports, and a same time-frequency resource is multiplexed for the DMRS ports in each DMRS port group in a code division multiplexing (CDM) manner; and in each resource unit, a time-frequency resource corresponding to the first DMRS port group is subcarrier 0, subcarrier 1, subcarrier 6, and subcarrier 7 on a first symbol in time domain, a time-frequency resource corresponding to the second DMRS port group is subcarrier 2, subcarrier 3, subcarrier 8, and subcarrier 9 on the first symbol in time domain, a time-frequency resource corresponding to the third DMRS port group is subcarrier 4, subcarrier 5, subcarrier 10, and subcarrier 11 on the first symbol in time domain; or in each resource unit of the at least one resource unit, time-frequency resources that can be used for the DMRS correspond to three DMRS port groups, the three DMRS port groups comprise a first DMRS port group, a second DMRS port group, and a third DMRS port group; each DMRS port group comprises two DMRS ports, and a same time-frequency resource is multiplexed for the DMRS ports in each DMRS port group in a code division multiplexing (CDM) manner; and in each resource unit, a time-frequency resource corresponding to the first DMRS port group is subcarrier 0, subcarrier 1, subcarrier 6, and subcarrier 7 on a first symbol and a second symbol in time domain, a time-frequency resource corresponding to the second DMRS port group is subcarrier 2, subcarrier 3, subcarrier 8, and subcarrier 9 on the first symbol and the second symbol in time domain, a time-frequency resource corresponding to the third DMRS port group is subcarrier 4, subcarrier 5, subcarrier 10, and subcarrier 11 on the first symbol and the second symbol in time domain. ### Claim 6 (depends on 5) The method according to claim 5, wherein the resource unit is a resource block (RB). ### Claim 7 (depends on 5) The method according to claim 5, wherein the first symbol and the second symbol are continuous in time domain. ### Claim 8 (depends on 5) The method according to claim 5, wherein the DMRS is for a downlink transmission or an uplink transmission. ### Claim 9 An indication method, comprising: sending indication information, wherein the indication information indicates a time-frequency resource used to carry a demodulation reference signal (DMRS) in at least one resource unit, wherein: in each resource unit of the at least one resource unit, time-frequency resources that can be used for the DMRS correspond to three DMRS port groups, the three DMRS port groups comprise a first DMRS port group, a second DMRS port group, and a third DMRS port group; each DMRS port group comprises two DMRS ports, and a same time-frequency resource is multiplexed for the DMRS ports in each DMRS port group in a code division multiplexing (CDM) manner; and in each resource unit, a time-frequency resource corresponding to the first DMRS port group is subcarrier 0, subcarrier 1, subcarrier 6, and subcarrier 7 on a first symbol in time domain, a time-frequency resource corresponding to the second DMRS port group is subcarrier 2, subcarrier 3, subcarrier 8, and subcarrier 9 on the first symbol in time domain, a time-frequency resource corresponding to the third DMRS port group is subcarrier 4, subcarrier 5, subcarrier 10, and subcarrier 11 on the first symbol in time domain; or in each resource unit of the at least one resource unit, time-frequency resources that can be used for the DMRS correspond to three DMRS port groups, the three DMRS port groups comprise a first DMRS port group, a second DMRS port group, and a third DMRS port group; each DMRS port group comprises two DMRS ports, and a same time-frequency resource is multiplexed for the DMRS ports in each DMRS port group in a code division multiplexing (CDM) manner; and in each resource unit, a time-frequency resource corresponding to the first DMRS port group is subcarrier 0, subcarrier 1, subcarrier 6, and subcarrier 7 on a first symbol and a second symbol in time domain, a time-frequency resource corresponding to the second DMRS port group is subcarrier 2, subcarrier 3, subcarrier 8, and subcarrier 9 on the first symbol and the second symbol in time domain, a time-frequency resource corresponding to the third DMRS port group is subcarrier 4, subcarrier 5, subcarrier 10, and subcarrier 11 on the first symbol and the second symbol in time domain. ### Claim 10 (depends on 9) The method according to claim 9, wherein the resource unit is a resource block (RB). ### Claim 11 (depends on 9) The method according to claim 9, wherein the first symbol and the second symbol are continuous in time domain. ### Claim 12 (depends on 9) The method according to claim 9, wherein the DMRS is for a downlink transmission or an uplink transmission. ### Claim 13 A method for receiving indication information, comprising: receiving indication information, wherein the indication information indicates a time-frequency resource used to carry a demodulation reference signal (DMRS) in at least one resource unit, wherein: in each resource unit of the at least one resource unit, time-frequency resources that can be used for the DMRS correspond to three DMRS port groups, the three DMRS port groups comprise a first DMRS port group, a second DMRS port group, and a third DMRS port group; each DMRS port group comprises two DMRS ports, and a same time-frequency resource is multiplexed for the DMRS ports in each DMRS port group in a code division multiplexing (CDM) manner; and in each resource unit, a time-frequency resource corresponding to the first DMRS port group is subcarrier 0, subcarrier 1, subcarrier 6, and subcarrier 7 on a first symbol in time domain, a time-frequency resource corresponding to the second DMRS port group is subcarrier 2, subcarrier 3, subcarrier 8, and subcarrier 9 on the first symbol in time domain, a time-frequency resource corresponding to the third DMRS port group is subcarrier 4, subcarrier 5, subcarrier 10, and subcarrier 11 on the first symbol in time domain; or in each resource unit of the at least one resource unit, time-frequency resources that can be used for the DMRS correspond to three DMRS port groups, the three DMRS port groups comprise a first DMRS port group, a second DMRS port group, and a third DMRS port group; each DMRS port group comprises two DMRS ports, and a same time-frequency resource is multiplexed for the DMRS ports in each DMRS port group in a code division multiplexing (CDM) manner; and in each resource unit, a time-frequency resource corresponding to the first DMRS port group is subcarrier 0, subcarrier 1, subcarrier 6, and subcarrier 7 on a first symbol and a second symbol in time domain, a time-frequency resource corresponding to the second DMRS port group is subcarrier 2, subcarrier 3, subcarrier 8, and subcarrier 9 on the first symbol and the second symbol in time domain, a time-frequency resource corresponding to the third DMRS port group is subcarrier 4, subcarrier 5, subcarrier 10, and subcarrier 11 on the first symbol and the second symbol in time domain. ### Claim 14 (depends on 13) The method according to claim 13, wherein the resource unit is a resource block (RB). ### Claim 15 (depends on 13) The method according to claim 13, wherein the first symbol and the second symbol are continuous in time domain. ### Claim 16 (depends on 13) The method according to claim 13, wherein the DMRS is for a downlink transmission or an uplink transmission. ### Claim 17 An apparatus for sending a demodulation reference signal (DMRS), comprising: at least one processor, and one or more memories coupled to the at least one processor and storing computer instructions for execution by the at least one processor to configure the apparatus for: sending the DMRS mapped on a time-frequency resource in at least one resource unit, wherein: in each resource unit of the at least one resource unit, time-frequency resources that can be used for the DMRS correspond to three DMRS port groups, the three DMRS port groups comprise a first DMRS port group, a second DMRS port group, and a third DMRS port group; each DMRS port group comprises two DMRS ports, and a same time-frequency resource is multiplexed for the DMRS ports in each DMRS port group in a code division multiplexing (CDM) manner; and in each resource unit, a time-frequency resource corresponding to the first DMRS port group is subcarrier 0, subcarrier 1, subcarrier 6, and subcarrier 7 on a first symbol in time domain, a time-frequency resource corresponding to the second DMRS port group is subcarrier 2, subcarrier 3, subcarrier 8, and subcarrier 9 on the first symbol in time domain, a time-frequency resource corresponding to the third DMRS port group is subcarrier 4, subcarrier 5, subcarrier 10, and subcarrier 11 on the first symbol in time domain; or in each resource unit of the at least one resource unit, time-frequency resources that can be used for the DMRS correspond to three DMRS port groups, the three DMRS port groups comprise a first DMRS port group, a second DMRS port group, and a third DMRS port group; each DMRS port group comprises two DMRS ports, and a same time-frequency resource is multiplexed for the DMRS ports in each DMRS port group in a code division multiplexing (CDM) manner; and in each resource unit, a time-frequency resource corresponding to the first DMRS port group is subcarrier 0, subcarrier 1, subcarrier 6, and subcarrier 7 on a first symbol and a second symbol in time domain, a time-frequency resource corresponding to the second DMRS port group is subcarrier 2, subcarrier 3, subcarrier 8, and subcarrier 9 on the first symbol and the second symbol in time domain, a time-frequency resource corresponding to the third DMRS port group is subcarrier 4, subcarrier 5, subcarrier 10, and subcarrier 11 on the first symbol and the second symbol in time domain. ### Claim 18 (depends on 17) The apparatus according to claim 17, wherein the resource unit is a resource block (RB). ### Claim 19 (depends on 17) The apparatus according to claim 17, wherein the first symbol and the second symbol are continuous in time domain. ### Claim 20 (depends on 17) The apparatus according to claim 17, wherein the DMRS is for a downlink transmission or an uplink transmission. ### Claim 21 An apparatus for receiving a demodulation reference signal (DMRS), comprising: at least one processor, and one or more memories coupled to the at least one processor and storing computer instructions for execution by the at least one processor to configure the apparatus for: receiving the DMRS by using a time-frequency resource in at least one resource unit, wherein: in each resource unit of the at least one resource unit, time-frequency resources that can be used for the DMRS correspond to three DMRS port groups, the three DMRS port groups comprise a first DMRS port group, a second DMRS port group, and a third DMRS port group; each DMRS port group comprises two DMRS ports, and a same time-frequency resource is multiplexed for the DMRS ports in each DMRS port group in a code division multiplexing (CDM) manner; and in each resource unit, a time-frequency resource corresponding to the first DMRS port group is subcarrier 0, subcarrier 1, subcarrier 6, and subcarrier 7 on a first symbol in time domain, a time-frequency resource corresponding to the second DMRS port group is subcarrier 2, subcarrier 3, subcarrier 8, and subcarrier 9 on the first symbol in time domain, a time-frequency resource corresponding to the third DMRS port group is subcarrier 4, subcarrier 5, subcarrier 10, and subcarrier 11 on the first symbol in time domain; or in each resource unit of the at least one resource unit, time-frequency resources that can be used for the DMRS correspond to three DMRS port groups, the three DMRS port groups comprise a first DMRS port group, a second DMRS port group, and a third DMRS port group; each DMRS port group comprises two DMRS ports, and a same time-frequency resource is multiplexed for the DMRS ports in each DMRS port group in a code division multiplexing (CDM) manner; and in each resource unit, a time-frequency resource corresponding to the first DMRS port group is subcarrier 0, subcarrier 1, subcarrier 6, and subcarrier 7 on a first symbol and a second symbol in time domain, a time-frequency resource corresponding to the second DMRS port group is subcarrier 2, subcarrier 3, subcarrier 8, and subcarrier 9 on the first symbol and the second symbol in time domain, a time-frequency resource corresponding to the third DMRS port group is subcarrier 4, subcarrier 5, subcarrier 10, and subcarrier 11 on the first symbol and the second symbol in time domain. ### Claim 22 (depends on 21) The apparatus according to claim 21, wherein the resource unit is a resource block (RB). ### Claim 23 (depends on 21) The apparatus according to claim 21, wherein the first symbol and the second symbol are continuous in time domain. ### Claim 24 (depends on 21) The apparatus according to claim 21, wherein the DMRS is for a downlink transmission or an uplink transmission. ### Claim 25 An indication apparatus, comprising: at least one processor, and one or more memories coupled to the at least one processor and storing computer instructions for execution by the at least one processor to configure the apparatus for: sending indication information, wherein the indication information indicates a time-frequency resource used to carry a demodulation reference signal (DMRS) in at least one resource unit, wherein: in each resource unit of the at least one resource unit, time-frequency resources that can be used for the DMRS correspond to three DMRS port groups, the three DMRS port groups comprise a first DMRS port group, a second DMRS port group, and a third DMRS port group; each DMRS port group comprises two DMRS ports, and a same time-frequency resource is multiplexed for the DMRS ports in each DMRS port group in a code division multiplexing (CDM) manner; and in each resource unit, a time-frequency resource corresponding to the first DMRS port group is subcarrier 0, subcarrier 1, subcarrier 6, and subcarrier 7 on a first symbol in time domain, a time-frequency resource corresponding to the second DMRS port group is subcarrier 2, subcarrier 3, subcarrier 8, and subcarrier 9 on the first symbol in time domain, a time-frequency resource corresponding to the third DMRS port group is subcarrier 4, subcarrier 5, subcarrier 10, and subcarrier 11 on the first symbol in time domain; or in each resource unit of the at least one resource unit, time-frequency resources that can be used for the DMRS corresponds to three DMRS port groups, the three DMRS port groups comprise a first DMRS port group, a second DMRS port group, and a third DMRS port group; each DMRS port group comprises two DMRS ports, and a same time-frequency resource is multiplexed for the DMRS ports in each DMRS port group in a code division multiplexing (CDM) manner; and in each resource unit, a time-frequency resource corresponding to the first DMRS port group is subcarrier 0, subcarrier 1, subcarrier 6, and subcarrier 7 on a first symbol and a second symbol in time domain, a time-frequency resource corresponding to the second DMRS port group is subcarrier 2, subcarrier 3, subcarrier 8, and subcarrier 9 on the first symbol and the second symbol in time domain, a time-frequency resource corresponding to the third DMRS port group is subcarrier 4, subcarrier 5, subcarrier 10, and subcarrier 11 on the first symbol and the second symbol in time domain. ### Claim 26 (depends on 25) The apparatus according to claim 25, wherein the resource unit is a resource block (RB). ### Claim 27 (depends on 25) The apparatus according to claim 25, wherein the first symbol and the second symbol are continuous in time domain. ### Claim 28 (depends on 25) The apparatus according to claim 25, wherein the DMRS is for a downlink transmission or an uplink transmission. ### Claim 29 An apparatus for receiving indication information, comprising: at least one processor, and one or more memories coupled to the at least one processor and storing computer instructions for execution by the at least one processor to configure the apparatus for: receiving indication information, wherein the indication information indicates a time-frequency resource used to carry a demodulation reference signal (DMRS) in at least one resource unit, wherein: in each resource unit of the at least one resource unit, time-frequency resources that can be used for the DMRS correspond to three DMRS port groups, the three DMRS port groups comprise a first DMRS port group, a second DMRS port group, and a third DMRS port group; each DMRS port group comprises two DMRS ports, and a same time-frequency resource is multiplexed for the DMRS ports in each DMRS port group in a code division multiplexing (CDM) manner; and in each resource unit, a time-frequency resource corresponding to the first DMRS port group is subcarrier 0, subcarrier 1, subcarrier 6, and subcarrier 7 on a first symbol in time domain, a time-frequency resource corresponding to the second DMRS port group is subcarrier 2, subcarrier 3, subcarrier 8, and subcarrier 9 on the first symbol in time domain, a time-frequency resource corresponding to the third DMRS port group is subcarrier 4, subcarrier 5, subcarrier 10, and subcarrier 11 on the first symbol in time domain; or in each resource unit of the at least one resource unit, time-frequency resources that can be used the DMRS correspond to three DMRS port groups, the three DMRS port groups comprise a first DMRS port group, a second DMRS port group, and a third DMRS port group; each DMRS port group comprises two DMRS ports, and a same time-frequency resource is multiplexed for the DMRS ports in each DMRS port group in a code division multiplexing (CDM) manner; and in each resource unit, a time-frequency resource corresponding to the first DMRS port group is subcarrier 0, subcarrier 1, subcarrier 6, and subcarrier 7 on a first symbol and a second symbol in time domain, a time-frequency resource corresponding to the second DMRS port group is subcarrier 2, subcarrier 3, subcarrier 8, and subcarrier 9 on the first symbol and the second symbol in time domain, a time-frequency resource corresponding to the third DMRS port group is subcarrier 4, subcarrier 5, subcarrier 10, and subcarrier 11 on the first symbol and the second symbol in time domain. ### Claim 30 (depends on 29) The apparatus according to claim 29, wherein the resource unit is a resource block (RB). ### Claim 31 (depends on 29) The apparatus according to claim 29, wherein the first symbol and the second symbol are continuous in time domain. ### Claim 32 (depends on 29) The apparatus according to claim 29, wherein the DMRS is for a downlink transmission or for an uplink transmission. ### Claim 33 A non-transitory computer-readable storage medium, wherein the non-transitory computer-readable storage medium stores computer instructions for being executed by at least one processor to perform operations comprising: sending the DMRS mapped on a time-frequency resource in at least one resource unit, wherein: in each resource unit of the at least one resource unit, time-frequency resources that can be used for the DMRS correspond to three DMRS port groups, the three DMRS port groups comprise a first DMRS port group, a second DMRS port group, and a third DMRS port group; each DMRS port group comprises two DMRS ports, and a same time-frequency resource is multiplexed for the DMRS ports in each DMRS port group in a code division multiplexing (CDM) manner; and in each resource unit, a time-frequency resource corresponding to the first DMRS port group is subcarrier 0, subcarrier 1, subcarrier 6, and subcarrier 7 on a first symbol in time domain, a time-frequency resource corresponding to the second DMRS port group is subcarrier 2, subcarrier 3, subcarrier 8, and subcarrier 9 on the first symbol in time domain, a time-frequency resource corresponding to the third DMRS port group is subcarrier 4, subcarrier 5, subcarrier 10, and subcarrier 11 on the first symbol in time domain; or in each resource unit of the at least one resource unit, time-frequency resources that can be used for the DMRS correspond to three DMRS port groups, the three DMRS port groups comprise a first DMRS port group, a second DMRS port group, and a third DMRS port group; each DMRS port group comprises two DMRS ports, and a same time-frequency resource is multiplexed for the DMRS ports in each DMRS port group in a code division multiplexing (CDM) manner; and in each resource unit, a time-frequency resource corresponding to the first DMRS port group is subcarrier 0, subcarrier 1, subcarrier 6, and subcarrier 7 on a first symbol and a second symbol in time domain, a time-frequency resource corresponding to the second DMRS port group is subcarrier 2, subcarrier 3, subcarrier 8, and subcarrier 9 on the first symbol and the second symbol in time domain, a time-frequency resource corresponding to the third DMRS port group is subcarrier 4, subcarrier 5, subcarrier 10, and subcarrier 11 on the first symbol and the second symbol in time domain. ### Claim 34 (depends on 33) The non-transitory computer storage medium according to claim 33, wherein the resource unit is a resource block (RB). ### Claim 35 (depends on 33) The non-transitory computer storage medium according to claim 33, wherein the first symbol and the second symbol are continuous in time domain. ### Claim 36 (depends on 33) The non-transitory computer storage medium according to claim 33, wherein the DMRS is for a downlink transmission or for an uplink transmission. ### Claim 37 A non-transitory computer-readable storage medium, wherein the non-transitory computer-readable storage medium stores computer instructions for being executed by at least one processor to perform operations comprising: receiving the DMRS by using a time-frequency resource in at least one resource unit, wherein: in each resource unit of the at least one resource unit, time-frequency resources that can be used for the DMRS correspond to three DMRS port groups, the three DMRS port groups comprise a first DMRS port group, a second DMRS port group, and a third DMRS port group; each DMRS port group comprises two DMRS ports, and a same time-frequency resource is multiplexed for the DMRS ports in each DMRS port group in a code division multiplexing (CDM) manner; and in each resource unit, a time-frequency resource corresponding to the first DMRS port group is subcarrier 0, subcarrier 1, subcarrier 6, and subcarrier 7 on a first symbol in time domain, a time-frequency resource corresponding to the second DMRS port group is subcarrier 2, subcarrier 3, subcarrier 8, and subcarrier 9 on the first symbol in time domain, a time-frequency resource corresponding to the third DMRS port group is subcarrier 4, subcarrier 5, subcarrier 10, and subcarrier 11 on the first symbol in time domain; or in each resource unit of the at least one resource unit, time-frequency resources that can be used for the DMRS correspond to three DMRS port groups, the three DMRS port groups comprise a first DMRS port group, a second DMRS port group, and a third DMRS port group; each DMRS port group comprises two DMRS ports, and a same time-frequency resource is multiplexed for the DMRS ports in each DMRS port group in a code division multiplexing (CDM) manner; and in each resource unit, a time-frequency resource corresponding to the first DMRS port group is subcarrier 0, subcarrier 1, subcarrier 6, and subcarrier 7 on a first symbol and a second symbol in time domain, a time-frequency resource corresponding to the second DMRS port group is subcarrier 2, subcarrier 3, subcarrier 8, and subcarrier 9 on the first symbol and the second symbol in time domain, a time-frequency resource corresponding to the third DMRS port group is subcarrier 4, subcarrier 5, subcarrier 10, and subcarrier 11 on the first symbol and the second symbol in time domain. ### Claim 38 (depends on 37) The non-transitory computer storage medium according to claim 37, wherein the resource unit is a resource block (RB). ### Claim 39 (depends on 37) The non-transitory computer storage medium according to claim 37, wherein the first symbol and the second symbol are continuous in time domain. ### Claim 40 (depends on 37) The non-transitory computer storage medium according to claim 37, wherein the DMRS is for a downlink transmission or an uplink transmission. ### Claim 41 A non-transitory computer-readable storage medium, wherein the non-transitory computer-readable storage medium stores computer instructions for being executed by at least one processor to perform operations comprising: sending indication information, wherein the indication information indicates a time-frequency resource used to carry a demodulation reference signal (DMRS) in at least one resource unit, wherein: in each resource unit of the at least one resource unit, time-frequency resources that can be used for the DMRS correspond to three DMRS port groups, the three DMRS port groups comprise a first DMRS port group, a second DMRS port group, and a third DMRS port group; each DMRS port group comprises two DMRS ports, and a same time-frequency resource is multiplexed for the DMRS ports in each DMRS port group in a code division multiplexing (CDM) manner; and in each resource unit, a time-frequency resource corresponding to the first DMRS port group is subcarrier 0, subcarrier 1, subcarrier 6, and subcarrier 7 on a first symbol in time domain, a time-frequency resource corresponding to the second DMRS port group is subcarrier 2, subcarrier 3, subcarrier 8, and subcarrier 9 on the first symbol in time domain, a time-frequency resource corresponding to the third DMRS port group is subcarrier 4, subcarrier 5, subcarrier 10, and subcarrier 11 on the first symbol in time domain; or in each resource unit of the at least one resource unit, time-frequency resources that can be used for the DMRS correspond to three DMRS port groups, the three DMRS port groups comprise a first DMRS port group, a second DMRS port group, and a third DMRS port group; each DMRS port group comprises two DMRS ports, and a same time-frequency resource is multiplexed for the DMRS ports in each DMRS port group in a code division multiplexing (CDM) manner; and in each resource unit, a time-frequency resource corresponding to the first DMRS port group is subcarrier 0, subcarrier 1, subcarrier 6, and subcarrier 7 on a first symbol and a second symbol in time domain, a time-frequency resource corresponding to the second DMRS port group is subcarrier 2, subcarrier 3, subcarrier 8, and subcarrier 9 on the first symbol and the second symbol in time domain, a time-frequency resource corresponding to the third DMRS port group is subcarrier 4, subcarrier 5, subcarrier 10, and subcarrier 11 on the first symbol and the second symbol in time domain. ### Claim 42 (depends on 33) The non-transitory computer storage medium according to claim 33, wherein the resource unit is a resource block (RB). ### Claim 43 (depends on 33) The non-transitory computer storage medium according to claim 33, wherein the first symbol and the second symbol are continuous in time domain. ### Claim 44 (depends on 33) The non-transitory computer storage medium according to claim 33, wherein the DMRS is for a downlink transmission or an uplink transmission. ### Claim 45 A non-transitory computer-readable storage medium, wherein the computer-readable storage medium stores computer instructions for being executed by at least one processor to perform operations comprising: receiving indication information, wherein the indication information indicates a time-frequency resource used to carry a demodulation reference signal (DMRS) in at least one resource unit, wherein: in each resource unit of the at least one resource unit, time-frequency resources that can be used for the DMRS correspond to three DMRS port groups, the three DMRS port groups comprise a first DMRS port group, a second DMRS port group, and a third DMRS port group; each DMRS port group comprises two DMRS ports, and a same time-frequency resource is multiplexed for the DMRS ports in each DMRS port group in a code division multiplexing (CDM) manner; and in each resource unit, a time-frequency resource corresponding to the first DMRS port group is subcarrier 0, subcarrier 1, subcarrier 6, and subcarrier 7 on a first symbol in time domain, a time-frequency resource corresponding to the second DMRS port group is subcarrier 2, subcarrier 3, subcarrier 8, and subcarrier 9 on the first symbol in time domain, a time-frequency resource corresponding to the third DMRS port group is subcarrier 4, subcarrier 5, subcarrier 10, and subcarrier 11 on the first symbol in time domain; or in each resource unit of the at least one resource unit, time-frequency resources that can be used for the DMRS corresponds to three DMRS port groups, the three DMRS port groups comprise a first DMRS port group, a second DMRS port group, and a third DMRS port group; each DMRS port group comprises two DMRS ports, and a same time-frequency resource is multiplexed for the DMRS ports in each DMRS port group in a code division multiplexing (CDM) manner; and in each resource unit, a time-frequency resource corresponding to the first DMRS port group is subcarrier 0, subcarrier 1, subcarrier 6, and subcarrier 7 on a first symbol and a second symbol in time domain, a time-frequency resource corresponding to the second DMRS port group is subcarrier 2, subcarrier 3, subcarrier 8, and subcarrier 9 on the first symbol and the second symbol in time domain, a time-frequency resource corresponding to the third DMRS port group is subcarrier 4, subcarrier 5, subcarrier 10, and subcarrier 11 on the first symbol and the second symbol in time domain. ### Claim 46 (depends on 45) The non-transitory computer storage medium according to claim 45, wherein the resource unit is a resource block (RB). ### Claim 47 (depends on 45) The non-transitory computer storage medium according to claim 45, wherein the first symbol and the second symbol are continuous in time domain. ### Claim 48 (depends on 45) The non-transitory computer storage medium according to claim 45, wherein the DMRS is for a downlink transmission or an uplink transmission. ### Claim 49 (depends on 1) The method according to claim 1, wherein before sending the DMRS mapped on a time-frequency resource in at least one resource unit, the method comprises: determining the time-frequency resource. ### Claim 50 (depends on 5) The method according to claim 5, wherein before receiving the DMRS using a time-frequency resource in at least one resource unit, the method comprises: determining the time-frequency resource. ### Claim 51 (depends on 9) The method according to claim 9, wherein before sending indication information, the method comprises: generating the indication information. ### Claim 52 (depends on 13) The method according to claim 13, wherein the method comprises: determining the time-frequency resource based on the indication information. ### Claim 53 (depends on 17) The apparatus according to claim 17, wherein the one or more memories coupled to the at least one processor and storing computer instructions for execution by the at least one processor to configure the apparatus for: before sending the DMRS mapped on a time-frequency resource in at least one resource unit, determining the time-frequency resource. ### Claim 54 (depends on 21) The apparatus according to claim 21, wherein the one or more memories coupled to the at least one processor and storing computer instructions for avaction hu the at least one pro or to configure the apparatus for before receiving the DMRS using a time-frequency resource in at least one resource unit, determining the time-frequency resource. ### Claim 55 (depends on 25) The apparatus according to claim 25, wherein the one or more memories coupled to the at least one processor and storing computer instructions for execution by the at least one processor to configure the apparatus for: before sending indication information, generating the indication information. ### Claim 56 (depends on 29) The apparatus according to claim 29, wherein the one or more memories coupled to the at least one processor and storing computer instructions for execution by the at least one processor to further configure the apparatus for: determining the time-frequency resource based on the indication information. ### Claim 57 (depends on 33) The non-transitory computer-readable storage medium according to claim 33, wherein before sending the DMRS mapped on a time-frequency resource in at least one resource unit, the operations comprises: determining the time-frequency resource. ### Claim 58 (depends on 37) The non-transitory computer-readable storage medium according to claim 37, wherein before receiving the DMRS using a time-frequency resource in at least one resource unit, the operations comprises: determining the time-frequency resource. ### Claim 59 (depends on 41) The non-transitory computer-readable storage medium according to claim 41, wherein before sending indication information, the operations comprises: generating the indication information. ### Claim 60 (depends on 45) The non-transitory computer-readable storage medium according to claim 45, wherein the operations comprises: determining the time-frequency resource based on the indication information.