An indication method, comprising: generating indication information, wherein the indication information is used to indicate a time-frequency resource used to carry a demodulation reference signal, DMRS, wherein the DMRS is carried on the time-frequency resource in at least one resource unit; and if a total quantity of system-supported DMRS ports is 6, the six DMRS ports are divided into three DMRS port groups, each DMRS port group comprises two DMRS ports, the three DMRS port groups comprise a first DMRS port group, a second DMRS port group, and a third DMRS port group, and a same time-frequency resource is multiplexed for the DMRS ports in each DMRS port group in a code division multiplexing, CDM manner, in each resource unit, a time-frequency resource to which the first DMRS port group is mapped comprises a subcarrier 12n, a subcarrier 12n+1, a subcarrier 12n+6, and a subcarrier 12n+7 that are in a first symbol in time domain, a time-frequency resource to which the second DMRS port group is mapped comprises a subcarrier 12n+2, a subcarrier 12n+3, a subcarrier 12n+8, and a subcarrier 12n+9 that are in the first symbol in time domain, and a time-frequency resource to which the third DMRS port group is mapped comprises a subcarrier 12n+4, a subcarrier 12n+5, a subcarrier 12n+10, and a subcarrier 12n+11 that are in the first symbol in time domain, wherein n is equal to 0; or the DMRS is carried on the time-frequency resource in at least one resource unit; and if a total quantity of system-supported DMRS ports is 6, the six DMRS ports are divided into three DMRS port groups, each DMRS port group comprises two DMRS ports, the three DMRS port groups comprise a first DMRS port group, a second DMRS port group, and a third DMRS port group, and a same time-frequency resource is multiplexed for the DMRS ports in each DMRS port group in a CDM manner, in each resource unit, a time-frequency resource to which the first DMRS port group is mapped comprises a subcarrier 12n, a subcarrier 12n+1, a subcarrier 12n+6, and a subcarrier 12n+7 that are in a first symbol and a second symbol in time domain, a time-frequency resource to which the second DMRS port group is mapped comprises a subcarrier 12n+2, a subcarrier 12n+3, a subcarrier 12n+8, and a subcarrier 12n+9 that are in the first symbol and the second symbol in time domain, and a time-frequency resource to which the third DMRS port group is mapped comprises a subcarrier 12n+4, a subcarrier 12n+5, a subcarrier 12n+10, and a subcarrier 12n+11 that are in the first symbol and the second symbol in time domain, wherein n is equal to 0; and sending the indication information. generating indication information, wherein the indication information is used to indicate a time-frequency resource used to carry a demodulation reference signal, DMRS, wherein the DMRS is carried on the time-frequency resource in at least one resource unit; and if a total quantity of system-supported DMRS ports is 6, the six DMRS ports are divided into three DMRS port groups, each DMRS port group comprises two DMRS ports, the three DMRS port groups comprise a first DMRS port group, a second DMRS port group, and a third DMRS port group, and a same time-frequency resource is multiplexed for the DMRS ports in each DMRS port group in a code division multiplexing, CDM manner, in each resource unit, a time-frequency resource to which the first DMRS port group is mapped comprises a subcarrier 12n, a subcarrier 12n+1, a subcarrier 12n+6, and a subcarrier 12n+7 that are in a first symbol in time domain, a time-frequency resource to which the second DMRS port group is mapped comprises a subcarrier 12n+2, a subcarrier 12n+3, a subcarrier 12n+8, and a subcarrier 12n+9 that are in the first symbol in time domain, and a time-frequency resource to which the third DMRS port group is mapped comprises a subcarrier 12n+4, a subcarrier 12n+5, a subcarrier 12n+10, and a subcarrier 12n+11 that are in the first symbol in time domain, wherein n is equal to 0; or the DMRS is carried on the time-frequency resource in at least one resource unit; and if a total quantity of system-supported DMRS ports is 6, the six DMRS ports are divided into three DMRS port groups, each DMRS port group comprises two DMRS ports, the three DMRS port groups comprise a first DMRS port group, a second DMRS port group, and a third DMRS port group, and a same time-frequency resource is multiplexed for the DMRS ports in each DMRS port group in a CDM manner, in each resource unit, a time-frequency resource to which the first DMRS port group is mapped comprises a subcarrier 12n, a subcarrier 12n+1, a subcarrier 12n+6, and a subcarrier 12n+7 that are in a first symbol and a second symbol in time domain, a time-frequency resource to which the second DMRS port group is mapped comprises a subcarrier 12n+2, a subcarrier 12n+3, a subcarrier 12n+8, and a subcarrier 12n+9 that are in the first symbol and the second symbol in time domain, and a time-frequency resource to which the third DMRS port group is mapped comprises a subcarrier 12n+4, a subcarrier 12n+5, a subcarrier 12n+10, and a subcarrier 12n+11 that are in the first symbol and the second symbol in time domain, wherein n is equal to 0; and sending the indication information.