Data transmission method, base station, and communication system

A base station, comprising:

• a non-transitory computer readable storage medium to store program(s), and
• computer hardware configured to implement, including configured by the program(s) to implement:
• a determining module, configured to determine to perform semi-persistent scheduling on data of user equipments;
• a setting module, configured to set a value of first information for the user equipment, the value of the first information utilizable by the user equipment to determine a cyclic shift value of a reference signal sequence of the user equipment, wherein the first information is determined by a three-bit cyclic shift indicator field of a demodulation reference signal on a physical downlink control channel (PDCCH), and the setting, by the base station, of the value of the first information for the user equipment comprises setting one bit or two bits of the three-bit cyclic shift indicator field to a fixed value;
• and
• an obtaining and demodulating module, configured to obtain the reference signal sequence of the user equipment, perform channel estimation according to the reference signal sequence of the user equipment, and perform demodulation on data information of the user equipment according to a channel coefficient obtained by the channel estimation.