Method of performing uplink channel estimation and base station using the same

A base station, applicable to serve at least two user equipments (UEs) in a communication system, wherein the at least two UEs are located in at least two beam sectors respectively, the base station comprising:

• a plurality of antennas;
• a transceiver circuit, configured to transmit and receive wireless signals through the plurality of antennas;
• a storage circuit, storing a plurality of program codes;
• and
• a processing circuit, coupled to the transceiver circuit and the storage circuit and configured to access the program codes to perform operations of:
• obtaining multipath information of the at least two UEs;
• determining whether multipath of the at least two UEs passing through a same beam sector according to the multipath information of the at least two UEs;
• assigning a first training sequence for a first UE of the at least two UEs and assigning a second training sequence for a second UE of the at least two UEs, wherein the first training sequence is orthogonal to the second training sequence in response to the multipath of the at least two UEs passing through the same beam sector;
• receiving a reference signal, wherein the reference signal is transmitted by the first UE and the second UE according to the first training sequence and the second training sequence;
• and
• performing channel estimation for the first UE and the second UE according to the reference signal, the first training sequence and the second training sequence.