Abstract: A method for determining a remote radio device and a distributed AP are provided. The method includes: A baseband device determines parameters of uplink signals received by N remote radio devices, where N is a natural number greater than 1. The baseband device selects, based on the parameters, at least one remote radio device from the N remote radio devices as a remote radio device in a target set. The baseband device performs decoding based on an uplink signal received by the remote radio device in the target set, or positions a terminal device based on an uplink signal received by the remote radio device in the target set.

Abstract: A time measurement method includes that a first device receives a first packet from a second device using a first antenna. The first device transmits a second packet to the second device using a second antenna. The first device receives an indication for a first transceiving delay from the second device, where the first transceiving delay is a delay from a time at which the second device transmits the first packet to a time at which the second device receives the second packet. The first device determines a round-trip time (RTT) between the first device and the second device based on a calibration delay from the second antenna to the first antenna, a recording moment at which the first device receives the first packet, a recording moment at which the first device transmits the second packet, and the first transceiving delay.

Abstract: A time calibration method includes a first station receives a first frame from a second station; the first station stores a receiving moment of the first frame; the first station receives a second frame from the second station, where the second frame includes a sending moment at which the second station sends the first frame; and the first station obtains a clock offset between a first clock of the first station and a second clock of the second station based on the receiving moment of the first frame and the sending moment of the first frame.

Abstract: A time measurement method includes that a first device receives a first packet from a second device using a first antenna. The first device transmits a second packet to the second device using a second antenna. The first device receives an indication for a first transceiving delay from the second device, where the first transceiving delay is a delay from a time at which the second device transmits the first packet to a time at which the second device receives the second packet. The first device determines a round-trip time (RTT) between the first device and the second device based on a calibration delay from the second antenna to the first antenna, a recording moment at which the first device receives the first packet, a recording moment at which the first device transmits the second packet, and the first transceiving delay.