A communications apparatus, wherein the apparatus is disposed on an access point AP apparatus in a wireless local area network and comprises: a channel contention unit, configured to obtain use permission of a channel; a measurement unit, configured to perform a self-interference measurement; a scheduling information determining unit, configured to: after the use permission of the channel is obtained, determine scheduling information for a station participating in full-duplex transmission, wherein the scheduling information comprises information about a first station that is to perform uplink transmission on the channel and information about a second station that is to perform downlink transmission on the channel at the same time, or the scheduling information comprises information about a third station that is to simultaneously perform uplink and downlink transmission on the channel; and a transmission unit, configured to send the scheduling information to the station participating in full-duplex transmission, being selected from the first station, the second station and the third station; wherein the scheduling information further comprises transmission duration or an upper limit of transmission duration of an uplink data frame sent by the first station or the third station, or transmission duration or an upper limit of transmission duration of a downlink data frame sent to the second station or the third station; where the self-interference measurement is performed when the transmission unit sends a trigger frame or in a transmission duration of a legacy preamble after receiving a trigger frame; where the self-interference measurement is performed in a time interval not shorter than a transmission duration of the legacy preamble and before the access point AP starts sending the downlink data frame. a channel contention unit, configured to obtain use permission of a channel; a measurement unit, configured to perform a self-interference measurement; a scheduling information determining unit, configured to: after the use permission of the channel is obtained, determine scheduling information for a station participating in full-duplex transmission, wherein the scheduling information comprises information about a first station that is to perform uplink transmission on the channel and information about a second station that is to perform downlink transmission on the channel at the same time, or the scheduling information comprises information about a third station that is to simultaneously perform uplink and downlink transmission on the channel; and a transmission unit, configured to send the scheduling information to the station participating in full-duplex transmission, being selected from the first station, the second station and the third station; wherein the scheduling information further comprises transmission duration or an upper limit of transmission duration of an uplink data frame sent by the first station or the third station, or transmission duration or an upper limit of transmission duration of a downlink data frame sent to the second station or the third station; where the self-interference measurement is performed when the transmission unit sends a trigger frame or in a transmission duration of a legacy preamble after receiving a trigger frame; where the self-interference measurement is performed in a time interval not shorter than a transmission duration of the legacy preamble and before the access point AP starts sending the downlink data frame.