A method at a network node that is configured to simultaneously transmit and receive wireless RF signals, comprising: transmitting, from the network node, a downlink message, the downlink message having a preamble that includes channel estimation information for estimating a self-interference channel; monitoring at the network node, during an initial duration while transmitting the downlink message, for the channel estimation information, and estimating a self-interference channel based on received portions of the channel estimation information; and using the estimated self-interference channel to cancel self-interference while receiving an uplink message and simultaneously transmitting a remainder of the downlink message.