Evaluation of Atomic Clock-based Joint Transmission for Full-Duplex in IEEE 802.11

Self-interference cancellation is an important technology to achieve full-duplex communication. The self-interference (SI) signal in IEEE 802.11 networks can be suppressed using Joint Transmission (JT) with null beamforming. This method requires a weight matrix that is obtained from the Channel State Information (CSI). However, JT requires very tight synchronization between multiple access points (APs). Since multiple APs run on different clock sources, offsets between APs might occur, making it difficult to cancel the SI signal. In this paper, we evaluate the SI cancellation of JT with null beamforming when an atomic clock is used in our simulation model. Our results show that SI cancellation with an atomic clock can have results similar to the ideal condition (i.e., the same external clock source is applied to all APs).