A method of providing over-the-air assistance information for interference cancellation or suppression to the receiver is proposed. Under a first solution, a two-stage DCI (downlink control information) or SCI (sidelink control information) scheduling method is proposed. The set of first-stage DCI or SCI provides a part of scheduling information which is beneficial for interference cancellation or suppression and is broadcasted by a transmitter or scheduler to all receivers. The set of second-stage DCI or SCI includes the remaining scheduling information and is unicasted by a transmitter or scheduler to each receiver. Under a second solution, assistance information DCI for interference cancellation or suppression is broadcasted by a transmitter or scheduler to all receivers.