A communication system includes a RF subsystem that communicates with a BB subsystem through a digital RF-BB interface multiplexing I/Q data and control signals in both TX and RX directions. The RF subsystem includes a FIFO buffer in each respective TX and RX chain and a timer that assigns a timestamp to the continuous stream in both TX and RX chains whenever it is equal to a time event from the BB subsystem. The BB subsystem includes a sample counter that counts the number (k) of data samples at the FIFO buffer and a controller that defines the time event. Precise alignment at the air interface between a data burst from the RF subsystem and a data burst from the BB subsystem can be achieved using the timer, based on the relation between the timer value (n) and the sample count (k).