Spreading sequences in active sensing: A review

Active sensing is a growing research field with long-standing open problems, whose applications range from CDMA communication systems, ultrasonic imaging or ranging systems to name a few. In those applications, spreading sequences are usually transmitted in a bursting manner, making their aperiodic correlation the most important feature to be considered, since it determines how easily the transmission can be detected by the receiver. Hence, the selection of the spreading sequence with good aperiodic correlation properties has a large impact on the final system performance. This paper presents a revision of the aperiodic spreading sequences used for active sensing systems available in the literature so it aims to serve as a reference for researchers in the field.