Novel variable spreading sequence length system for improving the processing speed of DS-UWB radar

A vehicular radar is an essential device to reduce traffic accidents. As such a radar, direct sequence-ultra wideband (DS-UWB) radar has been studied in recent years. It could detect the target at a high resolution. In order to apply the DS-UWB scheme to the vehicular radar system, we need to measure the distance between vehicles at high speed and control the vehicles with enough time margin. However, we have to enlarge the spreading sequence length very much to extend maximum detectable distance because the DS-UWB scheme use extremely short pulses that is 1ns. Therefore, we need to speed up correlation processing time in the case of measuring long distance. Research done to answer this needs has been scarce until now. In this paper, we propose a variable spreading sequence length system in order to improve accuracy and reliability by increasing the update rate of data of distance between vehicles. Some simulation results show that ranging time and accuracy could be improved by the proposed system.