Issue link: https://resources.mouser.com/i/1484091
24 The Future of Automotive Figure 3: Comparison of various wireless location and communication standards. (Source: Qorvo) Overview of Current Location Technologies There are five different approaches to distance/location measurements using modern wireless communication: RFID, Wi-Fi, Bluetooth, GPS, and UWB. RFID, Wi-Fi, and Bluetooth use RSSI to calculate distance. RSSI is a measure of the relative signal strength between a transmitting and receiving radio, which can be used to approximate the distance, given specific knowledge of the channel. Another method is GPS, which measures ToF between a user device (UE) and several time-synchronized satellites to determine the distance from each satellite, which can be used to calculate the 3D position relative to the satellite constellation. Lastly, there is Qorvo's IR UWB ToF technology (Figure 3). The main difference between these methods and Qorvo IR UWB ToF is that the UWB approach uses extremely wideband frequency signals that are extremely short in time. Narrowband ToF systems use short pulses, but only over a narrow frequency band. Wi-Fi, Bluetooth, and RFID also use ToF, but are also limited in bandwidth and aren't capable of producing extremely short pulses with sharp rise/fall times (clean edges) compared to UWB (Figure 4). The ultra- wideband bandwidth of UWB means that the signal energy is distributed over the entire ultra-wide frequency band, which means that the protocol is comparably immune to interference at any given frequency. The incredibly sharp rise/fall times and the brief time of the UWB pulses minimize the impact of multi-path interference and enable very accurate time measurements, resulting in enhanced accuracy.