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23 Qorvo 2022 How Does UWB Work? UWB uses extremely wideband and short pulses (~2 nanoseconds) with very sharp rise/fall times to encode data using binary phase-shift keying (BPSK) and/or burst position modulation (BPM). Two consecutive impulse radio (IR) signals are used in UWB to represent a symbol and can be within one of the chirp-intervals (Tc) that is within a time frame (Tf). The use of time-hopping code allows for the accurate determination of the position of a signal in a single dedicated time frame, which minimizes the chance of interference between two UWB systems (Figure 2). Each UWB communication is timestamped. Timestamping allows for the use of the Time-of-flight (ToF) of the signals between two radios to calculate the distance between the two radios, point-to-point (P2P) Two-Way Ranging (TWR). Figure 2: UWB transmits information using short sequences of extremely narrow pulses. (Source: Qorvo) This distance-measuring method is secure and distinct between the two UWB communicating radios and is immune to multi-path, as the shortest path will always be the shortest distance between the two radios. Extending this concept further to include additional anchors distributed throughout an environment can enable real-time navigation. With multiple synchronized anchors in space, the exact position of a tag in 3D space can be determined using Time Difference of Arrival (TDoA) or Reverse TDoA (RTDoA). Suppose a UWB tag is equipped with multiple antennas. In that case, the Phase Difference of Arrival (PDoA) can be used to calculate the relative position of the two devices by determining the distance and the bearing of the communication radios.