In this talk, a new Frequency Based Ranging (FBR) technique will be discussed and compared with Phase Based Ranging (PBR) for Bluetooth Channel Sounding. FBR is based on the Sinusoidal Frequency Modulated Continuous Wave (S-FMCW) ranging method. Propagation delays between Initiator and Reflector are converted to measurable frequency differences (analogous to phase differences in PBR). Similar to PBR, even FBR signals can be generated within existing Bluetooth packet structures. FBR offers two key advantages over PBR: (i) since frequency doesn’t need to be unwrapped, unlike phase, FBR allows ranging on a single channel; (ii) since measurements from multiple channels are not needed, much less time is needed for ranging. Consequently, FBR will allow ranging on just one Bluetooth channel and within a few milliseconds.
This talk will focus on a quantitative comparison between FBR and PBR in the context of Bluetooth applications. Performance and accuracy will be compared for different distances and propagation environments. It will be shown that while PBR is better at shorter distances with line of sight propagation, FBR has the edge at longer distances and in multipath environments. From the hardware perspective, FBR is also compatible with devices that are designed to implement Bluetooth PBR. Complementary capabilities of FBR and PBR, coupled with their hardware compatibility, suggest that they can be integrated to create a new robust channel sounding technology for Bluetooth.