Joint Positioning-Communications System Design and Experimental Demonstration

Communications and High-Precision Positioning (CHP2): Hardware Architecture, Implementation, and Validation

“…The receive timestamps discussed in Section 3 are estimated using three ToA estimation techniques: (a) a critically sampled matched filter [ 15 ], (b) an oversampled reference bank [ 14 ], and (c) an interpolated correlator [ 83 ].…”

“…We may limit this computational complexity by oversampling the reference signal x by a large factor (order 200), building a reference bank of shifted versions of x at this oversampled frequency, then downsampling the entries in this reference bank back to . This bank contains copies of x at the original sampling frequency , but each adjacent shift lies on the much more precise sampling lattice defined by the large oversampling frequency [ 14 ]. This allows us to test ToA hypotheses with much higher temporal resolution while still performing computations at the sampling frequency .…”

“…Label a coarse test point p some small number of samples before , index the “micro-shifts” in the reference bank by q , define the total number of test points as Q and construct the reference bank such that each row corresponds to a micro-shifted version of , which builds a matrix. The micro-resolution and the narrow-window cost function may be written [ 14 ] as …”

“…In controlled laboratory environments, this precision has been driven as low as 5 mm with only 10 MHz bandwidth while simultaneously enabling network communications and digitally synchronizing distributed users within a fraction of a nanosecond. When the platform geometries are known, these multi-antenna distance estimates may be translated into position and orientation estimates, the performance of which is subject to the geometric dilution of precision [ 13 , 14 ]. This precision enables sensitive applications such as automated landing and collision avoidance, while the small form factor allows installation into small vehicles such as UAV.…”

“…In these publications, the authors demonstrated a high-precision, two-way ranging prototype and explore tractable time-of-arrival estimation techniques. We extend these results by integrating modern RF convergence design principles [ 11 ], developing a complete hardware implementation on consumer-off-the-shelf hardware [ 18 , 19 ], and demonstrating a robust ranging prototype in over-the-air flight tests [ 14 ].…”