On the Distortion of UWB Circularly Polarized Time-Domain Pulses in Presence of Rotation

Abstract

The paper provides a first theoretical study on the effect of rotational Doppler on circularly polarized pulsed communication. Despite the circularly polarized communication being considered immune to signal fading due to rotary misalignment, such misalignment will cause a frequency-invariant phase-shift. This phase shift will significantly distort the shape of the time-domain pulse. The property can be used for integration of orientation sensing into well establish pulse-based localization. However, it has also the potential to distort communication for some pulse-modulated UWB systems.

Measurement of Orientation and Distance Change Using Circularly Polarized UWB Signals

“…This paper investigates for the first time the practical use of UWB CP signals [17] for simultaneous measurement of the orientation and distance change between the transmit and measured antenna. It significantly extends results from [6] by demonstrating that by analyzing the UWB CP pulse phase, one can accurately determine both the orientation and distance change in the presence of noise. The presented theory validates the performance of the technique for various axial ratio, bandwidth and Signal-to-Noise ratios.…”

“…This principle was used in a dualfrequency numerical study in [5], however the measurement results were prone to a significant error due to lack of redundancy. In [6] a qualitative discussion noted that a CP UWB pulse will be distorted in the presence of rotation. While it provides no quantitative results, it suggests the possibility of simultaneous measurement of the orientation and distance using such pulses.…”