Dual-polarized architectures for sensing with wireless communications signals

Methods for detecting object translation and/or motion using differential polarization-based sensing are described. Both time and frequency-based polarimetric sensing strategies are considered. The time-based detection statistic is formed using the differential time-averaged received signal polarization state. This approach suffers from the impact of polarization-sensitive channel impairments, especially polarization mode dispersion (PMD). As PMD effects become more prominent, the variability of the time-domain signal polarization increases and the average polarization over a detection interval may be substantially different from the instantaneous signal polarization states, detracting from the overall sensitivity of the detection statistic. Frequency-domain approaches, on the other hand, can leverage the relatively stable polarization-frequency signature of the received signal, and can be designed to easily exploit PMD using differential detection in the subbands. Integration of the detections over the full complement of subbands is then used to arrive at a final detection statistic. Using indoor measurements, the resulting subbanded architecture is found to provide improved detection sensitivity in comparison to the time-based version as well as to more conventional power-based techniques, including a subbanded power-based architecture.