Cisco Systems, Inc.
Determining a propagation condition of a wireless channel

Abstract:

In some embodiments, a method obtains raw data from one or more packets received over a wireless channel via an antenna. The raw data comprises raw amplitude values and raw phase values. Each raw amplitude value and raw phase value corresponds to a respective OFDM symbol and subcarrier of a respective packet. The method further comprises processing the raw data according to an interference mitigation process and using the resulting calibrated amplitude values and calibrated phase values to determine weighted phase values. Each weighted phase value corresponds to a respective subcarrier. The method determines a phase variance for the antenna based on comparing the plurality of weighted phase values across the plurality of subcarriers. The method determines whether the wireless channel experiences line-of-sight propagation or non-line-of-sight propagation based at least in part on the phase variance.