transmitting, from a first device, a plurality of signals through the wireless channel, including a first transmitted signal and a second transmitted signal, wherein the first transmitted signal comprises a signal code sequence being a predefined code stored in memory of the first device and a second device, and wherein the plurality of signals are modulated in transmission to generate a Doppler shift of the transmitted plurality of signals;

receiving, by a processor of the second device, the plurality of signals at a plurality of antennas, including a first received signal and a second received signal, wherein the first received signal corresponds to the first transmitted signal, and wherein the second received signal corresponds to the second transmitted signal, and wherein the second device is configured to receive Doppler-shifted signals through a switching system configured to switch between a channel sounding mode and a direction finding mode;

determining, by the processor of the second device, a phase difference between the received first transmitted signal and the received second transmitted signal;

characterizing the wireless channel using a channel sounding operation to estimate a characteristic value associated with the wireless channel, wherein the channel sounding operation comprises: (i) tuning to a carrier frequency, (ii) performing a time synchronization operation to determine a phase of root raised cosine pulses to maximize a signal-to-noise ratio (SNR), and (iii) Binary Phase Shift Keying (BPSK)-demodulating and match filtering the first transmitted signal with an inversed sequence of the signal code sequence to produce a channel impulse response;

determining, by the processor of the second device, an angle of arrival of the plurality of signals based on the estimated characteristic value and the determined phase difference; and

outputting, by the processor of the second device, at a graphic user interface of the second device, an indication of the determined angle of arrival.