Methods and apparatus for monitoring occupancy of wideband GHz spectrum and sensing and decoding respective frequency components of time-varying signals using sub-nyquist criterion signal sampling

A wireless communication device to receive and decode a plurality of signals respectively having carrier frequencies in the GHz range, the plurality of signals constituting, in combination, respective frequency components of a time-varying signal having a frequency bandwidth of interest BW and a Nyquist sampling criteria of N samples in a sampling time T, wherein N=T×BW, the wireless communication device comprising:

• A) a wideband receiver to receive the plurality of signals constituting, in combination, the respective frequency components of the time-varying signal;
• B) an analog-to-digital converter (ADC) apparatus, communicatively coupled to the wideband receiver, to provide a plurality of uniform sub-samples of the time-varying signal, wherein:
• at least a first pair of uniform sub-samples of the plurality of uniform sub-samples are time-shifted with respect to one another;
• and
• at least a second pair of uniform sub-samples of the plurality of uniform sub-samples are sub-sampled at different sampling rates;
• and
• C) at least one processor, communicatively coupled to the ADC apparatus, to sense and decode the plurality of signals constituting, in combination, the respective frequency components of the time-varying signal by:
• C1) computing a plurality of Fast Fourier Transforms (FFTs) based on the plurality of uniform sub-samples of the time-varying signal;
• C2) processing the plurality of FFTs so as to determine a magnitude value and a frequency position in the bandwidth of interest BW of each signal of the plurality of signals constituting, in combination, the respective frequency components of the time-varying signal,
• C3) providing a digital output representing at least respective frequency positions in the bandwidth of interest BW of the plurality of signals constituting, in combination, the respective frequency components of the time-varying signal, based at least in part on C1) and C2);
• and
• C4) decoding each signal of the plurality of signals based at least in part on C3).

A wireless communication method for receiving and decoding a plurality of signals respectively having carrier frequencies in the GHz range, the plurality of signals constituting, in combination, respective frequency components of a time-varying signal having a frequency bandwidth of interest BW and a Nyquist sampling criteria of N samples in a sampling time T, wherein N=T×BW, the wireless communication method comprising:

• A) receiving, via a wideband receiver, the plurality of signals constituting, in combination, the respective frequency components of the time-varying signal;
• B) uniformly sub-sampling the time-varying signal, via an analog-to-digital converter (ADC) apparatus communicatively coupled to the wideband receiver, so as to provide at least four sets of samples of the time-varying signal, the at least four sets of samples comprising:
• a first set of samples arising from uniform sub-sampling of the time-varying signal at a first time and a first sampling rate;
• a second set of samples arising from uniform sub-sampling of the time-varying signal at a second time different from the first time and the first sampling rate;
• a third set of samples arising from uniform sub-sampling of the time-varying signal at the first time and a second sampling rate different from the first sampling rate;
• and
• a fourth set of samples arising from uniform sub-sampling of the time-varying signal at a third time and the second sampling rate;
• and
• C) electronically processing, via at least one processor communicatively coupled to the ADC apparatus, the first, second, third and fourth sets of samples of the time-varying signal provided in B) by:
• C1) computing respective first, second, third and fourth Fast Fourier Transforms (FFTs) based on corresponding ones of the first, second, third and fourth sets of samples of the time-varying signal provided in B);
• C2) processing the first, second, third and fourth FFTs so as to determine a magnitude value and a frequency position in the bandwidth of interest BW of each signal of the plurality of signals constituting, in combination, the respective frequency components of the time-varying signal,
• C3) providing a digital output representing at least respective frequency positions in the bandwidth of interest BW of the plurality of signals constituting, in combination, the respective frequency components of the time-varying signal, based at least in part on C1) and C2);
• and
• C4) decoding each signal of the plurality of signals based at least in part on C3).