Chip-scale radio-frequency localization devices and associated systems and methods
摘要
說(shuō)明書(shū)
At act 1506, an estimate of the distance between the first interrogator and the target device may be determined by using the first RF signal transmitted at act 1502 and the second RF signal received at act 1504. This may be done in any suitable way. For example, in some embodiments, the first and second RF signals may be mixed (e.g., using a frequency mixer onboard the first interrogator device) to obtain a mixed RF signal. The mixed RF signal may be indicative of the time of flight and, consequently, the distance between the first interrogator and the target device. The mixed RF signal may be sampled (e.g., using an ADC) and a Fourier transform (e.g., an inverse discrete Fourier transform) may be applied to the samples to obtain a time-domain waveform. The time-domain waveform may be processed to identify the time of flight of an RF signal between the first interrogator and the target device. In some embodiments, the time-domain waveform may be processed to identify the time of flight by identifying a first time when a responsive RF signal generated by the target device is detected by the interrogator. This may be done in any suitable way. For example, the time-domain waveform may include multiple separated “peaks” (e.g., multiple Gaussian-like bumps each having a respective peak above the noise floor) and the location of the first such peak may indicate the first time when the responsive RF signal generated by the target is detected by the interrogator. This first time represents an estimate of the time of flight between the interrogator and target device. In turn, the estimate of the time of flight between the interrogator and the target device may be converted to an estimate of the distance between the interrogator and the target device.
