Blind phase-shift keying (PSK) and quadrature amplitude modulation (QAM) identification

摘要

Technology for blind phase-shift keying (PSK) and quadrature amplitude modulation (QAM) identification of a received radio frequency (RF) signal is disclosed. One method can include: uniform sub-sampling the received RF signal to eliminate a phase contribution from a carrier frequency of the received RF signal; and computing a likelihood function of observed phase differences of the sub-sampled received RF signal of a phase sequence for each PSK modulation type. Another method can include: non-uniformly sub-sampling the received RF signal for a distribution of signal amplitudes of the received RF signal; and computing a likelihood function of the signal amplitudes of the sub-samples of the received RF signal for each modulation type.

主权项

1. A blind phase-shift keying (PSK) and quadrature amplitude modulation (QAM) identification detector, having computer circuitry configured to:
non-uniformly sub-sample a received radio frequency (RF) signal for a distribution of signal amplitudes of the received RF signal; compute a likelihood function calculation of the signal amplitudes of the sub-sampled received RF signal for each modulation type; find a maximum value of the likelihood function calculation; determine if a single signal amplitude results from the likelihood function; uniform sub-sample the received RF signal when the single signal amplitude results from the likelihood function; compute a likelihood function of observed phase differences of the sub-samples of the received RF signal of a phase sequence for each PSK modulation type when the single signal amplitude results from the likelihood function; and identify a modulation type of the received RF signal based on the maximum value of the likelihood function calculation.