Patent ID: 9413584
Filing Date: 2016-08-09
CPC Classification: H04B,H04L

Claim Text:
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.