Abstract
Two problems on the blind detection of phase shift keying (PSK) signals are studied. One is the detection of the existence of PSK signals and the other is the detection of the transmitted PSK symbols. From the probability density function of the absolute values of the received signals, a likelihood ratio test is derived for the detection of the existence. Then, when PSK signals are present, a method to determine the decision regions to detect PSK symbols is developed. It is shown that the estimation can be approximated as a least squares problem that can be numerically solved. Simulation results show that our detector for the existence of QPSK signals slightly outperforms the energy detector. The bit error rates of the detection of QPSK symbols using the estimated decision regions are also provided to demonstrate the performance of our estimator.
