Blind Carrier and Noise Power and Roll-Off Factor Estimation for PCMA Signals

The Paired Carrier Multiple Access (PCMA) technology is adopted in modern satellite communication systems. It establishes duplex links between two ground stations while enhancing the bandwidth efficiency by assigning two single-carrier (SC) signals to the same time-frequency resource. For a blind receiver for the satellite downlink signal in such system, in contrast to the cooperating transceivers of the duplex link, no information about signaling, training sequences or data is available. Yet, it requires accurate knowledge about the signal and channel parameters because the task of jointly demodulating and detecting the data of both included SC signals is rather challenging. In this paper, we present several statistics based estimators for the respective powers of the SC signals and the noise from the mixture signal. We illustrate the benefits of the respective power estimation approaches for different modulation schemes by providing a performance evaluation based on numerical simulations. To provide the estimators with the knowledge of the respective roll-off factors that are used by the transmitters to generate the SC signals, we introduce a neural network classifier for roll-off factor estimation.