Banca de DEFESA: PEDRO THIAGO VALERIO DE SOUZA

Spectral Sensing and Signal Detection in MIMO Systems with Impulsive Noise and Multiple Path Fading

Spectral Sensing, Multiple-Input and Multiple-Output, Process Angular-Temporal Cycle Stationary, Correntropia, Impulsive Noise.

In mobile systems, information signals must be transmitted with high rates of data transmission and with high reliability. One of the possible solutions to achieve these desirable requirements is the use of systems with multiple transmitting and/or receiving antennas, featuring a MIMO system (Multiple Input-Multiple Output). However, signal processing techniques in MIMO systems depend on the Gaussianity of the transmission channel, decreasing their efficiency in non-Gaussian communication scenarios. To goal a robustness of this transmission technique, it will become imperative or to study this transmission technique in scenarios in which the channel is not exhibited by Gaussianity. In this work, a new signal detection technique in MIMO systems is proposed in scenarios characterized by non-Gaussian noise. A proposed reception technique is called Maximal Correntropy Detector (MCD) and it has been experimentally proven to treat a generalization of the MLD detector (Maximum Likelihood Detector) using the use of the correntropy complex. The MCD detector is analyzed on Gaussian and non-Gaussian channels and its performance is superior to classic detectors, without a significant increase in computational complexity. Together, this work also presents a new method of spectral sensing suitable for detecting signals that show non-linear phase variations over time. The proposed method is based on the use of theory of cyclostationary signals in waiting time, or which transformation employs signals to be a sensor in order to mitigate or effect non-linear variation of the phase. A proposed architecture is evaluated without a BPSK signal sensor and is compared to a temporal cyclostationary sensing technique. The results of the simulation tested prove the efficiency of the architecture proposal, presenting detection rates of primary users with an order of 8 dB.