Abstract
Signal classification is important in various commercial and military applications. Multiple antenna systems complicate the signal classification problem since there is now the issue of estimating the number and configuration of transmit antennas. The novel blind classification algorithm proposed in this paper exploits the cyclostationarity property of space-time block codes (STBCs) for the classification of multiple antenna systems in the presence of possible transmission impairments. Analytical expressions for the second-order cyclic statistics used as the basis of the algorithm are derived, and the computational cost of the proposed algorithm is considered. This algorithm avoids the need for a priori knowledge of the channel coefficients, modulation, carrier phase, and timing offsets. Moreover, it does not need accurate information about the transmission data rate and carrier frequency offset. Monte Carlo simulation results demonstrate a good classification performance with low sensitivity to phase noise and channel effects, including frequency-selective fading and Doppler shift.