  Automatic signal identification (ASI) has various millitary and commercial
applications, such as spectrum surveillance and cognitive radio. In this paper,
a novel ASI algorithm is proposed for the identification of GSM and LTE
signals, which is based on the pilot-induced second-order cyclostationarity.
The proposed algorithm provides a very good performance at low signal-to-noise
ratios and short observation times, with no need for channel estimation, and
timing and frequency synchronization. Simulations and off-the-air signals
acquired with the ThinkRF WSA4000 receiver are used to confirm the findings.
