Shift-keyed signal identification using time-frequency processing

The use of the cone kernel time-frequency representation (CK-TFR) for shift-keyed signal identification is introduced. In electronic warfare surveillance systems, the identification of phase shifts in a signal is an important topic due to the prevalent use of phase-shift keyed signalling schemes. Examples of TFR patterns for shift-keyed signals are presented. It is observed that, in addition to providing baud rate information about the signal, the CK-TFR clearly distinguishes between phase shifts of 180, +90, and -90°. A `spectral peak splitting´ effect is observed in the CK-TFR coincident with phase shifts in a signal. The mathematical foundation for the spectral peak splitting is explored