Complex optimal sequences with constant magnitude for fast channel estimation initialization

Optimal sounding sequences which satisfy a certain autocorrelation property are useful for fast channel estimation techniques which are based on noniterative channel sounding methods. We study optimal sequences consisting of complex symbols with constant magnitude. An indirect sequence construction method is derived by considering the phase difference between sequence symbols. Our construction method includes periodic and nonperiodic optimal sequences, and provides insight into the nature and properties of optimal sequences that are based on consecutive roots-of-unity phase difference sequences