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 non-iterative channel sounding methods. In this paper, we study optimal sequences consisting of complex symbols with constant magnitude. An indirect sequence construction method is derived by considering the phase diierence between sequence symbols. Our construction method includes periodic and non-periodic optimal sequences, and provides insight into the nature and properties of optimal sequences that are based on consecutive roots-of-unity phase diierence sequences.