  Constant amplitude zero autocorrelation (CAZAC) sequences have modulus one
and ideal periodic autocorrelation function. Such sequences are used in
cellular radio communications systems, e.g., for reference signals,
synchronization signals and random access preambles. We propose a new family
CAZAC sequences, which is constructed by interleaving a Zadoff-Chu sequence by
a quadratic permutation polynomial (QPP), or by a permutation polynomial whose
inverse is a QPP. It is demonstrated that a set of orthogonal interleaved
Zadoff-Chu sequences can be constructed by proper choice of QPPs.
