  Sets of sequences with good correlation properties are desired in many active
sensing and communication systems, e.g., multiple-input-multiple-output (MIMO)
radar systems and code-division multiple-access (CDMA) cellular systems. In
this paper, we consider the problems of designing complementary sets of
sequences (CSS) and also sequence sets with both good auto- and
cross-correlation properties. Algorithms based on the general
majorization-minimization method are developed to tackle the optimization
problems arising from the sequence set design problems. All the proposed
algorithms can be implemented by means of the fast Fourier transform (FFT) and
thus are computationally efficient and capable of designing sets of very long
sequences. A number of numerical examples are provided to demonstrate the
performance of the proposed algorithms.
