If the oPTS scheme has Mb
subblocks and C candidate signals in each antenna, it needs
C(Mb − 1)N multiplications of rotation factors, C(Mb − 1)N
complex additions in (7), CN complex multiplications to compute
the sample powers, and CN − 1 comparisons to find the
optimal candidate signal of each antenna. Finally, the minimax
criterion of (8) need 2C − 1 comparisons.