Comments on "A New ML Based Interference Cancellation Technique for Layered Space-Time Codes"

In this comment, we justify that the computational complexity proposed in the paper "A New ML Based Interference Cancellation Technique for Layered Space-Time Codes" (IEEE Trans. on Communications, vol. 57, no. 4, pp. 930-936, 2009) is O(N
³
) rather than the claimed O(N
²
), where N is the number of receive antennas.