An iterative multi-user detector for coded mutually orthogonal complementary sets with space-time coding

We propose an iterative multi-user detector scheme that exploits the properties of mutually orthogonal (MO) complementary sets and space-time codes for multi-user communications with spatial diversity and minimal bandwidth expansion. The properties of the MO sequences are used to distinguish between the desired user and the interferers, all of which are using multiple transmit antennas. We achieve a high order of diversity in flat Rayleigh fading channels and the ability to cancel multi-user interference. The performance of the system in the presence of multiple users is shown, both analytically and by simulation, to be comparable to the single user case.