Generalized nonlinear block space time modulation with rate one

In mobile communication systems downlink channel capacity is a central issue. Recent linear techniques for space time block codes, as they are applied, eg, in UMTS systems, can be constructed for 2 antennas only, if complex symbols are used and rate one is required. The latter is important, if existing systems are to be extended with space time coding techniques, since the rest of the transmission scheme remains untouched. We describe a generalized nonlinear coding scheme, which works with any number of antenna and channel symbols. It is proved, that codes exist which yield maximal diversity gain. We also discuss methods of optimal code construction and give some explicit examples. Furthermore, performance of these codes under Rayleigh fading conditions is simulated in order to support the theoretical results