by Guangyue Han Recently there has been considerable interest in wireless communication systems using multiple antennas. Theoretical analysis shows that such systems can provide spacial and temporal diversity gain if appropriate signal sets are employed. This dissertation analyzes and designs suitable signal constellations for such systems. Diversity product and diversity sum will be derived as...

In this paper we consider the use of non-uniform QAM constellations (Quadrature Amplitude Modulation) for broadcast or multicast transmissions within WCDMA-based systems (Wideband Code Division Multiple Access). These constellations are employed so as to increase the transmission efficiency, since they are able to provide unequal error protection. This allows the transmission of several simulta...

In this paper, multilevel coded asymmetric modulation with multistage decoding and unequal error protection (UEP) is discussed. These results further emphasize the fact that unconventional signal set partitionings are more promising than traditional (Ungerboeck-type) partitionings, to achieve UEP capabilities with multilevel coding and multistage decoding. Three types of unconventional partitio...

A full diversity constellation, that is, a set of unitary matrices whose differences have nonzero determinant, is a design criterion for codes with good performance using differential unitary space-time modulation. Recently, fixed-point free groups and the infinite group SU(2) have been used to produce full diversity unitary group constellations. In this paper, we present a new Bruhat decomposi...

Orthogonal sets of idempotents are used to design sets of unitary matrices, known as constellations, such that the modulus of the determinant of the difference of any two distinct elements is greater than 0. It is shown that unitary matrices in general are derived from orthogonal sets of idempotents reducing the design problem to a construction problem of unitary matrices from such sets. The qu...

The Ehresmann-Schein-Nambooripad (ESN) Theorem, stating that the category of inverse semigroups and morphisms is isomorphic to the category of inductive groupoids and inductive functors, is a powerful tool in the study of inverse semigroups. Armstrong and Lawson have successively extended the ESN Theorem to the classes of ample, weakly ample and weakly E-ample semigroups. A semigroup in any of ...