The main goal of this work is to provide a unified theory of QSTBCs for four transmit antennas and

one (or more) receive antennas. The thesis consists of two main parts: In the first part we analyze the

QSTBCs transmission without any channel knowledge at the transmitter and in the second part we analyze

transmission with QSTBCs assuming partial channel state (CSI) information at the transmitter.

For both cases, the QSTBCs are studied on spatially correlated and uncorrelated frequency flat MIMO

channels applying a Maximum Likelihood receivers as well as a low complexity linear Zero-Forcing

receivers. The spatial correlation is modelled by the so-called Kronecker Model. Measured indoor channels

are also used in our simulations to show the performance of the QSTBCs in real-world environment