| This thesis studies space-time block codes (STBC) over time-selective fading channels for known and estimation-assisted channel state information at the receiver. First, we examine STBCs over known time-selective fading channels and show the effects of time-selectivity on orthogonal STBCs. Alternate detectors are then introduced that are capable of mitigating the effects of time-selectivity, and are thus more robust to changes in fading rates. Next, we examine STBCs over estimation-assisted time-selective channels, where we present a novel adaptive scheme that performs joint channel estimation and data detection at the receiver. The channel is modeled as an autoregressive random process and estimated using the Kalman filter. Various components of the adaptive algorithm such as, initial conditions, pilot symbols, fading rate, and detection strategy, and their respective impacts on performance are examined. Using this scheme, we also show the effect of channel estimation errors on performance. Finally, we propose a modified joint adaptive estimation and detection algorithm that is robust to inaccurate initial conditions, at the expense of greater complexity at the receiver. |
