Joint Space-Time Coded Modulation and Channel Coding over Fading Channels with Cochannel Interference

摘要

In this report we study, design and evaluate the performance of space-time systems over fading wireless channels. We present a new method to derive closed-form expressions for the exact bit error probability for optimum combining (OC). Our method differs from previous approaches in that it starts from the decision metrics of OC instead of the moment generating function. This approach facilitates obtaining closed-form expressions. With these expressions for BEP, evaluating the performance of OC is easy and accurate. We propose a noncoherent detection scheme in which the channel gain of the desired signal is unknown to the receiver. The maximum likelihood decision statistic is derived for the detector and its performance is demonstrated by analysis and simulation. To reduce the computation complexity of the decision statistic, we present a sub-optimum decision feedback algorithm for iterative symbol detection. We also develop another noncoherent detection scheme, where the only required channel information is the channel amplitude of the interference. It is shown that when the interference level is high, this detection technique can achieve good performance.