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Abstract

In this thesis, we revisit differential and non-coherent transmission techniques over fading channels. In particular, we consider receiver design for differential space-time modulation (DSTM) over correlated multiple-input multiple-output (MIMO) fading channels and the performance analysis of differential phase shift keying (DPSK) and non-coherent frequency shift keying (FSK) in generalized K-fading. For DSTM over spatially correlated MIMO channels, we derive a multiple-symbol differential detection (MSDD) and a novel MSDD-based decision-feedback differential detection (MS-DFDD) receiver. We show that MS-DFDD outperforms previously proposed decision-feedback differential detection (DFDD) schemes that are based on scalar and vector prediction. In addition, we prove that at high signal-to-noise ratio (SNR) vector prediction decision-feedback differential detection (VP-DFDD) is equivalent to scalar prediction decision-feedback differential detection (SP-DFDD) and thus fails to properly exploit the spatial fading correlations. Furthermore, we derive closed-form expressions for the bit error probability (BEP) of two non-coherent transmission schemes over L diversity branches being subject to generalized K-fading. Specifically, focus is on binary DPSK (DBPSK) and binary non-coherent FSK modulation with equal-gain combining (EGC) at the receiver. We also discuss the extension of our results to M-ary modulation schemes. Considering both independent and correlated fading across the L branches, we derive expressions for the asymptotic diversity order, which reveal an interesting interplay between the two parameters, k and m, of the generalized K-distribution. Moreover, we show that the diversity order of the considered non-coherent transmission schemes is the same as in the case of coherent transmission. Finally, numerical performance results are presented, and our analytical results are corroborated by means of Monte-Carlo simulation.