Iterative downlink multi-user MIMO systems

In this treatise, we explore diverse multi-user transmission techniques and joint detection-decoding schemes designed for downlink multi-user transmissions, while maintaining a low complexity, a high throughput and a high integrity. More specifically, in Chapter 2 we will introduce various Multi-User Transmission (MUT) techniques for the Space Division Multiple Access Down-Link (DL-SDMA) employing the sophisticated linear SpatioTemporal Pre-processing (STP) schemes, which are capable of eliminating the multi-user interference at the Base Station (BS) and increase the transmission integrity at the Mobile Sta,ions (MS). Additionally, we will design signal detection techniques for the DL-SDMA system, which achieves a near-Maximum Likelihood (ML) performance at a fraction of the ML detector's complexity. In Chapter 3 we extend our research to a joint iterative detection and decoding based DL-SDMA system. We will introduce a precoder aided iterative DL-SDMA system, which is designed with the aid of Extrinsic Information Transfer (EXIT) charts and has an improved iterative decoding gain. Finally, we will characterize the impact of imperfect Channel State Information (CSI) on the proposed iterative DL-SDMA and introduce sophisticated IrRegular Convolutional Codes (IRCC) for improving the integrity of the iterative DL-SDMA system. In order to reduce the complexity of the iterative receivers, in Chapter 4 we will introduce a novel detection algorithm, which is referred to as the Irregular Generic Detection (IrGD) algorithm. The IrGD has a tunable • complexity and it was particularly designed for redUcing the complexity of the iterative decoding aided system. Furthermore, we will demonstrate the impact of imperfect CSI with the aid of EXIT charts. In addition, we will introduce an EXIT-Chart Optimized CSI Quantizer (ECO-CQ) for the iterative DL-SDMA system, which is capable of reducing CSI-related feedback overhead. In Chapter 5 we will introduce an advanced space-time signaling technique aided MUT designed for the DL-SDMA system, which results in an improved capacity. Furthermore, we will propose a low-complexity Irregular Sphere Detection (IrSD) scheme designed for approaching the capacity DL-SDMA systems, which is capable of maintaining a near-ML performance. Additionally, we will characterize our pilot assisted channel prediction aided DL-SDMA system using limited CSI feedback.EThOS - Electronic Theses Online ServiceGBUnited Kingdo