A Generalized Framework on Beamformer Design and CSI Acquisition for Single-Carrier Massive MIMO Systems in Millimeter Wave Channels

In this paper, we establish a general framework on the reduced dimensional channel state information (CSI) estimation and pre-beamformer design for frequency-selective massive multiple-input multiple-output MIMO systems employing single-carrier (SC) modulation in time division duplex (TDD) mode by exploiting the joint angle-delay domain channel sparsity in millimeter (mm) wave frequencies. First, based on a generic subspace projection taking the joint angle-delay power profile and user-grouping into account, the reduced rank minimum mean square error (RR-MMSE) instantaneous CSI estimator is derived for spatially correlated wideband MIMO channels. Second, the statistical pre-beamformer design is considered for frequency-selective SC massive MIMO channels. We examine the dimension reduction problem and subspace (beamspace) construction on which the RR-MMSE estimation can be realized as accurately as possible. Finally, a spatio-temporal domain correlator type reduced rank channel estimator, as an approximation of the RR-MMSE estimate, is obtained by carrying out least square (LS) estimation in a proper reduced dimensional beamspace. It is observed that the proposed techniques show remarkable robustness to the pilot interference (or contamination) with a significant reduction in pilot overhead

A space-time channel estimator and single-user receiver for code-reuse DS-CDMA systems

Published versio

Array communications in wireless sensor networks

Imperial Users onl

Space time transceiver design over multipath fading channels

Imperial Users onl

Ultra Wideband

Ultra wideband (UWB) has advanced and merged as a technology, and many more people are aware of the potential for this exciting technology. The current UWB field is changing rapidly with new techniques and ideas where several issues are involved in developing the systems. Among UWB system design, the UWB RF transceiver and UWB antenna are the key components. Recently, a considerable amount of researches has been devoted to the development of the UWB RF transceiver and antenna for its enabling high data transmission rates and low power consumption. Our book attempts to present current and emerging trends in-research and development of UWB systems as well as future expectations

Cooperative Transmitter-Receiver Arrayed Communications

This thesis is concerned with array processing for wireless communications. In particular, cooperation between the transmitter and receiver or between systems is exploited to further improve the system performance. Based on this idea, three technical chapters are presented in this thesis. Initially in Chapter 1, an introduction including array processing, multiple-input multiple-output (MIMO) communication systems and the background of cognitive radio is presented. In Chapter 2, a novel approach for estimating the direction-of-departure (DOD) is proposed using the cooperative beamforming. This proposed approach is featured by its simplicity (beam rotation at the transmitter) and effectiveness (illustrated in terms of channel capacity). Chapter 3 is concerned with integration of spatio-temporal (ST) processing into an antenna array transmitter, given a joint transmitter-receiver system with ST processing at the receiver but spatial-only processing at the transmitter. The transmit ST processing further improves the system performance in convergence, mean-square error (MSE) and bit error rate (BER). In Chapter 4, a basic system structure for radio coexistence problem is proposed based on the concept of MIMO cognitive radio. Cooperation between the licensed radio and the cognitive radio is exploited. Optimisation of the sum channel capacity is considered as the criterion and it is solved using a multivariable water-filling algorithm. Finally, Chapter 5 concludes this thesis and gives suggestions for future work