Multi-user MIMO

About: Multi-user MIMO is a research topic. Over the lifetime, 10265 publications have been published within this topic receiving 227206 citations. The topic is also known as: multi user mimo & MU-MIMO.

MIMO-based jamming resilient communication in wireless networks

Abstract: Reactive jamming is considered the most powerful jamming attack as the attack efficiency is maximized while the risk of being detected is minimized. Currently, there are no effective anti-jamming solutions to secure OFDM wireless communications under reactive jamming attack. On the other hand, MIMO has emerged as a technology of great research interest in recent years mostly due to its capacity gain. In this paper, we explore the use of MIMO technology for jamming resilient OFDM communication, especially its capability to communicate against the powerful reactive jammer. We first investigate the jamming strategies and their impacts on the OFDM-MIMO receivers. We then present a MIMO-based anti-jamming scheme that exploits interference cancellation and transmit precoding capabilities of MIMO technology to turn a jammed non-connectivity scenario into an operational network. Our testbed evaluation shows the destructive power of reactive jamming attack, and also validates the efficacy and efficiency of our defense mechanisms.

A Theory of Time-Reversed Impulse Multiple-Input Multiple-Output (MIMO) for Ultra-Wideband (UWB) Communications

Abstract: This paper proposes a new approach to taking advantage of rich multipath through the use of time-reversal combined with impulsive Multiple-Input Multiple-Output (MIMO) for Ultra-Wideband (UWB) Communications A comprehensive review of literature is also given

Pre-coding in multi-user MIMO

Abstract: In a multi-user communication system, a pre-coder in a transmitter comprises a Discrete Fourier Transform (DFT) spreader configured to spread reference-signal symbols with Fourier coefficients to generate DFT-spread reference symbols. An OFDM modulator, such as an inverse-DFT, modulates the DFT-spread reference symbols onto OFDM subcarriers to produce a pre-coded OFDM transmission signal.

Linear Precoding for the MIMO Multiple Access Channel With Finite Alphabet Inputs and Statistical CSI

Abstract: In this paper, we investigate the design of linear precoders for the multiple-input–multiple-output (MIMO) multiple access channel (MAC). We assume that statistical channel state information (CSI) is available at the transmitters and consider the problem under the practical finite alphabet input assumption. First, we derive an asymptotic (in the large system limit) expression for the weighted sum rate (WSR) of the MIMO MAC with finite alphabet inputs and Weichselberger's MIMO channel model. Subsequently, we obtain the optimal structures of the linear precoders of the users maximizing the asymptotic WSR and an iterative algorithm for determining the precoders. We show that the complexity of the proposed precoder design is significantly lower than that of MIMO MAC precoders designed for finite alphabet inputs and instantaneous CSI. Simulation results for finite alphabet signaling indicate that the proposed precoder achieves significant performance gains over existing precoder designs.

On Uplink Network MIMO under a Constrained Backhaul and Imperfect Channel Knowledge

Abstract: It is known that next generation mobile communications systems will most likely employ multi-cell signal processing - often referred to as network MIMO - in order to improve spectral efficiency and fairness. Many publications exist that predict strong achievable rate improvements, but usually neglecting various practical issues connected to network MIMO. In this paper, we analyse the impact of a constrained backhaul infrastructure and imperfect channel knowledge on uplink network MIMO from an information theoretical point of view. Especially the latter aspect leads to the fact that the channel conditions for which network MIMO is reasonably beneficial are strongly constrained. We observe different base station cooperation schemes in scenarios of maximal 3 base stations and 3 terminals, provide simulation results, and discuss the practicability of the discussed schemes and the implications of our results.