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.

Wireless Power Transfer-Based Multi-Pair Two-Way Relaying With Massive Antennas

Abstract: In this paper, we study a multi-pair two-way relay network consisting of two groups of user equipments (UEs), who want to exchange information through a common relay equipped with massive antennas In the multiple access phase, the UEs transmit information to the relay using the energy harvested in the last time block, and the relay decodes information using zero-forcing (ZF) or maximal ratio combining (MRC) technique In the broadcasting phase, the relay performs simultaneous wireless information and power transfer (SWIPT), and each UE receives energy and information using the power-splitting scheme Due to the channel hardening effect of the large-scale antenna array, the harvested energy of each UE in each time block is asymptotically constant Based on the derived achievable rates of UEs, a multi-objective optimization problem (MOOP) is formulated to maximize the achievable rates of all the pairs Through solving the MOOP, the power-splitting ratios of UEs can be determined in closed-form for the ZF-based relaying For the MRC-based relaying, a two-stage iterative Pareto improvement algorithm is proposed to achieve the Pareto optimality Simulation results are presented to validate our theoretical analysis and verify the efficiency of our proposed algorithm in improving the system rate

Large System Analysis of Sum Capacity in the Gaussian MIMO Broadcast Channel

Abstract: We analyze the achievable sum rate of the Gaussian MIMO broadcast channel. We first consider Multiple-Input Single-Output (MISO) channels and derive the large system limit of the sum capacity as the number of users and transmit antennas go to infinity with a fixed ratio. We then consider Multiple-Input Multiple-Output (MIMO) broadcast channels and fix the number of users and let the number of transmit and receive antennas tend to infinity with fixed ratio. As in this case an asymptotic expression for sum capacity is hard to obtain, we evaluate the large system sum rate corresponding to successive zero-forcing beamforming with Dirty-Paper Coding. The analysis gives a lower bound on the large system sum capacity, which is numerically observed to be quite close. In addition, large system analysis is applied to estimate the relatively small performance losses with respect to sum capacity of successive zero-forcing beamforming with and without Dirty-Paper Coding in finite MISO systems.

Review of optical multiple-input–multiple-output techniques in multimode fiber

Abstract: The success of optical multiple-input-multiple output (MIMO) systems in wireless communications has motivated interesting investigations of MIMO in optical fiber communications. This paper reviews various optical MIMO techniques in multimode fiber.

A Compact MIMO DRA Antenna

Abstract: Multiple input, multiple output (MIMO) is an antenna technology for wireless communications in which multiple antennas are used at both the source (transmitter) and the destination (receiver). The antennas at each end of the communications circuit are combined to minimize the errors and to optimize the data speed. MIMO-based antennas are of interest in relation to communication such as digital TV, wireless LAN and mobile communications. MIMO arrangements are of particular interest for other communication devices. When applying a dielectric resonator antenna (DRA) type in a MIMO system and using it for the transmission of two or more signals using the same frequency, high coupling often occurs between the different antenna signals. The occurrence of the coupling may seriously degrade the performance of such an antenna. Thus, it would be beneficial to provide a DRA that can be used to simultaneously transmit and receive more than one signal at the same frequency. Also, where the incidence of coupling between these antennas, signals is reduced. DAR offers several advantages such as wide bandwidth, small size, ease of fabrication and high radiation efficiency. This paper presents characteristics of DRA antenna for 2.6 GHz (UMTS band 7).