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.

Adaptive transmission and interference cancellation for MIMO radar

Abstract: A radar system has different modes of operation. In one mode the radar operates as a single-input, multiple-output (SIMO) radar system utilizing one transmitted signal from one antenna at a time. Codes with known excellent autocorrelation properties are utilized in this mode. At each receiver the response after correlating with various possible transmitted signals is measured in order to estimate the interference that each transmitter will represent at each receiver. The estimated effect of the interference from one transmitter on a receiver that correlates with a different code is used to mitigate the interference. In another mode, the radar operates as a MIMO radar system utilizing all the antennas at a time. Interference cancellation of the non-ideal cross correlation sidelobes when transmitting in the MIMO mode are employed to remove ghost targets due to unwanted sidelobes.

Method and system for communication channel optimization in a multiple-input multiple-output (MIMO) communication system

Abstract: A transmission method in a multiple-input multiple-output (MIMO) communication system, a transmitter in a MIMO communication system and a MIMO communication system are provided. The method comprises the steps of: receiving feedback data representing channel state information from respective receivers of the MIMO communication system; grouping the receivers into one or more groups based on the received feedback data; obtaining a precoding matrix for each group of receivers based on the received feedback data such that precoding vectors or sub-matrices in the precoding matrix associated with respective receivers of said each group of receivers are orthogonal to each other; and applying the precoding matrix to input signals for transmission to said each group of receivers.

Hybrid structure in massive MIMO: Achieving large sum rate with fewer RF chains

Abstract: Massive multiple-input multiple-output (MIMO) systems can attain a high channel capacity and spectral efficiency by using a very large antenna array at the base station (BS) However, the cost of having one radio frequency (RF) chain behind every antenna element can be prohibitive In addition, the overall power consumption of the RF hardware can be excessively high A hybrid analog-digital structure can be utilized to reduce the required number of RF chains at the BS In this paper, we present achievable rates of hybrid beamforming in multi-user MIMO (MU-MIMO) when employing only one RF chain per user The analysis and simulation results show that the asymptotic signal-plus-interference-to-noise ratio (SINR) of hybrid beamforming is reduced by a factor of π/4 compared to conventional beamforming methods, and the resulting achievable sum-rate degradation can be compensated by simply employing 27% more transmit antennas

A comparison of implicit and explicit channel feedback methods for MU-MIMO WLAN systems

Abstract: In this paper we compare the implicit and explicit methods of providing channel state information (CSI) to the transmitter in a multi-user multiple-input-multiple-output (MU-MIMO) system as specified in the draft specification IEEE 802.11ac [1]. The comparison is made on the basis of both overhead requirements and packet-error-rate (PER) performance. We also propose a hybrid feedback scheme that combines the explicit and implicit feedback methods thus benefiting from more frequent calibration without incurring extra overhead.

Mimo and mu-mimo ofdm preambles

Abstract: Certain aspects of the present disclosure present frame structures to support a plurality of standards, such as the IEEE 802.11 ac in addition to the IEEE 802.11 a/b/n/g. Preamble of the frame structure can be used by a receiver to detect transmission mode of the packet.