Results 221 to 230 of about 51,994 (258)
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Superimposed Pilots are Beneficial for Mitigating Pilot Contamination in Cell-Free Massive MIMO
IEEE Communications Letters, 2021In this letter, we present the first study for uplink cell-free massive multi-input multi-output (MIMO) systems with superimposed pilots (SPs). Closed-form linear minimum mean square error (LMMSE) channel estimation and achievable spectral efficiency (SE) expressions with maximal ratio combining (MRC) receiver filters are derived.
Yao Zhang 0016 +3 more
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Pilot contamination attacks in massive MIMO systems
2017 IEEE Conference on Communications and Network Security (CNS), 2017We consider a single-cell massive multiple-input multiple-output (MIMO) system in which a base station (BS) with a large number of antennas simultaneously transmits to K single-antenna users in the presence of an attacker. Massive MIMO systems often operate in a time division duplexing (TDD) fashion. The BS estimates the channel state information (CSI)
Berk Akgun +2 more
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Massive MIMO with clustered pilot contamination precoding
2013 Asilomar Conference on Signals, Systems and Computers, 2013In this paper, a practical approach to pilot contamination precoding (PCP) for massive MIMO is proposed through a joint clustering and pilot reuse scheme. We also introduce power scaling to enforce per-base station (BS) power constraints. We consider a massive MIMO system, where uncoordinated conventional beamforming is implemented in each cell.
Mahmood Mazrouei-Sebdani +1 more
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Suppression of pilot-contamination in massive MIMO systems
2014 IEEE 15th International Workshop on Signal Processing Advances in Wireless Communications (SPAWC), 2014We propose a novel channel estimation method for suppression of interference during uplink training in massive MIMO systems. The method makes use of the received uplink data to improve upon the estimation of solely training based estimators. It is based on the maximum a-posteriori criterion and outperforms state-of-the-art methods in terms of ...
David Neumann +2 more
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Eliminating Pilot Contamination Using Dual Pilot Sequences in Massive MIMO
2017 IEEE 86th Vehicular Technology Conference (VTC-Fall), 2017The uplink transmission in a Massive MIMO system is studied. Pilot contamination during the uplink training is the main inherent limitation that degrades the performance of Massive MIMO. Current approaches are using the same pilot sequences for every cell, leading to the so-called inter-cell interference. In this paper, a novel method that employs dual
A. Nasser Aljalai +3 more
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The impact of CSI errors and pilot contamination on the pilot-to-data power ratio
2017 International Symposium on Intelligent Signal Processing and Communication Systems (ISPACS), 2017Pilot symbols are used to estimate channel state information (CSI) in Massive Multiple-input Multiple-output (MIMO) systems, the pilot-to-data power ratio (PDPR) is known to have an impact on estimation result. However, the works before only consider the one cell model which has no pilot contamination.
Keping Lu, Hairong Wang, Chen Liu 0005
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The Effectiveness of Washing Clothing Contaminated With Cyclophosphamide: A Pilot Study
Clinical Journal of Oncology Nursing, 2023Measures to prevent exposure to anticancer drugs mitigate health hazards for caregivers, family members, and healthcare workers caring for patients with cancer. Previous studies have reported that anticancer drugs were detected on the linens of patients receiving chemotherapy.This pilot study investigated the effectiveness of the washing methods ...
Hiromu, Tanigawa +5 more
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Pilot Contamination Elimination in Massive MIMO Systems
2017The pilot contamination problem has been the primary limitation of massive multiple input multiple output (MIMO) systems. To improve it, in this paper, we propose a dynamical pilot assignment algorithm based on the priority of user location. First, we obtain the formulation of signal to interference plus noise power ratio (SINR) in uplink channel ...
Rui-Chao Hu, Bing-He Wang
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Joint pilot assignment and pilot contamination precoding design for massive MIMO systems
2017 26th Wireless and Optical Communication Conference (WOCC), 2017This paper investigates the joint design of pilot assignment and pilot contamination precoding (PCP) to combat pilot contamination in multi-cell multi-user massive MIMO systems. The system performance of the downlink transmission in massive MIMO with PCP is investigated and an optimization problem is formulated to find the best pilot assignment ...
Mei Zhao +3 more
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2016 IEEE Global Conference on Signal and Information Processing (GlobalSIP), 2016
In this paper, we analyze the downlink (DL) performance of superimposed pilots in time division duplexing massive multiple-input multiple-output (MIMO) systems, and show that superimposed pilots offer an increased resilience to pilot contamination with respect to time-multiplexed pilots and data.
Upadhya, Karthik +3 more
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In this paper, we analyze the downlink (DL) performance of superimposed pilots in time division duplexing massive multiple-input multiple-output (MIMO) systems, and show that superimposed pilots offer an increased resilience to pilot contamination with respect to time-multiplexed pilots and data.
Upadhya, Karthik +3 more
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