Results 181 to 190 of about 31,082 (236)
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Robust uplink to downlink spatial covariance matrix transformation for downlink beamforming
2004 IEEE International Conference on Communications (IEEE Cat. No.04CH37577), 2004We propose a new uplink to downlink spatial covariance matrix transformation technique that provides robustness against uplink steering vector mismatches for frequency duplex systems (FDD) in a frequency selective fading environment. Our approach leads to a matrix robust least squares (RLS) problem that can be formulated in a convex form as a second ...
Chalise, B.K. +2 more
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Asynchronous NOMA for Downlink Transmissions
IEEE Communications Letters, 2017In this letter, we propose a novel symbol-asynchronous non-orthogonal multiple access (ANOMA) scheme for downlink transmissions. First, ANOMA introduces an artificial symbol-offset between packets destined for different user equipment (UE) in order to reduce their mutual interference.
Jianxiong Cui +4 more
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CDMA downlink performance issues
Ninth IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (Cat. No.98TH8361), 2002Several key performance issues for the downlink of IS-95 based CDMA systems are explored. Performance data collected from a number of operational systems using CDMA diagnostic monitor equipment and post-processing analysis software is used to aid in the development of improved link and system performance prediction models.
Rod Walton +2 more
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Susceptibility of LTE to Downlink Jamming
2019 International Conference on Military Communications and Information Systems (ICMCIS), 2019As LTE gets established as the primary cellular standard it is important to examine its vulnerabilities and availability issues. Researchers started to uncover susceptibilities of the 4G standard by investigating the influence of interference and jamming on the network communication.
Daniel Vogel 0004 +2 more
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Confidential communication in downlink beamforming
2012 IEEE 13th International Workshop on Signal Processing Advances in Wireless Communications (SPAWC), 2012This paper deals with the problem of secure transmission in downlinkbeamforming. In this scenario, a base station, which usually serves information to an amount of users, wants to transmit a confidential message to one of the users. Focusing on the beamforming solution, we derive all possible weighted solutions.
Vázquez, Miguel Ángel +2 more
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2020 International Wireless Communications and Mobile Computing (IWCMC), 2020
In this paper, we propose two multi-bit feedback methods for hybrid automatic repeat request (HARQ). Both methods take into consideration of the coding gain of the forward error-correction codes. One method only considers the coding gain of the first transmission, which is named accumulated power (ACP) method. The other method considers the coding gain
Chulong Liang +3 more
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In this paper, we propose two multi-bit feedback methods for hybrid automatic repeat request (HARQ). Both methods take into consideration of the coding gain of the forward error-correction codes. One method only considers the coding gain of the first transmission, which is named accumulated power (ACP) method. The other method considers the coding gain
Chulong Liang +3 more
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Downlink eigenbeamformer with combining of eigenbeams
GLOBECOM'01. IEEE Global Telecommunications Conference (Cat. No.01CH37270), 2002For W-CDMA several closed-loop Tx diversity concepts employing 4 antenna elements at the base station (BS) are currently discussed to be included in 3GPP release 5. Among these, the downlink eigenbeamformer effectively uses long-term as well as short-term channel properties.
Alexander Seeger +3 more
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Hijacking Downlink Path Selection in LoRaWAN
2021 IEEE Global Communications Conference (GLOBECOM), 2021With the rise of the IoT, many protocols have been developed in order to fulfill the need for a wireless connectivity that assures energy efficiency and low-data rates. LoRaWAN is certainly one of the most widely used protocols. The LoRaWAN 1.1 specification aims to fix some serious security vulnerabilities in the 1.0 specification, however there still
Locatelli, Pierluigi +2 more
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Distributed Massive MIMO Downlink
ICC 2019 - 2019 IEEE International Conference on Communications (ICC), 2019The feasibility of adopting distributed massive multiple-input multiple-output (D-MMIMO) for mitigating the achievable rate loss incurred by spatially-correlated fading at space-constrained user antenna arrays when served by co-located massive MIMO (C-MMIMO) counterpart is investigated.
Dhanushka Kudathanthirige +1 more
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2018 IEEE Global Communications Conference (GLOBECOM), 2018
The performance of multi-cell massive multiple- input multiple-output (MIMO) downlink (DL) with nonorthogonal multiple access (NOMA) is investigated. A novel pilot assignment for NOMA users is proposed to mitigate intra-cluster pilot contamination and to alleviate the detrimental impact of inter-cluster in the useful operating regime.
Dhanushka Kudathanthirige +1 more
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The performance of multi-cell massive multiple- input multiple-output (MIMO) downlink (DL) with nonorthogonal multiple access (NOMA) is investigated. A novel pilot assignment for NOMA users is proposed to mitigate intra-cluster pilot contamination and to alleviate the detrimental impact of inter-cluster in the useful operating regime.
Dhanushka Kudathanthirige +1 more
openaire +1 more source