4.7k citations · 7.1k across the 34 of their papers we have counts for
29 papers · 1 filter
Trade-Offs in Decentralized Multi-Antenna Architectures: Sparse Combining Modules for WAX Decomposition
Juan Vidal Alegría, Fredrik Rusek
With the increase in the number of antennas at base stations (BSs), centralized multi-antenna architectures have encountered scalability problems from excessive interconnection ban…
Channel Orthogonalization with Reconfigurable Surfaces
Juan Vidal Alegria, Fredrik Rusek
Orthogonal multi-user multiple-input multiple-output (MU-MIMO) channels allow for optimum performance with simplified precoding/equalization, and they achieve maximum multiplexing…
Capacity Degradation with Modeling Hardware Impairment in Large Intelligent Surface
Sha Hu, Fredrik Rusek, Ove Edfors
In this paper, we consider capacity degradations stemming from potential hardware impairments (HWI) of newly proposed Large Intelligent Surface (LIS) systems. Without HWI, the util…
Impact of Relay Cooperation on the Performance of Large-scale Multipair Two-way Relay Networks
Muris Sarajlic, Liang Liu, Fredrik Rusek +2
We consider a multipair two-way relay communication network, where pairs of user devices exchange information via a relay system. The communication between users employs time divis…
Unmanned Aerial Vehicle Assisted Cellular Communication
Sha Hu, Jose Flordelis, Fredrik Rusek +1
In this paper, we consider unmanned aerial vehicles (UAVs) assisted cellular communication system, where UAVs can be used as amplify-and-forward (AF) relays. The effective channel…
Modulus Zero-Forcing Detection for MIMO Channels
Sha Hu, Fredrik Rusek
We propose a modulus based zero-forcing (MZF) detection for multi-input multi-output (MIMO) channels. Traditionally, a ZF detector nulls out all interferences from other layers whe…
On Time-of-Arrival Estimation in NB-IoT Systems
Sha Hu, Xuhong Li, Fredrik Rusek
We consider time-of-arrival (ToA) estimation of a first arrival-path for a device working in narrowband Internet-of-Things (NB-IoT) systems. Due to a limited 180 KHz bandwidth used…
User Assignment with Distributed Large Intelligent Surface (LIS) Systems
Sha Hu, Krishna Chitti, Fredrik Rusek +1
In this paper, we consider a wireless communication system where a large intelligent surface (LIS) is deployed comprising a number of small and distributed LIS-Units. Each LIS-Unit…
Beyond Massive-MIMO: The Potential of Data-Transmission with Large Intelligent Surfaces
Sha Hu, Fredrik Rusek, Ove Edfors
In this paper, we consider the potential of data-transmission in a system with a massive number of radiating and sensing elements, thought of as a contiguous surface of electromagn…
Sequential Channel Estimation in the Presence of Random Phase Noise in NB-IoT Systems
Fredrik Rusek, Sha Hu
We consider channel estimation (CE) in narrowband Internet-of-Things (NB-IoT) systems. Due to the fluctuations in phase within receiver and transmitter oscillators, and also the re…
Beyond Massive-MIMO: The Potential of Positioning with Large Intelligent Surfaces
Sha Hu, Fredrik Rusek, Ove Edfors
We consider the potential for positioning with a system where antenna arrays are deployed as a large intelligent surface (LIS), which is a newly proposed concept beyond massive-MIM…
Massive MIMO Performance - TDD Versus FDD: What Do Measurements Say?
Jose Flordelis, Fredrik Rusek, Fredrik Tufvesson +2
Downlink beamforming in Massive MIMO either relies on uplink pilot measurements - exploiting reciprocity and TDD operation, or on the use of a predetermined grid of beams with user…
Improving the Performance of OTDOA based Positioning in NB-IoT Systems
Sha Hu, Axel Berg, Xuhong Li +1
In this paper, we consider positioning with observed-time-difference-of-arrival (OTDOA) for a device deployed in long-term-evolution (LTE) based narrow-band Internet-of-things (NB-…
A Generalized Zero-Forcing Precoder with Successive Dirty-Paper Coding in MISO Broadcast Channels
Sha Hu, Fredrik Rusek
In this paper, we consider precoder designs for multiuser multiple-input-single-output (MISO) broadcasting channels. Instead of using a traditional linear zero-forcing (ZF) precode…
The Potential of Using Large Antenna Arrays on Intelligent Surfaces
Sha Hu, Fredrik Rusek, Ove Edfors
In this paper, we consider capacities of single-antenna terminals communicating to large antenna arrays that are deployed on surfaces. That is, the entire surface is used as an int…
Cramér-Rao Lower Bounds for Positioning with Large Intelligent Surfaces
Sha Hu, Fredrik Rusek, Ove Edfors
We consider the potential for positioning with a system where antenna arrays are deployed as a large intelligent surface (LIS). We derive Fisher-informations and Cramér-Rao lower b…
Optimal Channel Shortener Design for Reduced-State Soft-Output Viterbi Equalizer in Single-Carrier Systems
Sha Hu, Harald Kröll, Qiuting Huang +1
We consider optimal channel shortener design for reduced-state soft-output Viterbi equalizer (RS-SOVE) in single-carrier (SC) systems. To use RS-SOVE, three receiver filters need t…
Reciprocity Calibration for Massive MIMO: Proposal, Modeling and Validation
Joao Vieira, Fredrik Rusek, Ove Edfors +3
This paper presents a mutual coupling based calibration method for time-division-duplex massive MIMO systems, which enables downlink precoding based on uplink channel estimates. Th…
A Low-complexity Channel Shortening Receiver with Diversity Support for Evolved 2G Device
Sha Hu, Harald Kroll, Qiuting Huang +1
The second generation (2G) cellular networks are the current workhorse for machine-to-machine (M2M) communications. Diversity in 2G devices can be present both in form of multiple…
On the Design of Channel Shortening Demodulators for Iterative Receivers in MIMO and ISI Channels
Sha Hu, Fredrik Rusek
We consider the problem of designing demodulators for linear vector channels with memory that use reduced-size trellis descriptions for the received signal. We assume an overall it…
Physical Layer Security for Massive MIMO: An Overview on Passive Eavesdropping and Active Attacks
Dzevdan Kapetanovic, Gan Zheng, Fredrik Rusek
This article discusses opportunities and challenges of physical layer security integration in massive multiple-input multiple-output (MaMIMO) systems. Specifically, we first show t…
Modulation Formats and Waveforms for the Physical Layer of 5G Wireless Networks: Who Will be the Heir of OFDM?
Paolo Banelli, Stefano Buzzi, Giulio Colavolpe +3
5G cellular communications promise to deliver the gigabit experience to mobile users, with a capacity increase of up to three orders of magnitude with respect to current LTE system…
A Robust Low-Complexity MIMO Detector for Rank 4 LTE/LTE-A Systems
Shashi Kant, Fredrik Rusek, Basuki E. Priyanto
This paper deals with MIMO detection for rank 4 LTE systems. The paper revolves around a previously known detector [1, by Inkyu Lee, TCOM'2010] which we shall refer to as RCSMLD (R…
Massive MIMO performance evaluation based on measured propagation data
Xiang Gao, Ove Edfors, Fredrik Rusek +1
Massive MIMO, also known as very-large MIMO or large-scale antenna systems, is a new technique that potentially can offer large network capacities in multi-user scenarios. With a m…