103 citations · 133 across the 10 of their papers we have counts for
11 papers
Trade-Offs in Decentralized Gigantic MIMO with Hard-Boundary Constraints
Juan Vidal Alegría, Joao Vieira, Ove Edfors
To maintain the antenna apertures offered by 5G massive MIMO systems operating at the sub-6GHz band, known as FR1, 6G base stations (BSs) using the upper-mid band, FR3, should incr…
Achieving Distributed MIMO Performance with Repeater-Assisted Cellular Massive MIMO
Sara Willhammar, Hiroki Iimori, Joao Vieira +3
In what ways could cellular massive MIMO be improved? This technology has already been shown to bring huge performance gains. However, coverage holes and difficulties to transmit m…
Data-Driven Robust Beamforming for Initial Access
Sai Subramanyam Thoota, Joao Vieira, Erik G. Larsson
We consider a robust beamforming problem where large amount of downlink (DL) channel state information (CSI) data available at a multiple antenna access point (AP) is used to impro…
Dynamic Range Improvement in Bistatic Backscatter Communication Using Distributed MIMO
Ahmet Kaplan, Joao Vieira, Erik G. Larsson
Backscatter communication (BSC) is a promising solution for Internet-of-Things (IoT) connections due to its low-complexity, low-cost, and energy-efficient solution for sensors. The…
Direct Link Interference Suppression for Bistatic Backscatter Communication in Distributed MIMO
Ahmet Kaplan, Joao Vieira, Erik G. Larsson
Backscatter communication (BC) is a promising technique for future Internet-of-Things (IoT) owing to its low complexity, low cost, and potential for energy-efficient operation in s…
Phase Calibration of Distributed Antenna Arrays
Erik G. Larsson, Joao Vieira
Antenna arrays can be either reciprocity calibrated (R-calibrated), which facilitates reciprocity-based beamforming, or fully calibrated (F-calibrated), which additionally facilita…
Deep Convolutional Neural Networks for Massive MIMO Fingerprint-Based Positioning
Joao Vieira, Erik Leitinger, Muris Sarajlic +2
This paper provides an initial investigation on the application of convolutional neural networks (CNNs) for fingerprint-based positioning using measured massive MIMO channels. When…
Temporal Analysis of Measured LOS Massive MIMO Channels with Mobility
Paul Harris, Steffen Malkowsky, Joao Vieira +6
The first measured results for massive multiple-input, multiple-output (MIMO) performance in a line-of-sight (LOS) scenario with moderate mobility are presented, with 8 users serve…
Performance Characterization of a Real-Time Massive MIMO System with LOS Mobile Channels
Paul Harris, Steffen Malkowsky, Joao Vieira +5
The first measured results for massive MIMO performance in a line-of-sight (LOS) scenario with moderate mobility are presented, with 8 users served in real-time using a 100-antenna…
The World's First Real-Time Testbed for Massive MIMO: Design, Implementation, and Validation
Steffen Malkowsky, Joao Vieira, Liang Liu +7
This paper sets up a framework for designing a massive multiple-input multiple-output (MIMO) testbed by investigating hardware (HW) and system-level requirements such as processing…
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…