48 citations · 102 across the 21 of their papers we have counts for
22 papers
Performance Analysis of Cell-Free Massive MIMO under Imperfect LoS Phase Tracking
Noor Ul Ain, Lorenzo Miretti, Renato L. G. Cavalcante +1
We study the impact of imperfect line-of-sight (LoS) phase tracking on the uplink performance of cell-free massive MIMO networks. Unlike prior works that assume perfectly known or…
Beyond the Use-and-then-Forget (UatF) Bound: Fixed Point Algorithms for Statistical Max-Min Power Control
Renato Luis Garrido Cavalcante, Noor Ul Ain, Lorenzo Miretti +1
We introduce mathematical tools and fixed point algorithms for optimal statistical max-min power control in cellular and cell-less massive MIMO systems. Unlike previous studies tha…
Flexible and High-Performance Radio Access Networks for upcoming Sixth-Generation (6G) Systems
Peter Schefczik, Umar Toseef, Paolo Baracca +6
The collaborative research project 6G-ANNA develops concepts for the 6G radio access network (RAN) architecture and technology components. Previous RAN generations have become inhe…
A joint channel estimation and beamforming separation principle for massive MIMO systems
Lorenzo Miretti, Slawomir Stańczak, Giuseppe Caire
We demonstrate that separating beamforming (i.e., downlink precoding and uplink combining) and channel estimation in multi-user MIMO wireless systems incurs no loss of optimality u…
A Comparison among Single Carrier, OFDM, and OTFS in mmWave Multi-Connectivity Downlink Transmissions
Fabian Göttsch, Shuangyang Li, Lorenzo Miretti +2
In this paper, we perform a comparative study of common wireless communication waveforms, namely the single carrier (SC), orthogonal frequency-division multiplexing (OFDM), and ort…
On the Optimal Performance of Distributed Cell-Free Massive MIMO with LoS Propagation
Noor Ul Ain, Lorenzo Miretti, Sławomir Stańczak
In this study, we revisit the performance analysis of distributed beamforming architectures in dense user-centric cell-free massive multiple-input multiple-output (mMIMO) systems i…
Two-timescale weighted sum-rate maximization for large cellular and cell-free massive MIMO
Lorenzo Miretti, Emil Björnson, Sławomir Stańczak
We reconsider the problem of joint power control and beamforming design to maximize the weighted sum rate in large and potentially cell-free massive MIMO networks. In contrast to t…
Unlocking the Potential of Local CSI in Cell-Free Networks with Channel Aging and Fronthaul Delays
Lorenzo Miretti, Sławomir Stańczak
It is generally believed that downlink cell-free networks perform best under centralized implementations where the local channel state information (CSI) acquired by the access-poin…
Two-timescale joint power control and beamforming design with applications to cell-free massive MIMO
Lorenzo Miretti, Renato L. G. Cavalcante, Sławomir Stańczak
In this study we derive novel optimal algorithms for joint power control and beamforming design in modern large-scale MIMO systems, such as those based on the cell-free massive MIM…
Robust mmWave/sub-THz multi-connectivity using minimal coordination and coarse synchronization
Lorenzo Miretti, Giuseppe Caire, Sławomir Stańczak
This study investigates simpler alternatives to coherent joint transmission for supporting robust connectivity against signal blockage in mmWave/sub-THz access networks. By taking…
Characterization of the weak Pareto boundary of resource allocation problems in wireless networks -- Implications to cell-less systems
Renato Luis Garrido Cavalcante, Lorenzo Miretti, Slawomir Stanczak
We establish necessary and sufficient conditions for a network configuration to provide utilities that are both fair and efficient in a well-defined sense. To cover as many applica…
UL-DL duality for cell-free massive MIMO with per-AP power and information constraints
Lorenzo Miretti, Renato L. G. Cavalcante, Emil Björnson +1
We derive a novel uplink-downlink duality principle for optimal joint precoding design under per-transmitter power and information constraints in fading channels. The information c…
Little or no equalization is needed in energy-efficient sub-THz mobile access
Lorenzo Miretti, Thomas Kühne, Alper Schultze +5
By trading coverage and hardware complexity for abundance of spectrum, sub-THz mobile access networks are expected to operate under highly directive and relatively spectrally ineff…
Joint optimal beamforming and power control in cell-free massive MIMO
Lorenzo Miretti, Renato Luis Garrido Cavalcante, Slawomir Stanczak
We derive a fast and optimal algorithm for solving practical weighted max-min SINR problems in cell-free massive MIMO networks. For the first time, the optimization problem jointly…
Team Precoding Towards Scalable Cell-free Massive MIMO Networks
Lorenzo Miretti, Emil Björnson, David Gesbert
In a recent work, we studied a novel precoding design for cell-free networks called team minimum mean-square error (TMMSE) precoding, which rigorously generalizes centralized MMSE…
Closed-form max-min power control for some cellular and cell-free massive MIMO networks
Lorenzo Miretti, Renato L. G. Cavalcante, Slawomir Stanczak +3
Many common instances of power control problems for cellular and cell-free massive MIMO networks can be interpreted as max-min utility optimization problems involving affine interf…
Team MMSE Precoding with Applications to Cell-free Massive MIMO
Lorenzo Miretti, Emil Björnson, David Gesbert
This article studies a novel distributed precoding design, coined team minimum mean-square error (TMMSE) precoding, which rigorously generalizes classical centralized MMSE precodin…
Cooperative Multiple-Access Channels with Distributed State Information
Lorenzo Miretti, Mari Kobayashi, David Gesbert +1
This paper studies a memoryless state-dependent multiple access channel (MAC) where two transmitters wish to convey a message to a receiver under the assumption of causal and imper…
Achieving Vanishing Rate Loss in Decentralized Network MIMO
Antonio Bazco Nogueras, Lorenzo Miretti, Paul de Kerret +2
In this paper, we analyze a Network MIMO channel with 2 Transmitters (TXs) jointly serving 2 users, where each TX has a different multi-user Channel State Information (CSI), potent…
FDD massive MIMO channel spatial covariance conversion using projection methods
Lorenzo Miretti, Renato L. G. Cavalcante, Slawomir Stanczak
Knowledge of second-order statistics of channels (e.g. in the form of covariance matrices) is crucial for the acquisition of downlink channel state information (CSI) in massive MIM…
Error Bounds for FDD Massive MIMO Channel Covariance Conversion with Set-Theoretic Methods
Renato Luis Garrido Cavalcante, Lorenzo Miretti, Slawomir Stanczak
We derive novel bounds for the performance of algorithms that estimate the downlink covariance matrix from the uplink covariance matrix in frequency division duplex (FDD) massive m…
Downlink channel spatial covariance estimation in realistic FDD massive MIMO systems
Lorenzo Miretti, Renato L. G. Cavalcante, Slawomir Stanczak
The knowledge of the downlink (DL) channel spatial covariance matrix at the BS is of fundamental importance for large-scale array systems operating in frequency division duplexing…