229 citations · 531 across the 15 of their papers we have counts for
15 papers
An Orthogonal Approximate Message Passing Framework for Multiuser Communications
Burak Çakmak, Hao Yan, Alexander Fengler +2
We solve the open problem of constructing a Bayes-optimal iterative signal recovery algorithm for linear-Gaussian \emph{multiuser} communication systems with random precoding at th…
Sparse Regression LDPC Codes for the Block-Fading Non-Coherent SIMO Channel
Alexander Fengler, Burak Çakmak, Giuseppe Caire
Sparse regression codes (SPARCs) are a class of codes that encode information through the superposition of columns of a randomised coding matrix. The combination with an outer non-…
Removal of Small Weight Stopping Sets for Asynchronous Unsourced Multiple Access
Frederik Ritter, Jonathan Mandelbaum, Alexander Fengler +2
In this paper, we analyze the formation of small stopping sets in joint factor graphs describing a frame-asynchronous two-user transmission. Furthermore, we propose an algorithm to…
Coded Orthogonal Modulation for the Multi-Antenna Multiple-Access Channel
Alexander Fengler, Alejandro Lancho, Yury Polyanskiy
This study focuses on (traditional and unsourced) multiple-access communication over a single transmit and multiple () receive antennas. We assume full or partial channel state…
On the Advantages of Asynchrony in the Unsourced MAC
Alexander Fengler, Alejandro Lancho, Krishna Narayanan +1
In this work we demonstrate how a lack of synchronization can in fact be advantageous in the problem of random access. Specifically, we consider a multiple-access problem over a fr…
Finite-Blocklength Results for the A-channel: Applications to Unsourced Random Access and Group Testing
Alejandro Lancho, Alexander Fengler, Yury Polyanskiy
We present finite-blocklength achievability bounds for the unsourced A-channel. In this multiple-access channel, users noiselessly transmit codewords picked from a common codebook…
Pilot-Based Unsourced Random Access with a Massive MIMO Receiver: Interference Cancellation and Power Control
Alexander Fengler, Osman Musa, Peter Jung +1
In this work we treat the unsourced random access problem on a Rayleigh block-fading AWGN channel with multiple receive antennas. Specifically, we consider the slowly fading scenar…
Pilot-Based Unsourced Random Access with a Massive MIMO Receiver in the Quasi-Static Fading Regime
Alexander Fengler, Peter Jung, Giuseppe Caire
In this work we treat the unsourced random access problem on a Rayleigh block-fading AWGN channel with multiple receive antennas. Specifically, we consider the slowly fading scenar…
Unsourced Multiuser Sparse Regression Codes achieve the Symmetric MAC Capacity
Alexander Fengler, Peter Jung, Giuseppe Caire
Unsourced random-access (U-RA) is a type of grant-free random access with a virtually unlimited number of users, of which only a certain number are active on the same time sl…
Grant-Free Massive Random Access With a Massive MIMO Receiver
Alexander Fengler, Saeid Haghighatshoar, Peter Jung +1
We consider the problem of unsourced random access (U-RA), a grant-free uncoordinated form of random access, in a wireless channel with a massive MIMO base station equipped with a…
Non-Bayesian Activity Detection, Large-Scale Fading Coefficient Estimation, and Unsourced Random Access with a Massive MIMO Receiver
Alexander Fengler, Saeid Haghighatshoar, Peter Jung +1
In this paper, we study the problem of user activity detection and large-scale fading coefficient estimation in a random access wireless uplink with a massive MIMO base station wit…
On the Restricted Isometry Property of Centered Self Khatri-Rao Products
Alexander Fengler, Peter Jung
In this work we establish the Restricted Isometry Property (RIP) of the centered column-wise self Khatri-Rao (KR) products of matrix with iid columns drawn either unifo…
Massive MIMO Unsourced Random Access
Alexander Fengler, Giuseppe Caire, Peter Jung +1
We consider an extension of the massive unsourced random access originally proposed by Polyanskiy to the case where the receiver has a very large number of antennas (a massive MIMO…
SPARCs for Unsourced Random Access
Alexander Fengler, Peter Jung, Giuseppe Caire
Unsourced random-access (U-RA) is a type of grant-free random access with a virtually unlimited number of users, of which only a certain number are active on the same time sl…
Controlling contagious processes on temporal networks via adaptive rewiring
Vitaly Belik, Alexander Fengler, Florian Fiebig +2
We consider recurrent contagious processes on a time-varying network. As a control procedure to mitigate the epidemic, we propose an adaptive rewiring mechanism for temporary isola…