no code implementations • 6 Nov 2023 • Tianyi Liu, Frederic Matter, Alexander Sorg, Marc E. Pfetsch, Martin Haardt, Marius Pesavento
To further reduce the computation time in such scenarios, a relaxation-based approach can be employed to obtain an approximate solution of the MISDP reformulation, at the expense of a reduced estimation performance.
no code implementations • 13 Apr 2023 • Sepideh Gherekhloo, Khaled Ardah, Martin Haardt
A novel channel estimation method called Sequential Alternating Least Squares Approximation (SALSA) is proposed by exploiting a hidden tensor structure in the uplink measurement matrix.
no code implementations • 18 Nov 2022 • Bilal Ahmad, Kevin Weinberger, Aydin Sezgin, Bilal Zafar, Martin Haardt
To enable the full potential of RISs, we propose to use tensor-decomposition-based CE, which facilitates smart configuration of the RIS by providing the required channel components.
no code implementations • 14 Mar 2022 • Brenda Vilas Boas, Wolfgang Zirwas, Martin Haardt
In 3GPP New Radio (NR) Release 18 we see the first study item starting in May 2022, which will evaluate the potential of AI/ML methods for Radio Access Network (RAN) 1, i. e., for mobile radio PHY and MAC layer applications.
no code implementations • 15 Nov 2021 • Brenda Vilas Boas, Wolfgang Zirwas, Martin Haardt
Machine learning (ML) applications for wireless communications have gained momentum on the standardization discussions for 5G advanced and beyond.
no code implementations • 15 Nov 2021 • Brenda Vilas Boas, Wolfgang Zirwas, Martin Haardt
Based on the prior-CSIs, their locations and the location of the desired channel, the cGAN is trained to output the channel expected at the desired location.
no code implementations • 7 Oct 2021 • Khaled Ardah, Martin Haardt
This paper proposes a compressed sensing-based high-resolution direction-of-arrival estimation method called gradient orthogonal matching pursuit (GOMP).
no code implementations • 19 Sep 2021 • Khaled Ardah, Sepideh Gherekhloo, André L. F. de Almeida, Martin Haardt
Reconfigurable intelligent surfaces (RISs) have been proposed recently as new technology to tune the wireless propagation channels in real-time.
no code implementations • 29 Jul 2021 • Sepideh Gherekhloo, Khaled Ardah, André L. F. de Almeida, Martin Haardt
Utilizing such a structure, a tensor-based RIS channel estimation method (termed TenRICE) is proposed, wherein the tensor factor matrices are estimated using an alternating least squares method.
no code implementations • 22 Jun 2021 • Brenda Vilas Boas, Wolfgang Zirwas, Martin Haardt
A variety of wireless channel estimation methods, e. g., MUSIC and ESPRIT, rely on prior knowledge of the model order.
no code implementations • 17 Jun 2021 • Khaled Ardah, Martin Haardt, Tianyi Liu, Frederic Matter, Marius Pesavento, Marc E. Pfetsch
Finally, we address the measurement system design for linear and nonlinear measurements of sparse signals.
no code implementations • 20 May 2021 • Sepideh Gherekhloo, Khaled Ardah, Martin Haardt
In this work, we consider the design of hybrid analog-digital (HAD) multi-carrier MIMO-OFDM two-way relaying systems, where the relay station is equipped with a HAD amplify-and-forward architecture and every mobile station is equipped with a fully-digital beamforming architecture.
no code implementations • 10 Mar 2021 • Joseph Kibugi, Lucas N. Ribeiro, Martin Haardt
Channel state information (CSI) rapidly becomes outdated in high mobility scenarios, degrading the performance of wireless communication systems.
no code implementations • 24 Jan 2021 • Brenda Vilas Boas, Wolfgang Zirwas, Martin Haardt
Massive MIMO is one of the main features of 5G mobile radio systems.
no code implementations • 21 Sep 2020 • Lucas N. Ribeiro, Stefan Schwarz, André L. F. de Almeida, Martin Haardt
We present a novel and low-complexity massive multiple-input multiple-output (MIMO) precoding strategy based on novel findings concerning the subspace separability of Rician fading channels.
no code implementations • 30 Aug 2020 • Amir Weiss, Arie Yeredor, Sher Ali Cheema, Martin Haardt
In this paper we extend our results to the IVA problem, showing how the ML solution for the Gaussian model (with arbitrary covariance and cross-covariance matrices) takes the form of an extended SeDJoCo problem.
no code implementations • 30 Aug 2020 • Amir Weiss, Sher Ali Cheema, Martin Haardt, Arie Yeredor
As an immediate consequence of this result, we provide an asymptotically attainable lower bound on the resulting ISRs.
no code implementations • 8 Jan 2020 • Fazal-E-Asim, André L. F. de Almeida, Martin Haardt, Charles C. Cavalcante, Josef A. Nossek
To achieve a reliable communication with short data blocks, we propose a novel decoding strategy for Kronecker-structured constant modulus signals that provides low bit error ratios (BERs) especially in the low energy per bit to noise power spectral density ratio $(E_b/N_0)$.