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Related papers: No Downlink Pilots are Needed in TDD Massive MIMO

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Orthogonal delay-Doppler division multiplexing~(ODDM) modulation has recently been regarded as a promising technology to provide reliable communications in high-mobility situations. Accurate and low-complexity channel estimation is one of…

Signal Processing · Electrical Eng. & Systems 2025-07-29 Dezhi Wang , Chongwen Huang , Xiaojun Yuan , Sami Muhaidat , Lei Liu , Xiaoming Chen , Zhaoyang Zhang , Chau Yuen , Mérouane Debbah

Large multiple-input multiple-output (MIMO) networks promise high energy efficiency, i.e., much less power is required to achieve the same capacity compared to the conventional MIMO networks if perfect channel state information (CSI) is…

Information Theory · Computer Science 2015-06-17 An Liu , Vincent Lau

In this work, we present new results for the application of rate splitting multiple access (RSMA) to the downlink (DL) of a massive multiple-input-multiple-output (MaMIMO) system operating in frequency-division-duplex (FDD) mode. Due to the…

Signal Processing · Electrical Eng. & Systems 2023-01-31 Donia Ben Amor , Michael Joham , Wolfgang Utschick

We present a framework for joint amplification and phase shift optimization of the repeater gain in dynamic time-division duplex (TDD) repeater-assisted massive MIMO networks. Repeaters, being active scatterers with amplification and phase…

Signal Processing · Electrical Eng. & Systems 2026-04-24 Martin Andersson , Anubhab Chowdhury , Erik G. Larsson

A large majority of cellular networks deployed today make use of Frequency Division Duplexing (FDD) where, in contrast with Time Division Duplexing (TDD), the channel reciprocity does not hold and explicit downlink (DL) probing and uplink…

Information Theory · Computer Science 2019-12-09 Mahdi Barzegar Khalilsarai , Yi Song , Tianyu Yang , Saeid Haghighatshoar , Giuseppe Caire

In this paper, we consider massive multiple-input multiple-output (MIMO) systems for both downlink and uplink scenarios, where three radio units (RUs) connected via one digital unit (DU) support multiple user equipments (UEs) at the…

Information Theory · Computer Science 2016-11-17 Yeon-Geun Lim , Chan-Byoung Chae , Giuseppe Caire

By means of the emerging technique of dynamic Time Division Duplex (TDD), the switching point between uplink and downlink transmissions can be optimized across a multi-cell system in order to reduce the impact of inter-cell interference. It…

Information Theory · Computer Science 2015-05-07 A. M. Fouladgar , O. Simeone , O. Sahin , P. Popovski , S. Shamai

We consider the downlink of a multi-cell system with multi-antenna base stations and single-antenna user terminals, arbitrary base station cooperation clusters, distance-dependent propagation pathloss, and general "fairness" requirements.…

Information Theory · Computer Science 2016-11-18 Hoon Huh , Antonia M. Tulino , Giuseppe Caire

In this correspondence, we analytically characterize the benefit of digital processing in uplink massive multiple-input multiple-output (MIMO) with sub-connected hybrid architecture. By assuming that the number of radio frequency (RF)…

Information Theory · Computer Science 2019-03-29 Jingbo Du , Wei Xu , Bin Sheng , Chunming Zhao

Although the combination of the orthogonal time frequency space (OTFS) modulation and the massive multiple-input multiple-output (MIMO) technology can make communication systems perform better in high-mobility scenarios, there are still…

Information Theory · Computer Science 2021-05-21 Ding Shi , Wenjin Wang , Li You , Xiaohang Song , Yi Hong , Xiqi Gao , Gerhard Fettweis

A massive MIMO system, represented by a base station with hundreds of antennas, is capable of spatially multiplexing many devices and thus naturally suited to serve dense crowds of wireless devices in emerging applications, such as…

Information Theory · Computer Science 2017-09-06 Elisabeth de Carvalho , Emil Björnson , Jesper H. Sørensen , Erik G. Larsson , Petar Popovski

This work investigates the downlink performance of a multi-cell massive multiple-input multiple-output (MIMO) system that employs one-bit analog-to-digital converters (ADCs) and digital-to-analog converters (DACs) in the receiving and…

Information Theory · Computer Science 2023-03-08 Qurrat-Ul-Ain Nadeem , Anas Chaaban

A limitation of bandwidth in the wireless network and the exponential rise in the high data rate requirement prompted the development of Massive Multiple-Input-Multiple-Output (MIMO) technique in 5G. Using this method the ever rising data…

Signal Processing · Electrical Eng. & Systems 2024-06-11 Mariea Sharaf Anzum , Moontasir Rafique , Md. Asif Ishrak Sarder , Fehima Tajrian , Abdullah Bin Shams

Massive multiple-input--multiple-output (MIMO) systems can suffer from coherent intercell interference due to the phenomenon of pilot contamination. This paper investigates a two-layer decoding method that mitigates both coherent and…

Information Theory · Computer Science 2019-01-17 Trinh Van Chien , Christopher Mollén , Emil Björnson

The power consumption of digital-to-analog converters (DACs) constitutes a significant proportion of the total power consumption in a massive multiuser multiple-input multiple-output (MU-MIMO) base station (BS). Using 1-bit DACs can…

Signal Processing · Electrical Eng. & Systems 2019-06-11 Lei Chu , Fei Wen , Lily Li , Robert Qiu

The downlink channel covariance matrix (CCM) acquisition is the key step for the practical performance of massive multiple-input and multiple-output (MIMO) systems, including beamforming, channel tracking, and user scheduling. However, this…

Signal Processing · Electrical Eng. & Systems 2024-01-22 Kai Li , Ying Li , Lei Cheng , Qingjiang Shi , Zhi-Quan Luo

We propose a method for channel training and precoding in FDD massive MIMO based on deep neural networks (DNNs), exploiting Downlink (DL) channel covariance knowledge. The DNN is optimized to maximize the DL multi-user sum-rate, by…

Information Theory · Computer Science 2023-03-21 Yi Song , Tianyu Yang , Mahdi Barzegar Khalilsarai , Giuseppe Caire

Accurate downlink channel information is crucial to the beamforming design, but it is difficult to obtain in practice. This paper investigates a deep learning-based optimization approach of the downlink beamforming to maximize the system…

Information Theory · Computer Science 2021-09-17 Juping Zhang , Minglei You , Gan Zheng , Ioannis Krikidis , Liqiang Zhao

This paper considers pilot design to mitigate pilot contamination and provide good service for everyone in multi-cell Massive multiple input multiple output (MIMO) systems. Instead of modeling the pilot design as a combinatorial assignment…

Information Theory · Computer Science 2018-01-23 Trinh Van Chien , Emil Björnson , Erik G. Larsson

We consider transmission of system information in a cell-free massive MIMO system, when the transmitting access points do not have any channel state information and the receiving terminal has to estimate the channel based on downlink…

Information Theory · Computer Science 2019-01-29 Marcus Karlsson , Emil Björnson , Erik G. Larsson