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Related papers: Beamforming Gain with Nonideal Phase Shifters

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Fluid antenna systems encompass a broad class of reconfigurable antenna technologies that offer substantial spatial diversity for various optimization objectives and communication tasks. Their capability to enhance spatial resolution within…

Information Theory · Computer Science 2025-12-01 Jingyuan Xu , Zhentian Zhang , Jian Dang , Hao Jiang , Zaichen Zhang

This paper proposes a practical method for the definition of communication modes when antennas operate in the near-field region, by realizing ad-hoc beams exploiting the focusing capability of large antennas. The beamspace modeling proposed…

Signal Processing · Electrical Eng. & Systems 2021-12-07 Nicolò Decarli , Davide Dardari

Pinching antenna system (PASS) has recently shown its promising ability to flexibly reconfigure wireless channels via dynamically adjusting the positions of pinching antennas over a dielectric waveguide, termed as pinching beamforming. This…

Information Theory · Computer Science 2025-09-17 Guangji Chen , Qingqing Wu , Kangda Zhi , Xidong Mu , Yuanwei Liu

Distributed antennas must be phase-calibrated (phase-synchronized) for certain operations, such as reciprocity-based joint coherent downlink beamforming, to work. We use rigorous signal processing tools to analyze the accuracy of…

Information Theory · Computer Science 2024-01-23 Erik G. Larsson

We explicitly construct a large class of unitary transformations that allow to perform the ideal estimation of the phase-shift on a single-mode radiation field. The ideal phase distribution is obtained by heterodyne detection on two…

Quantum Physics · Physics 2009-11-10 F. Buscemi , G. M. D'Ariano , M. F. Sacchi

Hybrid beamforming for frequency-selective channels is a challenging problem as the phase shifters provide the same phase shift to all of the subcarriers. The existing approaches solely rely on the channel's frequency response and the…

Information Theory · Computer Science 2019-03-13 Sohail Payami , Mathini Sellathurai , Konstantinos Nikitopoulos

The new mechanism for obtaining a nonlinear phase shift has been proposed and the schemes are described for its implementation. As it is shown, the interference of two waves with intensity-dependent amplitude ratio coming from the second…

Optics · Physics 2007-05-23 V. P. Drachev , S. V. Perminov

We characterize operationally meaningful quantum gains in a paradigmatic model of lossless multiple-phase interferometry and stress insufficiency of the analysis based solely on the concept of quantum Fisher information. We show that the…

Quantum Physics · Physics 2022-01-28 Wojciech Gorecki , Rafal Demkowicz-Dobrzanski

The performance of broadband millimeter-wave (mmWave) RF architectures, is generally determined by mathematical concepts such as the Shannon capacity. These systems have also to obey physical laws such as the conservation of energy and the…

Information Theory · Computer Science 2018-03-05 Amine Mezghani , Robert W. Heath

This work gives a blind beamforming strategy for intelligent reflecting surface (IRS), aiming to boost the received signal-to-noise ratio (SNR) by coordinating phase shifts across reflective elements in the absence of channel information.…

Information Theory · Computer Science 2022-11-04 Shuyi Ren , Kaiming Shen , Yaowen Zhang , Xin Li , Xin Chen , Zhi-Quan Luo

We first consider an energy harvesting channel with fading, where only the transmitter harvests energy from natural sources. We bound the optimal long term throughput by a constant for a class of energy arrival distributions. The proposed…

Information Theory · Computer Science 2015-01-28 Jainam Doshi , Rahul Vaze

In this paper, we consider the effect of channel uncertainty on the rates reliably delivered to the users; i.e., the goodput. After the base station (BS) designs a set of beamformers for a specific objective, the BS must select the…

Signal Processing · Electrical Eng. & Systems 2019-08-30 Mostafa Medra , Andrew W. Eckford , Raviraj Adve

It remains an open problem to find the optimal configuration of phase shifts under the discrete constraint for intelligent reflecting surface (IRS) in polynomial time. The above problem is widely believed to be difficult because it is not…

Information Theory · Computer Science 2023-09-08 Shuyi Ren , Kaiming Shen , Xin Li , Xin Chen , Zhi-Quan Luo

Traditional approaches to outage-constrained beamforming optimization rely on statistical assumptions about channel distributions and estimation errors. However, the resulting outage probability guarantees are only valid when these…

Signal Processing · Electrical Eng. & Systems 2025-05-27 Xin Su , Qiushuo Hou , Ruisi He , Osvaldo Simeone

Beamforming for mmWave communications is well-studied in the PHY based on the channel parameters to develop optimum receiver processing techniques. However, even before signal processing, antenna structure and radiation parameters affect…

Information Theory · Computer Science 2020-03-31 Yavuz Yaman , Predrag Spasojevic

In this paper, we consider IRS-assisted transmissions from a multi-antenna access point (AP) to a receiver with uncertain channel information. By adjusting the magnitude of reflecting coefficients, the IRS can sustain its operations by…

Signal Processing · Electrical Eng. & Systems 2020-05-15 Yongchang Deng , Yuze Zou , Shimin Gong , Bin Lyu , Dinh Thai Hoang , Dusit Niyato

We introduce a new method for robust beamforming, where the goal is to estimate a signal from array samples when there is uncertainty in the angle of arrival. Our method offers state-of-the-art performance on narrowband signals and is…

Signal Processing · Electrical Eng. & Systems 2024-06-25 Nakul Singh , Coleman DeLude , Mark A. Davenport , Justin Romberg

A wireless network of multiple transmitter-user pairs overheard by an eavesdropper, where the transmitters are equipped with multiple antennas while the users and eavesdropper are equipped with a single antenna, is considered. At different…

Information Theory · Computer Science 2018-08-01 Zhichao Sheng , Hoang Duong Tuan , Trung Q. Duong , H. Vincent Poor

This paper considers an arbitrarily-varying fading channel consisting of one transmitter, one receiver and an arbitrarily varying adversary. The channel is assumed to have additive Gaussian noise and fast fading of the gain from the…

Information Theory · Computer Science 2021-06-15 Fatemeh Hosseinigoki , Oliver Kosut

We investigate the constrained capacity of multiple-antenna fading coherent channels, where the receiver knows the channel state but the transmitter knows only the channel distribution, driven by arbitrary equiprobable discrete inputs in a…

Information Theory · Computer Science 2012-10-26 Miguel Rodrigues