This paper considers an uplink cell-free massive multi-input multi-output (mMIMO) system with multi-antenna access points (APs) and users, assuming low-resolution analog-to-digital converter (ADC) architecture is employed at the APs. Leveraging on additive quantization noise model (AQNM), we derive a tight approximate expression for spectral efficiency (SE). trackable finding provides us tool easily quantifying impacts of number antenna arrays bit ADCs. We find 5-bit required in mMIMO ADCs...

In this letter, we introduce a mixed analog-todigital converter (ADC) receiver architecture to cell-free massive multi-input multi-output (mMIMO) system under Rician fading channels. particular, the mixed-ADC permits some of receiver's antennas be implemented with economical low-resolution ADCs, while rests are equipped highpriced perfect ADCs. Leveraging on additive quantization noise model (AQNM), tight approximate uplink spectral efficiency (SE) expression matched filtering is derived,...

A generalized uplink cell-free massive multi-input multi-output (MIMO) system assuming access points (APs) are paired with mixed-resolution analog-to-digital converters (ADCs) and digital-to-analog (DACs) is investigated in this article. Specifically, the mixed-ADC/DAC architecture sacrifices part of performance gains advocates a few low-precision ADCs/DACs to reduce power consumption. Based on antenna structure, we derive closed-form achievable rate expressions for maximal ratio combining...

In this paper, the uplink performance of cell-free massive multi-input multi-output (mMIMO) system with zero-forcing (ZF) and conjugate beamforming (CB) receivers is investigated. A novel tight approximate rate expression for ZF receiver derived, which provides us a tool easily quantifying impacts multi-antenna access point (AP), estimation error, pilot contamination, power control scheme. Then, leveraging on trackable pre-studied CB expression, two algorithms are proposed. particular, first...

In this paper, it investigates the uplink performance of cell-free massive multiple-input multiple-output with non-orthogonal multiple access (CF-mMIMO-NOMA) technique and derives a rigorous closed-form approximation spectral efficiency expression for conjugate beamforming receiver. Based on novel result, paper proposes total maximization algorithm, subjecting to each user's quality-of-service (QoS) constraint, transmission power successive interference cancellation (SIC) constraint. The...

In this article, a generalized uplink cell-free massive multi-input multi-output (MIMO) system with nonideal radio frequency (RF) chains and low-resolution analog-to-digital converters (ADCs) is investigated. Specifically, the RF impairments ADC imperfections not only hinder accuracy of channel estimation but also deteriorate strength received signal-to-interference-plus-noise ratio. Achievable closed-form rate expressions are first derived by leveraging on Gaussian impairment model linear...

In this paper, we present the detailed rate analysis for cell-free massive multiple-input multiple-output (MIMO) systems over spatially correlated Rayleigh fading channels. Taking realistic impairment effects of spatial channel correlation, pilot contamination, and estimation errors into account, lower-bounds achievable rates both uplink downlink are derived with low-complexity linear processing such as matched filter conjugate beamforming, which enable us to take cognizance impacts...

As one of the most critical tasks currently, it is essential to excavate status update performance. In this paper, we combine access control and pilot design minimize average age information (AoI) in cell-free (CF) massive multiple-input multiple-output (MIMO) system with grant-free (GF) random access, where positions both points (APs) machine-type communication devices (MTCDs) are geographically distributed as independent Poisson point processes (PPPs). Based on establish two-disk...

Predicting the corrosion rate for soil-buried steel is significant assessing service-life performance of structures in soil environments. However, due to large amount variables involved, existing prediction models have limited accuracy complex environment. The present study employs three machine learning (ML) algorithms, i.e., random forest, support vector regression, and multilayer perception, predict current density steel. Steel specimens were embedded samples collected from different...

This paper focuses on a secrecy constrained massive multiple-input multiple-output (MIMO) relaying system in terms of the optimal design parameters such as total number antennas at relay, where more practical mixed analog-to-digital converters (ADCs) scheme, double-resolution ADCs is proposed. In proposed M relay are divided into two parts, one which includes <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> with medium-resolution only...

In this paper, we investigate the downlink performance of cell-free massive multi-input multi-output non-orthogonal multiple access (CF-mMIMO-NOMA) system with conjugate beamforming precoder and compare against orthogonal (OMA) counterpart. A novel achievable closed-form spectral efficiency (SE) expression is derived, which characterizes effects channel estimation error, pilot contamination, imperfect successive interference cancellation (SIC) operation, power optimization technique. Then,...

In this paper, a pilot-contaminated uplink cell-free massive multiple-input multiple-output (mMIMO) system with zero-forcing (ZF) receiver is considered. Then paper derives novel lower-bound expression for energy efficiency (EE), which enables us to propose resource optimization problem maximize the total EE. This considered power scheme takes into account quality-of-service (QoS) requirement, each user constraint and consumption. Specifically, consumption model includes circuit power, data...

In this letter, we investigate the impact of multi-antenna on both users and access points (APs), low-resolution digital-to-analog converters (DACs) multigroup multicast cell-free massive multi-input multi-output (MIMO) systems. With distributed conjugate beamforming receiver generalized additive quantization noise model, derive a closed-form expression for achievable downlink sum spectral efficiency (SE), which provides us vigorous tool easily evaluating impacts key parameters. Due to joint...

Abstract The aqueous metal–H 2 O batteries have been paid rapidly increasing attention due to their large theoretical energy densities, attractive power density, and multiple applications (air, land, sea), especially in low‐content oxygen or nonoxygen conditions which metal–air cells are out of work. However, the requirements different order metal activities (Mg &gt; Al Zn) as well cells. Aqueous mainly include Al–H , Mg–H Zn–H with respective scientific problems, including battery...

In millimeter wave (mmWave) multiple-input multiple-output (MIMO) systems, the hybrid beamforming architecture has been put forward to reduce high hardware cost and power consumption, which are resulted from tremendous requirements of dedicated radio frequency (RF) chains. this paper, we propose several strategies design analog digital precoders for a point-to-point (P2P) MIMO system. Aiming at minimizing Euclidean distance between optimal precoder precoder, decouple matrix factorization...

In this article, the effects of multiantenna users and low-resolution analog-to-digital converters/digital-to-analog converters (ADCs/DACs) on multigroup multicast downlink cell-free massive multi-input multi-output (MIMO) systems are explored. Leveraging distributed conjugate beamforming receiver generalized additive quantization noise model, we first derive a closed-form expression for achievable sum spectral efficiency (SE). The resultant enables us to precisely quantify key parameters,...

Hierarchically macro-meso-microporous ZIF-67/nori-derived electrocatalysts were synthesized by using single-cell-array nori and ZIF-67 as macroporous microporous templates, KOH a meso/micropore-forming reagent. The ZIF-67/nori-800-based Zn-H2O2 battery achieved high maximum power density, of 476 mW cm-2, specific energy density 964 W h kg-1 at 50 mA cm-2.