In this paper, the performance of opportunistic random beamforming (RBF) and multiuser (MU) gain in millimeter-wave (mm-wave) MU multiple-input single-output (MISO) downlink systems are analyzed based on uniform single-path (UR-SP) channel model suitable for highly directional mm-wave radio propagation channels. It is shown that under UR-SP model, RBF achieves linear sum rate scaling with respect to (w.r.t.) number transmit antennas and, furthermore, yields optimal when large, if users...

In this paper, the problem of outer beamformer design based only on channel statistic information is considered for two-stage beamforming multi-user massive MIMO downlink, and approached signal-to-leakage-plus-noise ratio (SLNR). To eliminate dependence instantaneous state information, a lower bound average SLNR derived by assuming zero-forcing (ZF) inner beamforming, an method that maximizes proposed. It shown proposed SLNR-based reduces to trace quotient (TQP), which often encountered in...

Millimeter-wave (mm-wave) and sub-terahertz (sub-THz) communications are expected to be one of the biggest beneficiaries emerging reconfigurable intelligent surface (RIS) technology. RISs can compensate for large path loss blockage inherent mm-wave sub-THz frequency bands yield enhanced communication performance in these bands. To achieve high beamforming gain realize RIS-assisted wireless communication, acquisition accurate channel state information (CSI) is critical. In this article, we...

In this paper, a new two-phase-feedback-based user-scheduling-and-beamforming method is proposed for multi-user multiple-input multiple-output downlink in the context of two-stage beamforming. The key ideas are: 1) to use set orthogonal reference beams and construct cone around each beam select “nearly-optimal” semi-orthogonal users based only on channel quality indicator feedback; 2) apply post-user-selection design with zero-forcing beamforming (ZFBF) state information (CSI) feedback from...

The performance of random beamforming (RBF) with partial channel state information (CSI) feedback is investigated here for millimeter wave (mmWave) multiuser multiple-input single-output (MU-MISO) downlink systems using the uniform multipath (UR-MP) model. In particular, required number users in cell RBF to yield linear sum rate scaling respect transmit antennas identified under UR-MP model different levels sparsity. Then, problem user scheduling MU-MISO considered when not sufficiently...

As the pace of global 5G network deployments accelerates, now is moment for cellular industry to realize 6G communication. In this article, modular massive multiple-in-put multiple-output (mmMIMO) presented as one candidate technology improve spectral efficiency in low-frequency bands. The New Radio pushed boundary system's operating frequency high-frequen-cy bands, and trend will continue era. However, technical advances bands fall short, although are crucial serving a large number users...

In this paper, we investigate hybrid analog/digital beamforming for multiple-input multiple-output (MIMO) systems with low-resolution analog-to-digital converters millimeter wave (mmWave) communications. the receiver, propose to split analog combining subsystem into a channel gain aggregation stage followed by spreading stage. Both stages use phase shifters. Our goal is design two-stage combiner optimize mutual information (MI) between transmitted and quantized signals effectively managing...

Since the introduction of fifth-generation new radio (5G-NR) in Third Generation Partnership Project (3GPP) Release 15, swift progress has been made to evolve 5G with 3GPP 18 emerging. A critical aspect is design massive multiple-input multiple-output (MIMO) technology. In this line, paper makes several important contributions: We provide a comprehensive overview evolution standardized MIMO features from 15 17 for both time/frequency-division duplex operation across frequency range (FR)-1...

In this paper, coordinated beamforming based on relaxed zero forcing (RZF) for K transmitterreceiver pair multiple-input single-output (MISO) and multiple-output (MIMO) interference channels is considered.In the RZF beamforming, conventional zero-forcing leakage constraints are so that some predetermined to undesired receivers allowed in order increase beam design space larger rates than those of (ZF) scheme or make feasible when ZF impossible.In MISO case, it shown rate-maximizing vector...

We investigate uplink user scheduling for millimeter wave (mm-wave) hybrid analog/digital beamforming systems with low-resolution analog-to-digital converters (ADCs). Deriving new criteria the mm-wave systems, we show that channel structure in beamspace, addition to magnitude and orthogonality, plays a key role maximizing achievable rates of scheduled users due quantization error. The maximize rate given gain, channels need have 1) as many propagation paths possible unique angle-of-arrivals...

Employing low-resolution analog-to-digital converters (ADCs) for millimeter-wave receivers with large antenna arrays provides an opportunity to efficiently reduce power consumption of the receiver. Reducing ADC resolution, however, results in performance degradation due non-negligible quantization error. In addition, number radio frequency chains is still not desirable. Accordingly, conventional systems require more efficient designs minimize cost and complexity while maximizing performance....

In this paper, a novel adaptive beamforming algorithm is proposed under linearly and quadratically constrained minimum variance (LQCMV) framework, based on dual-domain projection approach that can efficiently implement quadratic-inequality constraint with possibly rank-deficient positive semi-definite matrix, the properties of are analyzed. As an application, relaxed zero-forcing (RZF) presented which adopts specific quadratic bounds power residual interference in beamformer output aid...

In this paper, a simple user-scheduling-and-beamforming method is proposed for massive multi-user multiple-input multiple-output (MU-MIMO) downlink adopting two-stage beamforming. The key ideas of the scheduling-and-beamforming are to divide users into several candidate subsets according level alignment user channels dominant directions channel covariance matrix and select in each subset based on certain quality indicator (CQI) apply post-selection zero-forcing beamforming (ZFBF) selected...

In this paper, a new beamformer design paradigm, named k-regular beamformer, is proposed for massive multiple-input multiple-output (MIMO) transmission systems to achieve most of the gain inherent large antenna array without too much complexity. beamforming scheme, each multiple data streams MIMO multiplied by k complex gains and assigned out available N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">T</sub> transmit antennas, signals same are...

In this paper, adaptive pilot beam sequence design for channel estimation in large millimeter-wave (mmWave) MIMO systems is considered. By exploiting the sparsity of mmWave channels with virtual representation and imposing a Markovian random walk assumption on physical movement line-of-sight (LOS) reflection clusters, it shown that sparse problem reduces to sequential detection finds locations values non-zero-valued bins two-dimensional rectangular grid, optimal can be cast into framework...

In this paper, the performance of random beamforming (RBF) which requires only partial channel state information (CSI) feedback is investigated for millimeter-wave (mmwave) multiple-input multiple-output (MIMO) downlink systems under a new model that captures both independent and identically-distributed (i.i.d.) Rayleigh fading MIMO uniform line-of-sight (UR-LoS) bridges two models. Under proposed model, we answer basic question "how many users in cell are required RBF to achieve linear sum...

In this paper, the multi-user (MU) gain and impact of training are investigated for random beamforming (RBF) in highly-directional millimeter-wave (mm-wave) MU multiple-input multiple-output (MIMO) downlink which is considered as one major technological thrusts 5G communications. To do so, uniform line-of-sight (UR-LoS) channel model suitable mm-wave radio propagation channels adopted. Based on UR-LOS model, performance RBF MIMO systems analyzed. It shown that there exists a transition point...

Wireless communication is now moving to automotive systems. In the near future, vehicles and road side units (RSUs) will be equipped with various sensors such as radars, LIDARs, cameras, GPSs generate enormous sensor information. To enhance safety efficiency, they share this raw information each other through Gbps data rates using millimeter-wave (mmWave) communications. realize vision, two unfavorable attributes of mmWave communications should addressed: 1) Overcoming blockage 2) fast link...

The impact of training on the performance millimeter wave multi-user multiple-input multiple-output downlink systems based hybrid analog/digital beamforming is investigated in regime a large number transmit antennas under uniform random single-path channel model. In particular, loss with respect to beams quantified for general training-based data transmission schemes several different beam designs when full not applicable. Our analysis provides insights into effective design and simulation...

Since the introduction of fifth-generation new radio (5G-NR) in Third Generation Partnership Project (3GPP) Release 15, swift progress has been made to evolve 5G with 3GPP 18 emerging. A critical aspect is design massive multiple-input multiple-output (MIMO) technology. In this line, paper makes several important contributions: We provide a comprehensive overview evolution standardized MIMO features from 15 17 for both time/frequency-division duplex operation across bands FR-1 and FR-2....

The performance of transmit random beamforming (RBF) with receive at each user is investigated for millimeter wave (mmWave) multiuser multiple-input multiple-output (MU-MIMO) downlink systems. It shown that RBF in MU-MIMO systems the total power inversely proportional to number antennas can achieve conventional scheme constant MU single-output (MISO) no beamforming, when large.

In this paper, we consider a distributed multi-input-multi-output (D-MIMO) system wherein multiple radio remote heads (RRHs) in cell are connected with single baseband unit. To enable coherent joint transmission from RRHs the D-MIMO system, propose several channel state information (CSI) codebooks as candidates for enhancements context of 3rd Generation Partnership Project (3GPP) 5G New Radio (NR) standardization. The proposed developed based on Release-16 Type-II CSI codebook framework....