Millimeter-wave communication is one way to alleviate the spectrum gridlock at lower frequencies while simultaneously providing high-bandwidth channels. MmWave makes use of MIMO through large antenna arrays both base station and mobile provide sufficient received signal power. This article explains how beamforming precoding are different in mmWave systems than their lower-frequency counterparts, due hardware constraints channel characteristics. Two potential architectures reviewed: hybrid...

In massive multiple-input multiple-output (MIMO) systems, it may not be power efficient to have a pair of high-resolution analog-to-digital converters (ADCs) for each antenna element. this paper, near maximum likelihood (nML) detector uplink multiuser MIMO systems is proposed where connected one-bit ADCs, i.e., one real and imaginary component the baseband signal. The exhaustive search over all possible transmitted vectors required in original (ML) detection problem relaxed formulate an ML...

With bandwidths on the order of a gigahertz in emerging wireless systems, high-resolution analog-to-digital convertors (ADCs) become power consumption bottleneck. One solution is to employ low resolution one-bit ADCs. In this paper, we analyze flat fading multiple-input multiple-output (MIMO) channel with Channel state information assumed be known at both transmitter and receiver. For single-output channel, derive exact capacity. single-input MIMO capacity infinite signal-to-noise ratio...

We develop a broadband channel estimation algorithm for millimeter wave (mmWave) multiple input output (MIMO) systems with few-bit analog-to-digital converters (ADCs). Our methodology exploits the joint sparsity of mmWave MIMO in angle and delay domains. formulate problem as noisy quantized compressed-sensing solve it using efficient approximate message passing (AMP) algorithms. In particular, we model angle-delay coefficients Bernoulli-Gaussian-mixture distribution unknown parameters use...

We develop channel estimation agorithms for millimeter wave (mmWave) multiple input output (MIMO) systems with one-bit analog-to-digital converters (ADCs). Since the mmWave MIMO is sparse due to propagation characteristics, problem formulated as a compressed sensing problem. propose modified EM algorithm that exploits sparsity and has better performance than conventional algorithm. also present second solution using generalized approximate message passing (GAMP) solve this optimization The...

Hybrid analog/digital architectures and receivers with low-resolution analog-to-digital converters (ADCs) are two low power solutions for wireless systems large antenna arrays, such as millimeter wave massive multiple-input multiple-output systems. Most prior work represents extreme cases in which either a small number of radio frequency (RF) chains full-resolution ADCs, or ADC RF equal to the antennas is assumed. In this paper, generalized hybrid architecture finite bits proposed. For...

This work studies the problem of secure connection in cooperative wireless communication with two relay strategies, decode-and-forward (DF) and randomize-and-forward (RF). The four-node scenario cellular are considered. For typical (source, destination, relay, eavesdropper) scenario, we derive optimal power allocation for DF strategy find that RF is always better than to enhance connection. In networks, show without it difficult establish connections from base station cell edge users. effect...

Millimeter wave (mmWave) is a viable technology for future cellular systems. With bandwidths on the order of gigahertz, high-resolution analog-to-digital converters (ADCs) become power consumption bottleneck. One solution to employ very low resolution one-bit ADCs. This paper analyzes flat fading multiple-input multiple-output (MIMO) channel with ADC. Bounds high signal-to-noise ratio (SNR) capacity are derived single-input (SIMO) and general MIMO channel. The results show how number paths,...

This paper studies the secure beamforming design in a multiple-antenna three-node system where two source nodes exchange messages with help of an untrusted relay node. The acts as both essential signal forwarder and potential eavesdropper. Both two-phase three-phase two-way strategies are considered. Our goal is to jointly optimize beamformers for maximizing secrecy sum rate communications. We first derive optimal beamformer structures. Then, iterative algorithms proposed find based on...

Future cellular networks will increasingly rely on the millimeter-wave bands to increase capacity. Migrating ever higher carrier frequencies require directional beamforming establish and maintain link. Intelligent beam management (BM) protocols be critical for establishing maintaining connections between base station user equipment in a dynamic channel. This article first provides brief overview of BM protocol Release 15 5G New Radio, then identifies six major challenges later releases that...

Providing physical-layer security for mobile users in future broadband wireless networks is of both theoretical and practical importance. In this paper, we formulate an analytical framework resource allocation a downlink OFDMA-based network with coexistence secure (SU) normal (NU). The SU's require data transmission at the physical layer while NU's are served conventional best-effort traffic. problem formulated as joint power subcarrier objective maximizing average aggregate information rate...

Beam alignment – the process of finding an optimal directional beam pair is a challenging procedure crucial to millimeter wave (mmWave) communication systems. We propose novel method that learns site-specific probing codebook and uses measurements predict narrow beam. An end-to-end neural network (NN) architecture designed jointly learn predictor. The learned consists beams can capture particular characteristics propagation environment. proposed relies on sweeping codebook, does not require...

A beam codebook of 5G millimeter wave (mmWave) for data communication consists multiple high-peak-gain beams to compensate the high pathloss at mmWave bands. These also have point different angular directions, such that by performing searching over codebook, a good signal coverage full sphere around terminal (spherical coverage) can be achieved. model-based design assumes ideal omni-directional antenna pattern, and neglects impact housing antenna, does not work well because radiation pattern...

We consider the symmetric Gaussian interference channel where two users try to enhance their secrecy rates in a cooperative manner.Artificial noise is introduced along with useful information.We derive power control and artificial parameter for kinds of optimal points, max-min point single user point.It shown that there exists critical value Pc constraint, below which an on rate region, above time-sharing between points achieves larger pairs.It also can help enlarge particular point.

This paper contributes a comprehensive study on the effect of user hand grip design 5G millimeter-wave (mmWave) mobile handsets, specifically in terms antenna module placement and beamforming codebook. The high-frequency structure simulator (HFSS) is used to characterize radiation fields for different placements 14 possible handgrip profiles based experiments that we conducted. loss from blockage gains can be up 20-25 dB, which implies need taken into account while designing Specifically,...

We study the degrees of freedom (DOF) a multiple-input multiple-output (MIMO) two-way X relay channel, where there are two groups source nodes and one node, each equipped with multiple antennas, in group exchanges independent messages other via node. It is assumed that every node <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">M</i> antennas while xmlns:xlink="http://www.w3.org/1999/xlink">N</i> antennas. first show upper bound on total DOF for...

Joint phase-time arrays (JPTA) emerge as a cost-effective and energy-efficient architecture for frequency-dependent beamforming in wideband communications by utilizing both true-time delay units phase shifters. This paper exploits the potential of JPTA to simultaneously serve multiple users near- far-field regions with single radio frequency chain. The goal is jointly optimize JPTA-based subband allocation maximize overall system performance. To this end, we formulate utility maximization...

Joint phase-time arrays (JPTA) is a new mmWave radio frequency front-end architecture constructed with appending time-delay elements to phase shifters for analog beamforming. JPTA allows the base station (BS) form multiple frequency-dependent beams single RF chain, exploiting extra degrees of freedom offer. Without requiring power-hungry chains, BS can schedule users in different directions frequency-division multiplexing (FDM) manner. A achieves various advantages over traditional...

Communication systems with low-resolution analog-to-digital-converters (ADCs) can exploit channel state information at the transmitter and receiver. This paper presents codebook designs performance analyses for limited feedback MIMO finite-bit ADCs. A point-to-point single-user is firstly considered. When received signal sliced by 1-bit ADCs, absolute phase receiver important to align of signals. new design beamforming, which separately quantizes direction residual phase, therefore proposed....

Hybrid beamforming is an attractive solution to build cost-effective and energy-efficient transceivers for millimeter-wave terahertz systems. However, conventional hybrid techniques rely on analog components that generate a frequency flat response such as phase-shifters switches, which limits the flexibility of achievable beam patterns. As novel alternative, this paper proposes new class called Joint phase-time arrays (JPTA), additionally use true-time delay elements in create...

Two-way relaying can considerably improve spectral efficiency in relay-assisted bidirectional communications. However, the benefits and flexible structure of orthogonal frequency division multiplexing (OFDM)-based two-way relay systems is much less exploited. Moreover, most existing works have not considered quality-of-service (QoS) provisioning for relaying. In this paper, we consider OFDM-based transmission where a pair users exchange information via assistance decode-and-forward (DF)...

Finding the optimal transmit and receive beam pair for reliable communication can be challenging, especially in highly dynamic environments. Side-information from on-board sensors at user equipment (UE) used to aid management (BM) process. In this work, we use orientation information coming inertial measurement unit (IMU) effective BM. Specifically, particle filter (PF) fuse reference signal received power (RSRP) with information. We perform extensive simulations using realistic ray-tracing...

Beam management (BM), i.e., the process of finding and maintaining a suitable transmit receive beam pair, can be challenging, particularly in highly dynamic scenarios. Side-information, e.g., orientation, from on-board sensors assist user equipment (UE) BM. In this work, we use orientation information coming inertial measurement unit (IMU) for effective We data-driven strategy that fuses reference signal received power (RSRP) with using recurrent neural network (RNN). Simulation results show...

From security perspective, a friendly relay may help to keep the confidential messages from being eavesdropped, while an untrusted intentionally eavesdrop when relaying. This paper studies secure beamforming for multiple-input multiple-output (MIMO) two-way communications, where two source nodes exchange information with of node. The adopts amplify-and-forward (AF) strategy and acts as both essential helper potential eavesdropper. Our goal is maximize secrecy sum rate bidirectional links by...

Communication systems with low-resolution analog- to-digital-converters (ADCs) can exploit channel state information at the transmitter (CSIT) and receiver. This paper presents initial results on codebook design performance analysis for limited feedback one-bit ADCs. Different from high-resolution case, absolute phase receiver is important to align of received signals when signal sliced by A new beamforming case proposed that separately quantizes direction residual phase.