This letter investigates the achievable spectral efficiency (SE) of massive multiple-input multiple-output transmission systems with hybrid architectures based on discrete Fourier transform (DFT) processing, where base station (BS) has perfect channel state information and baseband processing is performed by zero-forcing precoding. We derive tractable upper lower bounds SE. Based these results, effects number radio frequency (RF) chains, signal-to-noise ratio (SNR), users are revealed....

In this paper, we study the achievable ergodic sum-rate of multiuser multiple-input multiple-output downlink systems in Rician fading channels. We first derive a lower bound on average signal-to-leakage-and-noise ratio by using Mullen's inequality, and then use it to analyze effect channel mean information sum-rate. A novel statistical-eigenmode space-division multiple-access (SE-SDMA) transmission scheme is proposed. For scheme, an exact analytical closed-form expression for rate present...

In this paper, we investigate the downlink achievable ergodic spectral efficiency (SE) of a single-cell multi-user millimeter wave system, in which uniform rectangular array is used at base station (BS) to serve multiple single-antenna users. We adopt three-dimensional channel model by considering both azimuth and elevation dimensions under single-path propagation. derive SE for system with maximum ratio transmission precoding. This analytical expression enables accurate quantitative...

This paper investigates the downlink achievable spectral efficiency (SE) and energy (EE) of massive MIMO for hybrid architectures based on phase shifters, where base station (BS) has perfect channel state information baseband processing is done zero-forcing precoding. We derive an approximated upper bound SE architecture with ideal shifters. Based derived analytical expression, we find that total increases number BS antennas users signal-to-noise ratio (SNR). In order to acquire required...

In order to reap the full scale of benefits millimeter wave (mmWave) massive multiple-input multiple-output (MIMO) systems, design antenna arrays at transmitter or receiver becomes more critical due propagation characteristic mm-frequencies. this paper, we investigate steering vector and array factor by considering three types planar arrays, namely uniform rectangular (URPA), hexagonal (UHPA), circular (UCPA). Based on these results, directivity/gain achievable spectral efficiency in a...

In this letter, hybrid automatic retransmission request with incremental redundancy (HARQ-IR) is applied to assist integrated sensing and communication (ISAC). The long term average throughput (LTAT) of HARQ-IR-assisted ISAC maximized via power allocation while ensuring both reliability as well total budget. Since the LTAT maximization a non-convex problem, asymptotic outage approximation leveraged for problem relaxation. Subsequently, successive convex (SCA) exploited convert it into...

Due to the broadcast nature of wireless transmission, traditional two-hop relaying is vulnerable for eavesdroppers overhear messages. In order enhance physical-layer security, this paper studies one cooperative network with caching relays reduce transmission links overheard by eavesdropper. Relays are grouped into different clusters so that secrecy outage probability any cluster better than transmission. Based on and groups files, we propose a novel hybrid cache placement, which combines...

This article investigates the achievable spectral efficiency (SE) of millimeter wave massive multiple-input multiple-output systems with three different array topologies deployed at base station (BS), namely uniform rectangular (URA), linear (ULA) or circular (UCA). To be practical, both small scale fading and large path loss, shadowing effects are considered in analysis. A 3D channel model taking azimuth elevation domains into account is adopted for analysis URA UCA topologies. Considering...

Ultra-dense cloud radio access networks (C-RANs) are an example of the architectures that will be critical components next-generation wireless systems. In a C-RAN architecture, amorphous cellular framework, where each user connects to few nearby remote heads (RRHs) form its own cell, appears promising. this paper, we study ergodic capacity such at high signal-to-noise ratios (SNRs) model distribution RRHs by Poisson point process. We derive tractable approximations high-SNRs for arbitrary...

We analyze the downlink multiuser precoding of massive multiple input output (MIMO) system, where base station (BS) has ideal channel state information (CSI) and adopts three types different linear schemes, i.e., maximum ratio transmission (MRT), zero-forcing (ZF), minimum mean squared error (MMSE). Under a Rayleigh fading channel, we attain exact expressions on achievable rate for these schemes. Moreover, provide several insights rates reveal relation number BS antennas, users,...

In this paper, we investigate the achievable ergodic sum-rate for multiuser massive multiple-input multiple-output systems, where different array configurations such as uniform linear arrays (ULAs), planar (UPAs) and circular (UCAs), are deployed at base station (BS). The investigation is carried out based on a three dimensional spatial propagation channel model by taking into account both azimuth elevation angular domains. We first value of inner product two vectors, which closed-form...

This paper investigates the achievable uplink spectral efficiency (SE) of a massive multi-input multi-output (MIMO) system with mixed analog-to-digital converter (ADC) receiver architecture, in which some antennas are equipped full-resolution ADCs while others deployed low-resolution ADCs. We derive theoretical results and corresponding approximate expressions SE multi-cell systems maximum ratio combining (MRC) detector single-cell zero-forcing (ZF) detector. Based on approximated results,...

Intelligent reflecting surface (IRS) technology is highly anticipated in future smart communication systems as it can improve spectral efficiency (SE) by adjusting signal phase shifts. This article investigates the SE and energy (EE) of IRS-assisted multiuser multiple-input multiple-output (MIMO) systems, where base station (BS) antennas are equipped with low-resolution digital-to-analog converters (DACs). In pursuit maximizing achievable SE, we undertake complex task jointly optimizing...

We study the WiFi offloading problem in smart communications and adaptively seek for optimal strategies with consideration of mobility management dynamical nature network state. With users management, we formulate ratio optimization based on Markov process. Then, propose a novel Congestion‐Optimal Offloading (COWO) algorithm subgradient method, which aims to obtain each access point (AP) maximize throughput minimize congestion. Due computational complexity further improve COWO by equivalent...

In this paper, we investigate the achievable uplink spectral efficiency (SE) and its approximate analytical expression in massive multi-input multi-output (MIMO) systems, using finite precision analog-digital converters (ADCs) zeroforcing (ZF) technique at receivers. To analyze system performance, adopt additive quantization noise model, where is treated as an independent noise. Analytical results show that SE related to transmitted power of each user, number BS antennas bins. Numerical...

We investigate the achievable ergodic sum-rate of multi-user multiple-input multiple-output systems in Ricean fading channels. first derive a lower bound on average signal-to-leakage-and-noise ratio by utilizing Mullen's inequality, which is then used to analyze effect channel mean information sum-rate. With these results, novel statistical-eigenmode space-division multipleaccess downlink transmission scheme proposed. For this scheme, we an exact closed-form expression for Our results show...

Heterogeneous cloud radio access networks (H-CRANs), proposed to boost both spectral and energy efficiency while reducing the signaling overhead, have been regarded as a promising paradigm for fifth-generation wireless communication systems. To reduce network power consumption, in this paper, we propose joint remote head (RRH) activation outage constrained coordinated beamforming (CoBF) algorithm massive multiple-input multiple-output H-CRANs. Considering imperfect channel state information...

In this paper, we study the distributed cooperative spectrum sensing in heterogeneous cognitive radio networks, where each secondary user (SU) adopts a different algorithm and experience channel environment. To solve problem, propose fusion rule based on dynamic grouping, which can be used mobility of primary SUs. By introducing grouping parameter, proposed realize The SUs group-1 will not able to participate cooperation, groups-2 groups-3 have weighting factors. is only required process...

Low cost and high efficiency, defined as energy efficiency (EE) spectral (SE), have raised more attention in the fifth generation (5G) communication systems due to steadily rising hardware cost, consumption, mobile traffic. This paper studies hybrid architecture of multiuser massive MIMO systems, where digital domain utilizes zero‐forcing (ZF) precoding scheme analog uses discrete Fourier transform (DFT) processing that significantly reduces consumption. We derive analytical expressions on...

In this paper, we study the hybrid beamforming for wideband mmWave MIMO-OFDM system with observation of beam squint. Firstly, present squint effect in system. We further characterize channel from Saleh-Valenzuela model. Secondly, full-connected architecture, seek optimal precoder system, which aims to maximize spectral efficiency. The design problem is formulated as matrix factorization paper. To find precoder, precoding (WHP) algorithm proposed by using manifold optimization. Finally,...

In order to achieve accurate interference detection in complex electromagnetic environments, a two-step cooperative stochastic resonance energy (TCSRED) algorithm is proposed address the problem, where traditional (ED) performance susceptible noise uncertainty. By combining two thresholds and cooperation, generalized applied detection, which effectively reduces complexity time. particular, when certain decision result obtained first step of finished second unnecessary. Otherwise, performed...