scholarly journals Channel Measurement for Multiple Frequency Bands in Subway Tunnel Scenario

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Zhuomin Hu ◽  
Wenli Ji ◽  
Hengkai Zhao ◽  
Xuping Zhai ◽  
Asad Saleem ◽  
...  
Keyword(s):  
Antenna Array ◽  
Communication Systems ◽  
Mimo Systems ◽  
Network Capacity ◽  
Mimo Channel ◽  
Center Frequency ◽  
Delay Spread ◽  
Channel Measurements ◽  
Subway Tunnel ◽  
Frequency Bands

In next-generation radio communication systems, the use of higher frequency bands and the massive multiple-input-multiple-output (MIMO) systems has turned into hot research topics because they have the potential to increase network capacity significantly by exploiting the available narrowband and broadband spectrums. Therefore, the narrowband channel measurements are executed at the following five potential frequency bands, including 2.6 GHz, 3.5 GHz, 5.6 GHz, 10 GHz, and 28 GHz in the Shanghai subway tunnel environment in order to fulfill the latest standards of fifth generation (5G). Moreover, in the broadband channel measurements, the center frequency is 3.5 GHz and 5.6 GHz and the bandwidth is considered as 160 MHz, respectively. At the transmitter (Tx) side, a uniform rectangular antenna array composed of 32 elements is fixed on the platform near the tunnel walls. The receiver (Rx) is equipped with a uniform cylindrical antenna array consisting of 64 elements, which is set on a trolley along the track. Based on the acquired massive MIMO channel impulse responses, delay spread, angle spread, eigenvalue and channel capacity are analyzed. The results reveal that the multipath delay in the tunnel scenario is quite short, the delay spread and angle spread drop rapidly as the distance between Tx and Rx increases and the channel matrix gradually becomes serious. This research provides a reference for the deployment of future 5G systems in the subway tunnel.

scholarly journals RMS Delay Spread vs. Coherence Bandwidth from 5G Indoor Radio Channel Measurements at 3.5 GHz Band

Sensors ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 750 ◽  
Author(s):  
Wout Debaenst ◽  
Arne Feys ◽  
Iñigo Cuiñas ◽  
Manuel García Sánchez ◽  
Jo Verhaevert
Keyword(s):  
Ray Tracing ◽  
Communication Systems ◽  
Radio Channel ◽  
Measurement Data ◽  
Center Frequency ◽  
Fourth Generation ◽  
Delay Spread ◽  
Indoor Environments ◽  
Channel Measurements ◽  
Rms Delay Spread

Our society has become fully submersed in fourth generation (4G) technologies, setting constant connectivity as the norm. Together with self-driving cars, augmented reality, and upcoming technologies, the new generation of Internet of Things (IoT) devices is pushing the development of fifth generation (5G) communication systems. In 5G architecture, increased capacity, improved data rate, and decreased latency are the objectives. In this paper, a measurement campaign is proposed; we focused on studying the propagation properties of microwaves at a center frequency of 3.5 GHz, commonly used in 5G cellular networks. Wideband measurement data were gathered at various indoor environments with different dimensions and characteristics. A ray-tracing analysis showed that the power spectrum is dominated by the line of sight component together with reflections on two sidewalls, indicating the practical applicability of our results. Two wideband parameters, root mean square delay spread and coherence bandwidth, were estimated for the considered scenarios, and we found that they are highly dependent on the physical dimension of the environment rather than on furniture present in the room. The relationship between both parameters was also investigated to provide support to network planners when obtaining the bandwidth from the delay spread, easily computed by a ray-tracing tool.

scholarly journals Tripolarizated MIMO: Experimental Analysis and Modeling of Channel Properties in Both Indoor and Outdoor Scenarios

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Pan Tang ◽  
Jianhua Zhang ◽  
Zuolong Ying ◽  
Yuxiang Zhang ◽  
Lei Tian ◽  
...  
Keyword(s):  
Communication Systems ◽  
Large Scale ◽  
Mimo Systems ◽  
Mimo System ◽  
High Capacity ◽  
Small Scale ◽  
Delay Spread ◽  
Channel Measurements ◽  
Channel Properties ◽  
Indoor And Outdoor

The tripolarized MIMO system can provide one more degree of freedom and have a more compacted size over a dual-polarized MIMO system, which is attractive for high-capacity wireless communication systems. In this paper, we analyze and model channel properties for tripolarized MIMO systems based on experimental channel measurements in typical indoor and outdoor scenarios. Firstly, channel measurement campaigns in the laboratory and the Urban Micro (UMi) scenarios on sub-6 GHz bands are presented. Then, based on measured data, path loss, delay spread (DS), and cross-polarization discrimination (XPD) for 9 polarization combinations are analyzed and modeled in a statistical way. Statistical results of these channel properties are also given. It is observed that channel properties of both large-scale fading and small-scale fading depend strongly on the polarization direction. Furthermore, we evaluate the performance of tripolarized MIMO systems by analyzing the Demmel condition number and channel capacity gain (CG). For both the indoor and the outdoor scenarios, it is found that colocated tripolarized antenna can bring a nearly threefold CG with respect to the unipolarized one. These results can give good insights into the design and evaluation of tripolarized MIMO systems.

scholarly journals Effects of Narrow Beam Phased Antenna Arrays over the Radio Channel Metrics, Doppler Power Spectrum, and Coherence Time, in a Context of 5G Frequency Bands

2021 ◽  
Vol 11 (21) ◽  
pp. 10081
Author(s):  
Brian J. Sánchez ◽  
David H. Covarrubias ◽  
Leonardo F. Yepes ◽  
Marco A. Panduro ◽  
Elizvan Juárez
Keyword(s):  
Power Spectrum ◽  
Antenna Array ◽  
Antenna Arrays ◽  
Communication Systems ◽  
Radio Channel ◽  
Coherence Time ◽  
Narrow Beam ◽  
Frequency Bands ◽  
Phased Antenna Array ◽  
Doppler Power

With the arrival of 5G wireless communication systems, there has been increased interest in exploring higher frequency bands above 6 GHz, up to millimeter-wave frequencies. Radio wave propagation at these higher frequencies can suffer from substantial Doppler impairments. The linear dependency of Doppler shifts with carrier frequencies make them challenging to use in high-mobility 5G cellular scenarios. Therefore, the Doppler power spectrum (DPS) characteristics and radio channel coherence time (CT) of the received signals are of great importance for 5G wireless systems. In this way, this paper presents the effects of a narrow beam phased antenna array in reducing the DPS (due to user movement) and, simultaneously, increasing the coherence time (CT). Functional and complete descriptive assessments of beamwidths versus the DPS and CT, through different elements and geometries of the phased antenna array, are analyzed. Moreover, in terms of CT and the DPS, better performance on the 5G cellular scenarios was obtained.

scholarly journals Ray-Based Statistical Propagation Modeling for Indoor Corridor Scenarios at 15 GHz

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Qi Wang ◽  
Bo Ai ◽  
Ke Guan ◽  
David W. Matolak ◽  
Ruisi He ◽  
...  
Keyword(s):  
Communication Systems ◽  
Channel Model ◽  
Deterministic Model ◽  
Path Loss ◽  
Propagation Characteristic ◽  
Directional Antennas ◽  
Small Scale ◽  
Delay Spread ◽  
Channel Measurements ◽  
The Impact

According to the demands for fifth-generation (5G) communication systems, high frequency bands (above 6 GHz) need to be adopted to provide additional spectrum. This paper investigates the characteristics of indoor corridor channels at 15 GHz. Channel measurements with a vector network analyzer in two corridors were conducted. Based on a ray-optical approach, a deterministic channel model covering both antenna and propagation characteristic is presented. The channel model is evaluated by comparing simulated results of received power and root mean square delay spread with the corresponding measurements. By removing the impact of directional antennas from the transmitter and receiver, a path loss model as well as small-scale fading properties for typical corridors is presented based on the generated samples from the deterministic model. Results show that the standard deviation of path loss variation is related to the Tx height, and placing the Tx closer to the ceiling leads to a smaller fluctuation of path loss.

scholarly journals Massive MIMO Channel Models: A Survey

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Kan Zheng ◽  
Suling Ou ◽  
Xuefeng Yin
Keyword(s):  
Wireless Communication ◽  
Antenna Array ◽  
Communication Networks ◽  
Massive Mimo ◽  
Communication Systems ◽  
Channel Model ◽  
Spectrum Efficiency ◽  
Mimo Channel ◽  
Wireless Communication Networks ◽  
Channel Models

The exponential traffic growth of wireless communication networks gives rise to both the insufficient network capacity and excessive carbon emissions. Massive multiple-input multiple-output (MIMO) can improve the spectrum efficiency (SE) together with the energy efficiency (EE) and has been regarded as a promising technique for the next generation wireless communication networks. Channel model reflects the propagation characteristics of signals in radio environments and is very essential for evaluating the performances of wireless communication systems. The purpose of this paper is to investigate the state of the art in channel models of massive MIMO. First, the antenna array configurations are presented and classified, which directly affect the channel models and system performance. Then, measurement results are given in order to reflect the main properties of massive MIMO channels. Based on these properties, the channel models of massive MIMO are studied with different antenna array configurations, which can be used for both theoretical analysis and practical evaluation.

scholarly journals Hybrid Beamforming Analysis Based on MIMO Channel Measurements at 28 GHz

2020 ◽  
Author(s):  
Joerg Eisenbeis ◽  
Magnus Tingulstad ◽  
Nicolai Kern ◽  
Zsolt Kollár ◽  
Jerzy Kowalewski ◽  
...  
Keyword(s):  
Communication Systems ◽  
Channel Model ◽  
Multiple Input Multiple Output ◽  
Wireless Channel ◽  
Mimo Channel ◽  
Channel Measurements ◽  
Electromagnetic Propagation ◽  
Channel Models ◽  
Input Multiple Output ◽  
Hybrid Beamforming

<div>Hybrid beamforming systems represent an efficient</div><div>architectural solution to realize massive multiple-input multiple-output (MIMO) communication systems in the centimeter wave (cmW) and millimeter wave (mmW) region. These hybrid beamforming systems separate the beamforming process into a digital and analog beamforming network. The analog beamforming networks can be realized by different architectural solutions, which demand dedicated algorithms to determine the complex weighting factors in the digital and analog domain. To date, novel hybrid beamforming architectures and algorithms are solely compared in numerical simulations based on statistical channel models. These abstract channel models simplify the complicated electromagnetic propagation process, thereby not exactly reconstructing the wireless channel. Within this work, we present a measurement-based evaluation of hybrid beamforming algorithms and compare them with numerical results gained from a statistical path-based MIMO channel model. The results show that by adjustment of the channel model parameter the simulation achieves a good match with the measured maximum achievable spectral efficiencies.</div>

scholarly journals Enhancing the Capacity of the Indoor 60 GHz Band Via Modified Indoor Environments Using Ring Frequency Selective Surface Wallpapers and Path Loss Models

2018 ◽  
Vol 8 (5) ◽  
pp. 3003
Author(s):  
Nidal Qasem
Keyword(s):  
Communication Systems ◽  
Mimo Systems ◽  
Path Loss ◽  
Propagation Path ◽  
Delay Spread ◽  
Indoor Environments ◽  
60 Ghz ◽  
Loss Models ◽  
Frequency Selective ◽  
Ring Frequency

<span>The 60 GHz band has been selected for short-range communication systems to meet consumers’ needs for high data rates. However, this frequency is attenuated by obstacles. This study addresses the limitations of the 60 GHz band by modifying indoor environments with ring Frequency Selective Surfaces (FSSs) wallpaper, thereby increasing its utilization. The ring FSS wallpaper response at a 61.5 GHz frequency has been analyzed using both MATLAB and Computer Simulation Technology (CST) Microwave Studio (MWS) software. ‘Wireless InSite’ is also used to demonstrate enhanced wave propagation in a building modified with ring FSSs wallpaper. The demonstration is applied to Single Input Single Output (SISO) and Multiple Input Multiple Output (MIMO) systems to verify the effectiveness of FSSs on such systems’ capacity. The effectiveness of the suggested modification over delay spread has been studied for the MIMO scenario, as well as the effect of the human body on capacity. Simulation results presented here show that modifying a building using ring FSS wallpaper is an attractive scheme for significantly improving the indoor 60 GHz wireless communications band. This paper also presents and compares two large-scale indoor propagation Path Loss Models (PLMs), the Close-In (CI) free space reference distance model and the Floating Intercept (FI) model. Data obtained from ‘Wireless InSite’ over distances ranging from 4 to 14.31 m is analyzed. Results show that the CI model provides good estimation and exhibits stable behavior over frequencies and distances, with a solid physical basis and less computational complexity when compared to the FI model. </span>

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