scholarly journals Experimental UWB Propagation Channel Path Loss and Time-Dispersion Characterization in a Laboratory Environment

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Lorenzo Rubio ◽  
Juan Reig ◽  
Herman Fernández ◽  
Vicent M. Rodrigo-Peñarrocha
Keyword(s):  
Communication Systems ◽  
Path Loss ◽  
Propagation Channel ◽  
Dispersion Parameters ◽  
Laboratory Environment ◽  
High Data ◽  
Time Dispersion ◽  
Data Rates ◽  
Successful Design ◽  
Uwb Channel

The knowledge of the propagation channel properties is an important issue for a successful design of ultrawideband (UWB) communication systems enabling high data rates in short-range applications. From an indoor measurement campaign carried out in a typical laboratory environment, this paper analyzes the path loss and time-dispersion properties of the UWB channel. Values of the path loss exponent are derived for the direct path and for a Rake receiver structure, examining the maximum multipath diversity gain when anallRake (ARake) receiver is used. Also, the relationship between time-dispersion parameters and path loss is investigated. The UWB channel transfer function (CTF) was measured in the frequency domain over a channel bandwidth of 7.5 GHz in accordance with the UWB frequency range (3.1–10.6 GHz).

scholarly journals mmWave massive analog relay MIMO

2021 ◽  
Vol 2 (6) ◽  
pp. 43-55
Author(s):  
Kei Sakaguchi ◽  
Takumi Yoneda ◽  
Masashi Iwabuchi ◽  
Tomoki Murakami
Keyword(s):  
Communication Systems ◽  
Vehicular Networks ◽  
Mimo System ◽  
Multiple Input Multiple Output ◽  
Path Loss ◽  
Relay Nodes ◽  
High Data ◽  
Data Rates ◽  
Input Multiple Output ◽  
4G Lte

Millimeter-Wave (mmWave) communications are a key technology to realize ultra-high data rate and ultra-low latency wireless communications. Compared with conventional communication systems in the microwave band such as 4G/LTE, mmWave communications employ a higher frequency band which allows a wider bandwidth and is suitable for large capacity communications. It is expected to be applied to various use cases such as mmWave cellular networks and vehicular networks. However, due to the strong diffraction loss and the path loss in the mmWave band, it is difficult or even impossible to achieve high channel capacity for User Equipment (UE) located in Non-Line-Of-Sight (NLOS) environments. To solve the problem, the deployment of relay nodes has been considered. In this paper, we consider the use of massive analog Relay Stations (RSs) to relay the transmission signals. By relaying the signals by a large number of RSs, an artificial Multiple-Input Multiple-Output (MIMO) propagation environment can be formed, which enables mmWave MIMO communications to the NLOS environment. We describe a theoretical study of a massive relay MIMO system and extend it to include multi-hop relays. Simulations are conducted, and the numerical results show that the proposed system achieves high data rates even in a grid-like urban environment.

scholarly journals Propagation Channel Measurements in the mm- and Sub-mm Wave Range for Different Indoor Communication Scenarios

2021 ◽  
Vol 42 (4) ◽  
pp. 357-370
Author(s):  
M. A. Salhi ◽  
T. Kleine-Ostmann ◽  
T. Schrader
Keyword(s):  
Wireless Communication ◽  
Communication Systems ◽  
Wireless Communication Systems ◽  
Electromagnetic Spectrum ◽  
Channel Measurements ◽  
Frequency Range ◽  
Propagation Channel ◽  
Data Rates ◽  
Indoor Wireless ◽  
Wave Range

AbstractIncreasing data rates in wireless communications are accompanied with the need for new unoccupied and unregulated bandwidth in the electromagnetic spectrum. Higher carrier frequencies in the lower THz frequency range might offer the solution for future indoor wireless communication systems with data rates of 100 Gbit/s and beyond that cannot be located elsewhere. In this review, we discuss propagation channel measurements in an extremely broad frequency range from 50 to 325 GHz in selected indoor communication scenarios including kiosk downloading, office room communication, living rooms, and typical industrial environments.

scholarly journals Underwater Optical Wireless Communications with Chromatic Dispersion and Time Jitter

Computation ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 35 ◽  
Author(s):  
Roumelas ◽  
Nistazakis ◽  
Stassinakis ◽  
Volos ◽  
Tsigopoulos
Keyword(s):  
Wireless Communications ◽  
Communication Systems ◽  
Chromatic Dispersion ◽  
Mathematical Expression ◽  
Optical Wireless ◽  
Optical Wireless Communications ◽  
Time Jitter ◽  
High Data ◽  
Data Rates ◽  
Very High

The obsolete communication systems used in the underwater environment necessitates the development and use of modern telecommunications technologies. One such technology is the optical wireless communications, which can provide very high data rates, almost infinite bandwidth and very high transmission speed for real time fast and secure underwater links. However, the composition and the optical density of seawater hinder the communication between transmitter and receiver, while many significant effects strongly mitigate the underwater optical wireless communication (UOWC) systems’ performance. In this work, the influences of chromatic dispersion and time jitter are investigated. Chromatic dispersion causes the temporal broadening or narrowing of the pulse, while time jitter complicates the detection process at the receiver. Thus, the broadening of the optical pulse due to chromatic dispersion is studied and the influence of the initial chirp is examined. Moreover, the effect of the time jitter is also taken into consideration and for the first time, to the best of our knowledge, a mathematical expression for the probability of fade is extracted, taking into account the influence of both of the above-mentioned effects for a UOWC system. Finally, the appropriate numerical results are presented.

scholarly journals High efficiency Doherty power amplifier based on asymmetrical matching network

2021 ◽  
Vol 23 (2) ◽  
pp. 910
Author(s):  
Mussa Mabrok ◽  
Zahriladha Zakaria ◽  
Tole Sutikno
Keyword(s):  
Output Power ◽  
Power Amplifier ◽  
Communication Systems ◽  
High Efficiency ◽  
Design Strategy ◽  
Matching Network ◽  
High Data ◽  
Fifth Generation ◽  
Data Rates ◽  
Doherty Power Amplifier

Doherty power amplifier (DPA) with high efficiency at the output power back off is highly demanded for modern wireless communication systems to achieve high data rates and reduce the power consumption and operation costs. This paper presents a new design strategy for enhancing DPA’s back-off efficiency. New design strategy called asymmetrical matching network is used to achieve asymmetric operation, which helps to compensate for the low power delivered by the peaking stage in the conventional DPA. The simulation results showed an enhancement in the back-off efficiency, where the proposed design is able toachieve 46-52% drain efficiency at 8 dB output power back-off while maintains high efficiency of 73-80 % at saturation over the designed bandwidth of 3.4-3.6 GHz. The proposed design is suitable for high efficiency sub-6 GHz fifth-generation wireless applications.<br /><div> </div>

scholarly journals A Road towards 6G Communication—A Review of 5G Antennas, Arrays, and Wearable Devices

Electronics ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 169
Author(s):  
Muhammad Ikram ◽  
Kamel Sultan ◽  
Muhammad Faisal Lateef ◽  
Abdulrahman S. M. Alqadami
Keyword(s):  
Communication Systems ◽  
Wearable Devices ◽  
Next Generation ◽  
High Data ◽  
Wearable Antennas ◽  
Cellular Environment ◽  
Data Rates ◽  
Communication Devices ◽  
Key Features ◽  
Smart Traffic

Next-generation communication systems and wearable technologies aim to achieve high data rates, low energy consumption, and massive connections because of the extensive increase in the number of Internet-of-Things (IoT) and wearable devices. These devices will be employed for many services such as cellular, environment monitoring, telemedicine, biomedical, and smart traffic, etc. Therefore, it is challenging for the current communication devices to accommodate such a high number of services. This article summarizes the motivation and potential of the 6G communication system and discusses its key features. Afterward, the current state-of-the-art of 5G antenna technology, which includes existing 5G antennas and arrays and 5G wearable antennas, are summarized. The article also described the useful methods and techniques of exiting antenna design works that could mitigate the challenges and concerns of the emerging 5G and 6G applications. The key features and requirements of the wearable antennas for next-generation technology are also presented at the end of the paper.

Path-loss and time dispersion parameters for indoor UWB propagation

2006 ◽  
Vol 5 (3) ◽  
pp. 550-559 ◽  
Author(s):  
A. Muqaibel ◽  
A. Safaai-Jazi ◽  
A. Attiya ◽  
B. Woerner ◽  
S. Riad
Keyword(s):  
Path Loss ◽  
Dispersion Parameters ◽  
Time Dispersion

scholarly journals Wideband Channel Characterization for 6G Networks in Industrial Environments

Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 2015
Author(s):  
Ahmed Al-Saman ◽  
Marshed Mohamed ◽  
Michael Cheffena ◽  
Arild Moldsvor
Keyword(s):  
Radio Channel ◽  
Path Loss ◽  
Data Rate ◽  
Delay Spread ◽  
Channel Measurements ◽  
Data Traffic ◽  
Dispersion Parameters ◽  
Time Dispersion ◽  
K Factor ◽  
Industrial Environments

Wireless data traffic has increased significantly due to the rapid growth of smart terminals and evolving real-time technologies. With the dramatic growth of data traffic, the existing cellular networks including Fifth-Generation (5G) networks cannot fully meet the increasingly rising data rate requirements. The Sixth-Generation (6G) mobile network is expected to achieve the high data rate requirements of new transmission technologies and spectrum. This paper presents the radio channel measurements to study the channel characteristics of 6G networks in the 107–109 GHz band in three different industrial environments. The path loss, K-factor, and time dispersion parameters are investigated. Two popular path loss models for indoor environments, the close-in free space reference distance (CI) and floating intercept (FI), are used to examine the path loss. The mean excess delay (MED) and root mean squared delay spread (RMSDS) are used to investigate the time dispersion of the channel. The path loss results show that the CI and FI models fit the measured data well in all industrial settings with a path loss exponent (PLE) of 1.6–2. The results of the K-factor show that the high value in industrial environments at the sub-6 GHz band still holds well in our measured environments at a high frequency band above 100 GHz. For the time dispersion parameters, it is found that most of the received signal energy falls in the early delay bins. This work represents a first step to establish the feasibility of using 6G networks operating above 100 GHz for industrial applications.

scholarly journals Hard-Decision Coded Modulation for High-Throughput Short-Reach Optical Interconnect

Entropy ◽  
2020 ◽  
Vol 22 (4) ◽  
pp. 400
Author(s):  
Bin Chen ◽  
Yi Lei ◽  
Gabriele Liga ◽  
Chigo Okonkwo ◽  
Alex Alvarado
Keyword(s):  
Communication Systems ◽  
Forward Error Correction ◽  
Additive White Gaussian Noise ◽  
Coded Modulation ◽  
Fiber System ◽  
Modulation Formats ◽  
High Data ◽  
Data Rates ◽  
Forward Error ◽  
Hard Decision

Coded modulation (CM), a combination of forward error correction (FEC) and high order modulation formats, has become a key part of modern optical communication systems. Designing CM schemes with strict complexity requirements for optical communications (e.g., data center interconnects) is still challenging mainly because of the expected low latency, low overhead, and the stringent high data rate requirements. In this paper, we propose a CM scheme with bit-wise hard-decision FEC and geometric shaping. In particular, we propose to combine the recently introduced soft-aided bit-marking decoding algorithm for staircase codes (SCCs) with geometrically-shaped constellations. The main goal of this CM scheme is to jointly boost the coding gain and provide shaping gain, while keeping the complexity low. When compared to existing CM systems based on M-ary quadrature-amplitude modulation (MQAM, M = 64 , 128 , 256 ) and conventional decoding of SCCs, the proposed scheme shows improvements of up to 0 . 83 dB at a bit-error rate of 10 - 6 in the additive white Gaussian noise channel. For a nonlinear optical fiber system, simulation results show up to 24 % reach increase. In addition, the proposed CM scheme enables rate adaptivity in single-wavelength systems, offering six different data rates between 450 Gbit/s and 666 Gbit/s.

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