scholarly journals THE ANALYSIS OF PHYSICAL PROPERTIES OF THE ULTRA-WIDEBAND CHANNEL MODEL IN COMMUNICATION AT SHORT DISTANCES

2012 ◽  
Vol 15 (3) ◽  
pp. 17-26
Author(s):  
Nhan Chi Nguyen ◽  
Nghia Hoai Duong ◽  
Anh Van Dinh
Keyword(s):  
Physical Properties ◽  
Channel Coding ◽  
Communication Systems ◽  
Channel Model ◽  
Ultra Wideband ◽  
Signal Attenuation ◽  
Analysis And Design ◽  
Pulse Distortion ◽  
Key Features ◽  
Uwb Channel

Accurately modeling the channel is extremely important for the design of communication systems. Knowledge of the key features of the channel provides the designers with the ability to predict performance of the system for specific modulation, channel coding, and signal processing. In this paper, we will present the analysis of physical properties of the UWB channel model and propose an UWB channel model for short distance wireless communications (with a comparison to the IEEE 802.15.3a channel model). Through the analysis and design, conclusions related to the UWB channel model were drawn as follows: there are reflection, diffraction, multipath transmission, and signal attenuation with distance and frequency but there is no pulse distortion.

scholarly journals An Overview of Signal Processing Techniques for Terahertz Communications

2020 ◽  
Author(s):  
Hadi Sarieddeen ◽  
Mohamed-Slim Alouini ◽  
Tareq Y. Al-Naffouri
Keyword(s):  
Signal Processing ◽  
Channel Coding ◽  
Communication Systems ◽  
Channel Model ◽  
Mimo Systems ◽  
Future Generation ◽  
Data Detection ◽  
Wide Range ◽  
Processing Techniques ◽  
Signal Processing Techniques

Terahertz (THz)-band communications are a key enabler for future-generation wireless communication systems that promise to integrate a wide range of data-demanding applications. Recent advancements in photonic, electronic, and plasmonic technologies are closing the gap in THz transceiver design. Consequently, prospect THz signal generation, modulation, and radiation methods are converging, and the corresponding channel model, noise, and hardware-impairment notions are emerging. Such progress paves the way for well-grounded research into THz-specific signal processing techniques for wireless communications. This tutorial overviews these techniques with an emphasis on ultra-massive multiple-input multiple-output (UM-MIMO) systems and reconfigurable intelligent surfaces, which are vital to overcoming the distance problem at very high frequencies. We focus on the classical problems of waveform design and modulation, beamforming and precoding, index modulation, channel estimation, channel coding, and data detection. We also motivate signal processing techniques for THz sensing and localization.

scholarly journals On the Error Performance of Coding and Equalization in Low-Complexity Ultra-Wideband Communication Systems

2017 ◽  
Vol 2 (3) ◽  
pp. 245
Author(s):  
Robert H. Morelos-Zaragoza
Keyword(s):  
Channel Coding ◽  
Communication Systems ◽  
Convolutional Code ◽  
Ldpc Code ◽  
Similar Rate ◽  
Decision Feedback ◽  
Ultra Wideband ◽  
Indoor Environments ◽  
Error Performance ◽  
Coding Schemes

In this paper, the performance of various channel coding schemes is investigated in pulse-based ultra-wideband(UWB) communication systems for applications in short-range indoor environments. Pulse-based binary (BPSK) modulation and decision-feedback equalization (DFE) is considered. Concatenated adaptive equalization and coding is explored as an alternative to the more complex and often impractical joint coding and equalization. A block length of approximately 1000 bits is considered in this paper as it results in a static channel with minimal latency while still yielding relatively good error performance. The error performance of a previously proposed turbo product code (TPC), based on two identical Hamming (31,26) codes, is simulated and compared with that of otherchannel coding schemes of similar rate and code length. These include a regular LDPC (1057,813) code, a memory-6 rate-3/4 punctured convolutional code, a Reed-Solomon (127,89) code and a concatenated (off-the-shelf) code with a Reed-Solomon (255,239) outer code and a memory-6 rate-3/4 punctured convolutional inner code. The inclusion of the concatenated Reed-Solomon scheme serves as a reference, as this is an off-the-shelf classical and still popular solution. The simulation results show that, among the coding schemes considered, the LDPC code offers the best error performance.

scholarly journals An Overview of Signal Processing Techniques for Terahertz Communications

2020 ◽  
Author(s):  
Hadi Sarieddeen ◽  
Mohamed-Slim Alouini ◽  
Tareq Y. Al-Naffouri
Keyword(s):  
Signal Processing ◽  
Channel Coding ◽  
Communication Systems ◽  
Channel Model ◽  
Mimo Systems ◽  
Future Generation ◽  
Data Detection ◽  
Wide Range ◽  
Processing Techniques ◽  
Signal Processing Techniques

Terahertz (THz)-band communications are a key enabler for future-generation wireless communication systems that promise to integrate a wide range of data-demanding applications. Recent advancements in photonic, electronic, and plasmonic technologies are closing the gap in THz transceiver design. Consequently, prospect THz signal generation, modulation, and radiation methods are converging, and the corresponding channel model, noise, and hardware-impairment notions are emerging. Such progress paves the way for well-grounded research into THz-specific signal processing techniques for wireless communications. This tutorial overviews these techniques with an emphasis on ultra-massive multiple-input multiple-output (UM-MIMO) systems and reconfigurable intelligent surfaces, which are vital to overcoming the distance problem at very high frequencies. We focus on the classical problems of waveform design and modulation, beamforming and precoding, index modulation, channel estimation, channel coding, and data detection. We also motivate signal processing techniques for THz sensing and localization.

scholarly journals Spatial characterization of propagation channels for terahertz band

2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Bilal Aghoutane ◽  
Mohammed El Ghzaoui ◽  
Hanan El Faylali
Keyword(s):  
Communication Systems ◽  
Indoor Environment ◽  
Channel Model ◽  
Path Loss ◽  
Propagation Loss ◽  
Terahertz Band ◽  
Indoor Scenarios ◽  
Transmission Windows ◽  
Sv Channel

AbstractThe aim of this work consists in characterizing the Terahertz (THz) propagation channel in an indoor environment, in order to propose a channel model for THz bands. We first described a propagation loss model by taking into account the attenuation of the channel as a function of distance and frequency. The impulse response of the channel is then described by a set of rays, characterized by their amplitude, their delay and their phase. Apart from the frequency selective nature, path loss in THz band is also an others issue associated with THz communication systems. This work based on the conventional Saleh-Valenzuela (SV) model which is intended for indoor scenarios. In this paper, we have introduced random variables as Line of sight (LOS) component, and then merging it with the SV channel model to adopt it to the THz context. From simulation, we noted an important effect when the distance between the transmitter and the receiver change. This effect produces variations in frequency loss. The simulations carried out from this model show that to enhance the performance of THz system it is recommended to transmit information over transmission windows instead over the whole band.

scholarly journals Design of an Ultra-Wideband Microstrip-to-Slotline Transition on Low-Permittivity Substrate

Electronics ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1329
Author(s):  
Jung Seok Lee ◽  
Gwan Hui Lee ◽  
Wahab Mohyuddin ◽  
Hyun Chul Choi ◽  
Kang Wook Kim
Keyword(s):  
Microstrip Line ◽  
Return Loss ◽  
Analytical Formula ◽  
Parameter Tuning ◽  
Ultra Wideband ◽  
Design Parameters ◽  
Analytical Line ◽  
Cross Sectional ◽  
Analysis And Design ◽  
Low Permittivity

Analysis and design of an ultra-wideband microstrip-to-slotline transition on a low permittivity substrate is presented. Cross-sectional structures along the proposed transition are analyzed using conformal mapping assuming quasi-TEM modes, attaining one analytical line impedance formula with varying design parameters. Although the slotline is a non-TEM transmission line, the transitional structures are configured to have quasi-TEM modes before forming into the slotline. The line impedance is optimally tapered using the Klopfenstein taper, and the electric field shapes are smoothly transformed from microstrip line to slotline. The analytical formula is accurate within 5% difference, and the final transition configuration can be designed without parameter tuning. The implemented microstrip-to-slotline transition possesses insertion loss of less than 1.5 dB per transition and return loss of more than 10 dB from 4.4 to over 40 GHz.

scholarly journals Broadband Wireless Channel in Composite High-Speed Railway Scenario: Measurements, Simulation, and Analysis

2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Jianwen Ding ◽  
Lei Zhang ◽  
Jingya Yang ◽  
Bin Sun ◽  
Jiying Huang
Keyword(s):  
Ray Tracing ◽  
Communication Systems ◽  
High Speed ◽  
Channel Model ◽  
High Reliability ◽  
Rapid Development ◽  
Path Loss ◽  
Wireless Channel ◽  
Delay Spread ◽  
High Speed Railway

The rapid development of high-speed railway (HSR) and train-ground communications with high reliability, safety, and capacity promotes the evolution of railway dedicated mobile communication systems from Global System for Mobile Communications-Railway (GSM-R) to Long Term Evolution-Railway (LTE-R). The main challenges for LTE-R network planning are the rapidly time-varying channel and high mobility, because HSR lines consist of a variety of complex terrains, especially the composite scenarios where tunnels, cuttings, and viaducts are connected together within a short distance. Existing researches mainly focus on the path loss and delay spread for the individual HSR scenarios. In this paper, the broadband measurements are performed using a channel sounder at 950 MHz and 2150 MHz in a typical HSR composite scenario. Based on the measurements, the pivotal characteristics are analyzed for path loss exponent, power delay profile, and tap delay line model. Then, the deterministic channel model in which the 3D ray-tracing algorithm is applied in the composite scenario is presented and validated by the measurement data. Based on the ray-tracing simulations, statistical analysis of channel characteristics in delay and Doppler domain is carried out for the HSR composite scenario. The research results can be useful for radio interface design and optimization of LTE-R system.

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