scholarly journals Modeling and Simulation of MIMO Mobile-to-Mobile Wireless Fading Channels

2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
Gholamreza Bakhshi ◽  
Reza Saadat ◽  
Kamal Shahtalebi
Keyword(s):  
Fading Channels ◽  
Communication Systems ◽  
Cross Correlation ◽  
Reference Model ◽  
Simulation Models ◽  
Space Time ◽  
Closed Form Expression ◽  
Scattering Model ◽  
Analysis And Design ◽  
Special Cases

Analysis and design of multielement antenna systems in mobile fading channels require a model for the space-time cross-correlation among the links of the underlying multipleinput multiple-output (MIMO) Mobile-to-Mobile (M-to-M) communication channels. In this paper, we propose the modified geometrical two-ring model, a MIMO channel reference model for M-to-M communication systems. This model is based on the extension of single-bounce two-ring scattering model for flat fading channel under the assumption that the transmitter and the receiver are moving. Assuming single-bounce scattering model in both isotropic and nonisotropic environment, a closed-form expression for the space-time cross-correlation function (CCF) between any two subchannels is derived. The proposed model provides an important framework in M-to-M system design, where includes many existing correlation models as special cases. Also, two realizable statistical simulation models are proposed for simulating both isotropic and nonisotropic reference model. The realizable simulation models are based onSum-of-Sinusoids (SoS)simulation model. Finally, the correctness of the proposed simulation models is shown via different simulation scenarios.

scholarly journals A Review for the Adopted Techniques in Low SNR Communication Systems

2020 ◽  
pp. 40-52
Keyword(s):  
Low Power ◽  
Fading Channels ◽  
Communication Systems ◽  
Noise Power ◽  
Analysis And Design ◽  
Low Snr ◽  
Successful Communication ◽  
Unified Study ◽  
Energy Trade ◽  
Digital Communication Systems

The study and evaluation of digital communication systems in low signal-to-noise power ratio (LSNR) environments is a hot and important topic due to its wide contemporary applications. This review is an attempt to focus on the most distinctive vital parameters required in the analysis and design of such systems. It includes a brief literature survey for many algorithms, techniques, methodologies, and mitigations that have been used to overcome the high noise problem encountered in these systems in order to guarantee reliable communication. Amongst these topics, the study reviews the most widely utilized modulation techniques in LSNR communication systems such as the On-Off Keying (OOK) and binary PSK schemes. The capacity for both AWGN and wireless fading channels is also discussed along with a clarification of the minimum limits in these types of channels. On the other hand, some important and recommended detection and estimation techniques for low power communication systems are briefly covered. This unified study has additionally discussed spectral efficiency and bit energy trade-off within the low-power, and broadband systems, and different limitations are stated clearly. Finally, the survey throughout this paper recommends some significant techniques that can be used in the analysis and design of successful communication systems in LSNR regimes.

scholarly journals Physical-Layer Security Analysis over M-Distributed Fading Channels

Entropy ◽  
2019 ◽  
Vol 21 (10) ◽  
pp. 998 ◽  
Author(s):  
Sheng-Hong Lin ◽  
Rong-Rong Lu ◽  
Xian-Tao Fu ◽  
An-Ling Tong ◽  
Jin-Yuan Wang
Keyword(s):  
Lower Bound ◽  
Closed Form ◽  
Fading Channels ◽  
Physical Layer Security ◽  
Physical Layer ◽  
Exact Expression ◽  
Closed Form Expression ◽  
Secrecy Outage Probability ◽  
Secrecy Capacity ◽  
Special Cases

In this paper, the physical layer security over the M-distributed fading channel is investigated. Initially, an exact expression of secrecy outage probability (SOP) is derived, which has an integral term. To get a closed-form expression, a lower bound of SOP is obtained. After that, the exact expression for the probability of strictly positive secrecy capacity (SPSC) is derived, which is in closed-form. Finally, an exact expression of ergodic secrecy capacity (ESC) is derived, which has two integral terms. To reduce its computational complexity, a closed-from expression for the lower bound of ESC is obtained. As special cases of M-distributed fading channels, the secure performance of the K, exponential, and Gamma-Gamma fading channels are also derived, respectively. Numerical results show that all theoretical results match well with Monte-Carlo simulation results. Specifically, when the average signal-to-noise ratio of main channel is larger than 40 dB, the relative errors for the lower bound of SOP, the probability of SPSC, and the lower bound of ESC are less than 1.936%, 6.753%, and 1.845%, respectively. This indicates that the derived theoretical expressions can be directly used to evaluate system performance without time-consuming simulations. Moreover, the derived results regarding parameters that influence the secrecy performance will enable system designers to quickly determine the optimal available parameter choices when facing different security risks.

scholarly journals Quasi-Orthogonal Space-Time Block Coding Using Polynomial Phase Modulation

2011 ◽  
Vol 2011 ◽  
pp. 1-6
Author(s):  
Omar Granados ◽  
Jean Andrian
Keyword(s):  
Fading Channels ◽  
Phase Modulation ◽  
Communication Systems ◽  
Power Efficiency ◽  
Space Time ◽  
Time Block ◽  
Modulation Formats ◽  
Modulation Format ◽  
Full Diversity ◽  
Polynomial Phase

Recently, polynomial phase modulation (PPM) was shown to be a power- and bandwidth-efficient modulation format. These two characteristics are in high demand nowadays specially in mobile applications, where devices with size, weight, and power (SWaP) constraints are common. In this paper, we propose implementing a full-diversity quasiorthogonal space-time block code (QOSTBC) using polynomial phase signals as modulation format. QOSTBCs along with PPM are used in order to improve the power efficiency of communication systems with four transmit antennas. We obtain the optimal PPM constellations that ensure full diversity and maximize the QOSTBC's minimum coding gain distance. Simulation results show that by using QOSTBCs along with a properly selected PPM constellation, full diversity in flat fading channels and thus low BER at high signal-to-noise ratios (SNR) can be ensured. More importantly, it is also shown that QOSTBCs using PPM achieve a better error performance than those using conventional modulation formats.

scholarly journals Statistical Modeling, Simulation, and Experimental Verification of Wideband Indoor Mobile Radio Channels

2018 ◽  
Vol 2018 ◽  
pp. 1-13
Author(s):  
Yuanyuan Ma ◽  
Bjørn Olav Hogstad ◽  
Matthias Pätzold ◽  
Pedro M. Crespo
Keyword(s):  
Fading Channels ◽  
Experimental Verification ◽  
Communication Systems ◽  
Channel Model ◽  
Reference Model ◽  
Propagation Path ◽  
60 Ghz ◽  
Angle Of Arrival ◽  
Modeling Simulation ◽  
Channel Simulator

This paper focuses on the modeling, simulation, and experimental verification of wideband single-input single-output (SISO) mobile fading channels for indoor propagation environments. The indoor reference channel model is derived from a geometrical rectangle scattering model, which consists of an infinite number of scatterers. It is assumed that the scatterers are exponentially distributed over the two-dimensional (2D) horizontal plane of a rectangular room. Analytical expressions are derived for the probability density function (PDF) of the angle of arrival (AOA), the PDF of the propagation path length, the power delay profile (PDP), and the frequency correlation function (FCF). An efficient sum-of-cisoids (SOC) channel simulator is derived from the nonrealizable reference model by employing the SOC principle. It is shown that the SOC channel simulator approximates closely the reference model with respect to the FCF. The SOC channel simulator enables the performance evaluation of wideband indoor wireless communication systems with reduced realization expenditure. Moreover, the rationality and usefulness of the derived indoor channel model is confirmed by various measurements at 2.4, 5, and 60 GHz.

scholarly journals A Spectrum Sensing Scheme for Partially Polarized Waves over α-μ Generalized Gamma Fading Channels

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Mohamed A. Hankal ◽  
Islam A. Eshrah ◽  
Hazim Tawfik
Keyword(s):  
Fading Channels ◽  
Spectrum Sensing ◽  
Cooperative Spectrum Sensing ◽  
Superior Performance ◽  
Stokes Parameters ◽  
Closed Form Expression ◽  
Polarization Spectrum ◽  
Cluster Technique ◽  
Special Cases ◽  
Wide Range

Schemes for spectrum holes sensing for cognitive radio based on the estimation of the Stokes parameters of monochromatic and quasimonochromatic polarized electromagnetic waves are developed. Statistical information that includes the variations of the polarization state in both cases (present and absent) of Primary User (PU) is accounted for. A detector based on the fluctuation of the Stokes parameters is analyzed, and its performance is compared with that of energy detectors, which use only the scalar amplitude information to sense the PU signal. The cooperative spectrum sensing based on the polarization in which the reporting channels are noisy will be investigated. The cluster technique is proposed to reduce the bit error probability due to channel impairment. A closed-form expression for the polarization detection is derived using α-μ generalized fading model, which provides directly an expression for the special cases of Nakagami-m and Weibull models as well as their derivatives. These expressions are verified using simulation. The results show that the polarization spectrum sensing gives superior performance for a wide range of SNR over the conventional energy detection method.

scholarly journals Capacity ofκ-μShadowed Fading Channels

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Celia García-Corrales ◽  
Francisco J. Cañete ◽  
José F. Paris
Keyword(s):  
Closed Form ◽  
Fading Channels ◽  
Ergodic Capacity ◽  
Closed Form Expression ◽  
Underwater Acoustic Communications ◽  
Form Expression ◽  
Satellite Systems ◽  
Special Cases ◽  
Parameter Variations ◽  
Mobile Satellite

The ergodic capacity of fading channels modeled with aκ-μshadowed distribution is investigated to derive closed-form expressions. Theκ-μshadowed distribution is of particular interest because it contains, as special cases, other classical ones like one-side Gaussian, Rayleigh, Rician, Nakagami-m,κ-μ, and Rician shadowed distributions. The paper discusses the physical meaning of the distribution parameter variations and also their impact on the channel capacity. These results can be used to study the behavior of different channels like the ones in underwater acoustic communications, land mobile satellite systems, body centric communications, and other wireless communication applications. The analytical closed-form expression results are validated with numerical simulations.

scholarly journals Design of Wideband MIMO Car-to-Car Channel Models Based on the Geometrical Street Scattering Model

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Nurilla Avazov ◽  
Matthias Pätzold
Keyword(s):  
Correlation Function ◽  
Communication Systems ◽  
Channel Model ◽  
Reference Model ◽  
Multiple Input Multiple Output ◽  
Measurement Data ◽  
Scattering Model ◽  
Time Frequency ◽  
Comparison Results ◽  
Channel Simulator

We propose a wideband multiple-input multiple-output (MIMO) car-to-car (C2C) channel model based on the geometrical street scattering model. Starting from the geometrical model, a MIMO reference channel model is derived under the assumption of single-bounce scattering in line-of-sight (LOS) and non-LOS (NLOS) propagation environments. The proposed channel model assumes an infinite number of scatterers, which are uniformly distributed in two rectangular areas located on both sides of the street. Analytical solutions are presented for the space-time-frequency cross-correlation function (STF-CCF), the two-dimensional (2D) space CCF, the time-frequency CCF (TF-CCF), the temporal autocorrelation function (ACF), and the frequency correlation function (FCF). An efficient sum-of-cisoids (SOCs) channel simulator is derived from the reference model. It is shown that the temporal ACF and the FCF of the SOC channel simulator fit very well to the corresponding correlation functions of the reference model. To validate the proposed channel model, the mean Doppler shift and the Doppler spread of the reference model have been matched to real-world measurement data. The comparison results demonstrate an excellent agreement between theory and measurements, which confirms the validity of the derived reference model. The proposed geometry-based channel simulator allows us to study the effect of nearby street scatterers on the performance of C2C communication systems.

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