Hoyt Fading Research Articles

Performance Analysis of MRC Diversity Reception Over Double Hoyt Fading Channels

Performance Analysis of MRC Diversity Reception Over Double Hoyt Fading Channels

Average bit error probability performance of intelligent reflecting surface‐aided wireless communications over Hoyt fading

SummaryIn this article, the performance of a wireless communication system with an intelligent reflecting surface (IRS) panel installed between the transmitter and receiver is studied. The channel is considered to be the Hoyt faded and additive white Gaussian noise. Closed‐form expressions for average bit error probability (ABEP) for both coherent Gray‐coded rectangular quadrature amplitude modulation and non‐coherent modulation schemes are presented. We apply the moment‐generating function‐based method for the derivation. In addition, asymptotic ABEP expressions are also obtained. Using asymptotic ABEP expressions, we obtained diversity order which is a function of the number of IRS elements. The effect of the number of IRS elements and fading parameters on the ABEP is studied. The ABEP performance improves with an increase in the number of reflecting elements but degrades with an increase in the fading severity. The accuracy of each analytical ABEP expression is verified by the simulation of the system considered herewith.

Performance Evaluation of DCSS using Two Level 1-Bit Hard Decision Strategies over TWDP Fading Channel

The spectrum sensing method's dependability is greatly influenced by two of the most crucial factors, including various fading channels and nearby wireless users. Multipath fading, buried terminals, and shadowing are just a few of the challenges encountered by users of non-cooperative spectrum sensing systems. Cooperative spectrum sensing approach gives a remedy for this issue. With the use of the common receiver, CSS permits the user to detect the spectrum. Additionally, it has been separated into distributed CSS (D-CSS) and centralized CSS (C-CSS). By using particular rules to identify the presence of the licensed user, both concepts are compared to one another in this article. The effectiveness of cluster-based distributed cooperative spectrum sensing over two-wave diffuse power fading channels (TWDP Channel) is also examined in the article. Wei-bull and Hoyt fading channels are two examples of fading channels that have previously exploited this idea. In this paper, simulation findings for the less well-known two-wave with diffuse power channels are reviewed. This work mainly focused on CSS over TWDP fading channels along with several proposed approach for two stage hard decision strategies using AND fusion and OR fusion. The simulation performance findings for TWDP fading situation enhance the OR_AND fusion strategy detection performance at various SNR levels. The presented D-CSS approach helps users to get beyond the difficulty they have when using non-cooperative spectrum sensing and lists the relationship among detection efficiency and power consumption for Cognitive radio technology used in constrained wireless environments.

Performance analysis of variant MIMO systems over hoyt fading channel

Performance analysis of variant MIMO systems over hoyt fading channel

On the Transmission Probabilities in Quantum Key Distribution Systems Over FSO Links

In this paper, we investigate the transmission probabilities in three cases (depending only on the legitimate receiver, depending only the eavesdropper, and depending on both legitimate receiver and eavesdropper) in quantum key distribution (QKD) systems over free-space optical links. To be more realistic, we consider a generalized pointing error scenario, where the azimuth and elevation pointing error angles caused by stochastic jitters and vibrations in the legitimate receiver platform are independently distributed according to a non-identical normal distribution. Taking these assumptions into account, we derive approximate expressions of transmission probabilities by using the Gaussian quadrature method. To simplify the expressions and get some physical insights, some asymptotic analysis on the transmission probabilities is presented based on asymptotic expression for the generalized Marcum Q-function when the telescope gain at the legitimate receiver approaches to infinity. Moreover, from the asymptotic expression for the generalized Marcum Q-function, the asymptotic outage probability over Beckmann fading channels (a general channel model including Rayleigh, Rice, and Hoyt fading channels) can be also easily derived when the average signal-to-noise ratio is sufficiently large, which shows the diversity order and array gain.

Hardware Impaired Self-Energized Bidirectional Sensor Networks over Complex Fading Channels.

Rapid emergence of wireless sensor networks (WSN) faces significant challenges due to limited battery life capacity of composing sensor nodes. It is substantial to construct efficient techniques to prolong the battery life of the connected sensors in order to derive their full potential in the future Internet of Things (IoT) paradigm. For that purpose, different energy harvesting (EH) schemes are relying on a wide array of sources. Following the same objective, in this work, we have observed a time-switching EH for half-duplex (HD) bidirectional WSN, which performed in-between relaying over Hoyt fading channels. For its comprehensive performance analysis, rapidly converging infinite-series expressions have been provided with focus on the outage probability (OP) and achievable throughput of the hardware-impaired system. Additionally, asymptotic behavior of these performance measures has also been provided. Further, an approach to the symbol-error probability (SEP) analysis is also presented in the context of the observed system. Finally, we consider the shadowing influence along the WSN propagation path. Performance analysis of observed EH system operating over Rician-shadowed fading channels has been carried out, with deriving exact corresponding infinite-series expressions for outage probability (OP) and achievable throughput of the system under the hardware impairment conditions. In addition, bidirectional relaying in a mixed fading environment has been considered.

A Systematic Approach to Deriving the Covariance Matrix of Correlated Nakagami-$m$ Fading Channels

The covariance matrix plays an important role in second-order statistics, enabling numerous signal processing techniques. By exploiting the multivariate moment-generating function (MGF), this paper analytically derives an exact, closed-form joint probability density function (JPDF) of the envelopes of two correlated Nakagami- $m$ channels and their phase difference when $m\geq 1.0$ . By exploiting a common-variance approximation, an approximate, closed-form JPDF is derived for $0.5\leq m because of the in-phase/quadrature-phase (I/Q) imbalance property of Hoyt fading channels. According to the derived JPDFs, the covariance matrix can be calculated in a form consisting of only one definite integral. Simulations are conducted to confirm the analytical results in terms of the covariance matrix and the PDF of the phase difference.

The Rician Complex Envelope Under Line of Sight Shadowing

This letter investigates a Rician complex envelope which is subject to line-of-sight (LOS) shadowing. In particular, exact closed-form expressions are obtained for the joint envelope-phase distribution, the distribution of the phase, and that of the quadrature and in-phase signal components. Using the new formulation for the phase distribution, we find that for increasing shadowing severity, the phase becomes progressively more disperse. Interestingly, the phase is shown to be unimodal. This illustrates that the relationship which is known to exist between the envelope of Rician fading which undergoes LOS shadowing and Hoyt fading does not extend to the phase. We also provide two applications of our new results which investigate the average bit error probability and the average symbol error probability for phase-based modulation schemes operating in LOS shadowed fading channels. The results are shown to provide excellent agreement with Monte Carlo simulations.

Performance analysis of QAM for L-MRC receiver with estimation error over independent Hoyt fading channels

In modern wireless communication, smart receivers are used to overcome the effect of fading and includes the estimation of the channels as a part of its signal processing. From a theoretical point of view these type of receivers offer high grade performance, however from practical point of view the performance depends on the accuracy of the estimation of channels. In real practice, ideal channel estimator is very difficult, which leads to some estimation error in both phase and envelope of the estimated channels information. In this paper, a general expression for average bit error rate (ABER) has been presented for arbitrary branch Maximal Ratio Combining (MRC) while taking an Imperfect Channel Estimation (ICE) into consideration over independent Hoyt fading channels. The expression is formulated for M-ary Quadrature Amplitude Modulation (QAM) scheme. The degradation in the receiver operation due to this error estimation has been analyzed in this paper by numerical evaluation of the obtained expressions. From our analysis we have observed that the envelope estimation error is much critical from the receiver performance point of view.

Moment Generating Function Approach in Diversity Combiner with M-PSK over Hoyt Fading Channel

Wireless communication system is the processing, transmitting and receiving signals over an open space. This system suffers from time varying environment disturbance due to propagation of signals through different paths which prompt the signals to have different statistical distributions. The existing modified diversity combiners diversity such as Maximal Ratio Combiner (MRC), Equal Gain Combiner (EGC) with one Match Filter (MF) and one Radio Frequency (RF) chain, lack closed form expression. Therefore, in this paper, Moment Generating Function (MGF) approach is used to analyse the performance of the modified MRC over Hoyt fading distribution through the closed form expression. A closed formed expression is developed using the existing modified MRC with one Radio Frequency (RF) chain and one Matched Filter (MF) at the RF stage. Binary data of ten thousand bits are generated randomly as source data and modulated with M-ary Phase Shift Keying (M-PSK). The modulated signal is passed through the Hoyt fading channel which is then modeled using Moment Generating Function (MGF) approach in order to generate the resultant signals. The resultant signals at varying paths ‘L’ (2, 3 and 4) and Hoyt fading factors’q’ (0.2, 0.4 and 0.6) are combined using the modified MRC. The output signal is passed through a comparator which compares the output signal with 9.5 dB set as threshold value. The outage probability of the modified MRC using M-PSK (2-PSK and 4-PSK) at varying ‘L’ and ‘q’ is evaluated, while processing time is used to compare the performance of the conventional MRC with the modified MRC. The results obtained with the modified MRC using closed form expression give lower Outage Probability (OP) and processing time. The research can be used by satellite communication system designers to improve the quality of service.

Effect of estimation error on dual MRC receiver over Hoyt fading channels

ABSTRACTThe effect of antenna correlation and the estimation error on the dual maximal ratio combining receiver over Hoyt fading channels has been analysed in this paper. We have derived the expressions of bit error rate and outage probability to observe the quantum of performance degradation due to estimation error along with correlation. From our analysis, we have concluded that the error in envelope estimation degrades the performance of the receiver up to a great extent than the phase estimation error. Since both antenna correlation and estimation error are unavoidable in practical application, the authors feel that the provided results will assist the design engineers to sustain the quality of service in a wireless receiver.

Performance of multihop detect‐and‐forward relaying system over fluctuating two‐ray fading channels

AbstractThe performance of multihop detect‐and‐forward relaying system is analyzed over fluctuating two‐ray fading channels for 28 GHz millimeter wave communications. Exact closed‐form expressions for outage probability and average symbol error rate of various modulation schemes over nonidentically distributed fluctuating two‐ray fading channels have been obtained. The derived expressions are given in terms of the Lauricella hypergeometric functions and . Moreover, the derived expressions also accommodate several others reported results in the literature for two‐wave diffuse power, Rician, Rician shadowed, Nakagami‐m, and Hoyt fading channels. Asymptotic outage probability and average symbol error rate expressions are also derived, which provide useful insights on the factors governing the performance of the considered system. The numerical results have been verified with Monte‐Carlo simulation results.

Hoyt 페이딩 채널에서 MRC 다이버시티 기법이 적용된 MCIK-OFDM 시스템의 오류 확률 성능 분석

Hoyt 페이딩 채널에서 MRC 다이버시티 기법이 적용된 MCIK-OFDM 시스템의 오류 확률 성능 분석

Largest Eigenvalue Distribution of Noncircularly Symmetric Wishart-Type Matrices With Application to Hoyt-Faded MIMO Communications

This paper is concerned with the largest eigenvalue of the Wishart-type random matrix $\mathbf {{W}}=\mathbf {{X}}\mathbf {{X}}^\dagger$ (or $\mathbf {{W}}=\mathbf {{X}}^\dagger \mathbf {{X}}$ ), where $\mathbf {{X}}$ is a complex Gaussian matrix with unequal variances in the real and imaginary parts of its entries, i.e., $\mathbf {X}$ belongs to the noncircularly symmetric Gaussian subclass. By establishing a novel connection with the well-known complex Wishart ensemble, we here derive exact and asymptotic expressions for the largest eigenvalue distribution of $\mathbf {{W}}$ , which provide new insights on the effect of the real-imaginary variance imbalance of the entries of $\mathbf {X}$ . These new results are then leveraged to analyze the outage performance of multiantenna systems with maximal ratio combining subject to Nakagami- $q$ (Hoyt) fading.

Statistical Properties of Double Hoyt Fading With Applications to the Performance Analysis of Wireless Communication Systems

In this paper, we investigate the statistical properties of double Hoyt fading channels, where the overall received signal is determined by the product of two statistically independent but not necessarily identically distributed single Hoyt processes. Finite-range integral expressions are first derived for the probability density function (PDF), cumulative distribution function (CDF), level-crossing rate (LCR), and average duration of fades of the envelope fading process. A closed-form approximate solution is also deduced for the LCR by making use of the Laplace approximation theorem. Applying the derived PDF of the double Hoyt channel, we then provide analytical expressions for the average symbol error probability of both coherent M-ary phase-shift keying and square M-ary quadrature amplitude modulation schemes. It is shown that all the obtained theoretical results include those that are already known for double Rayleigh channels as a special case. In addition, simplified expressions for the Hoyt $\times $ Rayleigh, Rayleigh $\times $ one-sided Gaussian, and double one-sided Gaussian channels are presented. Moreover, the applicableness of the proposed model to measured real-world propagation channels is examined and discussed by comparing the derived CDF and LCR with published measurement data collected in inter-vehicular propagation environments. Numerical and simulation results are also provided to confirm the validity of the derivations.

A closed‐form expression for the coverage of cellular systems under Hoyt (Nakagami‐q) fading

A simple closed-form expression is provided for the coverage probability of cellular systems under Hoyt (Nakagami-q) fading, which models fading scenarios more severe than Rayleigh. The accuracy of the proposed framework is validated through Monte Carlo simulations.

MRC Receiver in Correlated Hoyt Fading Channel with Multiple Modulation Technique

MRC Receiver in Correlated Hoyt Fading Channel with Multiple Modulation Technique

Performance Analysis of Cooperative Spectrum Sensing Network Using Optimization Technique in Different Fading Channels

Spectrum sensing is an important task to find out the spectrum holes in a given radio spectrum. Spectrum sensing performance is improved with the aid of multiple cognitive radios (CRs) in the network and each CR having multiple antennas in different fading channels (Rayleigh, Hoyt and Weibull fading channel). In this paper, we have considered that each CR having multiple antennas and improved energy detector (IED) scheme is used for detection of primary user. Imperfect channel is considered between CRs and fusion center (i.e. in reporting channel) with an error probability rate (r). We have derived the novel expression for missed detection probability (P m ), closed form of expression to find out optimal value of number of CR users (N opt ), closed form of expression and procedure to find an optimal value of normalized threshold value (λ n,opt ), expression for optimal value of arbitrary power of received signal (P opt ) and calculation of minimum value of total error in different fading channels are provided. Performance is evaluated to find out (N opt ), (λ n,opt ), (P opt ) and to calculate minimum error value for various network parameters like SNR, r, λ n and multiple number of antennas (M). It is observed that detection performance is improved by using multiple antennas at each CR. Comparison between conventional energy detector and IED, comparison among Rayleigh, Hoyt and Weibull fading channels also provided for different cases of network parameters.

A New Framework for the Performance Analysis of Wireless Communications Under Hoyt (Nakagami- $q$ ) Fading

We present a novel relationship between the distribution of circular and non-circular complex Gaussian random variables. Specifically, we show that the distribution of the squared norm of a non-circular complex Gaussian random variable, usually referred to as squared Hoyt distribution, can be constructed from a conditional exponential distribution. From this fundamental connection we introduce a new approach, the Hoyt transform method, that allows to analyze the performance of a wireless link under Hoyt (Nakagami-q) fading in a very simple way. We illustrate that many performance metrics for Hoyt fading can be calculated by leveraging well-known results for Rayleigh fading and only performing a finite-range integral. We use this technique to obtain novel results for some information and communication-theoretic metrics in Hoyt fading channels.

Average Secrecy Mutual Information of the Non-Identically Independently Distributed Hoyt Fading Wireless Channels

Average Secrecy Mutual Information of the Non-Identically Independently Distributed Hoyt Fading Wireless Channels