Hoyt Fading Channels Research Articles

Performance Analysis of MRC Diversity Reception Over Double Hoyt Fading Channels

Performance Analysis of MRC Diversity Reception Over Double Hoyt Fading Channels

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.

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

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.

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.

Error exponents analysis of dual‐hop η ‐ μ and κ ‐ μ fading channel with amplify‐and‐forward relaying

In this study, the authors investigate the Gallager's error exponents of dual-hop amplify-and-forward systems over generalised η-μ and κ-μ fading channels, two versatile channel models which encompass a number of popular fading channels such as Rayleigh, Rician, Nakagami-m, Hoyt and one-sided Gaussian fading channels. The authors present new analytical expressions for the probability density function of the end-to-end signal-to-noise-ratio (SNR) of the system. These analytical expressions are then applied to analyse the system performance through the study of Gallager's exponents, which are classical tight bounds of error exponents and present the tradeoff between practical information rate and the reliability of communication. Two types of Gallager's exponents, namely, random coding error exponent and expurgated error exponent, are studied. Based on the newly derived analytical expressions, the authors provide an efficient method to compute the required codeword length to achieve a predefined upper bound of error probability. In addition, the analytical expressions are derived for the cutoff rate and ergodic capacity of the system. Moreover, simplified expressions are presented at the high SNR regime. All the analytical results are verified via Monte–Carlo simulations.

Asymptotic Error Probability Analysis of M-ary Modulation Schemes in Hoyt Fading Channels

This paper derives simple asymptotic closed-form formulas for the average error probabilities of various M-ary modulation schemes (i.e., M-ary differentially coherent phase shift-keying (DPSK) signals, noncoherent correlated binary (NCB) signals, M-ary coherent phase shift-keying (PSK) signals, and M-ary square quadrature amplitude modulation (QAM)), especially in Hoyt (or Nakagami-q) fading channels, since the formula can be effectively used to study the asymptotically achievable error performance. The derived expressions for the representative modulation schemes are much more concise than the existing conventional formulas, showing the very tightness to the error probability results from the existing exact formulas in the high signal-to-noise ratio (SNR) region. Through the rigorous numerical results, we clearly justify the validity of our derivations and analyses.

Performance of TAS/MRC Wireless Systems Under Hoyt Fading Channels

This paper presents the performance analysis of a wireless system with multiple transmit and receive antennas under Hoyt fading. Receive antennas are assumed to perform Maximal Ratio Combining (MRC), whereas the antenna at the transmit end that maximizes the instantaneous output signal-to-noise ratio (SNR) is selected for transmission. When the number of receive antennas is arbitrary, an exact compact expression is derived for the outage probability. For two receive antennas, closed-form expressions are presented for the ergodic capacity and the average error rates of different modulations, which are given as a finite sum of well known functions. An asymptotic error rate analysis is also performed when the number of receive antennas is arbitrary. It is shown that severe fading conditions do not always degrade wireless systems performance. Actually, our results show that severe fading can be beneficial in terms of channel capacity if the transmit array is large enough due to the antenna selection performed at the transmitter. Monte Carlo simulations have been carried out to validate the derived expressions, showing an excellent agreement with the analytical results.

Gallager's Exponent Analysis of STBC MIMO Systems over η-μ and κ-μ Fading Channels

In this paper, we analytically investigate Gallager's exponent for space-time block codes over multiple-input multiple-output block-fading channels with Gaussian input distribution. As a suitable metric of the fundamental tradeoff between communication reliability and information rate, Gallager's exponent can be used to determine the required codeword length to achieve a prescribed error probability at a given rate below the channel capacity. We assume that the receiver has full channel state information (CSI), while the transmitter has no CSI and performs equal power allocation across all transmit antennas. In the following, novel exact expressions for Gallager's exponent are derived for two well-known channel fading models, namely η-μ and κ-μ fading models. More importantly, the implications of fading parameters and channel coherence time on Gallager's exponent are investigated. In addition, we present new expressions for the Shannon capacity, cutoff rate and expurgated exponent for the above mentioned fading models, while in the high signal-to-noise ratio regime, simplified closed-form expressions are also derived. Finally, we highlight the fact that the presented analysis encompasses all previously known results on Nakagami-m, Rician, Rayleigh and Hoyt fading channels, as special cases.

Performance of L-SC Receiver over Hoyt Fading Channels with Arbitrary and Non-identical Fading Parameters

In [1], we have presented the performance-related expressions for L-selection combining (SC) receiver over Hoyt fading channels, in the form of infinite series. In this presentation, these expressions are simplified using Yacoub’s integral [2], a general solution to which is recently published [3]. The obtained expressions are compact containing Yacoub’s integral and hence are easily computable. Furthermore, the work in [1] is extended to non-identical branch fading parameter case in the remaining of the paper. Expressions for the probability density function of the SC output signal-to-noise ratio and average bit error rate are derived which are also compact and computationally efficient. Both numerical and computer simulation results are plotted and the effect of fading parameters on the performance is studied.