Average Bit Error Rate Research Articles

Bit Error Rate Analysis of Mobile Ad Hoc Networks over η − µ Fading Channels

In this paper the performance analysis of Mobile ad hoc networks (MANETs) is conducted for a differential QPSK (DQPSK) signals with post-detection equal gain combining (EGC) receiver operating over additive white Gaussian noise (AWGN) as well as for slow frequency nonselective η − µ fading channels, in which the diversity branches can have unequal signal-to-noise ratios (SNRs) as well as different severity parameters. The average bit error probability (ABEP) is evaluated using MGF-based approach. The average BER per multi-hop route of MANETs for this communication is studied.

Fully Improved Quadrature Spatial Modulation

In this paper, novel space modulation techniques (SMT), which we called fully improved quadrature spatial modulation (FIQSM) and fully improved quadrature space shift keying (FIQSSK), are presented for multiple-input–multiple-output (MIMO) communication systems. In these techniques, the improved structure that allows the use of an arbitrary number of Tx antennas is implemented. Unlike other SMT schemes, the spectral efficiency (SE) of proposed techniques increases linearly with the increase in the number of Tx antennas and a twofold increase in the number of spatially modulated bits is achieved with the aid of quadrature spatial structure. The bit error rate (BER) performance of the proposed techniques is investigated over Rayleigh fading channels for several MIMO designs. The average BER performances are also obtained analytically with the help of pairwise error probability and union-bound techniques in order to validate the simulation results. In addition, SE values achieved for varying SNR at a BER of $$10^{-3}$$ are obtained for both correlated and uncorrelated Rayleigh channels. In these figures, spatial multiplexing is considered as a benchmark as well as SMTs. As a result, the proposed modulation schemes outperform the benchmarks (e.g., spatial modulation, generalized spatial modulation, quadrature spatial modulation) in terms of BER at different spectral efficiencies. Additionally, the receiver complexity of the FIQSM scheme is equal to the benchmarks at the same spectral efficiency and the receiver complexity of the FIQSSK is lower than the others.

Performance analysis of MRR FSO communication system under Gamma–Gamma​ turbulence channel with pointing error

The performance of modulating retro-reflector (MRR) free space optical (FSO) communication system has been studied before for various atmospheric turbulence conditions. However, the effect of pointing error (PE) on the MRR FSO communication system has not been studied yet. In this work, we investigate the PE impact on the MRR FSO communication system. Specifically, we obtain the probability density function (PDF) of the system in closed form expression regarding Gamma–Gamma turbulence channel and Rayleigh PE. Using this PDF, we derive the statistical characteristics closed form expressions of the received optical signal-to-noise ratio (SNR) including PDF, cumulative distribution function (CDF), moments and moment generating function (MGF). Relying on the obtained analytical results, we derive the system average bit error rate (BER), outage probability, ergodic capacity (EC) and amount of fading (AF) performances in closed forms. The closed form expressions are given in terms of Meijer’s G-function with the exception of obtaining the moments of the received optical SNR and AF in terms of elementary functions. For the given weather, PE and system conditions, we optimize the beam divergence angle to minimize the system average BER. Based on this, we suggest controlling of the beam divergence angle with the transmission distance according to the optimum beam divergence angle to improve the system BER performance. Finally we demonstrate the system performances according to the optimum beam divergence angle.

A Two-Hop mmWave MIMO NR-Relay Nodes to Enhance the Average System Throughput and BER in Outdoor-to-Indoor Environments.

Millimeter-Wave (mmWave) bands are receiving enormous attention in 5G mobile communications, due to the capability to provide a multi-gigabit transmission rate. In this paper, a two-hop architecture for 5G communications with the capacity to support high end-to-end performance due to the use of Relay Nodes (RNs) in mmWave-bands is presented. One of the novelties of the paper is the implementation of Amplify-and-Forward (A&F) and Decode-and-Forward (D&F) RNs along with a mmWave-band transceiver chain (Tx/Rx). In addition, two approaches for channel estimation were implemented at the D&F RN for decoding the backhaul link. One of them assumes complete knowledge of the channel (PCE), and the other one performs the channel estimation through Least Square (LS) estimator. A large number of simulations, using MATLAB and Simulink software, were performed to verify the potential benefits of the proposal two-hop 5G architecture in an outdoor-to-indoor scenario. The main novelty in performing these simulations is the use of signals with 5G features, as DL-SCH transport channel coding, PDSCH generation, and SS Burst generation, which is another of the main contributions of the paper. On the other hand, mmWave transmitter and receiver chains were designed and implemented with off-the shelf components. The simulations show that the two-hop network substantially improves the Key Performance Indicators (KPIs), Bit Error Rate (BER), and Throughput, in the communications between the logical 5G Radio Node (gNodeB), and the New Radio User Equipment (NR-UE). For example, a throughput improvement of 22 Mbps is obtained when a 4 × 4 × 2 MIMO D&F with LS architecture is used versus a SISO D&F with PCE architecture for Signal-to-Noise Ratio (SNR) = 20 dB and 64-QAM signal. This improvement reaches 96 Mbps if a 256-QAM signal is considered. The improvement in BER is 11 dB and 10.5 dB, respectively, for both cases. This work also shows that the obtained results with D&F RNs are better than with A&F RNs. For example, an improvement of 17 Mbps in the use of SISO D&F with LS vs. SISO A&F, for the 64-QAM signal is obtained. Besides, this paper constitutes a first step to the implementation of a mmWave MIMO 5G cooperative network platform.

A Minimum Error Probability NOMA Design

Non-orthogonal multiple access (NOMA) enables massive connectivity and achieves high spectral efficiency. The vast majority of the NOMA literature has adopted the ideal information rate as performance metric assuming perfect successive interference cancellation (SIC) without any error propagation, which, however, may lead to NOMA designs adverse to SIC. In this paper, we take into account imperfect SIC and practical modulation schemes for power-domain NOMA design. To characterize the error propagation, we derive the bit error rates (BERs) of the users for arbitrary-order quadrature amplitude modulation (QAM) schemes. Then, we propose a minimum error probability NOMA (MEP-NOMA) design, minimizing the average BER of the users via power allocation. Considering the complicated error probability expressions of the MEP-NOMA design, we derive lower and upper bounds on the average BER, based on which a simple closed-form power allocation is obtained. We show that the proposed power allocation minimizes both the lower and upper bounds on the average BER for a sufficiently large power budget and provides near-optimal error performance. On this basis, we theoretically prove the superiority of MEP-NOMA over existing OMA and NOMA schemes in terms of error performance. Comprehensive numerical results are provided to verify the accuracy of the error probability analysis of the considered practical NOMA scheme with imperfect SIC and to demonstrate the efficacy of the proposed MEP-NOMA design.

Performance analysis of mid-symbol antenna transition spatial modulation approach over Rician fading channels

The mid-symbol antenna transition (MAT) approach reduces the number of transmitter antennas in spatial modulation (SM) systems. This paper studies the performance of MAT technique over correlated and uncorrelated wireless channels. We focus on the scenario wherein the channel consists of multiple paths with a line of sight component, i.e., Rician fading channel. An accurate closed form for the average bit error rate (ABER) performance of the MAT approach is derived. Traditional SM, generalized SM (GSM), and variable generalized SM (VGSM) approaches are used as benchmarks to evaluate the considered MAT approach. Simulation results validate the accuracy of the derived ABER closed form. Performance enhancements, in terms of ABER, of the MAT approach compared to SM, GSM, and VGSM approaches are affirmed analytically and by simulation results.

Performance analysis of uplink massive spatial modulation MIMO systems in transmit-correlated Rayleigh channels

In this paper, the performance of uplink multiuser massive multiple-input multiple-output (MIMO) system with spatial modulation over transmit-correlated Rayleigh fading channel is investigated, where a large number of antennas are deployed at the base station and linear zero-forcing (ZF) receiveris employed for detection. By taking the transmit correlation and the randomness of shadow fading in to account, the bit error rate (BER) performance of the system is analyzed. According to the performance analysis, an approximated expression of overall average BER of the system is attained. Besides, asymptotic performance is studied and the corresponding BER expression at high signal-to-noise ratio is derived. On this basis, the diversity gain of the system can be obtained for performance evaluation. Simulation results show that the derived theoretical expressions matchthe simulated values well, which verifies the correctness of our analysis.

Adaptive-Slope Squashing-Function-Based ANN for CSI Estimation and Symbol Detection in SFBC-OFDM System

This paper presents an adaptive-slope squashing-function (ASF)-based artificial neural network (ANN) for efficient estimation of smoothly time-varying multipath fading channels, in a $$4 \times 1$$ space-frequency-block-coded orthogonal-frequency-division-multiplexing (SFBC-OFDM) system using 64 subcarriers. The channel-state-information (CSI) estimated at first stage is further used for OFDM information symbol detection (through minimum mean square error criterion-based detection) at second stage. To combat the impact of smoothly time-varying environment, we emphasize on the utilization of ASF-ANN using backpropagation (BP) algorithm for the estimation of channel tap coefficients in frequency domain. The underlying ANN is modeled as feedforward multi-layered perceptron that updates the network weights. The major focus is on the gradient-descent algorithm-based adaptation of the slope of squashing-function (SF) along with other ANN parameters, which enhances the training efficiency of ASF-ANN in terms of the lower mean-squared channel estimation error in comparison with the traditional fixed-slope squashing-function (FSF) ANN technique. Simulation results corresponding to the underlying $$4 \times 1$$ SFBC-OFDM system are presented to depict that ASF-ANN-based approach outperforms the FSF-ANN technique by providing lower bit-error-rate (BER) due to the usage of well-estimated CSI. At 15 dB SNR and fade rate = 0.001, the average BER reduces to $$2.85 \times 10^{ - 4}$$ for the ASF-ANN based approach, due to improved CSI estimation, which accounts for approximately 5% improvement in the detection success rate as compared to the FSF-ANN-based approach.

Joint relay selection and opportunistic physical layer network coding for two-way relay channels

Physical layer network coding can significantly increase the throughput of two-way relay networks. However, fading phenomenon usually causes great asymmetry between two multiple access channels which can drastically degrade the performance of PNC protocol. To handle this issue, we propose an alternative detection method to improve the detection of physical layer network coded signal in multi-relay networks. First, we introduce single node detection to extract a single data from superimposed signal in the multiple access phase of physical layer network coding protocol. Then, we propose a relay selection method based on single node detection (RS-SND) and compare it to conventional relay selection method based on physical network coding (RS-PNC) in terms of average bit error rate for detection of XOR-ed data of the two source nodes. Closed-form expressions are derived for average BER of the proposed scheme and its asymptotic approximation at high signal to noise ratio. It is shown that RS-SND outperforms RS-PNC in Rayleigh fading channels when more than two relays are employed. Finally, we propose a relay selection-opportunistic physical layer network coding (RS-OPNC) method by dynamically selecting between RS-SND and RS-PNC schemes based on channel state information. Simulation results verify that RS-OPNC offers considerable SNR gain over conventional RS-PNC method.

Performance Analysis of a UAV-Assisted RF/FSO Relaying Systems for Internet of Vehicles

The Internet of Vehicles (IoV), as a development and complement of the Internet of Thing, has attracted extensive attention and is expected to play a crucial role in human society with the matured space-air-ground integrated networks (SAGIN). Here, we devote ourselves to establish and investigate a unmanned aerial vehicle (UAV)-assisted radio-frequency (RF)/free space optical (FSO) communication system under the amplified-and-forward protocol with variable gain. More specifically, we assume the RF link follows <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\kappa -\mu $ </tex-math></inline-formula> fading and the FSO link experiences Málaga fading, which can characterize the atmospheric turbulence under weak-to-strong condition excellently. In addition, both the pointing errors impairment and the detection techniques for the FSO link are also taken into account. Novel analytical expressions for the end-to-end system, e.g., the cumulative distribution function, probability density function, and moment generating function, are proposed. By capitalizing on these results, some system metrics of the UAV-assisted relaying system are given with the Meijer’s G function. To providing more insights for this UAV-assisted system for SAGIN, high signal-to-noise approximations of these metrics are also presented. Furthermore, the approximated expressions for the outage probability and average BER are given in presence of nonpointing error effect. Finally, all these analytical results are validated with the Monte Carlo simulations.

BER of Massive MIMO in time-variant channels using multiplexed, superimposed and hybrid channel estimation techniques

Massive MIMO (M-MIMO) is one of the most promising technologies towards fifth generation (5G) wireless systems. M-MIMO use a large number of antennas at the base station (BS) serving multiple user terminals (UTs). Therefore, it presents an exceptional performance in terms of the ergodic capacity and bit error rate (BER) using simpler linear detectors when time-invariant channels (TIC) and perfect channel state information (CSI) are considered. However, impairments introduced by the time-variant channel (TVC) and the imperfect channel estimation limit the M-MIMO performance. In this work, the impairments introduced by the multiplexed pilot estimation (MPE), superimposed pilot estimation (SPE), and hybrid pilot estimation (HPE), using the minimum-mean-square error (MMSE) estimator are analyzed for M-MIMO in TVCs. Furthermore, the system performance is evaluated in terms of the BER for the zero-forcing (ZF) detector. Closed-form expressions and simple lower bounds are derived. The results show that the average BER in TVCs is far from the average BER obtained for TICs. Moreover, MPE and HPE are more susceptible to the impairments of TVCs, and even increasing a considerable number of BS antennas, the BER improvement is negligible in some time-slots. Finally, the BER using SPE outperforms the other estimation techniques.

Performance of mobile networks under composite [formula omitted] fading channels

In this paper, the performance of a mobile wireless communication network operating over the Fisher-Snedecor F composite fading channel is analyzed. Specifically, a multi-antenna base station transmits information to a single-antenna mobile receiver, which employs the maximal-ratio transmission technique to improve the quality of the received signal. The well-known random waypoint mobility model is assumed to characterize the mobility of the receiver. Under this mobility scenario, we derive exact closed-form expressions for the probability density function, cumulative distribution function, and consequently for the Outage Probability (OP), the average Bit Error Rate (BER) for different digital modulation schemes, and the average channel capacity. To shed light into the impact of different channel parameters, simple asymptotic expressions at the high SNR regime are obtained for the OP and average BER. To validate our analytical expressions, the comprehensive Monte-Carlo simulations are conducted under various configurations and both results are in excellent agreement.

Performance of differential phase shift keying maritime laser communication over log-normal distribution turbulence channel

Laser communication is essential part of maritime-terrestrial-air intelligent communication/sensor network. Among them, different modulation formats would play a unique role in specific applications. Based on Rytov theory, we discussed system performance of the maritime laser communication with repeated coding technology in several modulation schemes. The closed-form expression of average bit error rate (BER) from weak to moderate atmospheric turbulence described by log-normal distribution is given. Differential phase shift keying (DPSK) modulation, as a potential solution for future maritime laser communication, has attracted a lot of attention. We analyzed the effects of atmospheric turbulence parameters (visibility, refractive index structure coefficient, non-Kolmogorov spectral power-law exponent, turbulence inner scale) and DPSK system parameters (receiver aperture diameter, repeat time) on average BER in detail. Compared with the aperture-averaging effects, the system BER can be well suppressed through increasing repeat time. This work is anticipated to provide a theoretical reference for maritime laser communication systems.

Performance Analysis in Terms of Bit Error Rate Over Fluctuating Two-Ray (FTR) Fading Channels

The fluctuating two-ray (FTR) channel is currently taken as a suitable small-scale fading model for fifth-generation millimeter-wave communications. This paper analyzes the performance in terms of the average bit error rate (ABER). The expressions of ABER of coherent and non-coherent modulation are evaluated using probability density function over FTR fading channels. Moreover, the behaviors of each modulation schemes are also studied based on the fading parameters. A comparison of the modulation schemes is also presented over FTR fading channels. The evaluated expressions are then verified with expected outcomes and Monte Carlo simulation.

Double Antenna-Transitions Spatial Modulation Performance Evaluation Over Nakagami- m Wireless Fading Channels

Recently, a novel spatial modulation (SM) scheme; termed Mid-symbol Antenna transition (MAT) spatial modulation, was developed to reduce the number of utilized transmitting antennas and improve the average bit error rate (ABER) performance. In this paper, the structure of the original MAT is extended to adapt Double-antenna transitions (DAT) during the symbol's transmission duration. Compared to the mid-symbol antenna-transition (MAT), the DAT scheme allows more reduction in the number of required transmitter antennas (TAs) and more enhancement of ABER performance, while achieving the same spectral efficiency (SE). DAT scheme reduces receiver complexity in comparison with generic SM, generalized SM (GSM), variable generalized SM (VGSM), and MAT schemes. The detailed DAT system design is presented. Furthermore, the theoretical closed-form of the ABER upper bound of the DAT system is quantified. The validity of the derived ABER upper bound is proved by contrasting it with the simulated ABER. Monte-Carlo simulations are utilized to evaluate the ABER of the DAT scheme over nakagami-m fading channels with respect to competing schemes. Furthermore, we study the impact of the spatial correlation on the considered schemes and the impact of varying nakagami-m factor on the performance of the DAT scheme. Our simulations demonstrate that DAT significantly outperforms the aforementioned rival schemes in terms of the average bit error rate (ABER) performance.

Performance analysis of TAS/MRC-based MIMO system over &lt;i&gt;K&lt;/i&gt; fading channels

This paper analyses the system performance such as outage probability and average bit error rate (ABER) of transmit antenna selection (TAS), multiple input multiple output (MIMO) system over K fading channels. The antenna selection is accomplished at the base station for downlink transmission and maximal ratio combining (MRC) is carried out at the receiver. Based on the channel state information (CSI), the best antenna is selected for transmission at the base station (BS). The closed-form expressions have been obtained for outage probability and ABER. The probability density function (PDF)-based approach is used to analyse the performance of the system. Also along with the fading parameter k, the effects of the number of transmitting and receiving antennas on the system performance are studied.

Unified Performance Analysis of Near and Far User in Downlink NOMA System over η - μ Fading Channel

The non-orthogonal multiple access (NOMA) scheme is considered as a frontier technology to cater the requirements of 5G and beyond 5G (B5G) communication systems. To fully exploit the essence of NOMA, it is very important to explore the behavior of NOMA users over the most realistic nonhomogenous fading conditions. In this paper, we derive unified closed-form expressions of the basic performance metrics of the NOMA users. Their performance is evaluated in terms of average bit error rate (ABER), average channel capacity (ACC) and outage probability (OP) over η−μ fading channel. These expressions are in terms of popular functions, such as Meijer G-function and Gauss hypergeometric function, leading to their versatile use in analytical research. Unlike the existing outage probability expressions in terms of Yacoub integral, the derived expressions are easier to implement in software packages like MATLAB. Moreover, we compare the obtained results with a reference system, consisting of genie-aided NOMA system. We interpret that genie-aided performance results provide benchmark bounds for the metrics. Extensive simulations are carried out to validate the derived analytical expressions.

Index Modulation Multiple-Access (IMMA): Efficient Techniques for Downlink Millimeter Waves Outdoor Channel

In this paper, we propose two new multiple-access schemes for downlink transmission based on the combination of orthogonal frequency division multiplexing (OFDM) with index modulation (IM), namely OFDM-IM. In the first proposed technique, namely, Index Modulation Multiple-Access (IMMA), the OFDM subcarriers are divided into multiple sets, and each set is assigned to a specific user, and their data bits are transmitted via the OFDM-IM technique. On the other hand, in the second proposed scheme, an extended version of IMMA is introduced where the different users are arranged into different pairs, and each pair of users shares a block of OFDM subcarriers. The two users of each pair are allocated into different domains: the index domain and the constellation domain. The focus in this paper is on the 28 GHz transmission band as it has been considered for an initial deployment of mm-waves wireless systems due to their relatively lower location within the mm-waves range and are hence characterized by lower attenuation. The fluctuating two ray model (FTR) was proposed as the propagation model for 28 GHz outdoor millimeter waves channels. Simulation results demonstrate that both schemes achieve improved average bit error rate (ABER) than classical OFDMA and NOMA-IM techniques.

Evaluating the Mobility Impact on the Performance of Heterogeneous Wireless Networks Over η – μ Fading Channels

The 5G and beyond networks will intrinsically accommodate a wide range of use-case scenarios and expand the limit of legacy mobile systems. The 5G network architecture can handle the seamless operation of various wireless channels in a heterogeneous environment. The $\eta $ - $\mu $ fading model is well-suited for versatile channels as it adapts to different fading behaviors in a broad-range propagation for non-line-of-sight (NLOS) circumstances. This paper evaluates the performance of heterogeneous wireless networks using $\eta $ - $\mu $ fading channel under mobility conditions. We incorporated the random waypoint (RWP) model with $\eta $ - $\mu $ distribution to model the dynamic behavior of non-homogeneous fading. The derivation of expressions for the probability density function (PDF) and cumulative distribution function (CDF) of the received signal power for a mobile network in all three-dimensional topologies is extracted. Consequently, the outage probability (OP) and average bit error rate (ABER) are analyzed to quantify the performance of the mobile system. The effect of co-channel interference (CCI) is investigated based on a desired and interfering signal transmitted in mobile networks. The proposed novel-form can characterize the performance of a mobile user, and the derivation is useful for measuring the effect of noise and interference on the signal. Finally, the novel-form applicability analyzes the impact of mobility incorporated in different fading channels such as Nakagami-m, Nakagami-q (Hoyt), Rayleigh, and one-sided Gaussian distributions.

FSO system performance analysis based on novel Gamma–Chi-square irradiance PDF model

In order to provide a novel analytically traceable free space optics (FSO) channel model for describing turbulence based irradiance fluctuations, following basic scintillation theory principles, we have derived closed-form expression for probability density function (PDF) of a new statistical Gamma–Chi-square model. Further, capitalizing on provided model, error performances of FSO system over on–off keying (OOK) transmission scheme both in the presence of atmospheric turbulence and misalignment fading (pointing error) is investigated. For both cases, the average bit error rate (ABER) at the receiving side of the system is determined in an analytically closed form. The results are graphically presented in order to analyze the impact of different levels of turbulence, as well as other relevant parameters, on the quality of the received signal in the OOK modulated FSO system.