Bit Error Rate Performance Of System Research Articles

Performance Assessment of OFDM Utilizing FFT/DWT over Rician Channel Effected by CFO

Orthogonal Frequency Division Multiplexing (OFDM) is a popular kind of multi-carrier based transmission technique that has found its applications in some wireless and wireline systems. But this system suffers from several facts that degrade its performance resulting in the interference of sub-carriers. Carrier Frequency Offset (CFO) is considered as one of the factor that causes interference in the system, leading to an Inter-Carrier Interference (ICI) between the carriers that results in a degradation in the performance factor of the system. In this research work, a comparative estimation is done on the Bit Error Rate (BER) performance of Discrete Wavelet Transform (DWT) OFDM and Fourier Transform (FFT) OFDM in the presence of CFO in both of the given systems. The research focuses mainly on the improvement of the BER in the system. The complete analysis is done by considering the channel to be Rician and the systems performance is estimated for some practical values of CFO. The complete simulation is done in the MATLAB. As the CFO increases the error in the system also increases, but still in that situation, DWT shows better improvement than the conventional system. The BER performance of OFDM systems shows improvement for all the diverse PSK modulation.

Investigation of the phase fluctuation effect on the BER performance of DPSK space downlink optical communication system on fluctuation channel

Phase fluctuation effect is an important phenomenon on bit error rate (BER) performance on fluctuation channel in space downlink optical communication system. During research process, both intensity scintillation and phase fluctuation caused by atmospheric turbulence have been considered on fluctuation channel. Through the analysis of simulation results, the influence of phase fluctuation is not sensitive for wavelength and APD gain factor at high data rate. Besides, receiving diameter and divergence angle can be adjusted properly in order to obtain optimal BER performance. This work is helpful to the research of phase fluctuation and the design of practical system.

Effect of repetition coding on the BER performance of interleave-division multiple access systems

This paper investigates the bit error rate (BER) performance of interleave-division multiple access (IDMA) schemes to show the effect of repetition coding on the system performance. The considered system is tested in the presence of repetition coding by varying system parameters such as number of simultaneous users, data length, spread length, iteration number, and code rate over additive white Gaussian noise channels. In addition, the performance of the considered system is also illustrated in Rayleigh flat fading channels for a more realistic scenario. Our simulation results show that the BER performance of IDMA systems with repetition coding can achieve significant performance gains over existing uncoded IDMA schemes.

Bit error rate performance of IR‐UWB ED‐PPM system using cooperative dual‐hop AF strategy

This study presents a novel analytical approach for evaluation of bit error rate (BER) performance of an impulse radio-ultra-wideband (IR-UWB) energy detector-pulse position modulation (ED-PPM) system, using dual-hop cooperative amplify and forward (AF) relaying strategy with optimum diversity combining, over IEEE 802.15.4a UWB channel. An approximate expression for BER has been derived based on energy detection principle. The analytical BER expression thus derived is validated with computer simulations, which confirm the accuracy in approximation used in investigation of BER. Furthermore, it is observed that the BER performance of IR-UWB ED-PPM system, improves substantially using dual-hop cooperative AF scheme, compared with non-cooperative scheme. Despite its poor BER performance, ED systems are preferred over AC systems, because of simplicity and low complexity.

Power Allocation in Orthogonal Frequency-division Multiplexing (OFDM) Based Two-way Relaying with Relay Selection

In this paper, error performance analysis of relay selection in orthogonal frequency-division multiplexing (OFDM) based amplify-and-forward (AF) relaying two-way cooperative communication system is examined over frequency selective Nakagami-m fading channels with power allocation at source, relay and destination nodes. Furthermore, we allocated the power to the sub-channels at three terminals. Power allocation is done under the total power constraints based on scaling factor obtained by available channel knowledge of links between the nodes. It is shown that as relay selection can achieve full diversity and improves bit error rate (BER) performance, the power allocation can further improve the performance. Results show that BER performance of proposed system increases with the power allocation and it improves through higher value of fading parameter m.

Average BER performance of FSO SIM-QAM systems in the presence of atmospheric turbulence and pointing errors

This paper presents the exact average bit error rate (BER) analysis of the free-space optical system employing subcarrier intensity modulation (SIM) with Gray-coded quadrature amplitude modulation (QAM). The intensity fluctuations of the received optical signal are caused by the path loss, atmospheric turbulence and pointing errors. The exact closed-form analytical expressions for the average BER are derived assuming the SIM-QAM with arbitrary constellation size in the presence of the Gamma–Gamma scintillation. The simple approximate average BER expressions are also provided, considering only the dominant term in the finite summations of obtained expressions. Derived expressions are reduced to the special case when optical signal transmission is affected only by the atmospheric turbulence. Numerical results are presented in order to illustrate usefulness of the derived expressions and also to give insights into the effects of different modulation, channel and receiver parameters on the average BER performance. The results show that the misalignment between the transmitter laser and receiver detector has the strong effect on the average BER value, especially in the range of the high values of the average electrical signal-to-noise ratio.

A Simplified Scheme of Estimation and Cancellation of Companding Noise for Companded Multicarrier Transmission Systems

Nonlinear companding transform is an effi- cient method to reduce the high peak-to-average power ratio (PAPR) of multicarrier transmission systems. However, the introduced companding noise greatly degrades the bit-error- rate (BER) performance of the companded multicarrier sys- tems. In this paper, a simplified but effective scheme of es- timation and cancellation of companding noise for the com- panded multicarrier transmission system is proposed. By ex- pressing the companded signals as the summation of original signals added with a companding noise component, and sub- tracting this estimated companding noise from the received signals, the BER performance of the overall system can be significantly improved. Simulation results well confirm the great advantages of the proposed scheme over other conven- tional decompanding or no decompanding schemes under various situations.

A One Bit Feedback Based Beamforming Scheme for FSO MISO System Over Gamma-Gamma Fading

In this paper, we study a beamforming scheme for multiple-input single-output (MISO) free space optical (FSO) system over Gamma-Gamma fading channels. The considered beamforming scheme requires feedback of only one information bit from the receiver about the channel state information. If the feedback bit is always received error free, then the beamforming technique reduces to best transmit aperture selection scheme. It is inferred by bit error rate (BER) analysis in a 2 × 1 FSO system over Gamma-Gamma fading links, that repetition coding is the best of all arbitrary beamforming schemes with non-zero transmit weights. Further, it is also analytically shown that the simple transmit aperture selection scheme (or one bit feedback based beamforming with error free feedback) has a coding gain advantage over repetition coding in 2 × 1 FSO system over Gamma-Gamma fading links. However, it is shown by analysis that the simple transmit aperture selection based beamforming scheme is very sensitive to errors in the feedback bit and loses diversity gain even for very small error in the feedback. Then we establish conditions under which a 2 × 1 FSO system, employing one bit based beamforming with erroneous feedback, achieves full diversity. A simplified asymptotic upperbound of BER of the proposed scheme is obtained by using the order statistics and an optimized beamforming vector is found by minimizing this upperbound. We also analyze the BER performance of a general FSO MISO system that employs equal partitioning of transmit apertures for beamforming, based on one bit feedback. It is shown by simulations that the proposed beamforming scheme

지상파 클라우드 방송 시스템의 성능 분석 연구

In this paper, we model the interference plus noise signal for terrestrial cloud transmission systems and present bit error rate (BER) performances. Since terrestrial cloud transmission systems experience co-channel interference from one or more transmitters, they have to operate under a negative signal-to-interference plus noise ratio (SINR) region. The interference plus noise signal can be modeled as Gaussian random variable under the required SINR region and we observe the BER performance of the cloud transmission system using the derived model. Also, we propose an improved channel estimation scheme by averaging the channel estimates based on least square based interpolation scheme. Simulation results show that the cloud transmission system can operate under negative SINR region using the proposed channel estimation scheme.

CRITICAL AND IMPORTANT FACTORS RELATED WITH ENHANCING WIRELESS COMMUNICATION USING MIMO TECHNOLOGY

This research propose analyze, simulate, test, and determine the optimal performance of cited three critical and important factors related with enhancing wireless communication using MIMO technology, for simulations throughout proposed work will employing Rayleigh flat and Additive White Gaussian Noise (AWGN). Orthogonal Frequency Division Multiplexing (OFDM) was the first factor simulated, to evaluate it is performance relating with the direct parameters presents the base bone of OFDM architecture such as OFDM model, channel types, FFT size, constellation and modulations. Secondly a simulation of channel capacity factor was done to assess the performance of capacity relating with SISO, SIMO, MISO, and MIMO. Finally from single antenna to multiantenna techniques was tested, to evaluate Bit Error Rate (BER) performance by using different receive and transmit diversity techniques have been simulated and tested for SIMO and MISO systems. Furthermore, different diversity techniques based on MIMO system have also been simulated and tested. All of these techniques are compared numerically and graphically with the BER performance of SISO system, in addition to their comparison with each other, by using various numbers of antennas. From proposed analysis, simulation, and testing of these three factors and their related parameters many of recommendations are obtained to set parameters of the three factors to build high performance PHY layer with wireless communication using MIMO technique. The implementation proposal was done under Matlab programming language

Filtering effects on the synchronization and error performance of promising wireless chaos-based secure communications

Synchronization is one of the most challenging topics involved in the development of promising chaos-based secure communication (CBSC) for wireless applications due its direct impact on the error performance and reliability. In this paper, effects of filtering chaotic signals on the synchronization and average bit-error-rate (BER) of CBSC caused by the limited bandwidth of realistic wireless communication channels and detection requirements are investigated. To overcome the possible drawbacks of filtering process, two efficient methods called chaotic signal reconstruction technique (CSRT) and pre-filtering chaos technique (PFCT) are proposed. The well known double scroll chaotic attractor generated from Chua's circuit is utilized at both transmit and receive nodes as in a drive---response configuration with identical synchronization, and a mathematical model of single-pole low-pass filter is employed in this study. Over Rayleigh fading channel and wide range of filter cut-off frequency (?), simulation results show that as ? decreased, lesser than the bandwidth of utilized chaotic signal, the synchronization mean squared error is increased due to the resulting high distortion in the attractor's ordinary state-space. Consequently, system BER performance is degraded significantly leading to increased possibility of communication link failure. When CSRT from received filtered signal and PFCT of drive chaotic signal are utilized, the achieved results are interesting in terms of robust synchronization and error performance, and provide potential step towards wide adoption of CBSC in future applications.

Phase-Separated DCSK: A Simple Delay-Component-Free Solution for Chaotic Communications

In this brief, a phase-separated differential chaos shift keying (PS-DCSK) modulation scheme is proposed as a simple delay-component-free version of DCSK modulation. Separated by orthogonal sinusoidal carriers rather than time delay, the reference and information-bearing signals in DCSK are transmitted simultaneously and parallel in the proposed system. As a result, PS-DCSK not only can avoid the difficult-to-implement radio-frequency delay line problem but also can achieve a doubled attainable data rate, enhanced communication security, and equivalent bit-error-rate (BER) performance with respect to DCSK. Finally, analytical expressions for the BER performance of the proposed system are derived and verified by computer simulation results over additive Gaussian white noise and Rayleigh fading channels.

Study on the Channel Model and BER Performance of Single-Polarization Satellite-Earth MIMO Communication Systems at Ka Band

The statistic models for evaluating the fading term caused by the incoherent scatter in clear and rainy environments are derived, which are critical for establishing the multiple-input multiple-output (MIMO) channel model at Ka band. The channel model of Ka-band single-polarization MIMO satellite-earth link is established, which comprehensively takes into account the propagation and scattering effects induced by those environments. Based on the channel model, the bit error rate (BER) performances in clear and rainy environments are investigated taking an assumed 2 × 2 satellite-earth link at 30 GHz in circular polarization as an example. During the investigation, the M-ary Phase Shift Keying (M-PSK) modulation modes with different M and the space-time codes of Space-Time Block Code (STBC), Space-Time Trellis Code (STTC) and Vertical Bell Laboratories Layered Space-Time (VBLAST) are considered. It is also discussed that the BER varies with propagation environment parameters, equivalent isotropically radiated power (EIRP), ground receiving antenna gain and elevation angle. The channel model given in this paper is also valid for the single-polarization MIMO satellite-earth link at other frequencies above 10 GHz.

CDSK 변조 방식과 카오스 송수신기의 지연시간에 따른 Boss Map의 BER 성능 평가

Chaos communication system is possible to improve the system security by using chaos signal. Further, it is possible to reduce the possibility of eavesdropping, and have strong characteristics from interference signal and jamming signal. However, BER(Bit Error Rate) performance of chaos system is worse than digital communication system. By this reason, researches in order to improve the BER performance of chaos communication system are being actively studied. In previous studies, we proposed a novel chaos map for BER performance improvement, and called it 'Boss map'. Also, we proposed a novel chaos transceiver for BER performance improvement. However, BER performance is evaluated differently according to delay time in transceiver. Therefore, in order to use Boss map effectively, we should find the optimal delay time in proposed chaos transceiver. In this paper, when Boss map is used, we evaluate BER performance of CDSK(Correlation Delay Shift Keying) system and novel chaos transceiver according to delay time. After evaluation of BER performance according to delay time, we find a delay time that is possible to have best BER performance in CDSK system and novel chaos transceiver. 논문 14-39A-07-01 The Journal of Korea Information and Communications Society '14-07 Vol.39A No.07 http://dx.doi.org/10.7840/kics.2014.39A.7.365 365 ※ 이 논문은 2012년도, 2013년도 정부(교육과학기술부)의 재원으로 한국연구재단의 지원을 받아 수행된 기초연구사업임(No. 20120173 39), (No.2013R1A2A2A01005849). First Author:Department of Electronic Engineering, Chungbuk National University, toogee89@nate.com, 학생회원 ° Corresponding Author:Department of Electronic Engineering, Chungbuk National University, ecomm@cbu.ac.kr, 정회원 * 한국전파진흥협회, hskeum@rapa.or.kr, ** SK Telecom, danny92@nate.com, 정회원 논문번호:KICS2014-03-094, Receved March 18 2014; Revised June 3, 2014; Accepted June 20, 2014 The Journal of Korea Information and Communications Society '14-07 Vol.39A No.07

Performance analysis comparison of transmit antenna selection with maximal ratio combining and orthogonal space time block codes in equicorrelated Rayleigh fading multiple input multiple output channels

In this study, bit error rate (BER) performance of multiple input multiple output (MIMO) systems employing transmit antenna selection with maximal ratio combining (TAS/MRC) and orthogonal space time block codes (OSTBC) is analysed and compared. Analysis has been done for several modulation schemes in equicorrelated Rayleigh fading channels. Novel infinite series expressions for BER of TAS/MRC are proposed in this work. The authors observe that the existing literature on performance analysis of TAS/MRC in correlated channels implicitly or explicitly assume no correlation on the transmitter side. In this work the authors overcome this shortcoming. An alternate closed-form expression for BER performance of OSTBC MIMO systems is derived. This closed-form expression is computationally efficient than existing expressions. Monte Carlo simulations were performed to validate the analytical results. It has been observed that TAS/MRC outperforms OSTBC in terms of BER performance in equicorrelated Rayleigh fading channel. As a case study, performance comparison of cognitive radio (CR) links employing OSTBC and TAS/MRC MIMO systems is investigated in order to show the usefulness of the present analytical study. Even though TAS is the optimum transmit antenna technique in terms of BER performance, OSTBC seems to be a promising alternative for more realistic scenarios in CR systems.

Precoding scheme based on constellation rotation for MISO systems

The error probability of a maximum-likelihood (ML) detector depends on the signal-to-noise ratio (SNR) and distances between each possible combined channel-transformed constellation (CCTC) point and its nearest neighbours. Among these distances, the minimum one dominates the bit-error rate (BER) performance. This paper proposes a precoder based on constellation rotation (CR) for multiple-input-single-output (MISO) systems armed with an ML detector, maximising the minimum distance according to the channel information optimally. With the proposed precoder, the BER performance of MISO systems is boosted remarkably in both quasistatic Rayleigh fading independent and correlated channels. Through systematic analysis, closed-form solutions of the optimal CR angle are derived for 2 × 1 MISO systems employing BPSK or QPSK. Simulation results demonstrate that there is performance improvement of at least 2 dB with the new 2 × 1 MISO system employing BPSK, and the improvement reaches at least 3dB when QPSK is employed. In addition, the new 2 × 1 MISO system outperforms the traditional one in correlated channels significantly.

BER Performance of Coherent Optical Communications Systems Employing Monolithic Tunable Lasers With Excess Phase Noise

We analyze the bit error rate (BER) performance of optical coherent communication systems employing multi-section monolithic tunable lasers with large excess phase noise. The BER of the coherent system utilizing a second-order decision-directed digital phase-locked loop (DD-PLL) for phase tracking was computed numerically. Experimental results have also been demonstrated with a 16-quadratic-amplitude modulation coherent system deploying a sampled-grating distributed Bragg reflector laser at 16 Gbaud that confirms the performance of the second-order DD-PLL in tracking the excess phase noise.

Application of the Joint Fast Walsh Hadamard-Inverse Fast Fourier Transform in a LDPC Coded OFDM Wireless Communication System: Performance and Complexity Analysis

An efficient low complexity T transform which combines the Walsh Hadamard Transform and Discrete Fourier Transform (DFT) into a single fast orthonormal unitary transform is considered for the application in low density parity check coded orthogonal frequency division multiplexing (LDPC-OFDM) across additive white Gaussian noise channel model and multipath fading channel models. The T-transform is developed through the sparse matrices factorization method using Kronecker product scheme. T-transform based COFDM system, which is capable of reducing peak to average power ratio (PAPR) of the transmitted symbols and improving the bit error rate (BER) performance at a reasonable reduced complexity. Several signaling formats such as Quadrature phase shift keying and 16- ary Quadrature amplitude modulation (16-QAM) are considered. A T COFDM system is described which could provide an alternative to DFT-COFDM system, and is therefore a better alternative to balance the transform complexity, PAPR reduction and system performance. Simulation results are used to examine and compare the complexity, PAR and the BER performance of T-OFDM system and DFT-OFDM system. Numerical results show that the T-COFDM system outperforms the DFT-COFDM based in the multipath channel models.

On the Performance of Cooperative Relaying Spectrum-Sharing Systems with Collaborative Distributed Beamforming

In this paper, we use joint distributed beamforming and cooperative relaying in cognitive radio relay networks in an effort to enhance the spectrum efficiency and improve the performance of the cognitive (secondary) system. In particular, we consider a spectrum sharing system where a set of potential relays are employed to help a pair of secondary users in the presence of a licensed (primary) user. Among the available relays, only the reliable ones participate in the beamforming process, where the beamformer weights are obtained based on a linear optimization method. We investigate two well-known strategies, namely, selection decode-and-forward (SDF) and amplify-and-forward (AF) relaying in conjunction with distributed optimal beamforming. However, given the complexity of the performance analysis with optimal beamforming, we use zero forcing beamforming (ZFB), and compare both approaches through simulations. In this context, for SDF, we derive expressions for the probability density function (PDF) of the received signal-to-interference noise ratio (SINR) at the relays as well as at the secondary destination. As for the AF scheme, we obtain the exact expression for the cumulative distribution function (CDF) and the moment generating function (MGF) of the equivalent end-to-end SNR at the secondary destination. For both schemes, we derive closed-form expressions for the outage probability and bit error rate (BER) over independent and identically distributed Rayleigh fading channels for binary phase shift keying (BPSK) and M-ary quadrature amplitude modulation (M-QAM) schemes. Numerical results demonstrate the efficacy of the proposed scheme in improving the outage and BER performance of the secondary system while limiting the interference to the primary system. In addition, the results show the effectiveness of the combination of the cooperative diversity and distributed beamforming in compensating for the loss in the secondary system's performance due to the primary user's co-channel interference (CCI).

Characteristics of Radiation Noise from an LED Lamp and Its Effect on the BER Performance of an OFDM System for DTTB

The characteristics of radiation noise from an LED lamp and its effect on the bit error rate (BER) performance of an orthogonal frequency-division multiplexing (OFDM) system for digital terrestrial television broadcasting (DTTB) are investigated. The waveform and frequency spectrum of radiation noise from an LED lamp are measured. A sequence of noise pulses is observed, caused by the switching circuit of the LED, and spread over the broadcast band of Japan. The relationship between the radiation noise from the LED lamp and its effect on the BER performance of the OFDM system using 64-quadrature amplitude modulation (64QAM) is evaluated using amplitude probability distribution (APD) measured with various resolution bandwidths. The behavior of the APD of the noise is similar to Gaussian noise when the resolution bandwidth becomes narrow. The BER performance of the OFDM system subjected to the noise of the LED lamp is estimated from the APD results, which agree well with measured results subjected to the LED noise. The characteristics of sequential LED noise are similar to the effect of Gaussian noise on the BER performance of the OFDM system for DTTB. Therefore, the APD measurement is a useful method to estimate the characteristics and effect of noise from an LED lamp on the OFDM system.