BER Simulation for Dual Hop Relaying System over Various Fading Channelsunder Different Condition

Non-orthogonal multiple access (NOMA) is one of the potential future mobile network methods that can give better spectral efficiency, huge connectivity, and low latency. As a result, academic and industry researchers have studied the error performances and capacity of NOMA systems. The main drawback of NOMA methods is user interference, which is generally addressed by interference cancellation techniques such as Successive Interference Cancellation (SIC) at receivers. Therefore, it is better to obtain the bit error rate (BER) performance of NOMA. Each user's power level is determined by the power level assigned to them. As a result, this work presents BER analysis for two NOMA users using BPSK modulation in additive white Gaussian noise (AWGN), Rayleigh, and Rician fading channels. Initially, we assessed BER performance for various Signal to Noise Ratio (SNR) values by assuming two users who are equally spaced from the base station (BS). Later, the BER performance for various transmit powers is assessed by assuming two users are situated at varying distances from the BS. The performances are discussed using MATLAB simulations. The comparative BER analysis is also studied for various fading environments.KeywordsBERNOMABPSKSICFading

This paper exploits an exponential-type approximation to express bit error rate (BER) for MQAM uncoded space-time labeling diversity with three transmit antennas in Rician fading channel. The average BER for diversity combining is obtained by using probability density function and moment generating functions. Arbitrarily tight approximations for the Gaussian probability integral are obtained from the numerical analysis technique; the trapezoidal rule. Simulation results show excellent agreement with the derived approximation expression in the high SNR. The solutions are general enough to include Rayleigh fading (K =3D 0) as a special case with varied K-factor for frequency non-selective slow Rician fading channels. The dependence of BER performance on diversity reception and the impact of channel correlation are also demonstrated.

This paper presents a new way to improve the performance of MIMO-OFDM (multiple input multiple output - orthogonal frequency division multiplexing) by reducing the Bit Error Rate (BER) using both Convolutional Coding (CC) and discrete wavelet transform (DWT). In this Paper, OFDM system was simulated and studied with three models, SISO-OFDM, MISO-OFDM and MIMO-OFDM. The final system (MIMO-OFDM) has been improved by using CC at a coding rate 1/2 and using a DWT instead of FFT and then using both CC and DWT. The communication channels used in the study are Rician and Rayleigh fading channels and the modulation technique is Binary Phase-Shift Keying (BPSK) with 64 number of carrier frequencies. The results showed that the use of both convolutional coding and discrete wavelet transform in the MIMO-OFDM system reduces the bit energy to the intensity of noise energy (Eb/N0) by 3.4 dB as the Rayleigh fading channel is used and 4.6 dB as the Rician fading channel is used when BER=10-3. The results were obtained by modeling in the MATLAB program.

Orthogonal frequency division multiplexing (OFDM) is a type of multicarrier modulation (MCM) technique in which larger bandwidth is divided into parallel narrow bands each of which is modulated by different subcarriers. All the subcarriers are orthogonal to each other and hence it reduces the interference among various subcarriers. OFDM technique is an efficient modulation technique used in certain wired and wireless application.In a wireless communication channel, the transmitted signal can travel from transmitter to receiver over multiple reflective paths. This results to multipath fading which causes fluctuations in amplitude, phase and angle of arrival of the received signal. For example, the signal which is transmitted from BTS (base transceiver station) may suffer multiple reflections from the buildings nearby, before reaching the mobile station. Such multipath fading channels are classified into slow fading/fast fading and frequency-selective/flat fading channels. This paper discusses the performance of OFDM system using various fading channels and channel coding. The parameter which is known as Bit error rate (BER) is calculated under different fading channels (AWGN, Rayleigh and Rician) for different digital modulation (BPSK, QPSK and QAM) and Channel coding (linear/Cyclic coding). Matlab Simulink tool is used to calculate the BER parameter.

The combination of the channel fading compensation technique and the coded modulation technique is discussed. The system presented is considered to operate under correlated Rayleigh or Rician fading channels. The channel correlation property has been used to carry out channel fading compensation with the aid of periodically inserted pilot symbols. A multidimensional BCM (block coded modulation) scheme was used to improve the system error performances. On decoding, a corresponding trellis is used; therefore, the Viterbi algorithm and channel state information become available. The error performances of the system are investigated through computer simulations. Combined with the fading compensation, the multidimensional BCM scheme gives good error performances under various fading channels. For the Rayleigh fading channel, 7.5-dB coding gain has been achieved at a bit error rate (BER) of 10/sup -3/. For the Rician fading channel with K=10 dB, the coding gain is 3.7 dB at BER=10/sup -4/.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

A multi-tone code division multiple access (MT-CDMA) system with post-detection diversity combining is analyzed. The analysis is presented in terms of average bit error rate (BER). The modulator uses differential quadrature phase shift keying (DQPSK) signaling over a slowly Rician fading and frequency selective channel in the indoor environment. Here, the influence of the order of diversity and number of tones is studied for given bandwidth (BW), bit rate and transmitter power. The paper also compares the BER performance between differential binary phase shift keying (DBPSK) and DQPSK based MT-CDMA systems.

In this paper, we analyze the Bit Error Rate (BER) performance of Golden coded Multiple-Input Multiple-Output Orthogonal Frequency Division Multiplexing (MIMO-OFDM) system over Rician multipath fading channel. We also compare the performance of the MIMO-OFDM system using Golden code in Rayleigh and Rician multipath fading channels. We discuss the effects of the presence of line-of-sight (LoS) component in the multipath fading environment which renders the improvement in the overall performance of the Golden coded MIMO-OFDM. This paper discusses the performance of Golden codes in a frequency selective Rician fading channel. To deal with the frequency selective fading channel, we use the OFDM (Orthogonal Frequency Division Multiplexing) modulation. The BER performance of the Golden coded MIMO-OFDM system under several propagation conditions has been evaluated. Keywords—MIMO, OFDM, Golden STBC, Rayleigh fading, Rician fading.

We propose the Optimum Power Allocation (OPA) scheme for Distributed Antenna Systems(DAS) in the time-varying Rayleigh fading channel. Recently, the OPA schemes which uses the Channel State Information (CSI) including a small scale (fast) fading have been proposed. However, the channel is changing vary fast over time due to small scale fading, therefore Bit Error Rate (BER) increases. Because of this reason, we derive the OPA for minimizing BER in DAS, which only uses a large scale fading to CSI and excepts a small scale fading. The simulation results show that the proposed OPA achieves better BER performance than conventional OPA considering a small scale fading in time-varying Rayleigh fading channel, and also has similar performance in Rayleigh flat-fading environment. The BER performance of proposed OPA which derived in Rayleigh fading channel is similar to minimum BER of Ricean fading channel which has small Line-of-Sight (LOS).

This paper proposes a new adaptive modulation scheme, which is robust to a fast time-variation of Rayleigh fading. Adaptive modulation, which chooses an appropriate modulation format according to the instantaneous carrier-to-noise power ratio (CNR) of the fading channel, is an efficient technique capable of improving the transmission performance in a multipath fading channel. However, in a fast fading channel environment, the performance improvement will drastically be reduced. When CNR varies during the transmission burst, the transmission often fails since the modulation format chosen at the beginning of the burst to obtain the required bit error rate (BER) does not satisfy the required BER at the end of the burst. In order to overcome this problem, we propose a new adaptive modulation scheme, which employs the array antenna based Doppler spread compensator. Computer simulation results show the proposed adaptive modulation scheme drastically improves the packet error rate and throughput performance in fast fading environment.

Development of LTE is a milestone in the field of communication engineering. Compared to the performance of 2G the network involving LTE provides much higher data rates and support much more services. The evolution to LTE has provided the users to utilize many commercial activities to bring forward to the public and provide them the improved services compared to older versions of communication technologies. As the growth of LTE has provided much faster network still there are improvements going on the new technology. Various performance measures have been taken into considerations has the networks has performed very well on such test. One of the performance analyses has been presented in this paper comparing the performance of the LTE system over the Rayleigh and Rician fading channel. In the paper the performance of the MIMO LTE has been analyzed for the networks with various modulation schemes for Rayleigh and Rician fading channel with a 2x2 MIMO channel for EPA 0Hz, EVA 5Hz, EVA 70Hz. By varying Signal to Noise Ratio (SNR), Bit Error Rate (BER) of LTE is calculated for different Multi-Input Multi-Output (MIMO) schemes. The analysis is concluded in terms of speed of the data rate in Mbps.

We investigate the effects of correlation on the performance of diversity systems in wideband wireless radio environments. Specifically, the average bit error rate (BER) performance of M-ary differential phase shift keying (MDPSK) on correlated frequency-selective slow Rayleigh fading channels is analyzed. A two-branch diversity receiver with postdetection equal gain combining is considered. Nyquist pulse shaping is used and differential detection is employed at the receiver. The effects of cochannel interference on the system performance are assessed using a Gaussian interference model. To further enhance the system performance, the effects of combined diversity and forward error correction (FEC) coding on the average BER are investigated. Results using short cyclic block codes with perfect bit interleaving are obtained. The effects of the root mean square (RMS) delay spread, the amount of correlation, and the level of modulation, M, on the average BER are investigated in detail for both coded and uncoded systems. The results show that dual branch diversity combining with a correlation coefficient of 0.5 outperforms (in terms of BER) short block codes with perfect bit interleaving, and that combined diversity and coding strategies are effective in combatting the effects of frequency-selective fading.

This study presents a detailed performance evaluation of the proposed free space optical-orthogonal frequency division multiplexing (FSO-OFDM) system compared with conventional schemes such as orthogonal frequency division multiplexing (OFDM), filter bank multi-carrier (FBMC), non-orthogonal multiple access (NOMA), and universal filtered multi-carrier (UFMC) under diverse optical channel conditions. Bit error rate (BER) results in Rayleigh fading channels indicate that the proposed method attains a BER of 10 −3 at only 6.2 dB Signal-to-Noise Ratio (SNR), yielding gains of 7.6 dB, 6.2 dB, 5.3 dB, and 3.4 dB over OFDM, FBMC, NOMA, and UFMC, respectively. In Rician fading channels, the same BER is achieved at just 5.4 dB SNR, with improvements of 7.2 dB, 5.8 dB, 4.8 dB, and 3.0 dB compared to the respective schemes. Peak-to-average power ratio (PAPR) analysis at a complementary cumulative distribution function (CCDF) of 10 −3 shows a value of 10.8 dB for the proposed system, reducing nonlinear distortions and improving amplifier efficiency. Capacity analysis confirms a peak of 300 units at 50 dB SNR, surpassing all competitors. Power spectral density (PSD) results reveal sidelobe suppression beyond −200 dBW/MHz, with significant out-of-band emission reductions. Overall, FSO-OFDM offers superior robustness, spectral efficiency, and throughput for high-capacity optical communication systems.

The fast changing frequency nonselective Ricean fading channel introduces a complicated multiple distortion and an extra additive noise component for an OFDM system. The multiple distortion is the average of the sum of N(N/spl ges/3) correlated Ricean random variables. We propose an approximate technique for calculating the probability density function (PDF) of the multiple distortion under the assumption that the channel response changes in a linear fashion during one OFDM symbol. As a result, the bit error rate (BER) formula of a BPSK modulated OFDM system is derived. The results obtained using the derived formula describe well the OFDM performance under the time variant channel and match very well with the simulation results.

Space time block coding is a modulation scheme recently discovered for the transmit antenna diversity to combat the effects of wireless fading channels. Using the equivalent Single-Input Single-Output (SISO) model, this paper presents closed-form expressions for the exact Symbol Error Rate (SER) and Bit Error Rate (BER) of Orthogonal Space-Time Block Codes (OSTBCs) with M-ary Phase-Shift Keying (MPSK) and M-ary Quadrature Amplitude Modulation (MQAM) over flat uncorrelated Nakagami-m and Ricean fading channels.

Recently, the differential detection scheme has attracted considerable attention as a demodulated scheme for digital mobile communications because of its robustness in the frequency nonselective fading channel. A problem of the differential detection scheme is that its bit error rate (BER) performance in the additive white Gaussian noise (AWGN) channel is inferior to that of the coherent detection scheme. To solve this problem, many methods to improve BER performance of the differential detection in the AWGN channel have been proposed. However, those methods require complex signal processings.This paper proposes a novel differential detection scheme as a simpler improvement method which estimates the differential phase of the transmitted signal by a sequence estimation scheme using the Viterbi algorithm. The proposed scheme is simplified in a manner such that its signal processing is composed of only additions and subtractions on the phase information of the received signal. Results of computer simulation show that BER performance of the proposed scheme is close to that of the ideal coherent detection in the AWGN channel. In addition, the trellis diagram of the Viterbi algorithm can be reduced without performance degradation introducing the signal processing similar to the Scarece State Transition (SST) type Viterbi decoding. The proposed scheme also is useful in the case of the fast Rician fading channel and the slow Rayleigh fading channel.