System In Terms Of Bit Error Rate Research Articles

Performance of STBC Based MIMO-OFDM Using Pilot-aided Channel Estimation

Many studies have been published to address the growing issues in wireless communication systems. Space-Time Block Coding (STBC) is an effective and practical MIMO-OFDM application that can address such issues. It is a powerful tool for increasing wireless performance by coding data symbols and transmitting diversity using several antennas. The most significant challenge is to recover the transmitted signal through a time-varying multipath fading channel and obtain a precise channel estimation to recover the transmitted information symbols. This work considers different pilot patterns for channel estimation and equalization in MIMO-OFDM systems. The pilot patterns fall under two general types: comb and block types, with a proper arrangement suitable to the multiple transmit antennas. The two main channel estimation methods, LS and MMSE, are compared by evaluating performance in terms of Bit Error Rate (BER) to analyze the performance of pilot-aided channel estimation for 2x2 and 4x4 MIMO arrangements utilizing LTE parameters and the effects of modifying different numbers of OFDM subcarriers under different channel models It has been discussed, a 4x4 system performs better than a 2x2 system in terms of BER with an acceptable amount of additional complexity.

Multiuser-MIMO Systems Using Comparator Network-Aided Receivers With 1-Bit Quantization

Low-resolution analog-to-digital converters (ADCs) are promising for reducing energy consumption and costs of multiuser multiple-input multiple-output (MIMO) systems with many antennas. We propose low-resolution multiuser MIMO receivers where the signals are simultaneously processed by 1-bit ADCs and a comparator network, which can be interpreted as additional virtual channels with binary outputs. We distinguish the proposed comparator networks in fully and partially connected. For such receivers, we develop the low-resolution aware linear minimum mean-squared error (LRA-LMMSE) channel estimator and detector according to the Bussgang theorem. We also develop a robust detector which takes into account the channel state information (CSI) mismatch statistics. By exploiting knowledge of the channel coefficients we devise a mean-square error (MSE) greedy search and a sequential signal-to-interference-plus-noise ratio (SINR) search for optimization of partially connected networks. Numerical results show that a system with extra virtual channels can outperform a system with additional receive antennas, in terms of bit error rate (BER). Furthermore, by employing the proposed channel estimation with its error statistics, we construct a lower bound on the ergodic sum rate for a linear receiver. Simulation results confirm that the proposed approach outperforms the conventional 1-bit MIMO system in terms of BER, MSE and sum rate.

Design and Implementation of Optimum LSD Coded Signal Processing Algorithm in the Multiple-Antenna System for the 5G Wireless Technology

The 5G system requires an optimum coding technique to achieve the high diversity gain, low bit error rate (BER), and low detection complexity. Various coding techniques were developed in recent times for improving the diversity performance of the MIMO systems. Space-time-coding (STC) is used to fulfill the requirement of handling large data flow in the 5G wireless communications. It is highly required to optimize the orthogonal nature of STC. The paper proposed a novel design of the optimum linearly scalable dispersion code (O-LSDC). In this paper, an optimum coefficient-based O-LSDC is designed based on the elementary matrix operations, unitary matrix normalization technique, and coefficient mapping strategy. Mapped coefficients are linearly solved for optimum value estimation. To find the optimum solution of the LSDC codes, five cases of LSDC are defined based on the scaling coefficients and then performance is evaluated against the BER vs. SNR. Evaluating the simulation results in terms of error probabilities for the five different orthonormal LSDC, this work simulates the system for multiple antennas using the Rayleigh fading MIMO system model. Also, evaluating the impact of the proposed LSDC over the BER performance for the varied number of Monte Carlo iterations, then the performance graph is plotted for multiple-antennas system. The proposed O-LSDC under Rayleigh fading channel using the M-PSK modulation enhances the performance of the 5G and beyond communication system in terms of BER and SNR.

Back Propagation Artificial Neural Network for Improving the Performance of STBC-based OFDM with Subcarrier Power Modulation

Orthogonal Frequency Division Multiplexing with Subcarrier-Power Modulation (OFDM-SPM) has recently been proposed as a promising, potential transmission technique for future wireless communications (i.e., 6G and beyond) due to its multiple beneficial characteristics, including higher spectral efficiency, low latency with good reliability while maintaining low complexity. In this paper, Orthogonal Frequency Division Multiplexing with Subcarrier-Power Modulation and Space-Time Block Coding (OFDM-SPM-STBC) technique is compounded with Back Propagation Artificial Neural Network (BPANN) in a multiple-input-single-output (MISO) setup to study, investigate and quantify the wireless system's performance of their combination over a multi-path Rayleigh fading channel. Particularly, we analyze two main performance metrics: bit-error-rate (BER) and throughput of the newly designed technique called OFDM-SPM-STBC-BPANN, and then quantify the amount of resulting gains in both BER and throughput due to using the proposed system. We also consider two scenarios for OFDM-SPM-STBC-BPANN transmission. The first one is the power re-assignment policy (PRP), and the second one is the power saving policy (PSP). It is found that the sub-carrier optimized power-reassignment scheme provides the best BER performance for the proposed transmission scheme. In contrast, the PSP for SPM is seen to provide an intermediate improvement in the average BER. The performance of the system in terms of BER and Throughput is improved furthermore by implementing Feed-Forward Back-Propagation Artificial Neural Network (BPANN) at the receiver side. It is observed an average SNR gain of about 7 dB in the BER by implementing BPANN with OFDM-SPM-STBC. It is also found that the optimized power-reassignment scheme provides the best BER performance for the proposed OFDM-SPM-STBC transmission scheme with BPANN at the receiver.

Improved two-way double-relay selection technique for cooperative wireless communications

In this article, a novel two-way double-relay selection strategy with its bit error rate (BER) performance analysis is proposed. In this novel strategy, as a first step we choose two relays out of a set of relay-nodes in a way to maximize the system performance in terms of BER and complexity. In the second step, the selected relays apply orthogonal space-time coding scheme using the three-phase protocol to establish a two-way communication between the transceivers, which will lead to a significant improvement in the achievable diversity and coding gain with a very low decoding complexity by using a symbol-wise decoder. Furthermore, the performance of the overall system is further enhanced through the use of a network coding method at the selected relay-nodes. Moreover, this paper proposes the analytical approximation of the BER performance. As well, we show that the analytical results match perfectly the simulated ones. In addition, we prove that our strategy outperforms the current state-of-the-art ones by proposing a better cooperative communication system in terms of BER.

Comparison of OFDM System in Terms of BER using Different Transform and Channel Coding

Orthogonal frequency division multiplexing is a type of multicarrier modulation technique which is used in wireless communication. OFDM can be used in various wireless and wired application such Digital audio broadcasting, digital video broadcasting & wireless LAN. The Performance of OFDM system depends on various parameters such as using different transform, different modulation and by putting various channel coding. In this paper OFDM system is modeled by using different transform (DWT/FFT), different modulation (BPSK, QPSK, QAM) and different channel coding (Linear / Cyclic block codes) for AWGN channel. The performance parameter is calculated as Bit error rate (BER) for various transform/modulation/channel coding based OFDM systems. MATLAB Simulink tool is used to calculate the bit error rate (BER).

Comparison of OFDM System in terms of BER using Different Transform and Channel Coding

<p>Orthogonal frequency division multiplexing is a type of multicarrier modulation technique which is used in wireless communication. OFDM can be used in various wireless and wired application such Digital audio broadcasting, digital video broadcasting & wireless LAN. The Performance of OFDM system depends on various parameters such as using different transform, different modulation and by putting various channel coding. In this paper OFDM system is modeled by using different transform (DWT/FFT), different modulation (BPSK, QPSK, QAM) and different channel coding (Linear / Cyclic block codes) for AWGN channel. The performance parameter is calculated as Bit error rate (BER) for various transform/modulation/channel coding based OFDM systems. MATLAB Simulink tool is used to calculate the bit error rate (BER).</p>

Recording Performance of a Pulsed HAMR Architecture

In most heat-assisted magnetic recording (HAMR) systems, the laser is ON and kept constant during the entire sector. In this architecture, the transitions are defined whenever the magnetic writer changes polarity. In a pulsed HAMR system, the laser pulses once per bit. In this architecture, the transition is defined by the rising edge of the first laser pulse after a magnetic writer current transition. In this paper, we compare the bit error rate (BER) and areal density capability (ADC) of both continuous wave (CW) HAMR and pulsed HAMR. For our testing conditions, we find that there is no penalty for using a pulsed HAMR system over a CW HAMR system in terms of BER and ADC capability.