scholarly journals Algorithm for Decreasing the Large Peak to Average Power Ratio in Mimo-Ofdm

2020 ◽  
Vol 8 (6) ◽  
pp. 2272-2276
Keyword(s):  
Error Rate ◽  
Communication System ◽  
Orthogonal Frequency Division Multiplexing ◽  
High Speed ◽  
Average Power ◽  
Symbol Error Rate ◽  
Power Ratio ◽  
Mapping Algorithm ◽  
Mimo Ofdm ◽  
Large Maximum

Every personal want to use high speed communication system but bandwidth is limited and users are unlimited in that case some of technologies are use for improving speed. One of the best technology called multiple inputs multiple outputs orthogonal frequency division multiplexing. Which provides very fast communication system but drawback of this technique is large maximum to average power ratio, these reduce efficiency of power amplifier. In this article developed new algorithm, for reduction of large maximum to average power ratio and improve bit or symbol error rate in MIMO-OFDM system. Proposed technique, called filter companding selected mapping algorithm technique (FC-SLM) to reduce PAPR using filtering and companding concept. In this techniques, after modulation of input data are converted into serial to parallel steam, phase mapping of all data from 0 to 360 degrees and perform IFFT operation, calculate PAPR and pass through desire range of filter and select minimum PAPR then perform companding and transmitted through an antenna. This scheme is reduce 2.3 dB PAPR and improve bit or symbol error rate. This is one of the most excellent promising techniques for next generation (5-G) communication system.

scholarly journals A Novel Hybrid Precoding-Companding Technique for Peak-to-Average Power Ratio Reduction in 5G and beyond

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1410
Author(s):  
Mohamed Mounir ◽  
Mohamed B. El_Mashade ◽  
Salah Berra ◽  
Gurjot Singh Gaba ◽  
Mehedi Masud
Keyword(s):  
Computational Complexity ◽  
Orthogonal Frequency Division Multiplexing ◽  
High Speed ◽  
Average Power ◽  
Papr Reduction ◽  
Power Ratio ◽  
Error Vector Magnitude ◽  
Hybrid Precoding ◽  
High Power Amplifier ◽  
Reduction Techniques

Several high-speed wireless systems use Orthogonal Frequency Division Multiplexing (OFDM) due to its advantages. 5G has adopted OFDM and is expected to be considered beyond 5G (B5G). Meanwhile, OFDM has a high Peak-to-Average Power Ratio (PAPR) problem. Hybridization between two PAPR reduction techniques gains the two techniques’ advantages. Hybrid precoding-companding techniques are attractive as they require small computational complexity to achieve high PAPR reduction gain. Many precoding-companding techniques were introduced to increasing the PAPR reduction gain. However, reducing Bit Error Rate (BER) and out-of-band (OOB) radiation are more significant than increasing PAPR reduction gain. This paper proposes a new precoding-companding technique to better reduce the BER and OOB radiation than previous precoding-companding techniques. Results showed that the proposed technique outperforms all previous precoding-companding techniques in BER enhancement and OOB radiation reduction. The proposed technique reduces the Error Vector Magnitude (EVM) by 15 dB compared with 10 dB for the best previous technique. Additionally, the proposed technique increases high power amplifier efficiency (HPA) by 11.4%, while the best previous technique increased HPA efficiency by 9.8%. Moreover, our proposal achieves PAPR reduction gain better than the most known powerful PAPR reduction technique with a 99% reduction in required computational complexity.

scholarly journals Fractional weighted ZF equalizer: A novel approach for channel equalization in MIMO-OFDM system under impulse noise environment

2021 ◽  
Vol 6 (1) ◽  
pp. 1-10
Author(s):  
S. P. Girija ◽  
Rameshwar Rao
Keyword(s):  
Error Rate ◽  
Orthogonal Frequency Division Multiplexing ◽  
Impulse Noise ◽  
Multiple Input Multiple Output ◽  
Symbol Error Rate ◽  
Mitigation Strategy ◽  
Ofdm System ◽  
Noise Mitigation ◽  
Zero Forcing ◽  
Mimo Ofdm

Impulse noise is the major factor degrading the performance of the wireless system, imposing the need for the impulse noise mitigation strategy. Mainly, in the multiple-input multiple-output (MIMO) and orthogonal frequency-division multiplexing (OFDM) system contaminated with the impulse noise creates a major impact in the performance as the conventional zero-forcing (ZF) equalizer as there is no satisfactory results. Thus, the paper concentrates on the impulse noise mitigation strategy based on the fractional weighed zero-forcing (FWZF) equalizer, which is the integration of the fractional concept in the Zero-Forcing equalizer. The noise impacts in the MIMO-OFDM system are minimized and the performance is enhanced due to the usage of the fractional theory in the ZF equalizer as the equalization values of the previous instances are interpreted for the formulation of the effective equalization value in the current instance of the ZF equalizer. The performance of the methods is done based on the valuation metrics, Bit Error Rate (BER), Mean Square Error (MSE), and Symbol Error Rate (SER) with respect to the Signal-to-Noise Ratio (SNR) and dissimilar antenna array size. It is found that the proposed Fractional Weighed Zero-Forcing equalizer outperformed the existing methods with a minimal BER and SER of 0.063, and 0.1038 while analyzing the methods in the Rayleigh environment.

Performance Comparison of MDFT Filter Bank with OFDM in Multi-Carrier Systems

2014 ◽  
Vol 926-930 ◽  
pp. 1822-1826
Author(s):  
Ling Zhuang ◽  
Ju Ge ◽  
Guang Yu Wang ◽  
Kai Shao
Keyword(s):  
Error Rate ◽  
Orthogonal Frequency Division Multiplexing ◽  
Filter Bank ◽  
Average Power ◽  
Symbol Error Rate ◽  
Performance Comparison ◽  
Frequency Division ◽  
System Prototype ◽  
Detailed Derivation ◽  
Carrier Systems

Based on the filter bank, the theory of multi-carrier modulation using Orthogonal Frequency Division Multiplexing (OFDM) and Modified Discrete Fourier Transform (MDFT) filter bank has been discussed and the detailed derivation process has been given. Following these discussions, the actual implementation of MDFT filter bank in multi-carrier modulation systems has been discussed, and then the comparison of their prototype functions, Peak to Average Power Ratio (PAPR) and Symbol Error Rate (SER) are drawn. Experimental results demonstrate that compared with the OFDM system, prototype functions of MDFT have obvious advantage in spectrum leakage. In terms of PAPR, they have similar performance. Whether using QPSK or 16QAM modulation, MDFT is superior to OFDM in symbol error rate as a whole and with increasing of filter length L, the advantage becomes more and more apparent.

scholarly journals Reduksi Peak-To-Average Power Ratio Pada Sistem STBC MIMO-OFDM dengan Metode Selected Mapping dan Partial Transmit Sequence

2017 ◽  
Vol 3 (1) ◽  
pp. 85
Author(s):  
Andi Maddanaca
Keyword(s):  
Bit Error Rate ◽  
Error Rate ◽  
High Power ◽  
Side Information ◽  
Average Power ◽  
Multipath Fading ◽  
Power Ratio ◽  
Partial Transmit Sequence ◽  
High Power Amplifier ◽  
Mimo Ofdm

Teknik OFDM merupakan teknik multicarrier yang mengefisienkan bandwidth. Penggunaan teknik OFDM dapat mengatasi multipath fading dan intersymbol interference (ISI). Namun demikian, OFDM mempunyai dua kelemahan, salah satunya adalah peak-to-average power ratio (PAPR) yang tinggi. PAPR yang tinggi akan menyebabkan distorsi nonlinear pada high power amplifier (HPA) karena HPA membatasi keluaran dengan nilai tertentu dan mengurangi efisiensi daya amplifier. Oleh karena itu, PAPR yang tinggi harus direduksi. Metode reduksi PAPR yang diajukan adalah dengan menggunakan metode Selected Mapping (SLM) dan Partial Transmit Sequence (PTS). Kedua metode ini memiliki kekurangan dalam hal kompleksitas multiplikasi dan penjumlahan dan adanya bit side information yang harus dikirimkan ke receiver. Oleh karena itu, penulis mengajukan pengembangan dari metode tersebut dengan memodifikasi faktor rotasi fasa menjadi pattern konversi terdefinisi yang lebih adaptif pada SLM, dan mengurangi iterasi pembangkitan faktor rotasi fasa pada metode PTS dengan pendefinisian faktor rotasi fasa yang terbatas. Hasil simulasi dengan 1000 simbol OFDM menunjukkan bahwa kemampuan reduksi PAPR pada metode m-SLM dan m-PTS mendekati kemampuan reduksi metode konvensional. Bit error rate (BER) yang dihasilkan juga mengalami perbaikan dibandingkan BER tanpa reduksi. m-SLM secara keseluruhan mengungguli kinerja dari m-PTS, baik pada nilai reduksi PAPR maupun pada perbaikan BER.

scholarly journals Experimental Evaluation of Machine learning based MIMO-OFDM System for Optimal PAPR and BER

2021 ◽  
Vol 16 ◽  
pp. 315-327
Author(s):  
Y. K Shobha ◽  
H. G Rangaraju
Keyword(s):  
Machine Learning ◽  
Error Rate ◽  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
Multiple Input Multiple Output ◽  
Average Power ◽  
Low Complexity ◽  
Spatial Multiplexing ◽  
Operational Cost ◽  
Mimo Ofdm

The hypothetically convenient structure is the Multiple-Input Multiple-Output Orthogonal Frequency Division Multiplexing (MIMO-OFDM) technique that is employed for upcoming generations in wireless communication systems. Some of the benefits offered by MIMO-OFDM are enhanced spatial multiplexing, reliability and network throughput, and so on. Due to the integration of spatial antenna that is based on multi-stream, the problems which are related to significantly high power takes place in the system of OFDM and provides complex processing strategies. Some of the popularly known systems that are used for standardizing the Peak to average power ratio (PAPR) are partial transmit sequences (PTS), adoptive tone reservation (ATR), probabilistic mapping, and clipping which are required to be truncated and aims for minimizing the operational cost. The framework of hybrid Selective Mapping (SLM)-PTS proposed in this paper minimizes the operational cost by integrating strategies of PTS and SLM. A reduction approach that is suitable for PAPR and BER are chosen for optimization purposes depending on the statistical threshold constraint of PAPR and Bit Error Rate (BER). Thus, the system preferred with the help of the machine learning technique demonstrates the efficiency in implementing a generalized strategy to evaluate a low complexity MIMO-OFDM model. Ultimately, with the help of the PAPR and BER techniques-driven from value bound the performance of the error rate is evaluated in this framework that interactively changes from one technique.

Improving Space-Time-Frequency MIMO-OFDM with ICI Self-Cancellation Scheme using Least Square Error Estimator

2015 ◽  
Vol 12 (1) ◽  
pp. 25
Author(s):  
Nur Farahiah Ibrahim ◽  
Zahari Abu Bakar ◽  
Azlina Idris
Keyword(s):  
Channel Estimation ◽  
Orthogonal Frequency Division Multiplexing ◽  
Symbol Error Rate ◽  
Space Time ◽  
Least Square ◽  
Error Estimator ◽  
Frequency Diversity ◽  
Time Frequency ◽  
Mimo Ofdm ◽  
Subcarrier Mapping

Channel estimation techniques for Multiple-input Multiple-output Orthogonal Frequency Division Multiplexing (MIMO-OFDM) based on comb type pilot arrangement with least-square error (LSE) estimator was investigated with space-time-frequency (STF) diversity implementation. The frequency offset in OFDM effected its performance. This was mitigated with the implementation of the presented inter-carrier interference self-cancellation (ICI-SC) techniques and different space-time subcarrier mapping. STF block coding in the system exploits the spatial, temporal and frequency diversity to improve performance. Estimated channel was fed into a decoder which combined the STF decoding together with the estimated channel coefficients using LSE estimator for equalization. The performance of the system was compared by measuring the symbol error rate with a PSK-16 and PSK-32. The results show that subcarrier mapping together with ICI-SC were able to increase the system performance. Introduction of channel estimation was also able to estimate the channel coefficient at only 5dB difference with a perfectly known channel.

A companding approach for PAPR suppression in OFDM based massive MIMO system

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ajay Kumar Yadav ◽  
Pritam Keshari Sahoo ◽  
Yogendra Kumar Prajapati
Keyword(s):  
Massive Mimo ◽  
Orthogonal Frequency Division Multiplexing ◽  
Mimo System ◽  
Multiple Input Multiple Output ◽  
Average Power ◽  
Base Station ◽  
Convex Optimization Problem ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Mimo Ofdm

Abstract Orthogonal frequency division multiplexing (OFDM) based massive multiuser (MU) multiple input multiple output (MIMO) system is popularly known as high peak-to-average power ratio (PAPR) issue. The OFDM-based massive MIMO system exhibits large number of antennas at Base Station (BS) due to the use of large number of high-power amplifiers (HPA). High PAPR causes HPAs to work in a nonlinear region, and hardware cost of nonlinear HPAs are very high and also power inefficient. Hence, to tackle this problem, this manuscript suggests a novel scheme based on the joint MU precoding and PAPR minimization (PP) expressed as a convex optimization problem solved by steepest gradient descent (GD) with μ-law companding approach. Therefore, we develop a new scheme mentioned to as MU-PP-GDs with μ-law companding to minimize PAPR by compressing and enlarging of massive MIMO OFDM signals simultaneously. At CCDF = 10−3, the proposed scheme (MU-PP-GDs with μ-law companding for Iterations = 100) minimizes the PAPR to 3.70 dB which is better than that of MU-PP-GDs, (iteration = 100) as shown in simulation results.

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