BER Improvement in OFDM Systems Using Wavelet Transform Based on Kalman Filter

2020 ◽  
pp. 102-124
Author(s):  
Sajjan Singh
Keyword(s):  
Kalman Filter ◽  
Wavelet Transform ◽  
Fading Channels ◽  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
High Speed ◽  
Performance Enhancement ◽  
Average Power ◽  
Discrete Wavelet ◽  
Rate Analysis

Orthogonal frequency division multiplexing (OFDM) is an efficient method of data transmission for high speed communication systems over multipath fading channels. However, the peak-to-average power ratio (PAPR) is a major drawback of multicarrier transmission systems such as OFDM is the high sensitivity of frequency offset. The bit error rate analysis (BER) of discrete wavelet transform (DWT)-OFDM system is compared with conventional fast Fourier transform (FFT)-OFDMA system in order to ensure that wavelet transform based OFDMA transmission gives better improvement to combat ICI than FFT-based OFDMA transmission and hence improvement in BER. Wavelet transform is applied together with OFDM technology in order to improve performance enhancement. In the proposed system, a Kalman filter has been used in order to improve BER by minimizing the effect of ICI and noise. The obtained results from the proposed system simulation showed acceptable BER performance at standard SNR.

scholarly journals Palm Date Leaf Clipping: A New Method to Reduce PAPR in OFDM Systems

Information ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 190 ◽  
Author(s):  
Brahim Bakkas ◽  
Reda Benkhouya ◽  
Idriss Chana ◽  
Hussain Ben-Azza
Keyword(s):  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
High Speed ◽  
Average Power ◽  
Papr Reduction ◽  
Frequency Division ◽  
Ofdm Systems ◽  
Leaf Clipping ◽  
Hyperbolic Cosine ◽  
Transmitted Signal

Orthogonal frequency division multiplexing (OFDM) is the key technology used in high-speed communication systems. One of the major drawbacks of OFDM systems is the high peak-to-average power ratio (PAPR) of the transmitted signal. The transmitted signal with a high PAPR requires a very large linear range of the Power Amplifier (PA) on the transmitter side. In this paper, we propose and study a new clipping method named Palm Clipping (Palm date leaf) based on hyperbolic cosine. To evaluate and analyze its performance in terms of the PAPR and Bit Error Rate (BER), we performed some computer simulations by varying the Clipping Ratio (CR) and modulation schemes. The obtained results show that it is possible to achieve a gain of between 7 and 9 dB in terms of PAPR reduction depending on the type of modulation. In addition, comparison with several techniques in terms of PAPR and BER shows that our method is a strong alternative that can be adopted as a PAPR reduction technique for OFDM-based communication systems.

scholarly journals PAPR reduction in OFDM system for DVB-S2

2020 ◽  
Vol 17 (1) ◽  
pp. 317
Author(s):  
Zainab M Abid ◽  
Awatif A Jaffaar ◽  
Suha Q Hadi
Keyword(s):  
Fading Channels ◽  
Power Amplifier ◽  
Spectral Efficiency ◽  
Orthogonal Frequency Division Multiplexing ◽  
High Speed ◽  
Average Power ◽  
Multipath Fading ◽  
Papr Reduction ◽  
Major Drawback ◽  
Ofdm Signal

<p>A special form of multicarrier modulation is Orthogonal Frequency Division Multiplexing (OFDM) which is offer high spectral efficiency for high speed data transmission through multipath fading channels. Many advantages can be achieved by using OFDM in addition to spectral efficiency like its robustness against intersymbol interference and multipath effect. One of a major drawback of OFDM is high Peak-to-Average Power Ratio (PAPR) of the transmitted signal which leads to a distortion in the power amplifier and causes decreasing the efficiency of power amplifier. To reduce PAPR of OFDM signal many of promising solutions have been proposed and implemented. In this paper, a joint Low Density Parity Check code (LDPC), Discrete Cosine Transform (DCT) and μ-law companding is proposed to reduce PAPR of OFDM signal at transmitter. Comparison of these PAPR reduction techniques is done based on CCDF performance of the system.</p>

scholarly journals Transformasi Wavelet dengan Teknik Clipping Filtering untuk Mereduksi PAPR pada OFDM

2020 ◽  
Vol 12 (1) ◽  
pp. 1-8
Author(s):  
Ni Made Ary Esta Dewi Wirastuti ◽  
Ida Bagus Dharma Dhyaksa
Keyword(s):  
Fourier Transform ◽  
Wavelet Transform ◽  
Orthogonal Frequency Division Multiplexing ◽  
Average Power ◽  
Simulation Method ◽  
Local Oscillator ◽  
Discrete Wavelet ◽  
Spectral Leakage ◽  
Synchronization Errors ◽  
Offset Frequency

Orthogonal Frequency Division Multiplexing (OFDM) is chosen as multiplexing techniques and broadly used in today’s radiocommunication environments to overcome spectrum insufficiency. With several superior advantages, however, OFDM is terribly affected by high peak to average power ratio (PAPR) due to offset frequency errors and local oscillator (LO) frequency synchronization errors. The high PAPR can cause nonlinear distortion, which outcomes in intermodulation and spectral leakage. This study aims to model the use of wavelet transform (discrete wavelet transform (DWT)) to replace Fourier transform (discrete Fourier transform (DFT)) that used in conventional OFDM, later in this paper is termed as DFT-OFDM. Clipping filtering techniques then applied to DWT-OFDM. The model was proposed to reduce PAPR in DFT-OFDM. The model was compared to DFT-OFDM using Matlab simulation method. The performance was evaluated using the Complementary Cumulative Distributive Function (CCDF) vs. PAPR. The results show that at PAPR 10-3for DFT-OFDM, it was produced PAPR of 10.6 dB whereas in DWT-OFDM, using Daubechies orde 7 (Daubechies7),  Symlet orde 7 (Symlet7), Coiflet orde 2 (Coiflet2), were reached PAPR 4.8 dB, PAPR 3.3 dB, PAPR 3 dB, respectively. It means Coiflet2 providing the best PAPR reduction among other orthogonal wavelets. By applied clipping filtering to wavelet Coiflet2, it was produced PAPR of 2.9 dB for classical clipping and 2.8 dB for deep clipping. It show that wavelet Coiflet2 with deep clipping provided the best PAPR.

scholarly journals A Novel GFDM Waveform Design Based on Cascaded WHT-LWT Transform for the Beyond 5G Wireless Communications

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1831
Author(s):  
Meryem Maraş ◽  
Elif Nur Ayvaz ◽  
Meltem Gömeç ◽  
Asuman Savaşcıhabeş ◽  
Ali Özen
Keyword(s):  
Fading Channels ◽  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
Additive White Gaussian Noise ◽  
Average Power ◽  
Hadamard Transform ◽  
Frequency Division Multiplexing ◽  
Frequency Division ◽  
Simulation Results ◽  
Walsh Hadamard Transform

In this paper, a new WHT-LWT-GFDM waveform obtained by combining Walsh–Hadamard Transform (WHT), Lifting Wavelet Transform (LWT), and Generalized Frequency Division Multiplexing (GFDM) is presented for use in next-generation wireless communication systems. The proposed approach meets the requirement of 5th-generation (5G) and beyond communication schemes in terms of low latency, low peak-to-average-power ratio (PAPR), and low bit-error rate (BER). To verify the performance of the presented waveform, PAPR and BER simulation results were obtained in additive white Gaussian noise (AWGN) and flat Rayleigh fading channels, and the performance of the proposed system was compared with conventional Orthogonal Frequency Division Multiplexing (OFDM), GFDM, and Walsh–Hadamard transform-based GFDM (WHT-GFDM). Simulation results show that the proposed waveform achieves the best BER and PAPR performances and it provides considerable performance gains over the conventional waveforms.

scholarly journals Analytical bound for the CCDF of Crest Factor in NC-OFDM Systems

2017 ◽  
Vol 11 (4) ◽  
pp. 180
Author(s):  
Mohammed Y. Bendimerad ◽  
Fatima Debbat ◽  
Fethi T. Bendimerad
Keyword(s):  
Fading Channels ◽  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
Average Power ◽  
Value Theory ◽  
Design Parameters ◽  
Wireless Communication Systems ◽  
Ofdm Systems ◽  
Crest Factor ◽  
Large Peak

Non-contiguous orthogonal frequency division multiplexing (NC-OFDM) is a promising framework for wireless communication systems due to OFDM characteristics like the spectral bandwidth efficiency, robustness to frequency selective fading channels, etc. However, it has been widely known that multicarrier signals generated by OFDM technique exhibit a large peak to average power ration (PAPR), one of the main impediment that has limited the applicability of OFDM systems. Several approaches are employed in literature to derive the PAPR distribution and thus try to reduce it in OFDM context, as Central limit theorem and modern extreme value theory. In new contexts like NC-OFDM systems when flexible access to spectrum is done with non-contiguous portions, the PAPR distribution remains generally unknown, and it is necessary to describe it, since this is one of the key design parameters. In this correspondence, we develop the PAPR bound expression in NC-OFDM context.

New Hybrid PAPR Reduction Techniques for OFDM-Based Visible Light Communication Systems

2018 ◽  
Vol 39 (4) ◽  
pp. 427-435 ◽  
Author(s):  
Haitham Freag ◽  
Emad S. Hassan ◽  
Sami A. El-Dolil ◽  
Moawad I. Dessouky
Keyword(s):  
Visible Light ◽  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
High Speed ◽  
Average Power ◽  
Visible Light Communication ◽  
Cumulative Distribution ◽  
Papr Reduction ◽  
Reduction Techniques ◽  
Ber Performance

Abstract Orthogonal frequency division multiplexing (OFDM) is used with visible light communication (VLC) systems to reduce the effects of inter-symbol interference (ISI) and to achieve communication with high speed of data transmission and huge bandwidth. However, OFDM-based VLC systems suffer from high peak-to-average power ratios (PAPRs). This paper proposes a new hybrid PAPR reduction technique based on signal transformation combined with clipping. The Hadamard transform is used in the proposed technique due to its advantages in reducing the PAPR without affecting the bit error rate (BER) of VLC systems. The optimum clipping threshold at which we can simultaneously reduce the PAPR and improve the BER of VLC systems is also determined. In this paper, we also propose a new OFDM structure based on using discrete cosine transform (DCT) precoding before inverse fast Fourier transform (IFFT) stage to further improve the PAPR reduction capability and BER performance. Several experiments are carried out to test the performance of the proposed technique in terms of complementary cumulative distribution function (CCDF) and the BER. The obtained results show that the proposed technique can simultaneously reduce the PAPR and achieve good BER performance when compared to the original OFDM-based VLC system.

scholarly journals Wavelet Theory and Application in Communication and Signal Processing

2021 ◽  
Author(s):  
Nizar Al Bassam ◽  
Vidhyalavanya Ramachandran ◽  
Sumesh Eratt Parameswaran
Keyword(s):  
Signal Processing ◽  
Fourier Transform ◽  
Wavelet Transform ◽  
Wavelet Transforms ◽  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
Applied Mathematics ◽  
Multimedia Systems ◽  
Biomedical Signal Processing ◽  
Discrete Wavelet

Wavelet analysis is the recent development in applied mathematics. For several applications, Fourier analysis fails to provide tangible results due to non-stationary behavior of signals. In such situation, wavelet transforms can be used as a potential alternative. The book chapter starts with the description about importance of frequency domain representation with the concept of Fourier series and Fourier transform for periodic, aperiodic signals in continuous and discrete domain followed by shortcoming of Fourier transform. Further, Short Time Fourier Transform (STFT) will be discussed to induce the concept of time frequency analysis. Explanation of Continuous Wavelet Transform (CWT) and Discrete Wavelet Transform (DWT) will be provided with the help of theoretical approach involving mathematical equations. Decomposition of 1D and 2D signals will be discussed suitable examples, leading to application concept. Wavelet based communication systems are becoming popular due to growing multimedia applications. Wavelet based Orthogonal Frequency Division Multiplexing (OFDM) technique and its merit also presented. Biomedical signal processing is an emerging field where wavelet provides considerable improvement in performance ranging from extraction of abnormal areas and improved feature extraction scheme for further processing. Advancement in multimedia systems together with the developments in wireless technologies demands effective data compression schemes. Wavelet transform along with EZW, SPIHT algorithms are discussed. The chapter will be a useful guide to undergraduate and post graduate who would like to conduct a research study that include wavelet transform and its usage.

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.

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