Joint Non Linear and Distortion based PAPR Reduction Technique for Optical OFDM Systems (original) (raw)
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A Modified Method Based on the Discrete Sliding Norm Transform to Reduce the PAPR in OFDM Systems
ETRI Journal, 2014
Orthogonal frequency division multiplexing (OFDM) is a modulation technique that allows the transmission of high data rates over wideband radio channels subject to frequency selective fading by dividing the data into several narrowband and flat fading channels. OFDM has high spectral efficiency and channel robustness. However, a major drawback of OFDM is that the peak-to-average power ratio (PAPR) of the transmitted signals is high, which causes nonlinear distortion in the received data and reduces the efficiency of the high power amplifier in the transmitter. The most straightforward method to solve this problem is to use a nonlinear mapping algorithm to transform the signal into a new signal that has a smaller PAPR. One of the latest nonlinear methods proposed to reduce the PAPR is the L 2 -by-3 algorithm, which is based on the discrete sliding norm transform. In this paper, a new algorithm based on the L 2 -by-3 method is proposed. The proposed method is very simple and has a low complexity analysis. Simulation results show that the proposed method performs better, has better power spectral density, and is less sensitive to the modulation type and number of subcarriers than L 2 -by-3.
PAPR REDUCTION USING EFFICIENT PEAK CLIPPING TECHNIQUE IN OFDM SYSTEMS
Orthogonal frequency division multiplexing (OFDM) is the most popular modulation technique which is used for high speed communication system. It provides high spectral efficiency and low implementation complexity. However the main issue of OFDM is its high Peak to Average Power Ratio (PAPR) which results from sum of several sinusoidal signals. So the Efficient Peak Clipping Technique has used to reduce the peak-to-average power ratio (PAPR) of OFDM systems. By introducing different number of Subcarriers N, Up sampling factor k, Number of all samples n, Mapping Order M, and Phase Offset P, a desired level of PAPR has been achieved. At the same time by introducing the proposed technique better tradeoff between BER and SNR has been maintained.
A Study of Various PAPR Reduction Techniques for Optical OFDM Systems
International Journal of Computer Applications, 2015
In present times, OFDM has emerged as a key area of research in optical communication. Ofdm is a modulation technique by which high data rates can be achieved by sending data simultaneously over multiple subcarrier frequencies. However the main problem of OFDM is high PAPR value. High PAPR enhances non linear effects in optical fibers as the effective refractive index of optical fiber depends upon the value of input power. Various techniques have been deployed to reduce PAPR .All techniques have their inherent advantages and limitations. This paper presents a review on some of the important PAPR reduction techniques for optical OFDM systems.
PAPR reduction in OFDM signals using clipping and companding technique
International journal of engineering research and technology, 2018
Orthogonal Frequency Division Multiplexing (OFDM) is a multicarrier modulation technique that divides the available spectrum into many carriers each one being modulated by a low data rate scheme. OFDM is similar to Frequency Division Multiple Access (FDMA) in that the multiple user access is achieved by subdividing the available bandwidth into multiple channels, which are then allocated to users.In OFDM, using guard band is cyclically extended in order to avoid inter-carrier interference (ICI). The major drawback of OFDM signals is high peak to average power ratio(PAPR). High PAPR signals would require a large range of dynamic linearity from the analog circuits which usually results in expensive devices and high power consumption with lower efficiency.
PAPR Reduction for Improved Efficiency of OFDM Modulation for Next Generation Communication Systems
International Journal of Electrical and Computer Engineering (IJECE)
Highly linear power amplifiers are required for transferring large amount of data for future communication. Orthogonal frequency division multiplexing (OFDM) provides high data rate transmission capability with robustness to radio channel impairments. It has been widely accepted for future communication for different services. But, it suffers from high value of peakto-average power ratio (PAPR). High value of PAPR drives high power amplifiers in saturation and causes it to operate in the nonlinear region. In this paper, comparative study of four different PAPR reduction techniques: clipping and filtering (CF), selective mapping method (SLM), partial transmit sequence (PTS) and DFT-spread technique have been done. Mathematical modeling and Matlab simulations have been performed to arrive at the results with 4 QAM modulation format and 1024 number of sub carriers. At 0.01 % of complementary cumulative distribution function (CCDF) significant reduction of 11.3, 3.5, 3.4 and 1.0 dB have been obtained with DFT-spread, SLM, PTS and CF techniques respectively.
Performance Improvement in OFDM System by PAPR Reduction
Signal & Image Processing : An International Journal, 2012
Power Ratio (PAPR) of the transmitted signals. OFDM consist of large number of independent subcarriers, as a result of which the amplitude of such a signal can have high peak values. Coding, phase rotation and clipping are among many PAPR reduction schemes that have been proposed to overcome this problem. Here two different PAPR reduction methods e.g. partial transmit sequence (PTS) and selective mapping (SLM) are used to reduce PAPR. Significant reduction in PAPR has been achieved using these techniques. The performances of the two methods are then compared.
Wireless Personal Communications, 2020
One of the main disadvantages of multicarrier transmission is the high peak-to-average power ratio (PAPR) of the transmitted signal. If the highest transmitted power is confined by the application restrictions or regulatory, the result is to decrease the average power permitted under multicarrier transmission. Selected mapping (SLM) is a standard PAPR reduction scheme that is appropriate for orthogonal frequency division multiplexing (OFDM) scheme as it realizes the performance of PAPR reduction without signal distortion. This paper proposes a method in order to handle the difficulties of high PAPR in OFDM scheme. The offered system is an arrangement of two distinguished methods, such as clipping and SLM. Compared to other hybrid methods, where the individual methods are implemented sequentially, this paper integrates the clipping method in the SLM procedure. This produces a supplementary PAPR reduction associated to the serial arrangement. Simulation results specify that the offered scheme acquires the performance of appropriate PAPR reduction with low computational complexity. The PAPR reduction at different number of subcarriers is analyzed and compared with the existing research work. The performance of relative energy efficiency has also been focused on this paper.
SELECTED MAPPING, CLIPPING AND DIFFERENTIAL SCALING FOR REDUCTION OF PAPR IN OFDM SYSTEM
In this paper, an SLM technique is introduced for the PAPR reduction of space-frequencyblock-coded OFDM systems with Alamouti coding scheme. Selected mapping (SLM) is a well-known technique for peak to-average-power ratio (PAPR) reduction of Orthogonal Frequency Division Multiplexing (OFDM) systems. In this paper, we also introduced a simple technique for the reduction of high Peak to Average Power Ratio (PAPR), based on Clipping and Differential Scaling, in Orthogonal Frequency Division Multiplexing (OFDM) systems. In this technique, the amplitude of complex OFDM signal is clipped and then scaled in such a way that the PAPR is reduced without causing much degradation in bit error rate (BER). We have determined the threshold values for clipping and scaling using Monte Carlo Simulations. We have also compared the performance of SLM with the clipping scaling technique.
A COMPARATIVE SURVEY ON PAPR REDUCTION TECHNIQUES FOR OFDM PERFORMANCE IMPROVEMENT
The Orthogonal Frequency Division Multiplexing is one of the modulation techniques widely used in the broadband wireless technology. One of the main problems of this technology is the high peak-to-average power ratio of transmission signal due to the superposition of many subcarriers. This paper presents a comparative studies of peak-to-average power ratio reduction technique, which compares among the selective mapping method, clipping method and Tone reservation techniques for PAPR reduction. The paper presents the performance of these different PAPR reduction techniques and compares it with unreduced PAPR.
PAPR REDUCTION OF OFDM SIGNALS USING SELECTIVE MAPPING AND CLIPPING HYBRID SCHEME
The Orthogonal Frequency Division Multiplexing is one of the modulation techniques widely used in the broadband wireless technology. One of the main problems of this technology is the high peak-to-average power ratio of transmission signal due to the superposition of many subcarriers. This paper presents a new hybrid peak-toaverage power ratio reduction technique, which combines a selective mapping method with the clipping method. The paper presents the performance and advantages of the new technique and compares it with other existing methods.