Boosted PTS Method with Mu-Law Companding Techniques for PAPR Reduction in OFDM Systems

This paper proposes an enhanced PAPR reduction technique which combines an enhanced PTS method with Mu-Law companding. The enhanced PTS method improves performances in both the partitioning and phase rotation steps. Enhancement in partitioning is achieved through a judicious incorporation of AP-PTS scheme into the IP-PTS. As for phase rotation, an optimal set of rotation vectors is derived based on the correlation properties of candidate signals. The PAPR reduction of this enhanced PTS method is further improved by annexing Mu-Law companding at the end of the enhanced PTS. This application of Mu-Law characteristic in the time domain of OFDM signal significantly improves the PAPR reduction capability of the approach. Simulation results show that the PAPR performance of the enhanced PTS method with Mu-Law companding technique on various scenarios with different modulation schemes is better than that of the PRP-PTS. This approach can be considered as a very attractive candidate for achieving a significant reduction of PAPR, while maintaining a low computational complexity

Blind Algorithm Development for Peak to Average Power Ratio Reduction in OFDM Systems under Frequency Selective Channels

One major drawback of orthogonal frequency division multiplexing (OFDM) system is peak to average power ratio (PAPR). This effect causes high power amplifier (HPA) to introduce intermodulation and out of band radiation as the signal goes through, thus degrades the performance of OFDM systems. This paper proposes blind algorithms which takes advantage of signal transformation technique and signal distortion technique. Simulation results show that at complementary cumulative distribution function (CCDF) level of 10-3 , the proposed algorithm achieved 3.2 dB PAPR improvement compared to discrete Fourier transform with interleaved frequency division multiple access (DFT-IFDMA) based algorithm. The bit error rate (BER) performance has degraded by 2 dB compared to the original OFDM signal with no distortion under frequency selective channel (FCS) at BER of 10-4 . These presented results, mark this algorithm as a better candidate for PAPR reduction algorithm in long term evolution (LTE) network. Under AWGN channels, the proposed algorithm performs better both in low and high signal power values. Under frequency selective channels, the existing and proposed algorithm converges after 10 dB of signal to noise power values. The low BER transmissions at low signal power values signify energy efficiency, ideal for portable wireless devices with limited battery power

Pembuatan Model Hybrid 2 Teknik Reduksi Peak-to-average Power Ratio Partial Transmit Sequence Dan Clipping Filtering Pada Sistem Mimo-ofdm

Sistem MIMO digunakan dalam sistem komunikasi nirkabel modern untuk memenuhi tuntutan kecepatan transmisi data yang tinggi untuk berbagai aplikasi dan layanan namun sistem MIMO-OFDM mempunyai kelemahan nilai PAPR (Peak to Average Power Ratio) yang tinggi dan membuat HPA (High Power Amplifier) bekerja pada daerah non-linier. Sehingga perlu dilakukan reduksi dengan teknik reduksi PAPR. dalam Penelitian ini dilakukan analisis reduksi PAPR pada sistem MIMO-OFDM menggunakan teknik hybrid Improved Partial Transmits Sequence dan Simplified Clipping Filtering. Analisis dilakukan dengan mengamati kinerja penggunaan teknik reduksi PAPR dan penggunaan tanpa teknik reduksi PAPR. Hasil simulasi menunjukkan pada probabilitas 1x10-5, hasil kinerja tanpa teknik reduksi dibutuhkan level threshold PAPR0 sebesar ± 12 dB, sedangkan ketika menggunakan teknik reduksi hybrid Improved PTS dan Simplified CF dibutuhkan level threshold PAPR0 rata-rata ± 6 dB dan membandingkan kinerja teknik reduksi Hybrid Improved PTS - Simplified CF dengan nilai Clipping ratio 1,4 dan 1,6. Maka kinerja reduksi PAPR terbaik adalah dengan menggunakan teknik reduksi hybrid Improved PTS dan Simplified CF dengan Clipping ratio 1,4 karena mampu menyuguhkan selisih nilai reduksi sebesar ± 5,7 dB daripada tanpa menggunakan teknik reduksi. dan penggunaan nilai Clipping Ratio yang semakin rendah menghasilkan nilai PAPR yang juga semakin rendah, karena Amplitudo maksimum semakin kecil

A Hybrid Segmentation Pattern of Partial Transmission in Computer Networks to Reduce the Complexity Level

Partial transmission sequence (PTS) is seen as a related project in the framework of the Orthogonal Frequency Division ‎Multiplexing (OFDM) to suppress the medium to high Peak-to-Average Power Ratio problem. The PTS chart data is based on dividing the back into subdivisions and their weight by combining step-by-step factors. Despite the fact that PTS can reduce the high specifications. The Computational Complexity Level (CC) limits the scope of application to match PTS use with ground applications. In PTS, there are three main distribution schemes. Interleaving projects (IL-PTS), arbitrary and alternate (PR-PTS) and Ad-PTS. In this paper, another algorithm called the Hybrid Pseudo-Random and Interleaving Cosine Wave Shape ‎‎(H-PRC-PTS) is presented and the PR-PTS equilibrium is established by stabilizing the cousin waveform between languages (S-IL-C- PTS), which was suggested in the previous work. The results showed that the proposed algorithm could reduce the validity of PAPR as a PR-PTS scheme, although the CC level was significantly reduced

AN EFFICIENT METHOD FOR PAPR REDUCTION IN OFDM SYSTEMS WITH REDUCED COMPLEXITY

Orthogonal Frequency Division Multiplexing (OFDM), widely used in digital wireless communication, has a major drawback of high Peak to Average Power Ratio (PAPR). A reduced complexity partial transmit sequence (PTS) scheme has been proposed to solve high peak to average power ratio (PAPR) of orthogonal frequency division multiplexing (OFDM) system. In the proposed PTS scheme, a function is generated by summing the power of time domain samples at time ‘n’ in each sub blocks, known as “Hn”.Only those samples, having Hn greater than or equal to a preset threshold value (αT) are used for peak power calculation during the process of selecting a candidate signal with the lowest PAPR for transmission. As compared to conventional PTS scheme, the proposed scheme achieves almost the same PAPR reduction performance with much lower computational complexity

Efficient PAPR reduction of OFDM signal using PTS technique with hybrid partitioning method

The high peak-to-average power ratio (PAPR) is one of the major problems of orthogonal frequency division multiplexing (OFDM) systems in wireless transmission.Therefore, partial transmit sequence (PTS), a promising scheme that can provide good PAPR reduction performance, has been proposed for OFDM transmission to eliminate distortion. The PTS method divides the input data block into disjoint sub-blocks, computes Inverse Fourier Transform of the subblocks, rotates the sub-blocks with appropriate phase factors and combines them to form the transmitted signal.This paper presents an enhanced PTS approach that combines two PTS partitioning schemes (adjacent and interleaved) to effectively reduce the PAPR of the OFDM systems. The influence of the proposed approach on performance is investigated by varying the size of the disjoint sub-blocks.The PAPR reduction performance of the proposed PTS method is compared with two well known sub-blocks partitioning schemes, namely, Adjacent Partitioning (AP), Interleaved Partitioning (IP).The various computer simulation results for the various sub-blocks confirmed that the proposed method provides better PAPR reduction performance compared with AP and IP partitioning based PTS scheme. In addition, these PTS schemes largely depend on the chosen size of the partitions

EFFICIENT PAPR REDUCTION OF OFDM SIGNAL USING PTS TECHNIQUE WITH HYBRID PARTITIONING METHOD

ABSTRACT The high peak-to-average power ratio (PAPR) is one of the major problems of orthogonal frequency division multiplexing (OFDM) systems in wireless transmission. Therefore, partial transmit sequence (PTS), a promising scheme that can provide good PAPR reduction performance, has been proposed for OFDM transmission to eliminate distortion. The PTS method divides the input data block into disjoint sub-blocks, computes Inverse Fourier Transform of the subblocks, rotates the sub-blocks with appropriate phase factors and combines them to form the transmitted signal. This paper presents an enhanced PTS approach that combines two PTS partitioning schemes (adjacent and interleaved) to effectively reduce the PAPR of the OFDM systems. The influence of the proposed approach on performance is investigated by varying the size of the disjoint sub-blocks. The PAPR reduction performance of the proposed PTS method is compared with two well known sub-blocks partitioning schemes, namely, Adjacent Partitioning (AP), Interleaved Partitioning (IP). The various computer simulation results for the various sub-blocks confirmed that the proposed method provides better PAPR reduction performance compared with AP and IP partitioning based PTS scheme. In addition, these PTS schemes largely depend on the chosen size of the partitions

Partial Shift Mapping Decoding Algorithm to PAPR Reduction in OFDM Systems

Orthogonal Frequency Division Multiplexing (OFDM) is a kind of modulation technique which allows the transmission of high data rates over wideband radio channels subject to frequency selective fading by dividing it to several narrow band and flat fading channels. OFDM has high spectral efficiency and Robustness to multipath fading. In contrast high peak to average power ratio (PAPR) of the transmitted signals is a major drawback of multicarrier systems like OFDM. High PAPR causes the nonlinear distortion in the received data and reduces the efficiency of the high power amplifier in transmitter. To solve the problem many techniques such as SLM and PTS algorithms are proposed. Recently a new simple method with low complexity respected to the SLM and PTS as Partial Shift Mapping (PSM) is proposed by Xing et al. He showed that the PSM method can reduce the PAPR parameter respected the other mentioned methods, effectively. In this paper we will design the corresponding decoder to the PSM technique and will evaluate its robustness respected to the high power amplifier distortion and the AWGN channel. Simulation results will show that the PSM method has a better Power spectrum density and is less sensitive to the type of modulation and number of subcarriers

PAPR reduction in OFDM system using combined MCS and DHMT precoding

Orthogonal Frequency Division Multiplexing (OFDM) has become a preferable scheme for most high data rate wireless communication standards. However, the non-linear power amplifier effect experienced in the OFDM system has increases the peak-to-average power ratio (PAPR). This paper proposed a Median Codeword Shift (MCS) as a new solution to alleviate the effect of high PAPR. MCS takes advantage of the codeword structure and bit position changes through the manipulation of the codeword structure and permutation process to achieve a low PAPR value. Additionally, the enhanced version of MCS is also being proposed by merging MCS with the Discrete Hartley matrix transform (DHMT) precoding method to boost the PAPR reduction. Simulation results show that MCS is capable of minimizing PAPR of conventional OFDM with 24% improvement and at the same time outperform Selective Codeword Shift (SCS) with a 0.5 dB gap. A remarkable result was also achieved by MCS-DHMT with a 15.1% improvement without facing any bit error rate (BER) degradation

An Enhanced Partial Transmit Sequence Based on Combining Hadamard Matrix and Partitioning Schemes in OFDM Systems

The partial transmit sequence (PTS) considered as one of the efficient approaches to restrain the high peak to average-power ratio (PAPR) in orthogonal frequency division multiplexing (OFDM) frameworks. PTS relied on partitioning the input data block and rotate them with a set of the phase vectors. In this study, a novel technique is suggested to improve the PAPR reduction performance in the PTS technique by combining Hadamard matrix and the popular kinds of the partitioning schemes interleaving scheme (IL-PTS), adjacent scheme (Ad-PTS), and pseudo-random scheme (PR-PTS). The new approach employed Hadamard matrix to change some of the subcarrier phases of the partitioning scheme in the frequency-domain. The simulation results demonstrated that the new method improved the PAPR diminishment performance better than that of the PR-PTS and Ad-PTS. However, the proposed method achieved the same PAPR performance compared with the IL-PTS scheme