A Survey on Peak to Average Power Ratio Reduction Methods for LTE-OFDM

OFDM (Orthogonal Frequency Division Multiplexing) is generally preferred for high data rate transmission in digital communication. The Long-Term Evolution (LTE) standards for the fourth generation (4G) wireless communication systems. Orthogonal Frequency Division Multiple Access (OFDMA) and Single Carrier Frequency Division Multiple Access (SC-FDMA) are the two multiple access techniques which are generally used in LTE.OFDM system has a major shortcoming of high peak to average power ratio (PAPR) value. This paper explains different PAPR reduction techniques and presents a comparison of the various techniques based on theoretical results. It also presents a survey of the various PAPR reduction techniques and the state of the art in this area

(SI10-062) Comprehensive Study on Methodology of Orthogonal Interleavers

Interleaving permutes the data bits by employing a user defined sequence to reduce burst error which at times exceeds the minimum hamming distance. It serves as the sole medium to distinguish user data in the overlapping channel and is the heart of Interleave Division Multiple Access (IDMA) scheme. Versatility of interleavers relies on various design parameters such as orthogonality, correlation, latency and performance parameters like bit error rate (BER), memory occupancy and computation complexity. In this paper, a comprehensive study of interleaving phenomenon and discussion on numerous interleavers is presented. Also, the BER performance of interleavers using IDMA scheme is displayed

Interleaving Technique Implementation to Reduce PAPR of OFDM Signal in Presence of Nonlinear Amplification with Memory Effects, Journal of Telecommunications and Information Technology, 2018, nr 3

In OFDM systems, peak-to-average power ratio (PAPR) reduction of the signal is one of the main challenges that need to be overcome in order to use the transmitter in an efficient manner. As one of attractive techniques, interleaving can be used in PAPR reduction for multicarrier signals without spectrum distortion. In this paper, the authors propose to extend the possibilities of interleaving to improve PAPR reduction, to use a new coding of interleaver keys at the transmitter and a robust decoding procedure at the receiver. In order not to degrade the data rate, the use of null subcarriers to transmit side information to the receiver is proposed and evaluated. Simulation results in the context of the WLAN 802.11a standard in the presence of a nonlinear power amplifier model with memory, show a reduction of PAPR of approximately 5.2 dB, and an improvement of bit error rate and error vector magnitude of about 2 decades and 4% respectively, while respecting the spectral mask specification

Peak-to-Average Power Ratio Reduction of DOCSIS 3.1 Downstream Signals

Tone reservation (TR) is an attractive and widely used method for peak-to-average power ratio (PAPR) reduction of orthogonal frequency division multiplexing (OFDM) signals, where both transmitter and receiver agree upon a number of subcarriers or tones to be reserved to generate a peak canceling signal that can reduce the peak power of the transmitted signals. The tones are selected to be mutually exclusive with the tones used for data transmission, which allows the receiver to extract the data symbols without distortions. This thesis presents two novel PAPR reduction algorithms for OFDM signals based on the TR principle, which do not distort the transmitted signals. The first proposed algorithm is performed in the time domain, whereas the second algorithm is a new clipping-and-filtering method. Both algorithms consist of two stages. The first stage, which is done off-line, creates a set of canceling signals based on the settings of the OFDM system. In particular, these signals are constructed to cancel signals at different levels of maximum instantaneous power that are above a predefined threshold. The second stage, which is online and iterative, reduces the signal peaks by using the canceling signals constructed in the first stage. The precalculated canceling signals can be updated when different tone sets are selected for data transmission, accommodating many practical applications. Simulation results show that the proposed algorithms achieve slightly better PAPR reduction performance than the conventional algorithms. Moreover, such performance is achieved with much lower computational complexity in terms of numbers of multiplications and additions per iteration. Among the two proposed algorithms, the time-domain algorithm gives the best peak reduction performance but the clipping-and-filtering algorithm requires considerably less number of multiplications per iteration and can be efficiently implemented using the fast Fourier transform (FFT)/inverse fast Fourier transform (IFFT) structure

Analysis and Implementation of PAPR reduction algorithms for C-OFDM signals

Nowadays multicarrier modulation has become a key technology for communication systems; for example C-OFDM schemes are used in wireless LAN (802.11a/g/n), terrestrial digital television (DVB-T) and audio broadcaster (DAB) in Europe, and discrete multitone (DMT) in x.DSL systems. The principal difficulty with OFDM is the occurrence of the coherent alignment of the time domain parallel signals at the transmitted side which forces system designer to introduce either additional hard computationally device or a suitable power back-off at the high power amplifier in order to cope with the large magnitude signal fluctuation. This leads to a significant increment in computational cost in the former case whereas in a worse allowable power utilization in the latter case with respect to the original system. However since both allowable power and computational cost are subject to a design as well as regulatory limit others solution must be accomplished. Peak reduction techniques reduce maximum-to-mean amplitude fluctuations nominating as a feasible solution. Peak-to-average power ratio is the key metric to measure this amplitude fluctuations at transmitter and to give a clear figure of merit for comparison among different techniques

Journal of Telecommunications and Information Technology, 2018, nr 3

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Underwater acoustic communications in warm shallow water channels

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PAPR Reduction Using Interleavers with Downward Compatibility in OFDM Systems

International audienceIn this paper, we propose a new PAPR reduction method using interleaving technique without data rate loss. The main idea is to set up all possibility of interleaving to get the best reduction of PAPR and to transmit the resulting information via null-subcarriers (NS) available in OFDM (Orthogonal Frequency Division Multiplexing) standards. Thus, we develop a new coding of interleaver key based on mapping symbols at the transmitter and a robust decoding procedure at the receiver. Simulation results in the context of WLAN IEEE 802.11a standard show an improvement of PAPR reduction about 5,2 dB, with the same performance in BER (Bit Error Rate), while respecting the communication criteria (Data Rate and spectrum specification)

PAPR Reduction Performance in WIMAX OFDM Systems using Interleavers with Downward-Compatibility

International audienc