OFDM Based on Low Complexity Transform to Increase Multipath Resilience and Reduce PAPR

Ahmed, Mohammed Sh.; Boussakta, S.; Sharif, B.S.; Tsimenidis, Charalampos C.

doi:10.1109/tsp.2011.2166551

Cited by 49 publications

(43 citation statements)

References 16 publications

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“…However, OFDM has also disadvantages. Its high peak to average power ratio (PAPR) [11] is an important drawback that hinders its application in power-limited devices. As the number of subcarriers increases, also grows the possibility of having several subcarriers being constructively added, resulting in a signal with high amplitude peaks in the time-domain.…”

Section: Introductionmentioning

confidence: 99%

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PAPR Reduction and Performance Improvement in OFDM Systems using WHT-based Schemes

Aquino¹,

Mendes²

2017

JCIS

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Abstract-Orthogonal frequency division multiplexing (OFDM) is a robust and reliable multicarrier modulation scheme that has proven to be adequate for broadband communications. It is widely used in broadcasting and broadband wireless and wireline systems. However, in scenarios where the communication devices are power-limited, such as mobile and satellite communications, OFDM has not been massively used or even not used at all. For instance, OFDM is used only in downlink of 4G networks, while the uplink uses single carrier frequency division multiplexing. One of the main culprits of this is the high peak to average power ratio (PAPR) of the OFDM signal. Reducing the PAPR of the OFDM signals is important for a large variety of application. Several PAPR reduction techniques for OFDM have been proposed recently. The aim of this paper is to present a tutorial about a set of algorithms based on Walsh-Hadamard transform (WHT) for reducing the PAPR of the OFDM symbols. We also propose a new technique, named selective mapping based on WHT without extended information (SLM-WHT-WEI), which does not convey the explicit information to the receiver. We will show that the approaches based on WHT can also improve the OFDM symbol error rate performance over frequency-selective channels. Different schemes based on the properties of the WHT are presented and compared, assuming linear and non-linear channels. The PAPR reduction performance analysis shows that the PAPR can be effectively reduced while good performance in terms of symbol error rate can be achieved even in severely constrained channel conditions.

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Section: Introductionmentioning

confidence: 99%

“…The main principle consists on mapping the data symbols to a new domain, where the probability of the constructive sum of the subcarriers is reduced. Selective Mapping (SLM) [25]- [28], Partial Transmit Sequence (PTS) [29]- [33] and WalshHadamard Transform (WHT) [11], [34]- [39] are the most well-known algorithms in this category.…”

Section: Introductionmentioning

confidence: 99%

PAPR Reduction and Performance Improvement in OFDM Systems using WHT-based Schemes

Aquino¹,

Mendes²

2017

JCIS

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“…Orthogonal Frequency Division Multiplexing (OFDM) is a digital multi-carrier modulation scheme that extends the concept of single subcarrier modulation by using multiple subcarriers within the same single channel [1]. It is an important technology because many developing communications standards require the high throughput and multi-path advantages that are possible, Using a large number of parallel narrow band sub carriers instead of a single wide band carrier to transport information, Some of the benefits of using OFDM signals it's very easy and efficient in dealing with multi-path and Robust again narrow-band interference.…”

Section: Introductionmentioning

confidence: 99%

PAPR Reduction of OFDM Systems using 2D Inverse Discrete Fourier Transform

Hassoon¹,

Ruhaima²,

Alghrairi³

2017

IJCA

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A tow-dimensional (2D) orthogonal frequency division multiplexing (OFDM) system with peak-to-average power ratio (PAPR), a multicarrier system, is an important part of wireless communications engineering. Since these signals divide the bandwidth into other sub channels n, so the OFDM signals accomplish top data rates. Although, High peak-toaverage power ratio (PAPR) of the transmit signal is a major problem of multicarrier transmission such as orthogonal frequency division multiplexing (OFDM). To make fewer the PAPR values, There are many of techniques have been introduced, including selected mapping and amplitude clipping. The method that produces the least bit-error rate (BER) performance, its method is Amplitude clipping and filtering which is the simplest method. And from the other side, SLM although it presents a computational complexity, it is considered the most suitable and distortion less. In this research, a new technique is proposed based on twodimensional discrete Fourier transform (2D-DFT). In this paper we present a new method that reduces the computational complexities and distortion less compared to the SLM method. The M-PSK mapping types show from theoretical analysis that the PAPR can be reduced to something like 0.0 dB, as proven mathematically and by computer simulations.

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“…One of the existing techniques, which has received amount of research attention, is based on spreading each data symbol across all OFDM subcarriers [6,7], so that each subcarrier contains a linear combination of all the data symbols. Then, the deeply degraded subcarriers can also be recovered through a de-spread process in the receiver.…”

Section: Introductionmentioning

confidence: 99%

“…Rather than maximum likelihood (ML) receiver, whose complexity would be exponential growth with the number of symbols spread, the simple linear receivers, like zero-forcing (ZF) and minimum mean square error (MMSE), are often used in S-OFDM [7,11]. However, the ZF detector has the disadvantage of amplifying noise; the MMSE detector, which cuts down amplifying noise, has to estimate the variance of noise [6].…”

Section: Introductionmentioning

confidence: 99%

An Improved Zero-Forcing Detection Algorithm of Spread OFDM for Underwater Acoustic Communications

Wang¹,

Shi²,

Liu³

et al. 2017

Proceedings of the 2017 International Conference on Electronic Industry and Automation (EIA 2017)

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Abstract-The so-called spread OFDM(S-OFDM) system is designed to resist frequency-dependent attenuation by using Walsh-Hadamard (WH) code for spreading the frequency-domain OFDM symbols in the transmitter, and linear detectors, like ZF or MMSE, are usually used to recover the signals in the receiver. In this paper, an improved ZF detection algorithm is proposed for reducing the problem of amplifying noise compared with common ZF algorithm for spread OFDM in underwater acoustic channels. In contrast to the MMSE, the proposed algorithm dose not require estimating the variance of noise. Simulation results show that the proposed ZF algorithm has much better performance than that of common ZF method in all SNR range. Even if compared with MMSE, the proposed algorithm also gets much performance gain in high SNR range.

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OFDM Based on Low Complexity Transform to Increase Multipath Resilience and Reduce PAPR

Cited by 49 publications

References 16 publications

PAPR Reduction and Performance Improvement in OFDM Systems using WHT-based Schemes

PAPR Reduction and Performance Improvement in OFDM Systems using WHT-based Schemes

PAPR Reduction of OFDM Systems using 2D Inverse Discrete Fourier Transform

An Improved Zero-Forcing Detection Algorithm of Spread OFDM for Underwater Acoustic Communications

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