Companding techniques for SC-FDMA and sensor network applications

El-Rahman, Amal Fawzy Abd; Ahmed, Rania A.; Elnaby, Mustafa M. Abd; Khamis, S.; Napoleon, Sameh A.; Abd‐Elnaby, Mohammed; Ahmed, Zeinab; El-Rabaie, El-Sayed M.; El‐Samie, Fathi E. Abd

doi:10.1080/21681724.2019.1600051

Cited by 10 publications

(5 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Optical signals are compressed at the transmission side and reconstructed again at the reception side. Here, μ-law and A-law companding techniques are introduced [33].…”

Section: Non-linear Companding Techniquesmentioning

confidence: 99%

Hybrid PAPR reduction schemes for different OFDM-based VLC systems

2024

Opto-Electronics Review

View full text Add to dashboard Cite

Orthogonal frequency division multiplexing has been widely used in many radio frequency wireless communication standards as a preferable multicarrier modulation scheme. The modulated signals of a conventional orthogonal frequency division multiplexing system are complex and bipolar. In intensity-modulated direct detection optical wireless communications, transmitted signals should be real and unipolar due to non-coherent emissions of an optical light emitting diode. In this paper, different hybrid optical systems have been proposed to satisfy real and unipolar signals. Peak-to-average power ratio is one of the biggest challenges for orthogonal frequency division multiplexing-based visible light communications. They are based on a combination of non-linear companding techniques with spreading or precoding techniques. Simulation evaluation is performed under direct current-biased optical orthogonal frequency division multiplexing, asymmetrically clipped optical orthogonal frequency division multiplexing, and Flip-orthogonal frequency division multiplexing systems in terms of peakto-average power ratio, bit error rate, and spectral efficiency. The proposed schemes are investigated to determine a scheme with a low peak-to-average power ratio and an acceptable bit error rate. MATLAB TM software has been successfully used to show the validity of the proposed schemes.

show abstract

“…Optical signals are compressed at the transmission side and reconstructed again at the reception side. Here, μ-law and A-law companding techniques are introduced [33].…”

Section: Non-linear Companding Techniquesmentioning

confidence: 99%

Hybrid PAPR reduction schemes for different OFDM-based VLC systems

2024

Opto-Electronics Review

View full text Add to dashboard Cite

show abstract

“…The Cos companding approach is based on cos and is calculated according to (31). At the RX point, the de‐companding operation is applied to obtain the inverse function of

h(x)

given as in (32) according to Reference 36. Here, the cos companding function at the transmitter end is described by expression (31), sign function (sgn( x )) and the cos function are used to reduce the size of the input signal x.…”

Section: Problem Formulationmentioning

confidence: 99%

“…With the employment of the proposed hybrid technique, energy efficiency can be efficaciously enhanced in the UWA system by reducing PAPR values according to Table 4. Considering the linear model of HPA, power efficiency has been presented by (36) and (37).…”

Section: Impact Of Papr Reduction On System Energy Efficiency and Per...mentioning

confidence: 99%

“…By comparing (36) and (37), it can be stated that HPA power efficiency can be boost by scaling down PAPR. Consequently, these hybrid approaches play an important role in the energy harvesting of low-powered transducers employed for UWA communication.…”

Section: Impact Of Papr Reduction On System Energy Efficiency and Per...mentioning

confidence: 99%

“…Consequently, these hybrid approaches play an important role in the energy harvesting of low-powered transducers employed for UWA communication. By performing a comparative analysis in Tables 4 and 5, respectively, the most significant value for energy efficiency and gain according to (36) for our proposed hybrid scheme is .363 and 8.29 dB, respectively (RFC-mu law), and the most significant value in other hybrid approaches is .227 and 5.16, respectively (PTS-mu law).…”

Section: Impact Of Papr Reduction On System Energy Efficiency and Per...mentioning

confidence: 99%

See 2 more Smart Citations

Energy efficiency augmentation in UWA‐OFDM transducer by peak to average power ratio alleviation through hybrid companding approach

Banoori

Shi

Khan

et al. 2023

Trans Emerging Tel Tech

View full text Add to dashboard Cite

Orthogonal frequency division multiplexing (OFDM) is a compelling contender for next‐generation fixed and wireless standards to realize high data transmission rates in underwater acoustic (UWA) systems. A specific challenge before transmission over the transducers of the UWA system within an OFDM signal is the high peak to average power ratio (PAPR), which severely affects the energy efficiency of the UWA system. This work aims to enhance the energy efficiency of the UWA system by alleviating the stumbling block mentioned earlier within the OFDM. Moreover, we recommend and design a methodology that incorporates modified repeated frequency‐domain filtering and clipping (RFC) and companding techniques to restrain the PAPR obstacle. Additionally, the modified RFC utilizes various companding techniques (including linear and nonlinear techniques) to achieve the desired objectives without complexity augmentation of the system. We simulate and test our proposed approach against four major parameters: PAPR, bit error rate, energy efficiency, and system performance gain. Statistical results show that our technique offers .36 high‐power amplifier power efficiency (), which is comparatively better than OFDM with selective mapping, OFDM with partial transmit sequences, and OFDM with other hybrid approaches.

show abstract