Results 141 to 150 of about 10,890,806 (175)

Nonlinear companding transform technique for reducing PAPR of ODFM signals

IEEE Transactions on Consumer Electronics, 2012
In this paper a novel nonlinear companding transform (NCT) scheme based on the inverse hyperbolic sine function is proposed for reducing the peak-to-average power ratio (PAPR) of orthogonal frequency division multiplexing (OFDM) signals. By introducing the variable companding parameters and an inflexion point in the companding function, it enables more
Yong Wang 0013, Lihua Wang 0003, Jianhua Ge, Bo Ai 0001   +3 more
openaire   +1 more source

Reversible watermarking method based on adaptive thresholding and companding technique

International Journal of Computer Mathematics, 2011
Embedding and extraction of secret information as well as the restoration of the original un-watermarked image are highly desirable in sensitive applications such as military, medical, and law enforcement imaging. This paper presents a novel reversible watermarking approach for digital images using integer-to-integer wavelet transform, companding ...
Nisar Ahmed Memon, Asifullah Khan, S. A. M. Gilani, Mushtaq Ahmad   +3 more
openaire   +1 more source

Peak-to-Average Power Ratio (PAPR) Reduction Using Combination of Precoding and Companding Techniques for VLC OFDM Systems

2019 TEQIP III Sponsored International Conference on Microwave Integrated Circuits, Photonics and Wireless Networks (IMICPW), 2019
In VLC system, increase in data rate leads to inter symbol interference (ISI). It is desired to reduce the high ISI using suitable modulation technique for high rate data traffic.
N. Sharan, S. Ghorai, Ajit Kumar
semanticscholar   +1 more source

Performance enhancement of SC-FDMA systems using a companding technique

annals of telecommunications - annales des télécommunications, 2010
In this paper, a companding technique is proposed to effectively reduce the peak-to-average power ratio (PAPR) in single-carrier frequency division multiple access (SC-FDMA) systems. By companding the samples with large amplitudes, while enhancing those with small amplitudes, a significant reduction in the PAPR can be achieved.
Fathi E. Abd El-Samie, Faisal S. Al-Kamali, Moawad I. Dessouky, Bassiuny M. Sallam, Farid Shawki   +4 more
openaire   +1 more source

Novel companding technique for PAPR reduction in OFDM system

International Conference on Recent Advances and Innovations in Engineering (ICRAIE-2014), 2014
High value of PAPR and Inter-carrier Interference are two main drawbacks of the orthogonal frequency division multiplexing (OFDM) based wireless systems. The problem of high value of PAPR has been addressed in this work. A novel companding technique is proposed to reduce the PAPR of OFDM signals.
Eashendra Singh, Mohammad Arif
openaire   +1 more source

A companding technique for PAPR reduction in DWT OFDM systems

2014 IEEE International Conference on Advanced Communications, Control and Computing Technologies, 2014
Orthogonal frequency division multiplexing (OFDM) technique is considered as a advance technology in realizing high-speed wireless digital communications. However, high peak-to-average power ratio (PAPR) of transmitted signals is a major drawback for multi-carrier modulation systems such as orthogonal frequency division multiplexing and discrete ...
Bhawana Mohanty, Srinivas Ramavath
openaire   +1 more source

Two "noninvasive" techniques for syllabic companding in signal processors

IEEE Transactions on Circuits and Systems II: Analog and Digital Signal Processing, 2001
Two novel methods are described for syllabic companding in signal processors. These methods make state variable updating unnecessary, for piecewise constant input and output gains. Measurements and simulations are used as confirmation of the validity of the proposed techniques.
L. Toth, G. Palaskas, Y.P. Tsividis
openaire   +1 more source

A New Companding Technique for PAPR Reduction in OFDM Communication Systems

Wireless Communications, 2011
One of the major disadvantages of OFDM communication systems is their high peak-to-average power ratio (PAPR) which degrades system performance when nonlinear power amplifiers are employed. Among the proposed PAPR techniques companding is favorable due to its simplicity and easy of implementation.
openaire   +2 more sources

Partial companding as a PAPR reduction technique of an OFDM system

2012 International Conference on Informatics, Electronics & Vision (ICIEV), 2012
In this paper, a new technique of BER minimization in a companding based PAPR reduction scheme is proposed. In this approach, the conventional companding scheme is only applied for those OFDM signals whose amplitude exceeds a predefined threshold level, which results in lower BER and lower computational time. Though for the proposed scheme, improvement
Tabassum Haque, Subaha Mahmuda, Feroz Ahmed   +2 more
openaire   +1 more source

Companding technique for PAPR reduction in OFDM systems based on an exponential function

GLOBECOM '05. IEEE Global Telecommunications Conference, 2005., 2005
In this paper, a new non-linear companding technique, called "exponential companding", is proposed to reduce the high peak-to-average power ratio (PAPR) of orthogonal frequency division multiplexing (OFDM) signals. Unlike the mu-law companding scheme, which enlarges only small signals so that increases the average power, the schemes based on ...
Tao Jiang 0001, Yang Yang 0001, Yong-Hua Song   +2 more
openaire   +1 more source