Results 51 to 60 of about 322 (180)

Companding technique for AM-SCM-PCMlightwave CATV systems

Electronics Letters, 1994
The companding technique has been shown theoretically to be effective for improving the fundamental CNR limit of AM-SCM-PCM lightwave CATV systems. For an 8 bit and 10 bit system, the improvement could be 3 and 4 dB, respectively, by use of erf-type companding, the corresponding CNR limits being raised to 44.8 and 56.8 dB, respectively.
Q. Pan, R.J. Green
openaire   +1 more source

Piecewise Companding Transform Assisted Optical-OFDM Systems for Indoor Visible Light Communications

IEEE Access, 2017
In visible light communications (VLCs) relying on intensity-modulation and direct detection (IM/DD), the conversion from electrical signals to optical signals and the limited dynamic range of the light-emitting diodes (LEDs) constitute the fundamental ...
Hongming Zhang, Lie-Liang Yang, Lajos Hanzo   +2 more
doaj   +1 more source

Simplified technique for syllabic companding inlog-domain filters

Electronics Letters, 2000
It is shown that when syllabic companding is applied to log-domain filters using dynamic biasing, their large signal linearity can be exploited to eliminate the state variable compensation circuit. Owing to its simplicity, the proposed technique has several advantages over previous approaches.
N. Krishnapura, Y. Tsividis, D.R. Frey
openaire   +1 more source

Constrained RS coding for Low Peak to Average Power Ratio in FBMC - OQAM Systems [PDF]

Journal of Electrical and Electronics Engineering, 2019
Multi-carrier modulation techniques have now become a standard in many communication protocols. Filter bank based multi-carrier (FBMC) generation techniques have been discussed in the literature as a means for overcoming the shortcomings of IFFT/FFT ...
Job CHUNKATH, V.S. SHEEBA, Nisha VARGHESE   +2 more
doaj  

A Novel Companding-Based Hermitian Symmetry Free ACO-UFMC Scheme for IM/DD in Low-Power IoT-Centric Future Wireless Communications

IEEE Access
For optical communication, the transmitted signal must be real-valued that can be achieved by employing Hermitian symmetry (HS). But the HS results in increased power consumption and decreased spectral efficiency (SE). Therefore, a HS free asymmetrically
Vijaya Durga Chintala, Rani Deepika Balavendran Joseph, Subba Rao Suddapalli, Vinay K. Tiwari, Anuradha Sundru   +4 more
doaj   +1 more source

An Enhanced Companding Algorithm for Universal Filtered Multi-Carrier System

ETRI Journal
This paper proposes a new companding scheme called three μ-law compand-ing to reduce the peak-to-average power ratio (PAPR) in a universal filtered multicarrier system. The proposed scheme is more flexible and provides better PAPR reduction and bit error
Vijaya Durga Chintala, Shri Ramtej Kondamuri, Subba Rao Suddapalli, Anuradha Sundru   +3 more
doaj   +1 more source

Improving bit error rate in optical wireless OFDM systems through hybrid companding and precoding strategies

EURASIP Journal on Wireless Communications and Networking
Visible light communication (VLC) is a promising wireless high-data-rate transmission technology that uses visible light. Optical Orthogonal Frequency Division Multiplexing (OOFDM)-based systems, especially asymmetrically clipped optical OFDM (ACO-OFDM),
Amal Yasser, Albashir A. Youssef, Mohamed Abaza   +2 more
doaj   +1 more source

A Comparison of ICF and Companding for Impulsive Noise Mitigation in Powerline Communication Systems [PDF]

, 2017
In future smart cities, smart grid technologies which are usually enabled by Powerline Communication (PLC) techniques are required. However, data transmission over powerline channel traverses a non-Gaussian media due to the presence of Impulsive Noise ...
Adebisi, B, Mohammad Hammoudeh, Kelvin Anoh, Bamidele Adebisi, Hammoudeh, M, Anoh, KOO   +5 more
core   +1 more source

Improved scheme of asymmetrically clipped optical-orthogonal frequency division multiplexing (ACO-OFDM) for wireless IM/DD optical systems

Results in Engineering
Visible light communication (VLC) systems that employ optical orthogonal frequency division multiplexing (O-OFDM) face a critical challenge in the form of a high peak-to-average power ratio (PAPR), which limits transmission efficiency and system ...
Mohamed M. Elnabawy, Ehab K I Hamad, Yasser A. Zenhom, Ahmed Z A Zaki, Haytham Gamal, Alaa Rabie, M.B. Badawi, Shuja Ansari, Mahmoud A. Shawky   +8 more
doaj   +1 more source

Vector quantization by companding a union of Z-lattices

, 2005
An encoding scheme is presented based on random coding theory in conjunction with companding techniques. This combination provides an easy design, and a low-storage quantizer. The groundwork of the study is Gaussian sources.
Shabestary, T. Z.,, Shabestary, T. Z., Hedelin, Per,, Hedelin, Per   +3 more
core   +1 more source