We propose a method of image enhancement, based on a spatial domain technique called histogram equalization. Traditional histogram equalization is only useful for images with backgrounds and foregrounds that are both bright or both dark, whereas our method works for images with high dynamic range. The technique is to segment the image into large regions with high contrast separations which are ...

Battery equalization can increase batteries’ life cycle, utilization, and reliability. Compared with battery equalization topologies based on resistance or energy storage components, the topologies based on transformers have the advantages of high balancing current and efficiency. However, the existence of switching losses will reduce the reliability and service life span of the equalization ci...

Recently, a new frequency-domain equalization (FDE) technique, called overlap FDE, that requires no GI insertion was proposed. However, the residual inter/intra-block interference (IBI) cannot completely be removed. In addition to this, for multicode direct sequence code division multiple access (DS-CDMA), the presence of residual interchip interference (ICI) after FDE distorts orthogonality am...

This work is mainly focused on showing experimental results using a combination of two methods for noise compensation which are shown to be complementary: classical spectral subtraction algorithm and histogram equalization. While spectral subtraction is focused on the reduction of the additive noise in the spectral domain, histogram equalization is applied in the cepstral domain to compensate t...

Abstract The use of frequency-domain equalization (FDE) based on minimum mean square error (MMSE) criterion can significantly improve the downlink bit error rate (BER) performances of DSand MC-CDMA in a frequency-selective fading channel. However, the uplink BER performance degrades due to strong multi-user interference (MUI) since different users’ signals go through different channels and henc...

Abstract A modification of transmit filtering in single-carrier (SC) transmission contributes to an improvement of system performance in terms of peak-to-average power ratio (PAPR) and bit error rate (BER). Using minimum mean-square error based frequency-domain equalization (MMSE-FDE) at the receiver can combat the problem of inter-symbol interference (ISI) arising from channel frequency-select...

Frequency-domain equalization (FDE) based on the minimum mean square error (MMSE) criterion can increase the downlink bit error rate (BER) performance of DS-CDMA beyond that possible with conventional rake combining in a frequency-selective fading channel. FDE requires accurate channel estimation. Recently, we proposed a pilot-assisted channel estimation (CE) based on the MMSE criterion. Using ...

Abstract The multiple-access interference (MAI) limits the performance of the DS-CDMA uplink transmission. 2D OVSF spread/chip-interleaved DS-CDMA is an MAI-free system, and hence single-user coherent frequency-domain equalization (FDE) can be used instead of complicated multiuser detection (MUD). However, coherent FDE needs channel estimation. Pilot-assisted channel estimation is not reliable ...

The purpose of this paper is to compare the turbocoded orthogonal frequency division multiplexing (OFDM) and turbo-coded single carrier frequency domain equalization (SCFDE) systems under the effects of carrier frequency offset (CFO), symbol timing offset (STO) and phase noise in wideband VoglerHoffmeyer HF channel model. The BER performance versus CFO, STO and phase noise obtained through Mont...

Single-carrier (SC) multiple access is a promising uplink multiple access technique because of its low peak-to-average power ratio (PAPR) property and high frequency diversity gain that is achievable through simple one-tap frequency-domain equalization (FDE) in a strong frequency-selective channel. The multiple access capability can be obtained by combining either frequency division multiple ac...