Histograms are the basis for numerous spatial domain image processing techniques. Histogram manipulation can be used effectively for image enhancement. In addition to providing image statistics, the information inherent in the histogram is also quiet useful in other image processing applications, such as image compression and segmentation. Histograms are simple in manipulation as well as econom...

Joint frequency-domain equalization (FDE) and antenna diversity combining is applied to the reception of multi-rate DS-CDMA signals to achieve the frequency diversity effect while suppressing interpath interference (IPI) resulting from the asynchronism of different propagation paths. At a receiver, fast Fourier transform (FFT) is applied for FDE and then inverse FFT (IFFT) is used to obtain a f...

Orthogonal multi-carrier direct sequence code division multiple access (orthogonal MC DS-CDMA) is a combination of time-domain spreading and orthogonal frequency division multiplexing (OFDM). In orthogonal MC DS-CDMA, the frequency diversity gain can be obtained by applying frequency-domain equalization (FDE) based on minimum mean square error (MMSE) criterion to a block of OFDM symbols and can...

Orthogonal signal-division multiplexing (OSDM) is a newly emerged modulation scheme which provides a generalized framework unifying conventional orthogonal frequency-division multiplexing (OFDM) and single-carrier frequency domain equalization. In this letter, a space-frequency block coding (SFBC) scheme based on OSDM is proposed for time-varying underwater acoustic channels. The receiver proce...

In this paper, a new method based on the class-based histogram equalization to compensate the acoustic mismatch between training and test conditions of speech recognizers is proposed. The proposed method improves the speech recognition accuracy in noisy environments by reducing two limitations of the conventional histogram equalization: The discrepancy of phonetic class distributions between tr...

We propose an adaptive iterative layered space−frequency equalization (AILSFE) structure for multiple−input multiple−output (MIMO) time−varying frequency selective channels, which incorporates iterative frequency−domain equalization (FDE) with hybrid interference cancellation. It is shown that AILSFE significantly outperforms the previously proposed LSFE with a modest increase of complexity, an...

Frequency-domain equalization (FDE) technique may play an important role for broadband packet transmission using MCand DS-CDMA. The downlink performance is significantly improved with FDE; however, the uplink performance is limited by the multi-access interference (MAI). To remove the MAI while gaining the frequency diversity effect through the use of FDE, frequency-domain block spread CDMA can...

For coded data transmission over channels introducing inter-symbol interference, one approach for joint equalization and decoding in the receiver is Turbo Equalization. We rederive existing linear equalization algorithms applicable to Turbo Equalization for 2m-ary signal alphabets and compare their computational complexity. Moreover, by evaluating the algorithm performance properly, we select f...