In this paper, the Bit Error Rate (BER), performance of conventional Discrete Fourier Transform (FFT) OFDM system is compared with Nonconventional Discrete Cosine Transform (DCT)OFDM system in AWGN and Rayleigh fading environment. Performance has been given with conventional mapping schemes like BPSK, QPSK and nonconventional mapping schemes like DQPSK and π/4 DQPSK. Simulation results show tha...

This paper addresses the most relevant aspects of lossy image coding techniques, and presents an evaluation study on this subject, using several transforms and different methods in the transform domain. We developed different transform based image coders/decoders (codecs) using different transforms, such as the discrete cosine transform, the discrete wavelet transform and the S transform. Besid...

Keywords: Biorthogonal transform Image compression JPEG algorithm All phase biorthogonal transform (APBT) Dual biorthogonal basis vectors Walsh transform (WT) Discrete cosine transform (DCT) Inverse discrete cosine transform (IDCT) Peak signal to noise ratio (PSNR) a b s t r a c t This paper proposes new concepts of the all phase biorthogonal transform (APBT) and the dual biorthogonal basis vec...

The widely known Discrete Fourier Transform (DFT), the frequency-domain representation of a finite-length time-domain sequence is an orthogonal transform and has been for very long time found many application. popularity DFT increased tremendously after publication Fast (FFT) algorithm by Cooley Tukey in 1965 <xref ref-type="bibr" rid="ref1" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:...

Biorthogonal wavelet transform has been widely used in the fields of image denoising and image coding. It is usually realized by linear phase filters. All phase digital filter is a new type of linear phase digital filter which has been proposed in recent years and has frequency structure. On the basis of analyzing principle of biorthogonal wavelet transform and discrete cosine sequency filter (...

The human visual system demonstrates powerful image processing functionalities. Inspired by the principles from neuroscience, a spiking neural network is proposed to perform the discrete cosine transform for visual images. The structure and the properties of the network are detailed in this paper. Simulation results show that the network is able to perform the discrete cosine transform for visu...