This study focused mainly on the derivation of the 2 and 3-point block methods with constant coefficients for solving special second order ordinary differential equations directly based on Newton-Gregory backward interpolation formula. The performance of the new methods was compared with the conventional 1-point method using a standard set of test problems. Numerical results were presented to i...

We introduce upper bounds on the achievable rates of binary linear block codes under maximum-likelihood (ML) decoding, and lower bounds on the asymptotic density of their parity-check matrices; the transmission of these codes is assumed to take place over an arbitrary memoryless binary-input output-symmetric channel. The bounds hold for every sequence of binary linear block codes. The new bound...

In this paper we investigate the suitability and performance of space-frequency block coded Multi-band orthogonal frequency division multiplexing (MB-OFDM) system under UWB channel model. The employment of transmit diversity techniques based on block codes is expected to achieve enhancement in such systems since it greatly reduces the detrimental effects of multipath fading. In the proposed MB-...

Video coding schemes rely on motion estimation and compensation methods to exploit temporal redundancies. Due to their simplicity and low overhead information, block matching techniques are widely used. They however induce annoying artifacts due the hypothesis of uniform motion within each block. In this paper, a VQ-based segmentation entailing a re nement of the motion eld is proposed. The seg...

H.264/AVC standard provides a significant improvement in digital video compression but it requires more computation power. In this paper a fast variable size block motion estimation algorithm based on adaptive search is implemented to describe a mode of variable size block motion compensation. This algorithm will adaptively change the threshold value depending upon the variable block sizes and ...

A fast, degradation-free solution for the DCT block extraction problem is proposed. The problem is defined as extracting a DCT block from a DCT compressed frame composed of DCT blocks. This problem is encountered in both video/image manipulations in the compressed domain and transcodecs, for example, converting from MPEG to Motion JPEG. Traditionally, solutions involve using the pixel domain ma...

In this correspondence, block and convolutional coding for Gaussian minimum shift keying (GMSK) in additive white Gaussian noise (AWGN) channels is investigated. The performance improvement that can be obtained without an increase in bandwidth is found for block and convolutional codes with various block lengths and constraint lengths, respectively, when a simple suboptimal demodulation scheme ...

A technique for performing progressive mesh-based motion estimation in a layered fashion is presented. Motion compensation based on image warping provides a block prediction free of block artifacts. The smooth prediction can be used to identify motion-active regions by comparing with the reference frame and generate a partial denser mesh, thus forming layers of mesh. This approach provides a hi...