Key performance specifications Up to 1.6 Gb/s Pattern Generator/Error detector for fast, accurate characterization of digital communications signaling systems PRBS or 8 Mb user-defined patterns provide the versatility to debug or verify any combination of digital signaling ANSI jitter measurements (RJ, DJ, and TJ) to measure the impact of random and deterministic jitter on the total jitter at B...

We consider combined rate and power adaptations in direct-sequence code-division multiple-access communications, where the transmission power and the data rate are adapted relative to channel variations. We discuss the power gain that the combined adaptations provide over power adaptation. Then, we consider an integrated voice and data transmission system that offers a constant bit rate voice s...

EEective rate variation during active speech is a necessary component of sophisticated variable rate speech compression schemes. Here, we use open-loop estimates of spectral shape to roughly determine signal bandwidth and bit allocations for variable rate encoding of spectral parameters. We analyze the application of the relative entropy functional to sets of Line-Spectrum Pairs (LSPs) and tran...

In this paper, the generalized Gaussian distribution is employed to model the 16(4*4) integer transform coefficients of the residue image in H.264 videos. Then the distortion−rate function of generalized Gaussian model is analyzed as well as a flexible rate−distortion (R−D) model is developed to approximate the actual R−D function. Finally, an effective variable bit rate (VBR) algorithm for H.2...

This paper proposes an adaptive frame layer rate control scheme for H.264 by introducing a linear model to predict the mean absolute difference (MAD) of current frame by that of previous one. The target bit rate for each frame is computed by adopting a fluid flow traffic model and linear tracking theory. The corresponding quantization parameter is computed by using a quadratic rate– distortion ...

Real-time services, including constant bit rate (CBR) and real-time variable bit rate traffic (rt-VBR), have become increasingly important owing to the rapid proliferation of multimedia applications. A cell multiplexing method capable of handling real-time traffic should satisfy related quality of service (QoS) requirements, including cell transfer delay (CTD), cell delay variation (CDV) and ce...

An algorithm recently introduced by Breiman, Friedman, Olshen, and Stone in the context of classification and regression trees is reinterpreted and extended to cover a variety of applications in source coding and modeling in which trees are involved. These include variable-rate and minimum-entropy tree-structured vector quantization, minimum expected cost decision trees, variable-order Markov m...

Pattern-based video coding representing moving regions in macroblock has very good potential for improved coding efficiency over existing standard H.264/AVC in the very low bit-rate range. However, the coding efficiency diminishes compared to H.264 with the bit rates because variable block sizes of H.264 for motion estimation and compensation are successfully selected for any bit rates using we...

In this paper, we present a novel background noise coding scheme for variable rate speech coders. Existing approaches to noise coding at very low bit rates (i.e. below 1 kbps) fail to faithfully reproduce background noise resulting in a degradation of the overall perceptual quality. In our approach, classification of the noise type is used to select the type of excitation to be used at the rece...