A scaler is one of the most important modules in various video applications, such as ultra-high definition TV and scalable video systems. A variety of scaling techniques have been used to increase the video quality when the resolution of the source image has to be up- and down-scaled. Some conventional schemes exploit the property of local block data. Others consider the edge information of the data to be scaled. In this paper, we formulate a scaling problem to minimize the information loss resulting from the resizing process. The loss is considered in both the spatial and the frequency domains, and then it is minimized to optimize the kernel of the scaler. The simulation results show that the proposed algorithm reduces the information loss more than conventional schemes. When compared with the conventional algorithms, the proposed method outperforms those with similar complexity.

The IS-856 standard provides bandwidth-efficient and high-speed wireless internet services to mobile subscribers. It can provide a maximum data rate of 2.4 Mbps on the forward link and 153.6 kbps on the reverse link by adopting advanced techniques. On the reverse link, there is a distributed rate control algorithm, which is based on a probabilistic model. Each mobile determines its data rate at the beginning of a new frame using a reverse activity bit and persistence probabilities. In this paper, the performance of the rate control is analyzed by modeling it as a Markov process. The results show that there is a trade-off between the reverse link throughput and the outage probability. In addition, the performance of the rate control is highly dependent on system parameters of IS-856.