We point out the unstable operation of reverse traffic management in the cdma2000 1xEV-DO system, and propose a new rate control scheme that controls the reverse traffic load more precisely. The proposed scheme is modeled as a multidimensional Markov process and compared with the conventional scheme. The analysis results show that the proposed rate control scheme has a lower overload probability and higher reverse link throughput than the conventional one.

The high-speed downlink packet access (HSPDA) system is expected to effectively support voice services when Release 7/8 features are adopted in the system. In this letter, we point out that a voice packet can be transmitted at a lower power level than normal in the HSDPA network. We propose a power allocation scheme that adjusts the transmission power of voice packets optimally and allocates the remaining transmission power to data services in order to improve data throughput. The proposed power allocation is analyzed with a Rayleigh fading channel model and compared to conventional fixed power allocation.

The mode of intra prediction in H.264/AVC is encoded based on the most probable mode (MPM). To increase coding efficiency, the probability of the case that MPM is equal to coding mode of the current block should increase. In this paper we propose an efficient scheme to make MPM which is matched for the spatial direction property of pixels in the current block. Simulation results show that the proposed scheme gives significant coding gains when compared with the conventional techniques.