Programmable H.263-based wireless video transceivers forinterference-limited environments

摘要

In order to exploit the nonuniformly distributed channel capacity over the cell area, an intelligent 7.3-kB programmable videophone transceiver is proposed, which is capable of exploiting the higher channel capacity of uninterfered, high-channel-quality cell areas, while supporting more robust, but lower bit-rate operation in more interfered areas. The system employed an enhanced H.263-compatible video codec. Since most existing wireless systems exhibit a constant bit-rate, the video codec's bit-rate fluctuation was smoothed by a novel adaptive packetization algorithm, which is capable of supporting automatic repeat request (ARQ)-assisted operation in wireless distributive video transmissions, although in the proposed low-latency interactive videophone transceiver, we refrained from using ARQ. Instead, corrupted packets are dropped by both the local and remote decoders in order to prevent error propagation. The minimum required channel signal-to-interference-plus-noise ratio (SINR) was in the range of 8-28 dB for the various transmission scenarios, while the corresponding video peak-signal-to-noise ratio (PSNR) was in the range of 32-39 dB. The main system features are summarized