Abstract
This paper describes a low bit rate standalone portable video communication system developed for wireless applications. The video codec is based on H.263, and the audio codec is based on G.723.1. The transmission bandwidth is limited to 25 kHz. In order to have reasonable good video and audio quality, the source bit rate is set to 38 kbps. This includes video, audio and synchronization. The bit stream is embedded with 26 kbps for the error protection, resulted in 64 kbps. A 16-QAM is used for the modulation in order to meet the bandwidth requirement. The whole system deployed three general purposes DSP for the real time implementation of video coding, audio coding, channel coding and system control. Besides, a RF module is developed for the transmission on UHF band.