Robust transmission of packet-based H.264/AVC video with data partitioning over DS-CDMA wireless channels

In this paper, we address the problem of robust transmission of packet based H.264/AVC video over direct sequence-code division multiple access (DS-CDMA) channels. H.264 based data partitioning is used to produce video packets of unequal importance with regards to their need in terms of the decoded video quality. In the proposed transmission system, the data partitioned video packets are packetized as per IP/UDP/RTP protocol stack and are sorted into different levels for giving unequal error protection (UEP) using Rate Compatible Punctured Convolutional (RCPC) codes. Constant size framing is done at the link layer and Cyclic Redundancy Check header (CRC) is attached for error detection. Link layer buffering and packet interleaving schemes are proposed to improve the efficiency of the system. A multipath Rayleigh fading channel with Additive White Gaussian Noise (AWGN) and interference from other users is considered at the physical layer. The link layer frames are channel encoded, spread and transmitted over the channel. The received data is despread/demodulated using the Auxiliary Vector (AV) filter or RAKE matched filter (RAKE-MF) receiver and subsequently channel and source decoded. Our experimental results show the effectiveness of using data partitioning for wireless transmissions when compared to the system not using data partitioning. Also the superior interference mitigation capabilities of AV receiver is shown in comparison to the RAKE-MF receiver.