Pilot-assisted 16-level QAM for wireless video

This paper presents a twin-class transmission system for narrowband radio access channels suitable for handheld video phone and multimedia portable PC applications. The transmission system is comprised of a hierarchical 16-QAM modulation technique and a channel-coding scheme. The formation of dual-priority transmission is due to differing error resiliencies of the bits that make up a given symbol in a Gray-coded 16-QAM. On this basis, a twin-class pilot-assisted fade-estimation technique that can gracefully reduce the power loss caused by the transmission of pilot overhead is developed. The twin-class 16-QAM system is then used to transport a compressed video bitstream, which is partitioned to match the bit-error sensitivity of the transmitted symbol. The partitioning scheme is based on a separation of the variable-length (VL) coded discrete cosine transform (DCT) coefficients within each DCT block. This partitioning scheme is then applied to split the ITU-T H.263-coded bitstream. The ...

• Type: Journal
• Year: 2002
• Where: TCSV
• Authors: Hamid Gharavi
• Keywords: Partitioning Scheme, TCSV 2002, Transmission System, Twin-class Transmission