Hierarchical transmission system using multi-code/multi-rate DS/SS modulation

For the transmission of video signals, it is important that the system allows a certain degree of flexibility in the bit rate as well as the quality depending upon the requirement of the media and channel conditions. We discuss the hierarchical transmission of Huffman code using a multi-code/multi-rate DS/SS system to realize flexible transmission. We first discuss and show that the structure of the Huffman code tree directly expresses the hierarchical structure, and parallel transmission of Huffman code can achieve hierarchical transmission. By assigning a different transmission data rate, it is possible to transmit a different amount of information from each stratum. Further, we show a quality of each of stratum can easily controlled by an appropriate power distribution to each parallel transmission branch