STUDY ON MULTIMEDIA MOBILE INFORMATION NETWORK

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Towards the realization of high rate and highly reliable multi-media communication over mobile radio channel, basic key techniques have been studied. Major research results are summarized as follows.・ Interference canceler, not only canceling co-channel interference but also overcoming severe intersymbol interference caused by multipath propagation, has been studied. In particular, trellis coded interference canceler (TCC) and simple yet poweful single-user type interference canceler have been proposed and studied in detail for TDMA and CDMA,respectively.・ A dynamic channel allocation algorithm suitable for integrated traffic consisting of voice and data, for instance, has been proposed. Its superior performance has been verified assuming single slot voice and three slot data traffic.・ A dynamic channel allocation algorithm suitable for an asymmetric channel where up-link and down-link traffic are not balanced has been studied assuming TDMA/TDD system. By allocating more channels to the heavier traffic side between up and down links, better performance has been confirmed.・ In highly data compressed image transmission, variable lenght coding is frequently used. It is, therefore, likely to lose frame synchronization and bursty errors occur. We have proposed to combine error resiliant entropy coding (EREC) and unequal error protection coding, and confirmed its superior performance.・ In moving image transmission, interframe predictive coding is often used. Errors tend to propagate through the succeeding frames. Thus, to prevent error propagation, an error control scheme based on ARQ which takes the advantage of the assumed source coding into account has been proposed, and its superior performance has been confirmed.