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The objective of this proposal is to optimize the interactions between different components of a very high data rate wireless communications system so that the geographical area over which communications can reliably take place is maximized.
When very high data rates are transmitted over a wireless channel, the distance over which such transmissions can take place is very limited. This is because the higher the data rate, the larger is the power that is required. Since a handheld terminal can only transmit a fixed amount of power, due to many factors, such as health and battery life considerations, the transmission range at high data rates can be significantly smaller than the range at low data rates. Indeed, to the extent that high data rates make sufficiently wide coverage unfeasible, the growth of broadband wireless services will be limited. Thus, what we propose is an interdisciplinary research program to determine the best techniques to maximize the coverage of high data rate wireless communications systems. The results of the research being proposed are relevant to either satellite or terrestrial systems for which peak power limitations impose unacceptable restrictions on the size of cells/footprints.
It is desired to perform basic research, primarily at the physical and MAC layers, to determine whether it is feasible to transmit high data rate (e.g., an aggregate of 45 Mbps), multimedia, traffic, over wireless/mobile channels. The proposed interdisciplinary research program has concentrations of effort in the areas of source coding/data compression, forward error correction (FEC) coding, digital communications theory and MAC protocol design. The overall theme of the proposal is the design and performance analysis of wireless systems which will maximize geographical coverage at data rates of, say, T3 and higher. Note that at such high data rates, wide-area coverage becomes very difficult from a mobile unit, because, for a multiplicity of reasons, a mobile unit can only transmit at a relatively low power level, and, at a high data rate, the energy-per-bit that can be transmitted is thus necessarily low. For a terrestrial mobile system, the range of transmission is correspondingly limited; for a satellite system, where spot beams become the equivalent of cells, the footprints of each spot beam will have to shrink, due to the need for more directional antennas to compensate for the energy loss.
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Affiliated Faculty
CoRe Research Projects