The challenges related to the deployment of ultrawideband (UWB) radios are posed in terms of interference issues that UWB radio systems will encounter. The problem of coexistence with a Global Positioning System (GPS) receiver is used as an experimental example. Calculation of an upper bound to UWB transmitter power illustrates the effect of one possible type of regulation for a given UWB antenna system. The inteference environment for a UWB receiver is used to lower bound the UWB transmitter power necessary for a given data rate. Sample measurements are provided.

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Traditionally, multiple listener room equalization is performed to improve sound quality at all listeners, during audio playback, in a multiple listener environment (e.g., movie theaters, automobiles, etc.). A typical way of doing multiple listener equalization is through spatial averaging, where the room responses are averaged spatially between positions and an inverse equalization filter is found from the spatially averaged result. However, the equalization performance, will be affected if there is a mismatch between the position of the microphones (which are used for measuring the room responses for designing the equalization filter) and the actual center of listener head position (during playback). In this paper, we will present results on the effects of microphone-listener mismatch on spatial average equalization performance. The results indicate that, for the analyzed rectangular configuration, the region of effective equalization depends on (i) the distance of a listener from the source, (ii) the amount of mismatch between the responses, and (iii) the frequency of the audio signal. We also present some convergence analysis to interpret the results.

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