Abstract

We use statistical multiplexing and power control to define a notion of delay limited capacity, valid for traffic such as voice and video that cannot tolerate delay. Our capacity bounds the performance of schemes that are robust to changes in the rate of the fading processes. 1 Introduction Fading poses severe problems in mobile, wireless communications. An important technique currently used to mitigate fading is error control coding. Shannon theory enables us to calculate the maximum possible rate in bits/sec that can be reliably sent on the channel. It is not clear, however, that such Shannon capacities are always useful measures if the traffic is delay limited. With block lengths constrained by the delay requirements of the traffic, it is not clear that the fading will always be sufficiently fast to allow averaging over the block length. In the present paper, we show that a notion of "delay limited capacity" can be defined. We first consider a white Gaussian noise model in which us...

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