OFDMA_Part21 - shown in Figure 7. The left graph is for a...

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21 sensitive applications. An interesting part of this capacity region is the zero-outage capacity region. In the zero-outage region, the allocation policy maintains a constant rate for each user regardless of the channel state. In other words, it ensures no starvation happens for any user. In [25], the authors propose a combination of constraints that satisfy both ergodic and zero- outage capacity regions. The result of imposing these constraints is the new region that is named the minimum rate capacity region. In this scenario, some power is used to maintain the minimum data rates for all users while the rest of the power is used to maximize the long-term sum of user rates. The minimum rate region lies between the zero-outage region and the ergodic region as
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Unformatted text preview: shown in Figure 7. The left graph is for a small minimum rate value and the right graph is for a high minimum rate value. Therefore, the minimum region in the left graph is larger than the one in the right graph because it has higher excess power. Figure 7. Illustration of the Minimum Rate Capacity Region [25] The minimum rate capacity region is the sum of the ergodic capacity region of the effective channel and the minimum user data rates R* . The effective channel is the channel with power constraint P’ and effective noise n i e : …(E14) The resource allocation scheme used for this capacity region is a multilevel extension of the...
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This note was uploaded on 09/27/2009 for the course ECE 399 taught by Professor Prof during the Spring '09 term at University of Texas at Austin.

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