We propose and analyze new finger assignment/management techniques that
are applicable for RAKE receivers when they operate in the soft handover region.
Two main criteria are considered: minimum use of additional network resources and
minimum call drops. For the schemes minimizing the use of network resources, basic
principles are to use the network resources only if necessary while minimum call drop
schemes rely on balancing or distributing the signal strength/paths among as many
base stations as possible. The analyses of these schemes require us to consider joint
microscopic/macroscopic diversity techniques which have seldom been considered before
and as such, we tackle the statistics of several correlated generalized selection
combining output signal-to-noise ratios in order to obtain closed-form expressions for
the statistics of interest. To provide a general comprehensive framework for the assessment
of the proposed schemes, we investigate not only the complexity in terms of
the average number of required path estimations/comparisons, the average number
of combined paths, and the soft handover overhead but also the error performance of
the proposed schemes over independent and identically distributed fading channels.
We also examine via computer simulations the effect of path unbalance/correlation as
well as outdated/imperfect channel estimations. We show through numerical exam ples that the proposed schemes which are designed for the minimum use of network
resources can save a certain amount of complexity load and soft handover overhead
with a very slight performance loss compared to the conventional generalized selection
combining-based diversity systems. For the minimum call drop schemes, by
accurately quantifying the average error rate, we show that in comparison to the
conventional schemes, the proposed distributed schemes offer the better error performance
when there is a considerable chance of loosing the signals from one of the
active base stations.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/ETD-TAMU-1489 |
| Date | 15 May 2009 |
| Creators | Choi, Seyeong |
| Contributors | Alouini, Mohamed-Slim, Georghiades, Costas N. |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Dissertation, text |
| Format | electronic, application/pdf, born digital |
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