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Design and Performance Evaluation of Space–time Receivers with Dynamically Adjustable Tap Delays

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The delay elements of a conventional two-dimensional space–time receiver are fixed. The rather inflexible design is inappropriate since the received signals among the antenna branches are correlated due to limited spacing, and the fading environment is time-varying. In this paper we propose a dynamic finger assignment strategy for a space–time receiver, where the delay taps are adjusted dynamically, based on the theory of finite projective planes, to improve the signal-to-noise ratio in correlated antenna branches. The proposed finite projective plane (FPP) based finger assignment scheme maximizes the collected energy by dynamically setting the tap delays depending on the correlation among antenna branches and the delay spread of the channel. In the performance evaluation, we demonstrate that the FPP based finger assignment scheme can improve the signal-to-noise ratio significantly in comparison to the conventional mesh-grid configuration when the correlation among antenna branches is high and the channel dispersion is relatively long in comparison to the overall span of the fingers. However, the gain is moderate if the channel dispersion ratio is short, where the gain of reduced correlation among antenna branches must compensate for the reduced signal-to-noise ratio due to the missed signals.

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Author information

Correspondence to Tai-Kuo Woo.

Additional information

This research is supported partially by National Science Council, Taipei, Taiwan.

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Woo, T. Design and Performance Evaluation of Space–time Receivers with Dynamically Adjustable Tap Delays. Wireless Pers Commun 46, 429–449 (2008). https://doi.org/10.1007/s11277-008-9445-x

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  • Space–time receivers
  • RAKE receivers
  • MIMO
  • Finite projective plane