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arXiv · 0911.4896

Diversity Order in ISI Channels with Single-Carrier Frequency-Domain Equalizers

Ali Tajer·Aria Nosratinia
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Abstract

This paper analyzes the diversity gain achieved by single-carrier frequency-domain equalizer (SC-FDE) in frequency selective channels, and uncovers the interplay between diversity gain $d$, channel memory length $\nu$, transmission block length $L$, and the spectral efficiency $R$. We specifically show that for the class of minimum means-square error (MMSE) SC-FDE receivers, for rates $R\leq\log\frac{L}{\nu}$ full diversity of $d=\nu+1$ is achievable, while for higher rates the diversity is given by $d=\lfloor2^{-R}L\rfloor+1$. In other words, the achievable diversity gain depends not only on the channel memory length, but also on the desired spectral efficiency and the transmission block length. A similar analysis reveals that for zero forcing SC-FDE, the diversity order is always one irrespective of channel memory length and spectral efficiency. These results are supported by simulations.

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Ali Tajer, Aria Nosratinia. 2009-11-25. Diversity Order in ISI Channels with Single-Carrier Frequency-Domain Equalizers. https://arxiv.org/abs/0911.4896

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