Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Low ML-Decoding Complexity, Large Coding Gain, Full-Rate, Full-Diversity
  STBCs for 2 X 2 and 4 X 2 MIMO Systems   This paper (Part of the content of this manuscript has been accepted for
presentation in IEEE Globecom 2008, to be held in New Orleans) deals with low
maximum likelihood (ML) decoding complexity, full-rate and full-diversity
space-time block codes (STBCs), which also offer large coding gain, for the 2
transmit antenna, 2 receive antenna ($2\times 2$) and the 4 transmit antenna, 2
receive antenna ($4\times 2$) MIMO systems. Presently, the best known STBC for
the $2\times2$ system is the Golden code and that for the $4\times2$ system is
the DjABBA code. Following the approach by Biglieri, Hong and Viterbo, a new
STBC is presented in this paper for the $2\times 2$ system. This code matches
the Golden code in performance and ML-decoding complexity for square QAM
constellations while it has lower ML-decoding complexity with the same
performance for non-rectangular QAM constellations. This code is also shown to
be \emph{information-lossless} and \emph{diversity-multiplexing gain} (DMG)
tradeoff optimal. This design procedure is then extended to the $4\times 2$
system and a code, which outperforms the DjABBA code for QAM constellations
with lower ML-decoding complexity, is presented. So far, the Golden code has
been reported to have an ML-decoding complexity of the order of $M^4$ for
square QAM of size $M$. In this paper, a scheme that reduces its ML-decoding
complexity to $M^2\sqrt{M}$ is presented.

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The categories of this paper are: dg-ga
3
The categories of this paper are: physics
0
The categories of this paper are: hep-ph
17
The categories of this paper are: q-fin
26
The categories of this paper are: bayes-an
29
The categories of this paper are: funct-an
33
The categories of this paper are: plasm-ph
6
The categories of this paper are: astro-ph
25
The categories of this paper are: patt-sol
14
The categories of this paper are: math-ph
30
The categories of this paper are: q-alg
32
The categories of this paper are: atom-ph
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The categories of this paper are: comp-gas
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The categories of this paper are: mtrl-th
12
The categories of this paper are: nucl-th
31
The categories of this paper are: ao-sci