Best Paper Nomination
Communication Theory Symposium
Paper #1569303854, “Benefits of Transmit Antenna Selection in Ad Hoc Networks”
by Yueping Wu (HKUST), Raymond Hall Yip Louie (Univ. Sydney), Matthew R McKay
(HKUST), and Iain B. Collings (CSIRO Australia).
We considered the top twelve highest scoring papers in our session with an
emphasis on novelty, timeliness, and rigor. The first thing we noticed about this
manuscript is the quality and stature of the reviewers: the fact that this paper
received the highest weighted score from such well-known reviewers impressed us.
The next thing that impressed us about this manuscript is the way in which is
applies theoretic principles to address a very practical problem. The analysis is
rigorous and mature. The results of this work are an important step in making
MIMO a practical part of ad-hoc networks.
The fact that MIMO can produce performance gains in wireless networks is wellknown in communication theory circles. However, the complexity of achieving these
performance gains is usually deemed prohibitive. This paper uses information
theoretic concepts to establish the performance gains possible with a lowcomplexity approach to MIMO based on transmit antenna selection. By using a
subset of the available transmit antennas, both the amount of channel state
information in the receiver-to-transmitter feedback path and the network
interference are reduced. In addition to quantifying these gains (via new
mathematical expressions for the network throughput and the transmission
capacity), the paper also identifies the conditions under which these gains are
possible. Because the conditions are relatively common in real ad-hoc networks, the
potential application space for this result is enormous.
In summary, this is a well-written paper, with glowing reviews by outstanding
reviewers, that embodies the ideal of using highly theoretical concepts and rigorous
mathematical analysis to solve a very practical problem.
Relevance and
timeliness
Excellent (5)
Technical content and
scientific rigor
Solid work of notable
importance. (4)
Novelty and originality
Quality of presentation
Significant original work
and novel results. (4)
Excellent. (5)
Strong aspects (Comments to the author: what are the strong aspects
of the paper)
This paper studies transmit antenna selection in an adhoc wireless network that contains an
arbitrary number of multi-antenna transmitter receiver pairs. Each transmitter wants to transmit
possibly multiple streams to a single receiver. The independent streams are transmitted accross
a subset of the available N transmit antennas, that is where the antenna selection becomes
relevant. The receiver uses zero forcing to decode the symbols.
One of the strengths of the paper is that the authors employ quite a practical antenna selection
scheme; the antennas are selected based on the transmitter-receiver channel state, no
information regarding the interferers is required. Even in such a partially noncoherent selection
scenario, their scheme is shown to outperform a scheme where the antennas are selected
randomly. They also provide an approximate analysis of their scheme which performs reasonably
close to the actual performance. The approximations are well justified and reasonable as far as
the scale of the network and the generality of the model is considered.
Finally, they obtain a criterion that shows how many of the transmitter antennas should be
selected to achieve an increasing transmission capacity. This criterion depends on the number of
transmitter antennas and the path loss exponent.
To summarize, their scheme is simple, elegant, and they demonstrate that it works by (almost)
careful analysis. I suggest acceptance.
Weak aspects (Comments to the author: what are the weak aspects of
the paper?)
No weak aspects.
Recommended changes (Recommended changes. Please indicate
any changes that should be made to the paper if accepted.)
No changes recommended.
Relevance and
timeliness
Excellent (5)
Technical content and
scientific rigor
Solid work of notable
importance. (4)
Novelty and originality
Quality of
presentation
Significant original work and
novel results. (4)
Excellent. (5)
Strong aspects (Comments to the author: what are the strong aspects
of the paper)
This paper is a nontrivial extension of the transmit antenna selection briefly considered in [2] to
the case where there are N receive antennas. Also, a new and more accurate and complete
method for computing outage probability is given, which is somewhat cumbersome but
nevertheless accurate. It also permits transmission capacity to be computed and scaling to be
observed, which allows some intuitive lessons to be drawn.
The paper is well written and results are pretty clear considering their complexity.
Weak aspects (Comments to the author: what are the weak aspects of
the paper?)
The paper suffers from length restrictions, since some key proofs and expressions are omitted,
but this is not the fault of the authors.
The abstract was initially confusing where they refer to "single antenna transmission" after just
referring to multiple antenna transmitters. It took me a minute to realize they mean the case
where just one of the N antennas is used.
Recommended changes (Recommended changes. Please indicate
any changes that should be made to the paper if accepted.)
Above comment on abstract. Plus it would be nice if arxiv version with full results was made
available with link.
Relevance and
timeliness
Excellent (5)
Technical content and scientific
rigour
Excellent work and outstanding
technical content. (5)
Novelty and originality
Quality of
presentation
Significant original work
and novel results. (4)
Excellent. (5)
Strong aspects (Comments to the author: what are the strong aspects
of the paper)
The papers present a pragmatic approach to MIMO transmission in wireless ad hoc networks.
This approach operates under the assumption that only knowledge of the Tx-> Rx channel is
available (and not the information about any interferers), which is the most practical case. The
results are interesting and show that single-antenna selection offers the best performance in
many cases.
Weak aspects (Comments to the author: what are the weak aspects of
the paper?)
None identified (other than I could not check one of the main results because the proof had to be
omitted because of space limitations.
Recommended changes (Recommended changes. Please indicate
any changes that should be made to the paper if accepted.)
No necessary changes were identified.