Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Interference Channel Revisited: Aligning Interference by Adjusting
  Receive Antenna Separation   It is shown that a receiver equipped with two antennas may null an arbitrary
large number of spatial directions to any desired accuracy, while maintaining
the interference-free signal-to-noise ratio, by judiciously adjusting the
distance between the antenna elements. The main theoretical result builds on
ergodic theory. The practicality of the scheme in moderate signal-to-noise
systems is demonstrated for a scenario where each transmitter is equipped with
a single antenna and each receiver has two receive chains and where the desired
spacing between antenna elements is achieved by selecting the appropriate
antennas from a large linear antenna array. We further extend the proposed
scheme to show that interference can be eliminated also in specular multipath
channels as well as multiple-input multiple-output interference channels where
a single extra receiver suffices to align all interferers into a
one-dimensional subspace. To demonstrate the performance of the scheme, we show
significant gains for interference channels with four as well as six users, at
low to moderate signal-to-noise ratios (0-20 dB). The robustness of the
proposed technique to small channel estimation errors is also explored.

15
The categories of this paper are: nucl-ex
16
The categories of this paper are: stat
29
The categories of this paper are: funct-an
23
The categories of this paper are: solv-int
3
The categories of this paper are: physics
18
The categories of this paper are: econ
9
The categories of this paper are: nlin
0
The categories of this paper are: hep-ph
17
The categories of this paper are: q-fin
27
The categories of this paper are: comp-gas
25
The categories of this paper are: patt-sol
14
The categories of this paper are: math-ph
34
The categories of this paper are: chem-ph
12
The categories of this paper are: nucl-th
6
The categories of this paper are: astro-ph
32
The categories of this paper are: atom-ph