Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Adaptive Limited Feedback for Sum-Rate Maximizing Beamforming in
  Cooperative Multicell Systems   Base station cooperation improves the sum-rates that can be achieved in
cellular systems. Conventional cooperation techniques require sharing large
amounts of information over finite-capacity backhaul links and assume that base
stations have full channel state information (CSI) of all the active users in
the system. In this paper, a new limited feedback strategy is proposed for
multicell beamforming where cooperation is restricted to sharing only the CSI
of active users among base stations. The system setup considered is a linear
array of cells based on the Wyner model. Each cell contains single-antenna
users and multi-antenna base stations. Closed-form expressions for the
beamforming vectors that approximately maximize the sum-rates in a multicell
system are first presented, assuming full CSI at the transmitter. For the more
practical case of a finite-bandwidth feedback link, CSI of the desired and
interfering channels is quantized at the receiver before being fed back to the
base station. An upper bound on the mean loss in sum rate due to random vector
quantization is derived. A new feedback-bit allocation strategy, to partition
the available bits between the desired and interfering channels, is developed
to approximately minimize the mean loss in sum-rate due to quantization. The
proposed feedback-bit partitioning algorithm is shown, using simulations, to
yield sum-rates close to the those obtained using full CSI at base stations.

18
The categories of this paper are: econ
35
The categories of this paper are: mtrl-th
30
The categories of this paper are: q-alg
20
The categories of this paper are: acc-phys
6
The categories of this paper are: astro-ph
29
The categories of this paper are: funct-an
26
The categories of this paper are: bayes-an
33
The categories of this paper are: plasm-ph
36
The categories of this paper are: cmp-lg
10
The categories of this paper are: q-bio
9
The categories of this paper are: nlin
4
The categories of this paper are: cond-mat
7
The categories of this paper are: hep-th
22
The categories of this paper are: chao-dyn
28
The categories of this paper are: alg-geom
19
The categories of this paper are: eess