Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Fountain Code-Inspired Channel Estimation for Multi-user Millimeter Wave
  MIMO Systems   This paper develops a novel channel estimation approach for multi-user
millimeter wave (mmWave) wireless systems with large antenna arrays. By
exploiting the inherent mmWave channel sparsity, we propose a novel
simultaneous-estimation with iterative fountain training (SWIFT) framework, in
which the average number of channel measurements is adapted to various channel
conditions. To this end, the base station (BS) and each user continue to
measure the channel with a random subset of transmit/receive beamforming
directions until the channel estimate converges. We formulate the channel
estimation process as a compressed sensing problem and apply a sparse
estimation approach to recover the virtual channel information. As SWIFT does
not adapt the BS's transmitting beams to any single user, we are able to
estimate all user channels simultaneously. Simulation results show that SWIFT
can significantly outperform existing random-beamforming based approaches that
use a fixed number of measurements, over a range of signal-to-noise ratios and
channel coherence times.

34
The categories of this paper are: chem-ph
5
The categories of this paper are: gr-qc
15
The categories of this paper are: nucl-ex
31
The categories of this paper are: ao-sci
0
The categories of this paper are: hep-ph
20
The categories of this paper are: acc-phys
25
The categories of this paper are: patt-sol
12
The categories of this paper are: nucl-th
24
The categories of this paper are: dg-ga
4
The categories of this paper are: cond-mat
28
The categories of this paper are: alg-geom
3
The categories of this paper are: physics
30
The categories of this paper are: q-alg
10
The categories of this paper are: q-bio
14
The categories of this paper are: math-ph
37
The categories of this paper are: supr-con