Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Channel Estimation in Massive MIMO Systems   We introduce novel blind and semi-blind channel estimation methods for
cellular time-division duplexing systems with a large number of antennas at
each base station. The methods are based on the maximum a-posteriori principle
given a prior for the distribution of the channel vectors and the received
signals from the uplink training and data phases. Contrary to the
state-of-the-art massive MIMO channel estimators which either perform linear
estimation based on the pilot symbols or rely on a blind principle, the
proposed semi-blind method efficiently suppresses most of the interference
caused by pilot-contamination. The simulative analysis illustrates that the
semi-blind estimator outperforms state- of-the-art linear and non-linear
approaches to the massive MIMO channel estimation problem.

26
The categories of this paper are: bayes-an
35
The categories of this paper are: mtrl-th
21
The categories of this paper are: adap-org
0
The categories of this paper are: hep-ph
37
The categories of this paper are: supr-con
15
The categories of this paper are: nucl-ex
8
The categories of this paper are: hep-ex
14
The categories of this paper are: math-ph
10
The categories of this paper are: q-bio
5
The categories of this paper are: gr-qc
34
The categories of this paper are: chem-ph
24
The categories of this paper are: dg-ga
33
The categories of this paper are: plasm-ph
4
The categories of this paper are: cond-mat
36
The categories of this paper are: cmp-lg
30
The categories of this paper are: q-alg