Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Clustering-based Joint Channel Estimation and Signal Detection for
  Grant-free NOMA   We propose a joint channel estimation and signal detection technique for the
uplink non-orthogonal multiple access using an unsupervised clustering
approach. We apply the Gaussian mixture model to cluster received signals and
accordingly optimize the decision regions to enhance the symbol error rate
(SER). We show that when the received powers of the users are sufficiently
different, the proposed clustering-based approach with no channel state
information (CSI) at the receiver achieves an SER performance similar to that
of the conventional maximum likelihood detector with full CSI. Since the
accuracy of the utilized clustering algorithm depends on the number of the data
points available at the receiver, the proposed technique delivers a tradeoff
between the accuracy and block length.

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The categories of this paper are: q-alg
29
The categories of this paper are: funct-an
0
The categories of this paper are: hep-ph
4
The categories of this paper are: cond-mat
16
The categories of this paper are: stat
15
The categories of this paper are: nucl-ex
37
The categories of this paper are: supr-con
31
The categories of this paper are: ao-sci
22
The categories of this paper are: chao-dyn
23
The categories of this paper are: solv-int
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The categories of this paper are: mtrl-th
18
The categories of this paper are: econ
7
The categories of this paper are: hep-th
33
The categories of this paper are: plasm-ph
3
The categories of this paper are: physics
36
The categories of this paper are: cmp-lg