Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Balancing Queueing and Retransmission: Latency-Optimal Massive MIMO
  Design   One fundamental challenge in 5G URLLC is how to optimize massive MIMO systems
for achieving low latency and high reliability. A natural design choice to
maximize reliability and minimize retransmission is to select the lowest
allowed target error rate. However, the overall latency is the sum of queueing
latency and retransmission latency, hence choosing the lowest target error rate
does not always minimize the overall latency. In this paper, we minimize the
overall latency by jointly designing the target error rate and transmission
rate adaptation, which leads to a fundamental tradeoff point between queueing
and retransmission latency. This design problem can be formulated as a Markov
decision process, which is theoretically optimal, but its complexity is
prohibitively high for real-system deployments. We managed to develop a
low-complexity closed-form policy named Large-arraY Reliability and Rate
Control (LYRRC), which is proven to be asymptotically latency-optimal as the
number of antennas increases. In LYRRC, the transmission rate is twice of the
arrival rate, and the target error rate is a function of the antenna number,
arrival rate, and channel estimation error. With simulated and measured
channels, our evaluations find LYRRC satisfies the latency and reliability
requirements of URLLC in all the tested scenarios.

14
The categories of this paper are: math-ph
0
The categories of this paper are: hep-ph
34
The categories of this paper are: chem-ph
19
The categories of this paper are: eess
15
The categories of this paper are: nucl-ex
22
The categories of this paper are: chao-dyn
24
The categories of this paper are: dg-ga
33
The categories of this paper are: plasm-ph
6
The categories of this paper are: astro-ph
9
The categories of this paper are: nlin
27
The categories of this paper are: comp-gas
16
The categories of this paper are: stat
21
The categories of this paper are: adap-org
32
The categories of this paper are: atom-ph
5
The categories of this paper are: gr-qc
3
The categories of this paper are: physics