Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Truncated Polynomial Expansion Downlink Precoders and Uplink Detectors
  for Massive MIMO   In TDD reciprocity-based massive MIMO it is essential to be able to compute
the downlink precoding matrix over all OFDM resource blocks within a small
fraction of the uplink-downlink slot duration. Early implementation of massive
MIMO are limited to the simple Conjugate Beamforming (ConjBF) precoding method,
because of such computation latency limitation. However, it has been widely
demonstrated by theoretical analysis and system simulation that Regularized
Zero-Forcing (RZF) precoding is generally much more effective than ConjBF for a
large but practical number of transmit antennas. In order to recover a
significant fraction of the gap between ConjBF and RZF and yet meeting the very
strict computation latency constraints, truncated polynomial expansion (TPE)
methods have been proposed. In this paper we present a novel TPE method that
outperforms all previously proposed methods in the general non-symmetric case
of users with arbitrary antenna correlation. In addition, the proposed method
is significantly simpler and more flexible than previously proposed methods
based on deterministic equivalents and free probability in large random matrix
theory. We consider power allocation with our TPE approach, and show that
classical system optimization problems such as min-sum power and max-min rate
can be easily solved. Furthermore, we provide a detailed computation latency
analysis specifically targeted to a highly parallel FPGA hardware architecture.

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The categories of this paper are: atom-ph
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The categories of this paper are: adap-org
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The categories of this paper are: supr-con
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The categories of this paper are: astro-ph
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The categories of this paper are: hep-ex
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The categories of this paper are: stat
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The categories of this paper are: hep-ph
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The categories of this paper are: chem-ph
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The categories of this paper are: acc-phys
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The categories of this paper are: eess
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The categories of this paper are: nucl-th
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The categories of this paper are: chao-dyn
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The categories of this paper are: econ
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The categories of this paper are: hep-lat
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The categories of this paper are: patt-sol
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The categories of this paper are: funct-an