Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Time Reversal with Post-Equalization for OFDM without CP in Massive MIMO   This paper studies the possibility of eliminating the redundant cyclic prefix
(CP) of orthogonal frequency division multiplexing (OFDM) in massive
multiple-input multiple-output systems. The absence of CP increases the
bandwidth efficiency in expense of intersymbol interference (ISI) and
intercarrier interference (ICI). It is known that in massive MIMO, different
types of interference fade away as the number of base station (BS) antennas
tends to infinity. In this paper, we investigate if the channel distortions in
the absence of CP are averaged out in the large antenna regime. To this end, we
analytically study the performance of the conventional maximum ratio combining
(MRC) and realize that there always remains some residual interference leading
to saturation of signal to interference (SIR). This saturation of SIR is
quantified through mathematical equations. Moreover, to resolve the saturation
problem, we propose a technique based on time-reversal MRC with zero forcing
multiuser detection (TR-ZF). Thus, the SIR of our proposed TR-ZF does not
saturate and is a linear function of the number of BS antennas. We also show
that TR-ZF only needs one OFDM demodulator per user irrespective of the number
of BS antennas; reducing the BS signal processing complexity significantly.
Finally, we corroborate our claims as well as analytical results through
simulations.

15
The categories of this paper are: nucl-ex
19
The categories of this paper are: eess
33
The categories of this paper are: plasm-ph
0
The categories of this paper are: hep-ph
18
The categories of this paper are: econ
36
The categories of this paper are: cmp-lg
27
The categories of this paper are: comp-gas
10
The categories of this paper are: q-bio
29
The categories of this paper are: funct-an
17
The categories of this paper are: q-fin
14
The categories of this paper are: math-ph
23
The categories of this paper are: solv-int
31
The categories of this paper are: ao-sci
11
The categories of this paper are: hep-lat
37
The categories of this paper are: supr-con
30
The categories of this paper are: q-alg