Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Enhanced asymmetrically-clipped optical OFDM   Asymmetrically clipped optical orthogonal frequency-division multiplexing
(ACO-OFDM) is a technique that sacrifices spectral efficiency in order to
transmit an orthogonally frequency-division multiplexed signal over a unipolar
channel, such as a directly modulated direct-detection fiber or free-space
channel. Several methods have been proposed to regain this spectral efficiency,
including: asymmetrically clipped DC-biased optical OFDM (ADO-OFDM), enhanced
U-OFDM (EU-OFDM), and spectral and energy efficient OFDM (SEE-OFDM). This paper
presents a new method that offers the highest receiver sensitivity for a given
optical power at spectral efficiencies above 3 bit/s/Hz, having a 7-dB
sensitivity advantage over DC-biased OFDM for 1024-QAM at 87.5% of its spectral
efficiency, at the same bit rate and optical power.

22
The categories of this paper are: chao-dyn
36
The categories of this paper are: cmp-lg
31
The categories of this paper are: ao-sci
14
The categories of this paper are: math-ph
13
The categories of this paper are: quant-ph
17
The categories of this paper are: q-fin
30
The categories of this paper are: q-alg
10
The categories of this paper are: q-bio
4
The categories of this paper are: cond-mat
21
The categories of this paper are: adap-org
8
The categories of this paper are: hep-ex
12
The categories of this paper are: nucl-th
0
The categories of this paper are: hep-ph
9
The categories of this paper are: nlin
7
The categories of this paper are: hep-th
5
The categories of this paper are: gr-qc