Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Achievable Rates for Short-Reach Fiber-Optic Channels with Direct
  Detection   Spectrally efficient communication is studied for short-reach fiber-optic
links with chromatic dispersion (CD) and receivers that employ
direction-detection and oversampling. Achievable rates and symbol error
probabilities are computed by using auxiliary channels that account for memory
in the sampled symbol strings. Real-alphabet bipolar and complex-alphabet
symmetric modulations are shown to achieve significant energy gains over
classic intensity modulation. Moreover, frequency-domain raised-cosine (FD-RC)
pulses outperform time-domain RC (TD-RC) pulses in terms of spectral efficiency
for two scenarios. First, if one shares the spectrum with other users then
inter-channel interference significantly reduces the TD-RC rates. Second, if
there is a transmit filter to avoid interference then the detection complexity
of FD-RC and TD-RC pulses is similar but FD-RC achieves higher rates.

3
The categories of this paper are: physics
24
The categories of this paper are: dg-ga
30
The categories of this paper are: q-alg
36
The categories of this paper are: cmp-lg
14
The categories of this paper are: math-ph
7
The categories of this paper are: hep-th
13
The categories of this paper are: quant-ph
5
The categories of this paper are: gr-qc
4
The categories of this paper are: cond-mat
33
The categories of this paper are: plasm-ph
16
The categories of this paper are: stat
23
The categories of this paper are: solv-int
29
The categories of this paper are: funct-an
18
The categories of this paper are: econ
9
The categories of this paper are: nlin
27
The categories of this paper are: comp-gas