Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Combination of OFDM and CDMA for high data rate UWB   For Wireless Personal Area Network (WPAN) systems, resource allocation
between several users within a piconet and the coexistence of several piconets
are very important points to take into consideration for the optimization of
high data rate Ultra Wide Band (UWB) systems. To improve the performance of the
Multi-Band OFDM (Orthogonal Frequency Division Multiplex) solution proposed by
the Multi-Band OFDM Alliance (MBOA), the addition of a spreading component in
the frequency domain is a good solution since it makes resource allocation
easier and also offers better robustness against channel frequency selectivity
and narrowband interference. The Spread Spectrum - Multi-Carrier - Multiple
Access (SS-MC-MA) system proposed in this article offers not only the
advantages of Multi-Carrier - Coded Division Multiple Access (MC-CDMA) brought
by frequency spreading, but also a more effective dynamic resource allocation
in a multi-user and multi-piconet context. These improvements are obtained
without increasing the complexity of the radio-frequency part compared to the
classical MBOA solution.

28
The categories of this paper are: alg-geom
0
The categories of this paper are: hep-ph
21
The categories of this paper are: adap-org
25
The categories of this paper are: patt-sol
9
The categories of this paper are: nlin
36
The categories of this paper are: cmp-lg
8
The categories of this paper are: hep-ex
13
The categories of this paper are: quant-ph
33
The categories of this paper are: plasm-ph
1
The categories of this paper are: cs
6
The categories of this paper are: astro-ph
4
The categories of this paper are: cond-mat
37
The categories of this paper are: supr-con
27
The categories of this paper are: comp-gas
5
The categories of this paper are: gr-qc
34
The categories of this paper are: chem-ph