A Novel WLAN Receiver Performance in Highly Dispersive and
Nonlinear Environment
Shubhangi Rathkanthiwar
1
, Chandrashekhar Dethe
2
and Kishore Kulat
1+
1
Associate Professor, Yeshwantrao Chavan college of Engineering, Nagpur, India
2
Principal, Priyadarshini Institute of Technology, Nagpur, India
3
Professor and Head, Department of Electronics Engg, Viswesaraya National Institute of Technology,
Nagpur, India
Abstract: An efficient, adaptive and intelligent transmission–reception system, which will take care of challenging
fading multipath problems in real case scenario, is always needed in digital communications. This paper presents a
novel, neural based method to improve performance of WLAN receiver in presence of nonlinear distortions
introduced by high power amplifiers, Doppler effect, delay spread and many other fading multipath problems.
Keywords: BER, HPA, OFDM, SOM, PAPR, WLAN
1. Introduction
There is still a gap between previous research conducted on performance improvement in receiver
structure in fading multipath environment and use of neural networks as learning systems which can
incorporate constraints on their capability to handle several problems coming in upcoming technologies in
the wireless communications [1]. Main gap is exponentially growing demand for great quality services at
high data rates and implementation of structures using computational intelligence to take care of many
complex cases arising in multicarrier communications [2,3].
As OFDM is the most promising candidate in present as well as future generation wireless
communications, we have selected wireless local area network model Hiperlan2 for constructing this paper,
as it uses OFDM as multiplexing/ modulation technique. One of the most challenging issues in OFDM based
system that has still remained unresolved is the problem of nonlinear distortion. It has been taken into
consideration along with multipath fading problems.
Main idea behind use of neural networks in OFDM based systems is the signal classification. If the
classification is done properly in presence of environment harshly deteriorating the signal, we say that there
is an improvement in the performance of the system. Neural networks are the learning systems that allow the
people to specify what the systems should do for each case. It can decide in a reasonable way what to do in a
particular situation from previous experiences and/or provided examples of appropriate behaviors even
though the situation may not be experienced by the system before. Review of research work clearly indicated
limitations of the supervised network approaches like MLP and RBF in handling migratory signals whose
stochastic properties such as average values of signals in each cluster are varying continuously.
We have identified the self-organizing map (SOM) method as a powerful software tool for the
visualization of high-dimensional data. It converts complex, nonlinear statistical relationships between high
dimensional data into simple geometric relationships on a low dimensional display. It thereby compresses
information while preserving the most important topological relationships of the primary data elements.
Visualization and abstraction are the two aspects that occur in a number of complex engineering tasks such
as process analysis, machine perception, control, and communication[4].
2012 International Conference on Networks and Information (ICNI 2012)
IPCSIT vol. 57 (2012) © (2012) IACSIT Press, Singapore
DOI: 10.7763/IPCSIT.2012.V57.01
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