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As a promising technique, OFDM has been widely used in emerging
broadband communication systems, such as digital audio broadcasting
(DAB), high-definition television (HDTV), and wireless local area
network (IEEE 802.11a and HIPERLAN/2). However, as the OFDM signals
are the sum of signals with random amplitude and phase, they are
likely to have large PAPR that require a linear high-power-
amplifier (HPA) with an extremely high dynamic range which is
expensive and inefficient. Furthermore, any amplifier nonlinearity
causes intermodulation products resulting in unwanted out-of-band
power. A number of approaches have been proposed to deal with the
PAPR problem, including amongst others, clipping,
clipping-and-filtering (CF), coding, companding transform, active
constellation extension (ACE), selected mapping (SLM), and partial
transmit sequence (PTS). This book proposes an improvement in the
selected mapping technique. The resulting scheme can also be
applied to the multiple transmitting antenna cases. Further, it
compares the simulation results to the existing techniques namely
exponential companding transform, repeated clipping and filtering,
and adaptive active constellation extension.
Master's Thesis from the year 2012 in the subject Engineering -
Communication Technology, grade: none, - (CSIT Durg), course:
M.Tech, language: English, abstract: As a promising technique, OFDM
has been widely used in emerging broadband communication systems,
such as digital audio broadcasting (DAB), high-definition
television (HDTV), wireless local area network (IEEE 802.11a and
HIPERLAN/2). However, as the OFDM signals are the sum of signals
with random amplitude and phase, they are likely to have large PAPR
that requires a linear high-power- amplifier (HPA) with an
extremely high dynamic range, which is expensive and inefficient.
Furthermore, any amplifier nonlinearity causes intermodulation
products resulting in unwanted out-of-band power. A number of
approaches have been proposed to deal with the PAPR problem,
including clipping, clipping-and-filtering (CF), coding, companding
transform, active constellation extension (ACE), selected mapping
(SLM), partial transmit sequence (PTS), and so on. This thesis
proposes an improvement in Selected Mapping technique and
Simulation results are compared to existing techniques namely
Exponential Companding Transform, Repeated Clipping and Filtering
and Adaptive Active Constellation Extension. The improvements which
are proposed in classical Selective Mapping technique satisfies the
PAPR Reduction criteria with reducing the computational complexity.
Also this new scheme has an important advantage of avoiding the
extra bits along with the transmitted OFDM signal .This scheme can
also be applied to the multiple transmitting antenna cases.
As a promising technique, OFDM has been widely used in many new and
emerging broadband communication systems, such as digital audio
broadcasting (DAB), high-definition television (HDTV), wireless
local area network (IEEE 802.11a and HIPERLAN/2). However, as the
OFDM signals are the sum of signals with random amplitude and
phase, they are likely to have large PAPR that requires a linear
high-power- amplifier (HPA) with an extremely high dynamic range,
which is expensive and inefficient. Furthermore, any amplifier
nonlinearity causes intermodulation products resulting in unwanted
out-of-band power and also increases complexity of DAC-ADC
convertors.This work describes some of the PAPR Reduction
Techniques and comparison among them.
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