Zakaria, Jamaluddin
(2013)
On The Analysis Of Mcm Systems Papr
Profiles And The Wp-Ofdm System Papr
Reduction Techniques.
Masters thesis, Universiti Sains Malaysia.
Abstract
Orthogonal frequency division multiplexing (OFDM) is a prominent system in transmitting
multicarrier modulation (MCM) signals over selective fading channel. It has several magnificent
properties such as attaining a higher degree of bandwidth efficiency, higher data transmission,
robust to narrowband frequency interference and low-complexity implementation. However,
the system has its shortage which needs improvement; high peak-to-average power ratio
(PAPR) where the signals work in the nonlinear region of the high power amplifier (HPA) results
in poor performance and other signal property impairments. Apart from that, an attractive
dynamic tool which is wavelet analysis is utilized, and its derivatives such as wavelet packet
transform (WPT) possesses almost the same criteria of the orthogonal Fourier base MCM system.
Wavelet base analysis surpasses Fourier base by inherent flexibility in terms of windows
function for non-stationary signal analysis. The subset base of WPT known as discrete wavelet
transforms (DWT). In MCM system, these two base functions construct the orthogonal modulation
signal system as the fast Fourier transform (FFT) do in the conventional OFDM (COFDM)
system. Applying both WPT and DWT in the MCM system, produces orthogonal
signals known as the wavelet packet-based OFDM (WP-OFDM) and wavelet-based OFDM
(WOFDM) signals respectively. With no cyclic prefix (CP) need to be applied, these orthogonal
signals hold higher bandwidth efficiency. Hence, a comprehensive study is established by
performing manipulation on specified parameters using WP-OFDM, WOFDM and C-OFDM
signals under the additive white Gaussian noise (AWGN) channel. Furthermore, Partial Transmit
Sequence (PTS) is an efficient technique to mitigate the large PAPR in WP-OFDM signals.
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