1. Orthogonal frequency division multiplexing (OFDM) has been shown to be an effective technique to combat multipath fading in wireless communications. It has been successfully used for HF radio applications and has been chosen as the standard for digital audio broadcasting and digital terrestrial TV broadcasting in Europe and high-speed wireless local areas networks. In this tutorial, we present the basic principles of OFDM and discuss the problems, and some of the potential solutions, in implementing an OFDM system. Techniques for peak-to-average power ratio reduction, time and frequency synchronization, and channel estimation will be discussed. We conclude with a brief overview of current application areas 2. The Orthogonal Frequency Division Multiplexing (OFDM) technique, wireless channel models, and a pair of new inter carrier interference self-cancellation methods are investigated in this thesis. The first chapter addresses the history of OFDM, along with its principles and applications. Chapter two consists of three parts: the principal, the modern OFDM models, and the Peak to Average Power Ratio (PAPR) problem. Chapter two also summarizes possible PAPR solutions. Chapter three discusses a series of well-known wireless channel models, as well as the general formula for wireless channels. In Chapter four, ICI problem has been discussed, along with its existing solutions. Chapter five focuses on two new ICI self-cancellation schemes, namely the clustering method and the multi-codebook method. These two new methods show promising results through the simulations. A summary of this thesis and the discussion of future research are also provided in Chapter five. 3. Orthogonal frequency division multiplexing (OFDM) is an appealing technique for achieving high-bit-rate data transmission, due to its robustness against the multipath fading and Inter symbol Interference (ISI). However, the occurrence of the potentially high peak-to-average power ratio (PAPR) restricts its application. Several methods have been proposed to reduce the PAPR, including offset selection, and various coding techniques. Here, the partial transmit sequences (PTS) approach has been investigated to improve the PAPR statistics. The PTS technique manipulates the phase rotations of the partial transmit sequences and performs exhaustive search for optimized transmit signal, in order to obtain an improved power distribution of the OFDM signal. In this paper, MATLAB simulation will be used to verify the effectiveness of the PTS technique, in eliminating the PAPR. 4.
1. Orthogonal frequency division multiplexing (OFDM) has been
shown to be an effective technique to combat multipath fading in
wireless communications. It has been successfully used for HF radio
applications and has been chosen as the standard for digital audio
broadcasting and digital terrestrial TV broadcasting in Europe and
high-speed wireless local areas networks. In this tutorial, we
present the basic principles of OFDM and discuss the problems, and
some of the potential solutions, in implementing an OFDM system.
Techniques for peak-to-average power ratio reduction, time and
frequency synchronization, and channel estimation will be
discussed. We conclude with a brief overview of current application
areas
2. The Orthogonal Frequency Division Multiplexing (OFDM)
technique, wireless channel models, and a pair of new inter carrier
interference self-cancellation methods are investigated in this
thesis. The first chapter addresses the history of OFDM, along with
its principles and applications. Chapter two consists of three
parts: the principal, the modern OFDM models, and the Peak to
Average Power Ratio (PAPR) problem. Chapter two also summarizes
possible PAPR solutions. Chapter three discusses a series of
well-known wireless channel models, as well as the general formula
for wireless channels. In Chapter four, ICI problem has been
discussed, along with its existing solutions. Chapter five focuses
on two new ICI self-cancellation schemes, namely the clustering
method and the multi-codebook method. These two new methods show
promising results through the simulations. A summary of this thesis
and the discussion of future research are also provided in Chapter
five.
3. Orthogonal frequency division multiplexing (OFDM) is an
appealing technique for achieving high-bit-rate data transmission,
due to its robustness against the multipath fading and Inter symbol
Interference (ISI). However, the occurrence of the potentially high
peak-to-average power ratio (PAPR) restricts its application.
Several methods have been proposed to reduce the PAPR, including
offset selection, and various coding techniques. Here, the partial
transmit sequences (PTS) approach has been investigated to improve
the PAPR statistics. The PTS technique manipulates the phase
rotations of the partial transmit sequences and performs exhaustive
search for optimized transmit signal, in order to obtain an
improved power distribution of the OFDM signal. In this paper,
MATLAB simulation will be used to verify the effectiveness of the
PTS technique, in eliminating the PAPR.
