Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : FFT

Comparison of FFT-Based and DCT-Based Channel Estimation and ECC for OFDM System

Awatif Ali Jafaar

Engineering and Technology Journal, 2015, Volume 33, Issue 3, Pages 682-693

Orthogonal Frequency Division Multiplexing (OFDM) has become a popular modulation method for high data rate wireless communications. In this paper, two schemes are proposed. In the first scheme the Bit Error Rate (BER) and the Packet Error Rate(PER) performancesof Fast Fourier Transform-FFT based OFDM are compared with Discrete Cosine Transform DCT -based OFDM using (QPSK) and (16 QAM)as modulation techniques over Additive White Gaussian Noise environment (AWGN) and Multipath Rayleigh Fading environment.
To improve the performance of the uncoded OFDM schemes,the second coded scheme is investigated .Convolution coding is used to enhance the BER for the previous systems. The proposed systems have been tested and evaluated using MATLAB 7 package.

Watermarking in WAV Files Bases on Phase Coding

Salah S. Alrawi; Rasheed Abdulshaheed; Akeel A. Alhadithy

Engineering and Technology Journal, 2011, Volume 29, Issue 4, Pages 770-780

The growth of the network multimedia open the illegal ways for users to use the
digital media without any hindrance or control. This state created, the need for the
copyright protection of various digital media. WAV audio files is one of these media,
these media file format itself has no built in copy protection controls. Other systems
must be used to prevent illegal copying called watermarking. In this paper, we used
the phase coding method to embed the watermark, by using FFT method in two ways.
The first way used the block size of the wave data equal to (22) and the second way
used the block size of the wave data equal to (23).
The results of the above two ways shows that, when we use the first way the
noise of the sound will be very smaller than the results of the second way. On the
other hand the length of the watermark in second way will be longer than when use
the first way. Finally, we can say that the two ways yield good results.

Spectral Eigenface Representation for Human Identification

Hana; a M. Salman

Engineering and Technology Journal, 2010, Volume 28, Issue 19, Pages 5960-5972

Human identification based on face images, as physical biometric means, plays an
imperative role in many applications area. The methods for human identification using
face image uses either part of the face, all face, or mixture from these methods, in either
time domain or frequency domain. This paper investigate the ability to implement the
eigenface in frequency domain, the result spectral eigenface is utilize as a feature vector
means for human identification. The converting from eigenface implementation in time
domain, into spectral eigenface implementation in frequency domain, is based on
implemented the correlation by using FFT. The Min-max is invoked as normalization
techniques that increase spectral eigenface robustness to variations in facial geometry
and illumination. Two face images are contrast in terms of their correlation distance. A
threshold (10.50x107) is used to restrict the impostor face image from being identified.
The experimental results point up the effectiveness of a new method in either using
varying (noisy images, unknown image, face expressions, illumine, and scale s), with
identification value of 100%.