This paper proposes a new distributed space-time block code (DSTBC) over frequency-selective fading channels for two-hop amplify and forward relay networks, consisting of a source node (S), two relay nodes (R1 and R2), and a destination node (D). The proposed DSTBC is designed to achieve maximal spatial diversity gain and decoupling detection of data blocks with a lowcomplexity receiver. To ach...

In our previous study, we proposed the waveform interpolation (WI) approach to model the excitation signals for hidden Markov model (HMM)-based speech synthesis. This letter presents several techniques to improve excitation modeling within the WI framework. We propose both the time domain and frequency domain zero padding techniques to reduce the spectral distortion inherent in the synthesized ...

This article deals with the estimation of sinusoidal parameters for non stationary sinusoids. It will be shown that for linear amplitude and frequency modulation only the frequency modulation creates additional estimation bias for the standard sinusoidal parameter estimator. Then a new algorithm for frequency domain demodulation of spectral peaks is proposed that can be used to obtain an approx...

In this paper, we propose a novel algorithm for pitch modification. The linear prediction residual is obtained from pitch synchronous frames by inverse filtering the speech signal. Then Discrete Cosine Transform (DCT) is applied on these pitch synchronous frames. Based on the desired factor of pitch modification, the dimension of the DCT vector is changed by truncation or zero padding, and then...

Inorder to apply a multi-dimensional linear transform over an arbitrarily shaped support, the usual practice is to ll out the support to a hypercube by zero padding. This does not however yield a satisfactory de nition for transforms in two or more dimensions. The problem that we tackle is: how do we rede ne the transform over an arbitrary shaped region suited to a given application? We present...

Multiple Input Multiple Output (MIMO) systems has provide high transmission data rate without increasing transmitting power for wireless communication systems. The performance can be further improved by properly estimating the channel at the receiver side. In this paper, investigation on various channel estimation techniques for MIMO-OFDM has been done and a new approach based on time-domain in...

In this paper, we explore security issues of wireless sensor networks, and in particular propose an efficient link layer security scheme. The scheme provides transparent security services such as encryption, decryption and authentication at the link layer of the network protocol stack. To minimize computation and communication overheads of the scheme, we design a lightweight CBC-X mode Encrypti...

In this paper, an algorithm for rectifying heterogeneous and uncalibrated pairs of stereo images is presented. In particular, a pair of images is captured by using a combination of static and dynamic cameras at unequal zoom, thus having different focal lengths and/or image resolutions. The rectification of such pairs of images is made in two steps. In the first step, image shrinking based on fo...

To successfully provide a fast FIR filter with FTT algorithms, overlapped-save algorithms can be used to lower the computational complexity and achieve the desired real-time processing. As the length of the input block increases in order to improve the efficiency, a larger volume of zero padding will greatly increase the computation length of the FFT. In this paper, we use the overlapped block ...

The Fourier interpolation of 3D data-sets is a performance critical operation in many fields, including certain forms of image processing and density functional theory (DFT) quantum chemistry codes based on plane wave basis sets, to which this paper is targeted. In this paper we describe three different algorithms for performing this operation built from standard discrete Fourier transform oper...