In this paper we introduce a new 2D modulation technique called OTFS (Orthogonal Time Frequency & Space) that transforms information carried in the Delay-Doppler coordinate system to the familiar time-frequency domain utilized by traditional modulation schemes such as OFDM, CDMA and TDMA. OTFS converts the fading, time-varying wireless channel into a non-fading, time-independent interaction rev...

Multi-antenna communication systems with OFDM modulation have the potential to play an important role in the design of the next generation broadband wireless communication systems. In this paper, we propose a general framework for the performance analysis of space-timefrequency coded MIMO-OFDM systems. Our approach incorporates the space-time and space-frequency coding approaches as special cas...

Anomaly is an incident or event that cannot be explained by the dominant theories. Anomalies are situated in confronting with the efficient market theory, so that it provides conditions for stock trading strategies with additional returns in case of existing predetermined returns. Therefore, in this study, the anomaly due to monthly effects on the stock volume trading and the Tehran Stock Excha...

Abstract. The time-frequency analysis of a signal is often performed via a series expansion arising from well-localized building blocks. Typically, the building blocks are based on frames having either Gabor or wavelet structure. In order to calculate the coefficients in the series expansion, a dual frame is needed. The purpose of the present paper is to provide constructions of dual pairs of f...

Wavelet transformation is one of the most practical mathematical transformations in the field of image processing, especially image and signal processing. Depending on the nature of the multiresolution analysis, Wavelet transformation become more accessible and powerful tools. In this paper, we refer to the mathematical foundations of this transformation.   Introduction: The...