Recently, the authors introduced an algebraic design framework for space–time coding in flat-fading channels [1]–[4]. In this correspondence, we extend this framework to design algebraic codes for multiple-input multiple-output (MIMO) frequency-selective fading channels. The proposed codes strive to optimally exploit both the spatial and frequency diversity available in the channel. We consider...

We introduce a new and simple technique for human gait classification based on the time-frequency analysis of radar data. The focus is on the classification of arm movements to discern free vs. confined arm swinging motion. The latter may arise in hostage situation or may be indicative to carrying objects with one or both hands. The motion signatures corresponding to the arm and leg movements a...

The difficulty of selecting the optimal time-frequency distribution (TFD) for a given real-life signal has been one of the major limiting factors to a wider use of time-frequency analysis tools in practice. This paper, by extending our earlier works on the objective assessment of the performance of TFDs, presents a novel automatic approach for selecting a real-life signal best-performing time-f...

We present an efficient method for robustly calculating time-frequency attributes of a signal, including instantaneous mean frequency, bandwidth, and kurtosis. Most current approaches involve a costly intermediate step of computing a (highly oversampled) 2-d bilinear time-frequency representation (TFR), which is then collapsed to the I-d attribute. Using the principles of hybrid linearhilinear ...