—The method of block orthogonal amplitude modulation (QAM) is presented and the demodulation recognition method is studied in this paper. Based on ordinary orthogonal modulation, the basic feature vector is extracted from the received signal cluster sample to estimate the signal parameters of data block for achievement of data block demodulation by using matrix transformation which can reach t...

A generalization of frequency modulation is developed in which state trajectories of dynamical systems are used as carrier waves. Our focus is on the design and analysis of modulators and demodulators for such generalized frequency modulation systems. In particular, we show that for a class of dynamical systems, among which are certain chaotic systems, it is possible to develop a general approa...

We present a spatial adaptive asynchronous algorithm for fringe pattern demodulation. The proposed algorithm is based on the standard five-step asynchronous method with the one modification that we select the best sample spacing for each point of the fringe pattern. As we show, the frequency response of any asynchronous method depends on the sample spacing. This interesting behavior is used to ...

A pair of photogates is employed as a high frequency demodulation pixel for three dimensional time-of-flight image sensor. Using a 192×108 array of the pixels, demodulation contrast above 50% is achieved at 20MHz frequency and the test chip exhibits distance error less than 1% up to 7 m detection of the object. Modulation frequency dependent behavior of dark current is observed: dark current is...

A technique is presented for filtering and normalizing noisy fringe patterns, which may include closed fringes, so that single-frame demodulation schemes may be successfully applied. It is based on the construction of an adaptive filter as a linear combination of the responses of a set of isotropic bandpass filters. The space-varying coefficients are proportional to the envelope of the response...

The implementation of digital demodulators using FPGA platform has been presented in this paper. The softwarehardware platform based on Spartan 3A has been developed for digital signal processing purposes .This platform represents the optimal choice from the standpoint of costs, performance and power consumption. The bank of FIR filters is particularly designed for signal analysis applications....

Power consumption of nodes in a wireless sensor network (WSN) determines the life cycle of the WSN, so it is particularly important to design low-power and high-performance wireless sensor nodes in the network. Based on a simple analysis of the IEEE802.15.4 protocol specifications and comparison among the efficiencies of different physical layers, this paper illustrates the design and implement...