Digital signal

About: Digital signal is a research topic. Over the lifetime, 44213 publications have been published within this topic receiving 345279 citations.

Digital communication techniques : signal design and detection

Abstract: 1. Introduction to Telecommunications. 2. Power Spectral Density of Digital Modulations. 3. Scalar and Vector Communications Over the Discrete Memoryless Channel. 4. Coherent Communication with Waveforms. 5. Noncoherent Communication with Waveforms. 6. Partially Coherent Communication with Waveforms. 7. Differentially Coherent Communication with Waveforms. 8. Double Differentially Coherent Communication with Waveforms. 9. Communication over Bandlimited Channels. 10. Demodulation and Detection of Other Digital Modulations. 11. Coded Digital Communications. 12. Block-Coded Digital Communications. 13. Convolutional-Coded Digital Communications. Index.

Reversible data embedding into images using wavelet techniques and sorting

Abstract: The proliferation of digital information in our society has enticed a lot of research into data-embedding techniques that add information to digital content, like images, audio, and video. In this paper, we investigate high-capacity lossless data-embedding methods that allow one to embed large amounts of data into digital images (or video) in such a way that the original image can be reconstructed from the watermarked image. We present two new techniques: one based on least significant bit prediction and Sweldens' lifting scheme and another that is an improvement of Tian's technique of difference expansion. The new techniques are then compared with various existing embedding methods by looking at capacity-distortion behavior and capacity control.

Power consumption reduction in medical devices employing multiple digital signal processors

Abstract: Power consumption in medical devices is reduced through the use and operation of multiple digital signal processing systems. Each processor of the multiple systems performs at least one particular function in a predetermined time period. The multiple digital signal processors of such systems can be operated at lower clock frequencies relative to those that would be required by one of such processors to complete the multiple functions within the predetermined time period. With reduced clock frequency, power consumption is reduced. Further, with reduced clock speed, supply voltages applied to such digital signal processors may also be reduced.

Blind separation of synchronous co-channel digital signals using an antenna array. I. Algorithms

Abstract: We propose a maximum-likelihood (ML) approach for separating and estimating multiple synchronous digital signals arriving at an antenna array at a cell site. The spatial response of the array is assumed to be known imprecisely or unknown. We exploit the finite alphabet property of digital signals to simultaneously estimate the array response and the symbol sequence for each signal. Uniqueness of the estimates is established for BPSK signals. We introduce a signal detection technique based on the finite alphabet property that is different from a standard linear combiner. Computationally efficient algorithms for both block and recursive estimation of the signals are presented. This new approach is applicable to an unknown array geometry and propagation environment, which is particularly useful In wireless communication systems. Simulation results demonstrate its promising performance.