Measuring Frequency Content in
Signals
I this section we will study some non parametric methods for spectrum estimation
of a stochastic process. These methods are described in the literature.
All methods are based on the Periodogram which is defined for a sequence x[n]
with length N according to
This paper shows the development of a 1024-point
radix-4 FFT VHDL core for applications in hardware signal processing, targeting low-cost FPGA technologies. The developed core is targeted into a Xilinx廬 Spartan鈩?3 XC3S200 FPGA with the inclusion of a VGA display interface and an external 16-bit data acquisition system for performance evaluation purposes. Several tests were performed in order to verify FFT core functionality, besides the time performance analysis highlights the core advantages over commercially available DSPs and Pentium-based PCs. The core is compared with similar third party IP cores targeting resourceful FPGA technologies. The novelty of this work is to provide a lowcost, resource efficient core for spectrum analysis
applications.
The second edition of WiMax Operator鈥檚 Manual includes most of the material from the first
edition, plus new discussions of
鈥?The ultra-high-speed mobile telephone standard, HSDPA
鈥?Ultrawideband (UWB)
鈥?Changes to DSL technologies
鈥?Mobile voice
鈥?Mobile entertainment
鈥?New backup systems
The new edition also reflects the changes that have occurred in the industry over the last year and half, including the emergence of restandards wireless broadband equipment with fully developed mobile capabilities, ignificant alterations in the competitive landscape, and he opening of valuable new spectrum for roadband wireless operators.
This application report discusses the design of non-invasive optical plethysmography
also called as pulsoximeter using the MSP430FG437 Microcontroller (MCU). The
pulsoximeter consists of a peripheral probe combined with the MCU displaying the
oxygen saturation and pulse rate on a LCD glass. The same sensor is used for both
heart-rate detection and pulsoximetering in this application. The probe is placed on a
peripheral point of the body such as a finger tip, ear lobe or the nose. The probe
includes two light emitting diodes (LEDs), one in the visible red spectrum (660nm) and
the other in the infrared spectrum (940nm). The percentage of oxygen in the body is
worked by measuring the intensity from each frequency of light after it transmits
through the body and then calculating the ratio between these two intensities.
P3.18. An analog signal xa(t) = sin (100πt) is sampled using the following sampling intervals. In
each case plot the spectrum of the resulting discrete-time signal.
Ts= 0.1 ms, Ts= 1 ms, Ts = 0.01 Sec
Wi-Fi pollution, or an excessive number of access points in the area, especially on the same or neighboring channel, can prevent access and interfere with the use of other access points by others, caused by overlapping channels in the 802.11g/b spectrum
The Schumann resonance frequencies are a set of eigenmodes in the extremely low frequency (ELF) portion of the electromagnetic field spectrum. These frequencies are only present for planetary-like bodies with a substantial ionosphere acting as a perfect electric conductor, thus forming a resonance cavity with the surface. In this example, the Schumann resonance frequencies for the Earth are calculated.
The Open Radar Data Acquisition (ORDA)
subsystem replaces the current WSR-88D Radar
Data Acquisition subsystem with improved
receiver and signal processing hardware and with
improved user interface, signal processing and
diagnostics software. This paper will discuss the
input data from the digital receiver, the ORDA
signal processing, and the data output from the
ORDA hardware. Specifications of the ORDA
digital receiver will be presented. The paper
outlines the critical radar signal processing flow
and provides analysis of new spectrum width
computations and clutter filtering schemes used in
the ORDA system. Where appropriate, ORDA
performance enhancements, data quality
improvements and reliability and maintenance
improvements will be highlighted.
