Search Results
The search returned 1,237 publication(s) on its.ntia.gov.
Man-made radio noise measurements were conducted in a 1.16-MHz bandwidth at 112.5, 221.5, and 401 MHz at two residential and two business locations in the Boulder/Denver, Colorado, area. The measurement frequencies and bandwidth were selected using t...
In early 2009, the Federal Aviation Administration (FAA) became aware of interference to Terminal Doppler Weather Radars (TDWRs) that operate in the 5600–5650 MHz band and provide quantitative measurements of gust fronts, windshear, microbursts, and ...
Wireless communications experience temporal variations in received signal level that are characteristic of the propagation channel. Propagation channel fading at VHF and above is predominantly caused by the complex scattering environment through whic...
How much bandwidth is required for good quality video for a given screen resolution? Data acquired during two Video Quality Experts Group (VQEG) projects allow at least a partial answer to this question. This international subjective testing produced...
This paper describes radio channel sounding measurements and analysis using pseudo-noise (PN) codes. It presents a channel sounding model and shows how channel measurements can be made. A measurement system is described that can be implemented using ...
Digital video transmission systems consisting of a video encoder, a digital transmission method (e.g., Internet Protocol—IP), and a video decoder can produce pauses in the video presentation, after which the video may continue with or without skippin...
Subjective testing is the most direct means of assessing multimedia quality as experienced by users. When multiple dimensions must be evaluated, these tests can become slow and costly. We present gradient ascent subjective testing (GAST) as an effic...
The quality perception of an audiovisual sequence is heavily influenced by the quality of the audio, the quality of the video, and the audiovisual time synchronization. The questions then arise: what is the relative importance of each factor, and can...
This progress report describes the activities related to the Spectrum Sharing Innovation Test-Bed Pilot Program undertaken during Fiscal Year 2010. The National Telecommunications and Information Administration (NTIA), in coordination with the Fede...
The Institute for Telecommunication Sciences (ITS) is the research and engineering laboratory of the National Telecommunications and Information Administration (NTIA) of the U.S. Department of Commerce (DOC). ITS provides technical support to NTIA in...
We present and evaluate a new multiple–description coding extension to the international standard for pulse code modulation speech coding (ITU–T Rec. G.711). This extension is inserted between the G.711 encoder and decoder. It uses speech–polarity de...
In early 2009, the Federal Aviation Administration (FAA) became aware of interference to Terminal Doppler Weather Radars (TDWRs) that operate in the 5600–5650 MHz band and provide quantitative measurements of gust fronts, windshear, microbursts, and ...
Digital signal processing algorithms are commonly used to obtain radio spectrum estimates based on measurements. Such algorithms allow the user to apply a variety of time–domain windows and the discrete Fourier transform to RF signals and noise. The ...
This report describes a recent measurement effort conducted by the Institute for Telecommunication Sciences at a chamber located at the NASA Space Power Facility (SPF) in Sandusky, Ohio. The report describes the chamber and the measurement system, a...
NTIA/ITS has conducted a series of studies to quantify the effects that individual audio and video qualities have on the overall Mean Opinion Score (MOS) for a given set of audiovisual clips. The experiment described in this report studies the effec...
This handbook provides the radio frequency (RF) analyst with the capability to calculate the effects of noise and interference on RF communications receivers. A receiver is modeled as a sequence of modules. Each module has a transfer function that r...
Even under ideal circumstances, insufficient spectrum is available for assigning a unique band of frequencies to each communication system. In less ideal circumstances, when a communication system experiences outages due to equipment failure or natur...
This NTIA Technical Memorandum provides a single, comprehensive set of derivations of the mathematical relationships among power in a radio transmitter or measurement circuit, the associated incident field strength in space, transmitter-receiver ante...
This technical memorandum examines issues related to the potential interference impact of a specific Cellular Radiotelephone Service (Cellular) and Personal Communications Service (PCS) jammer transmitter on selected out-of-band and in-band receiver...
This report describes emission–spectrum measurements of a denial-of-service (jammer) transmitter that was operated temporarily in 800 MHz and 1900 MHz cellular and PCS bands at a prison location. The jammer targeted signals indoors within a minimum-s...