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Previously published field test results showed frequent solid state marine radar (SS-MR) interference in magnetron marine radars (M-MRs) at 0.34 nautical miles distance separation and 55 MHz frequency separation. The interference was mitigated but no...

Channel sounders are used to measure channel characteristics for radio systems. There are several types of channel sounders used today: continuous-wave (CW), direct pulse, frequency domain using a vector network analyzer (VNA), correlation-based, an...

Objective speech quality and intelligibility estimators do not correctly assess speech generated by deep neural networks (DNNs). We use 256 speech files and subjective scores that cover 14 DNN speech conditions and 18 nonDNN speech conditions to sho...

We present a set of relatively small-scale proof-of-concept experiments where we construct no-reference (NR) speech quality estimators that give reliable values of system-under-test (SUT) input speech quality in spite of the fact that NR estimators ...

This report describes the rationale, measurement methods, and analysis techniques for assessing Long Term Evolution (LTE) user equipment (UE) emissions in the Advanced Wireless Services - 1 (AWS-1) uplink band within the observable range of aeronauti...

This technical memorandum describes a method to design, characterize and optimize a system for performing field measurements of aggregate interference from LTE user equipment transmissions. It explains the computation of the system’s antenna gain ove...

This technical memorandum provides the results of a compatibility assessment between terrestrial GPS L1 coarse/acquisition (C/A) code receivers operating in the 1559-1610 MHz RNSS band and terrestrial operations in the 1526-1536 MHz, 1627.5 1637.5 M...

This Technical Report provides details about protection of federal operations in the 5.850–5.925 GHz (5.9 GHz) band from new operations considered by the Federal Communications Commission (FCC) as part of the agency’s comprehensive review intended t...

This report describes a methodology that measures the precision of objective metrics that assess image quality, video quality, speech quality, or the overall audiovisual quality. We assess the confidence intervals of 60 subjective tests and use a con...

In situ measurements of radio frequency (RF) spectrum activity provide insight into the physics of radio frequency wave propagation and validate existing and new spectrum propagation models. Both of these parameters are essential to supporting and p...

This GitHub repository presents MATLAB®/Octave and C++ implementations of Wideband Audio Waveform Evaluation networks or WAWEnets. This WAWEnets implementation produces one or more speech quality or intelligibility values for each input speech signa...

This report presents spectrum occupancy results for 3.45–3.55 GHz and for 3.55−3.65 GHz at sensor sites near San Diego CA (SD), Norfolk VA (NF), San Francisco CA (SF), and Astoria OR (AS). Sensors operated at the following {start date, end date, 2018...

Building on prior work we have developed a no-reference (NR) waveform-based convolutional neural network (CNN) architecture that can accurately estimate speech quality or intelligibility of narrowband and wideband speech segments. These Wideband Aud...

Channel modeling often provides a basis for the design and deployment of wireless technology. Engineers design systems to operate under certain expected channel conditions. Channel models are typically based on the statistics of a collection of many ...

We need data sets of images and subjective scores to develop robust no reference (or blind) visual quality metrics for consumer applications. These applications have many uncontrolled variables because the camera creates the original media and the im...

As part of its ongoing effort to identify candidate bands for repurposing to accommodate commercial wireless services, NTIA selected the 3450–3550 MHz band to study for potential sharing between federal systems and a variety of non-federal commercia...

This paper describes ongoing work within the video quality experts group (VQEG) to develop no-reference (NR) audiovisual video quality analysis (VQA) metrics. VQEG provides an open forum that encourages knowledge sharing and collaboration. The VQEG n...

This paper analyzes the performance of eight no-reference (NR) metrics. Seven assess image quality (BRISQUE, CurveletQA, IL-NIQE, NIQE, OG-IQA, QAC and SSEQ) and one assesses video quality (VIIDEO). The challenge we address in this paper is moving fr...

This technical memorandum provides technical details for the video quality subjective experiment its4s4. This experiment includes 196 videos, each 4 seconds in duration, depicting camera pans at different speeds. Other impairments are avoided where p...

This report is a case-history of the development, deployment, and operational experiences associated with 5 GHz unlicensed national information infrastructure (U–NII) devices that incorporate a detect-and-avoid approach to spectrum sharing. Such dyna...