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Millimeter wave (mmWave) systems operating over a wide bandwidth and using a large number of antennas impose a heavy burden on power consumption. In a massive multiple-input multiple-output (MIMO) uplink, analog-to-digital converters (ADCs) would be the primary consumer of power in the base station receiver. This paper proposes a bit allocation (BA) method for mmWave multi-user (MU) massive MIMO systems...
Being able to automatically predict digital picture quality, as perceived by human observers, has become important in many applications where humans are the ultimate consumers of displayed visual information. Standard dynamic range (SDR) images provide 8 bits/color/pixel. High dynamic range (HDR) images which are usually created from multiple exposures of the same scene, can provide 16 or 32 bits/color/pixel,...
Measuring visual quality, as perceived by human observers, is becoming increasingly important in the many applications in which humans are the ultimate consumers of visual information. This paper assesses the visual quality in mapping of high dynamic range (HDR) images to standard dynamic range (SDR) images with 8 bits/color/pixel. In previous work, the Tone-Mapped image Quality Index (TMQI) compares...
In this paper, we propose space-time fronthaul compression of baseband uplink LTE signals for cellular networks, in which baseband units (BBUs) support remote radio heads (RRHs) through fronthaul links. In particular, we assume massive antenna arrays in which the number of antennas in a RRH is much larger than the number of active users. The proposed method consists of two phases: dimensionality reduction...
Narrowband powerline communications (NB-PLC) and unlicensed wireless communications are considered as two leading communications technologies for emerging Smart Grid applications. The diversity provided by the simultaneous transmission of the same information over powerline and wireless links can be exploited to enhance the overall system reliability. In this paper, we propose an efficient technique...
Measuring visual quality, as perceived by human observers, is becoming increasingly important in many applications where humans are the ultimate consumers of visual information. Significant progress has been made for assessing the subjective quality of natural images, such as those taken by optical cameras. Natural Scene Statistics (NSS) is an important tool for no-reference visual quality assessment...
Measuring visual quality, as perceived by human observers, is becoming increasingly important in the many applications in which humans are the ultimate consumers of visual information. For assessing subjective quality of natural images, such as those taken by optical cameras, significant progress has been made for several decades. To aid in the benchmarking of objective image quality assessment (IQA)...
Non-Gaussian noise/interference severely limits communication performance of narrowband powerline communication (PLC) systems. Such noise/interference is dominated by periodic impulsive noise whose statistics varies with the AC cycle. The periodic impulsive noise statistics deviate significantly from that of additive white Gaussian noise, thereby causing dramatic performance degradation in conventional...
Internet traffic primarily consists of packets from Transmission Control Protocol (TCP) flows. Based on passive, flow level TCP network measurements, our previous work has focused on using the principal component method to perform factor analysis on flow class throughput correlation matrices in order to infer which classes of TCP flows are sharing bottlenecks in the network. In this paper, we present...
Providing reliable smart grid communication from customers to the local utility faces significant challenges due to noise, interference, frequency selectivity, path loss and fading. For transmission over narrowband powerline channels (3–500 kHz) and unlicensed wireless channels (902–928 MHz), this paper reviews previous approaches for (a) channel modeling and estimation and (b) noise/interference...
Sonar sensor arrays potentially produce huge amounts of data to be recorded or transmitted over a telemetry system. Compression can reduce the required storage or transmission bandwidth, or allow a larger or higher fidelity array. We use a dataset for a sonar array receiving acoustic communication signals from a transmitter in a lake test. We compress the received signals to evaluate the effect of...
Natural Scene Statistics (NSS) has been applied to natural images obtained through optical cameras for automated visual quality assessment. Since NSS does not need a reference image for comparison, NSS has been used to assess user quality-of-experience, such as for streaming wireless image and video content acquired by cameras. In this paper, we take an important first step in using NSS to automate...
We propose two real-time motion smoothing algorithms for video stabilization using a pure 3D rotation motion model with known camera projection parameters. Both proposed algorithms aim at smoothing 3D rotation matrix sequences in a causal way. The first algorithm smooths the 3D rotation sequences in a way similar to 1st-order IIR filtering. The second algorithm uses sequential probabilistic estimation...
An all-digital PWM-based delta-sigma (ΔΣ) ADC is proposed. This system takes advantages of the duration of a pulse, rather than voltage or current, as the analog operand used in its closed-loop operation. Unlike VCO-based ADCs, this ADC as a linear input sampling stage with adequate uncalibrated performance. Furthermore, the architecture allows inherently matched multi-bit quantizer/DAC blocks by...
In this article, a novel method of performing subband analysis of digital signals is proposed. Conventional subband decomposition algorithms typically use a binary tree filterbank structure comprised of halfband filters. Due to design limitations of finite length filters, conventional decomposition algorithms typically suffer from interference due to aliasing. While longer halfband filters may reduce...
Periodic impulsive noise synchronous to the main powerline frequency is the dominant noise component in OFDM-based narrowband (NB) powerline communications (PLC). Such noise occurs in periodic bursts, where a single burst could corrupt multiple OFDM symbols. Standardized NB PLC systems use frequency-domain interleaving (FDI) in combination with forward error correction to combat impulsive noise. Alternate...
Gyroscope is playing a key role in helping estimate camera rotation during mobile video capture. The fusion of gyroscope and visual measurements needs the knowledge of camera projection parameters, the gyroscope bias and the relative orientation between gyroscope and camera. Moreover, the timestamps of gyroscope and video frames are usually not well synchronized. In this paper, we propose an online...
Modern cellular networks such as Long-Term Evolution (LTE) transport complex-baseband samples between remote radio hardware and processing equipment. Common Public Radio Interface (CPRI) links are widely used in practice and enable flexible radio head deployments, distributed antenna systems, and advanced spatial processing such as coordinated multi-point (CoMP) transmission and reception. Current...
Civil Global Navigation Satellite System (GNSS) signals are vulnerable to spoofing attacks that deceive a victim receiver into reporting counterfeit position or time information. The primary contribution of this paper is a non-cryptographic GNSS anti-spoofing technique that “sandwiches” a spoofer between a correlation function distortion monitor and a total in-band power monitor. The defense exploits...
Conventional orthogonal frequency division multiplexing (OFDM) communication systems are typically designed assuming additive white Gaussian noise and interference statistics. However, in many applications, such as Wi-Fi and powerline communications (PLC), impulsive statistics are often observed. Impulsive noise can degrade the signal-to-noise ratio (SNR) of all subcarriers and impair communication...
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