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A major challenge in low power sensor networks is collecting data from large number of nodes with low latency. Access point (AP) typically needs to poll large number of nodes individually and schedule transmission times for each of the nodes resulting in large latency. In this paper, we propose a physical layer technique that parallelizes the polling response from multiple nodes (so called parallel...
This paper studies a spectrum sharing cognitive radio (CR) network coexisting with a primary network. In particular, the channel state information (CSI) between the secondary transmitter (STx) and the primary receiver (PRx) is assumed to be outdated due to channel feedback latency. We assume that the secondary user (SU) shall satisfy a given delay quality-of-service (QoS) constraint as well as the...
In this paper a detailed analysis of an UltraWideband correlation receiver is presented. The synchronization methods are discussed and analyzed in terms of practical realizability. All algorithms are implemented on FPGA and tested with a real UWB transceiver. The measurement results are then evaluated and compared to the ones found in the literature. Finally an application example for the correlation...
In this paper, we investigate the detection of multi-path signal propagation in a Time Difference of Arrival (TDOA) localization scenario. Usually, TDOA measurements are obtained by determining the absolute maximum of the cross correlation function of signals recorded at different sensor nodes in a sensor network. Multipath signal propagation causes multiple peaks in the cross correlation function...
Noncoherent UWB receivers promise low power consumption and low processing complexity but their peak data rate is limited by the delay spread of the multipath radio channel. A recently proposed multichannel autocorrelation receiver (AcR) can break this rate limit due to its multicarrier signal demodulation capability. In this paper, the hardware implementation of this receiver architecture is addressed...
Enhanced external efficiency, improved coherence and tunability are demonstrated for silicon PIN THz emitters by utilizing the internal reflection and multi optical pulse excitation.
Carrier aggregation (CA) has been proposed as a key feature of the 4G cellular networks to achieve the very high data rates. It is known that the correlation between the subchannels, including both small- and large-scale fading, is critical in determining the performance gain we can obtain from the multicarrier transmission. However, due to the prohibitively high complexity and cost in simultaneously...
A metallic CNT renders a short circuit between drain and source in a CNTFET. Technologies capable of removing metallic CNTs create open circuits which degrades SRAM cell performance and functionality. In this paper we present a design approach to tolerate removed metallic CNT in CNTFET SRAM. –x00D7; CNTs to form a CNTFET. An extremely high probability of having a functional memory array can be obtained...
For high-accuracy AC voltage measurements, sampling errors can contribute significantly to increase the incertitude. Fractional delay is a simple technique to reduce sampling errors, improving the accuracy of electrical digital measurements. In this paper we combine the fractional delay sampling technique with Principal Component Analysis, applying this technique to high-accuracy measurements.
Traditional G-P algorithm exist two drawbacks in solving the correlation dimension of chaotic time series. The one is the subjective existence to determine scaleless range, the other is calculation error is large when the amount of data is small. For two shortcomings, the fuzzy C-means clustering is introduced to the G-P algorithm to determine the no-scales range. Least-squares fitting method is used...
An absolute calibrate of BOC signal transmitting channel on navigation satellite based on software defined radio is addressed. At first, the BOC navigation signal and the pulse per second (PPS) generated by navigation time keeping system are sampled synchronously. After the sampling data of BOC signal is preprocessed, a serial-to-parallel transform is done for the intermediate frequency carried BOC...
A systematic method is proposed to address modeling challenges in accurate chip level leakage prediction, namely a precise total leakage width count method, a simple model to quantify leakage uplift caused by systematic across-chip variation, and a consistent model to capture 3-sigma leakage and leakage spread at fixed performance.
It has been shown that due to its smaller signal bandwidth (96 KHz), DRM+ signal could suffer from flat fading degradation at low receiver speeds, particularly in urban environments. To alleviate this problem, a simple transmit delay diversity (TDD) has been proposed in the standard. This paper tries to investigate this issue by presenting the performance results of multipath fading characterizations...
Some chaotic sequences have poor autocorrelation performance or modulated autocorrelation performance, but previously we didn't know the rule and couldn't improve their performances effectively. Using recently presented Autocorrelation and modulated Autocorrelation theorems based on a Phase Space method, we can find and mend the structure defects of chaotic sequences and improve their autocorrelation...
Radar designers seek transmit waveforms that have an acceptable time envelope (modulus), power spectral density, and ambiguity function. However, these three waveform properties are often derived from different sources, which can result in requirement inconsistency. This paper re-examines the design of radar waveforms with disjoint spectral support (also known as sparse frequency or thinned spectrum...
Increasing process variations result in increasing statistical diversity in manufactured devices. Test plans that are developed without this diversity in mind are bound to result in poor test quality/yield and/or long test times. Adaptive testing is a general term that is used to tailor the test strategy to accommodate a wide range of variation in the statistical characteristics of manufactured devices...
Noncoherent UWB receivers promise low power consumption and low processing complexity but their peak data rate is limited by the delay spread of the multipath radio channel. A recently proposed multichannel autocorrelation receiver (AcR) can break this rate limit because it can demodulate multicarrier signals. The hardware implementation of this receiver architecture is addressed in this paper. We...
A lot of Ultra Wideband (UWB) antenna designs, especially printed antenna, have been proposed so far. However, among those proposed designs, only single unit antenna analysis i.e. return loss and radiation pattern at particular frequencies are usually observed. This paper reports a deeper transmission analysis by considering UWB antenna as a system; so called system characterization. For a specific...
Abstract: In view of using symmetrical normalization for smaller deviation than standard normalization for the multi-tau photon correlator in the whole delay time range but need more monitor channels. We suggest employing symmetrical normalization when the lag time larger than 16384 and standard normalization smaller than 16384. Deviation of symmetrical normalization and standard normalization was...
An accurate channel estimation is crucial for the novel time domain synchronous orthogonal frequency-division multiplexing (TDS-OFDM) scheme in which pseudo noise (PN) sequences serve as both guard intervals (GI) for OFDM data symbols and training sequences for synchronization/channel estimation. This paper studies the channel estimation method based on the cross-correlation of PN sequences. A theoretical...
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