The agnostic sampling transceiver

Increasing capacity demands in the access networks require inventive concepts for the transmission and distribution of digital as well as analog signals over the same network. Here a new transceiver system, which is completely agnostic for the signals to be transmitted is presented. Nyquist sampling and time multiplexing of N phase and intensity modulated digital and analog channels with one single modulator, as well as the transmission and demultiplexing with another modulator have been demonstrated. The aggregate symbol rate corresponds to the modulator bandwidth and can be further increased by a modification of the setup. No high-speed electronic signal processing or high bandwidth photonics is required. Apart from its simplicity and the possibility to process high bandwidth signals with low bandwidth electronics and photonics, the method has the potential to be easily integrated into any platform and thus, might be a solution for the increasing data rates in future access networks

Orthogonal Sampling based Broad-Band Signal Generation with Low-Bandwidth Electronics

High-bandwidth signals are needed in many applications like radar, sensing, measurement and communications. Especially in optical networks, the sampling rate and analog bandwidth of digital-to-analog converters (DACs) is a bottleneck for further increasing data rates. To circumvent the sampling rate and bandwidth problem of electronic DACs, we demonstrate the generation of wide-band signals with low-bandwidth electronics. This generation is based on orthogonal sampling with sinc-pulse sequences in N parallel branches. The method not only reduces the sampling rate and bandwidth, at the same time the effective number of bits (ENOB) is improved, dramatically reducing the requirements on the electronic signal processing. In proof of concept experiments the generation of analog signals, as well as Nyquist shaped and normal data will be shown. In simulations we investigate the performance of 60 GHz data generation by 20 and 12 GHz electronics. The method can easily be integrated together with already existing electronic DAC designs and would be of great interest for all high-bandwidth applications

A Juxtaposition of Wittgenstein’s and Mozi’s Theory of Knowledge to Develop New Perspectives on the Traditional Problems of Western Epistemology

This paper juxtaposes the later Wittgenstein's and Mozi's theories of knowledge to provide us with new perspectives for addressing the deadlocks faced by a representational theory of knowledge that hinges on direct realism in order to devise a solution that incorporates the best of both philosophers' thinking. This article highlights the Chinese understanding of mind and knowledge in terms of competence, compared to Western epistemology that focuses on having an accurate representative model of reality, allowing for a dichotomy between representation and mind-independent reality. I argue that we should aim for the middle way by synthesizing both these philosophers' insights on contextualism to overcome the deadlocks faced by the traditional Western epistemological focus on representation and by extending Mozi's version of contextualism into other areas of knowledge, beyond social and moral issues

Towards Automating a Risk-First Threat Analysis Technique

During the past decade, secure software design techniques have found their way into the software development lifecycle. In this context, threat modeling (or analysis) methodologies are used to systematically identify threats in the design phase of software development. However, threat modeling is often performed manually, which is time-consuming and errorprone. An existing methodology called eSTRIDE tries to solve the problem of high manual effort by introducing security related enrichment’s to the software architecture models and by introducing reductions during the analysis. But the lack of tool support may counteract the advantages of using the methodology. Therefore, the aim of this work is to find out how to support semi-automation of eSTRIDE.We have produced a prototype tool using the design science research methodology, which allows the user to create or modify an extended Data Flow Diagram of their system and perform eSTRIDE. A workshop with ten participants was used to evaluate the tool. We studied the average precision, recall and productivity of the analysis results. Finally, we found the perceived usability of the tool, which was mostly positive

High-Bandwidth Arbitrary Signal Detection Using Low-Speed Electronics

The growing demand for bandwidth and energy efficiency requires new solutions for signal detection and processing. We demonstrate a concept for high-bandwidth signal detection with low-speed photodetectors and electronics. The method is based on the parallel optical sampling of a high-bandwidth signal with sinc-pulse sequences provided by a Mach-Zehnder modulator. For the electronic detection and processing this parallel sampling enables to divide the high-bandwidth optical signal with the bandwidth B into N electrical signals with the baseband bandwidth of B/(2N) . In proof-of-concept experiments with N=3 , we present the detection of 24 GHz optical signals by detectors with a bandwidth of only 4 GHz. For ideal components, the sampling and bandwidth down-conversion does not add an excess error to the signals and even for the non-ideal components of our proof-of-concept setup, it is below 1%. Thus, the rms error for the measurement of the 24 GHz signal was reduced by a factor of about 3.4 and the effective number of bits were increased by 1.8

Low-Bandwidth Photonics-Assisted Receiver for Broad-Bandwidth Wireless Signals

This paper introduces a photonics-assisted receiver that enables the reception of high-bandwidth wireless signals with low-bandwidth electronics. The receiver down-converts the input signal into parallel low-bandwidth sub-signals, employing photonics-based orthogonal sampling. This sampling is based on a multiplication and not switching, so, it does not introduce additional aperture jitter. Therefore, the photonics-assisted analog-to-digital converter (ADC) converts the wireless signal with a higher signal-to-noise-and-distortion ratio (SINAD), which improves the Q-factor for the detection. This Q-factor improvement is especially high, when the orthogonal sampling is carried out with low-jitter oscillators. Compared to the direct detection with 30 GHz, the simulation demonstrates a 2.2 dB Q-factor enhancement for the detection of a 30 GHz signal, with 10 GHz electronics. The same improvement is revealed in the experiment for the detection of 12 GHz signals with 4 GHz electronics