Switched-RC radio frequency N-path filters

Tunable on-chip Radio Frequency (RF) filtering is highly desirable for cost effective wireless communication devices. As mobile wireless devices increasingly support multiple RF-bands, tunable RF filtering is wanted. The tremendous growth of wireless communication combined with scarcely available spectrum asks for new, more programmable radio hardware. This has led to the concept of a cognitive radio capable of smart dynamic spectrum access (DSA) which asks for software-defined radio (SDR) hardware, with flexibly programmable tunable filtering. \ud In this thesis N-path switched-RC circuits are explored, aiming for RF pre-filtering for wireless transceivers. The filter concept fits well to SDR as the center frequency is programmable by the switching frequency, i.e. via a digital clock. As new CMOS technologies provide higher density capacitors and MOS switches with low on-resistance and low parasitic capacitance, N-path filtering benefits from Moore’s law. \ud To demonstrate feasibility, a 4-path differential switched-RC bandpass filter, an 8-path single-ended, as well as an 8-path differential bandstop (notch) filter have been implemented in 65nm CMOS technology. A mathematical analysis is presented to describe the filtering behavior as well as various imperfections for the N-path bandpass and notch filters. The implemented bandpass filter provides an in-band input referred third order intercept point IIP3in-band>+14 dBm with compression point P1dB,in-band>0 dBm at a noise figure NF<6 dB. The filter is tunable from 0.1-1 GHz. For the 8-path notch filters, IIP3in-band>17 dBm, P1dB,in-band>2 dBm and NF<3 dB are achieved while the notch frequency is tunable from 0.1-1.2 GHz with the rejection of >20 dB. Especially the compression point and IIP3 are much higher than what is typically achieved with RF CMOS receivers.\ud The N-path filtering technique can also be applied for spatial filtering purposes. A 4-element phased-array system has been implemented in 65nm CMOS technology. 8-phase passive mixers translate the Spatial- and frequency-domain filtering from baseband to RF frequencies at the antenna inputs. As a result a remarkable input compression point P1dB of up to +10 dBm is achieved for out-of-band/beam blockers

A Differential 4-Path Highly Linear Widely Tunable On-Chip Band-Pass Filter

A passive switched capacitor RF band-pass filter with clock controlled center frequency is realized in 65nm CMOS. An off-chip transformer which acts as a balun, improves filter-Q and realizes impedance matching. The differential architecture reduces clock-leakage and suppresses selectivity around even harmonics of the clock. The filter has a constant -3dB bandwidth of 35MHz and can be tuned from 100MHz up to 1GHz. IIP3 is better than 19dBm, P1dB=2dBm and NF<;5.5dB at Pdiss=2mW to 16mW.\u

Scalable SD Erlang Computation Model

The technical report presents implementation of s groups and semi-explicit placement of the Scalable Distributed (SD) Erlang. The implementation is done on the basis of Erlang/OTP 17.4. The source code can be found in https://github.com/release-project/otp/tree/17.4-rebased. We start with a discussion of differences between distributed Erlang global groups and SD Erlang s groups (Chapter 1). Then we discuss the implementation of s groups and the features of sixteen functions that were modified and introduced in global and s group modules (Chapter 2). After that we discuss semi-explicit placement, node attributes and choose node/1 function (Chapter 3). These functions were unit tested (Chapter 4). Finally, we discuss future work (Chapter 5)

Scalable Persistent Storage for Erlang

The many core revolution makes scalability a key property. The RELEASE project aims to improve the scalability of Erlang on emergent commodity architectures with 100,000 cores. Such architectures require scalable and available persistent storage on up to 100 hosts. We enumerate the requirements for scalable and available persistent storage, and evaluate four popular Erlang DBMSs against these requirements. This analysis shows that Mnesia and CouchDB are not suitable persistent storage at our target scale, but Dynamo-like NoSQL DataBase Management Systems (DBMSs) such as Cassandra and Riak potentially are. We investigate the current scalability limits of the Riak 1.1.1 NoSQL DBMS in practice on a 100-node cluster. We establish for the first time scientifically the scalability limit of Riak as 60 nodes on the Kalkyl cluster, thereby confirming developer folklore. We show that resources like memory, disk, and network do not limit the scalability of Riak. By instrumenting Erlang/OTP and Riak libraries we identify a specific Riak functionality that limits scalability. We outline how later releases of Riak are refactored to eliminate the scalability bottlenecks. We conclude that Dynamo-style NoSQL DBMSs provide scalable and available persistent storage for Erlang in general, and for our RELEASE target architecture in particular

Consumer rights in Iran’s telecom: Investigation effective drivers on permission base mobile marketing

Nowadays the SMS advertisements in Iran are sent without observing the regulations which protect the consumer rights; this practice has proved to be a major annoyance to Iranian mobile users. In this paper, the factors which need to be examined before gaining mobile user’s permission were evaluated. The hypothesized model is empirically tested using data collected from a survey in Tehran theater-e-shahr audiences. Structural Equation Modeling (SEM) was used to evaluate the causal model and Confirmatory Factor Analysis (CFA) was performed to examine the reliability and validity of the measurement model. It is concluded that mobile marketing experience extremely affects the process of getting mobile users’ permission

The scalability of reliable computation in Erlang

With the advent of many-core architectures, scalability is a key property for programming languages. Actor-based frameworks like Erlang are fundamentally scalable, but in practice they have some scalability limitations. The RELEASE project aims to scale the Erlang's radical concurrency-oriented programming paradigm to build reliable general-purpose software, such as server-based systems, on emergent commodity architectures with 10,000 cores. The RELEASE consortium works to scale Erlang at the virtual machine, language level, infrastructure levels, and to supply profiling and refactoring tools. This research contributes to the RELEASE project at the language level. Firstly, we study the provision of scalable persistent storage options for Erlang. We articulate the requirements for scalable and available persistent storage, and evaluate four popular Erlang DBMSs against these requirements. We investigate the scalability limits of the Riak NoSQL DBMS using Basho Bench up to 100 nodes on the Kalkyl cluster and establish for the first time scientifically the scalability limit of Riak as 60 nodes, thereby confirming developer folklore. We design and implement DE-Bench, a scalable fault-tolerant peer-to-peer benchmarking tool that measures the throughput and latency of distributed Erlang commands on a cluster of Erlang nodes. We employ DE-Bench to investigate the scalability limits of distributed Erlang on up to 150 nodes and 1200 cores. Our results demonstrate that the frequency of global commands limits the scalability of distributed Erlang. We also show that distributed Erlang scales linearly up to 150 nodes and 1200 cores with relatively heavy data and computation loads when no global commands are used. As part of the RELEASE project, the Glasgow University team has developed Scalable Distributed Erlang (SD Erlang) to address the scalability limits of distributed Erlang. We evaluate SD Erlang by designing and implementing the first ever demonstrators for SD Erlang, i.e. DE-Bench, Orbit and Ant Colony Optimisation(ACO). We employ DE-Bench to evaluate the performance and scalability of group operations in SD-Erlang up to 100 nodes. Our results show that the alternatives SD-Erlang offers for global commands (i.e. group commands) scale linearly up to 100 nodes. We also develop and evaluate an SD-Erlang implementation of Orbit, a symbolic computing kernel and a generalization of a transitive closure computation. Our evaluation results show that SD Erlang Orbit outperforms the distributed Erlang Orbit on 160 nodes and 1280 cores. Moreover, we develop a reliable distributed version of ACO and show that the reliability of ACO limits its scalability in traditional distributed Erlang. We use SD-Erlang to improve the scalability of the reliable ACO by eliminating global commands and avoiding full mesh connectivity between nodes. We show that SD Erlang reduces the network traffic between nodes in an Erlang cluster effectively

Consumer rights in Iran’s telecom: Investigation effective drivers on permission base mobile marketing

Nowadays the SMS advertisements in Iran are sent without observing the regulations which protect the consumer rights; this practice has proved to be a major annoyance to Iranian mobile users. In this paper, the factors which need to be examined before gaining mobile user’s permission were evaluated. The hypothesized model is empirically tested using data collected from a survey in Tehran theater-e-shahr audiences. Structural Equation Modeling (SEM) was used to evaluate the causal model and Confirmatory Factor Analysis (CFA) was performed to examine the reliability and validity of the measurement model. It is concluded that mobile marketing experience extremely affects the process of getting mobile users’ permission

Scalable Reliable SD Erlang Design

This technical report presents the design of Scalable Distributed (SD) Erlang: a set of language-level changes that aims to enable Distributed Erlang to scale for server applications on commodity hardware with at most 100,000 cores. We cover a number of aspects, specifically anticipated architecture, anticipated failures, scalable data structures, and scalable computation. Other two components that guided us in the design of SD Erlang are design principles and typical Erlang applications. The design principles summarise the type of modifications we aim to allow Erlang scalability. Erlang exemplars help us to identify the main Erlang scalability issues and hypothetically validate the SD Erlang design

The current advances of CRISPR/Cas-based systems for the detection of COVID-19

The novel coronavirus disease 2019 (COVID-19) still poses a serious threat to every human on the planet nearly 1.5 years after its beginning. Unfortunately, the current diagnostic methods, although highly sensitive and specific, still suffer from many shortcomings. Faster and easy-to-operate diagnostic systems are undoubtedly sorely needed. The CRISPR/Cas platform has gained much attention in recent years in a wide range of biomedical sciences. Besides its treatment potential and drug and vaccine development, it can be used for disease diagnosis. Thus, the CRISPR/Cas-based system holds great promise for providing a rapid and easily deployable COVID-19 detection and is on par with the conventional diagnostic approaches in terms of sensitivity and specificity. In this review article, we discuss the latest advances of CRISPR/Cas technology as a fast and reliable severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) detection method