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Despite recent attempts to relax the phase-noise demands on voltage-controlled oscillators (VCOs) for cellular communications [1], mainstream radios require harmonic VCOs capable of a very low phase noise with moderate power consumption, associated to a large tuning range (TR) and a high insensitivity to interfering signals. Ideally, the TR should be in excess of one octave, since this allows the
As a part of the LDTA 2011 Tool Challenge, we implemented a compiler for the language Oberon-0 using the metacompilation tool JastAdd. In this paper, we report on this implementation, and reflect on aspects of it such as ease of use, modularity, and safety.
We consider detection over intersymbol interference channels that are unknown at the receiver. For such a kind of systems, we consider an alternative approach to the design of a reduced-complexity receiver based on channel shortening without the explicit estimation of the channel impulse response. The proposed solution allows a simplification of the receiver architecture and a faster convergence f
Using the metric of channel capacity, three dual-antenna multiple-input multiple-output (MIMO) terminals with adaptive impedance matching were evaluated at LTE Band 13 in four different user scenarios using simulation. Each of the three terminals is equipped with a slot-monopole antenna and a planar inverted-F antenna (PIFA). The slot monopole is fixed at one edge of the chassis, whereas the locat
This paper presents a decoder for multi-carrier modulated signals employing Faster-than-Nyquist (FTN) signaling. FTN signaling is a method of improving bandwidth efficiency at the expense of higher processing complexity in the transceiver. The decoder can switch between orthogonal and FTN signaling modes and exploits channel properties to improve bandwidth efficiency. The decoder is fabricated in
In the paper we consider a commonly known network design problem with demand restoration assuming stub release. No compact linear programming (LP) formulation for the problem is known, and all known non-compact LP formulations of the problem require NP-hard path generation (pricing). Therefore, the problem itself is suspected to be NP-hard - this, however, is not actually known. The main result of
Reference attributed grammars (RAGs) extend Knuth’s attribute grammars with references. These references can be used to extend the abstract syntax tree to a graph. We investigate how RAGs can be used for implementing tools for visual languages. Programs in those languages can often be expressed as graphs.
This paper presents a low voltage continuous-time delta-sigma modulator (DSM) intended for the receiver of an ultra-low-power radio. The DSM features a 2nd-order loop filter implemented with a single operational amplifier to reduce the power consumption. Furthermore, a 4-bit quantizer is used to achieve high resolution while keeping the sampling frequency low. The quantizer is realized using the s
Gm-C filters suffer from limited dynamic range due to a trade-off between noise and linearity in OTA design. This paper therefore presents a filter with a linearization technique to break this trade-off. This technique is demonstrated by a low power 4th order 10MHz Butterworth Gm-C low pass filter. The filter was implemented in 65nm CMOS technology with a core area of 0.19mm2 and a total current c
Abstract in UndeterminedThe radio channels between nodes of an indoor peer-to-peer network show specific fast fading characteristics. Depending on the mobility and on the scattering properties of the environment, different kinds of fading distributions can occur: Ricean fading between static nodes, but also Rayleigh or even double-Rayleigh fading between mobile nodes. We investigate fast fading in
Background. Software engineering is in search for general principles that apply across contexts, for example to help guide software quality assurance. Fenton and Ohlsson presented such observations on fault distributions, which have been replicated once. Objectives.We intend to replicate their study a second time in a new environment. Method.We conducted a close replication, collecting defect data
In the paper we present integer programming (IP) optimization models for flexgrid elastic optical networks (EON). We consider several different basic assumptions regarding flexibility of EON that lead to a variety of IP formulations differing in precision and complexity. As usual, detailed models aiming at precisely describing technological aspects of EON suffer from tractability issues resulting
In this paper, we construct protograph-based spatially coupled low-density parity-check (LDPC) codes by coupling together a series of L disjoint, or uncoupled, LDPC code Tanner graphs into a single coupled chain. By varying L, we obtain a flexible family of code ensembles with varying rates and frame lengths that can share the same encoding and decoding architecture for arbitrary L. We demonstrate
A low-power high linearity CMOS G(m)-C channel select filter for WLAN/WiMAX receivers in 90-nm CMOS technology is presented. To reduce power consumption a biquad cell with simple architecture is used. A simple but efficient technique is also proposed to improve the linearity of the filter without increasing its power consumption. Coarse and fine tuning techniques are used to tune the cutoff freque
From the network layer perspective, the problem of burst losses is one of the most challenging problems which restrain the development of optical burst switching (OBS) networks. Indeed, OBS is a buffer-less technology and the consequent lack of guarantees for data delivery may affect significantly the quality of service (QoS) perceived by end users. To overcome these obstacles, dedicated network m
The proposed time-to-digital converter (TDC) arranges two Vernier gated-ring-oscillator (GRO) branches in a 2-dimension (2-D) fashion. All delay differences between X-axis phases and Y-axis phases (based on 2-D definition) can be used, rather than only the diagonal line. The large latency time inherited from Vernier structure is therefore dramatically reduced. The TDC is implemented in a 90nm CMOS
The COST 2100 channel model is a geometry-based stochastic channel model (GSCM) that can reproduce the stochastic properties of multi-link Multiple-Input Mulitple-Output (MIMO) channels over time, frequency and space. By contrast to other popular GSCMs, the COST 2100 approach is generic and flexible, making it suitable to model multi-user or distributed MIMO scenarios. In this paper a concise over
Recent years have seen an increasing attention given to wireless Personal Area Networks (PANs), which are typically networks with small transmitter-receiver (TX-RX) separation. The desire for high data rates has led to an interest in deploying multiple-input multiple-output (MIMO) transmission for such systems, but up until this date there exists, to the authors’ best knowledge, no MIMO channel mo
