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Context: In large software organizations with a product line development approach, system test planning and scope selection is a complex task. Due to repeated testing: across different testing levels, over time (test for regression) as well as of different variants, the risk of redundant testing is large as well as the risk of overlooking important tests, hidden by the huge amount of possible test
Like many engineering programs in Europe, the final part of most Swedish software engineering programs is a longer project in which the students write a Master's thesis. These projects are often conducted in cooperation between a university and industry, and the students often have two supervisors, one at the university and one in industry. In particular, the Bologna Process that is currently unde
The COST 2100 channel model is a geometry based stochastic channel model (GSCM) for multiple-input multiple-output (MIMO) simulations. This paper presents parameterization and validation of the channel model for peer-to-peer communication in the 300 MHz band. Measurements were carried out in outdoor environments for both line-of-sight (LOS) and non line-of-sight (NLOS) scenarios. The COST 2100 cha
The immediate environment of handset antennas, including the casings and the users holding the handsets, has a strong impact on the radio channel in mobile communication. In this paper we investigate a composite channel method that synthetically combines double-directional measurements of the userless propagation channel with measured super-antenna patterns, i.e., patterns of the combined antenna-
This paper presents an iterative decoder for faster-than-Nyquist (FTN) and orthogonal signaling multi-carrier systems. 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 fabricat
Human beings make errors and that is nothing that we can avoid completely. We can however lower the risk of people doing wrong in situations where, for example, medical devices are used. The overall objective of the research presented in this paper is to investigate how usability testing can contribute to software risk management process in the medical device domain. Experience has been collected
In radio communications, a set of links that can transmit in parallel with a tolerable interference is called a compatible set. Finding a compatible set with maximum weighted revenue of the parallel transmissions is an important subproblem in wireless network management. For the subproblem, there are two basic approaches to express the signal to interference plus noise ratio (SINR) within integer
This paper presents the co-design of a class-D digitally-controlled oscillator (DCO) and a low-dropout voltage regulator (LDO) generating the supply voltage for the DCO. Despite the high intrinsic supply pushing of the class-D oscillator topology, the LDO noise has only a very marginal impact on the DCO phase noise. The class-D DCO and LDO have been integrated in a 65nm CMOS process without any th
This paper studies optimization issues related to a proposed traffic protection strategy referred to as flow-thinning strategy (FTS). FTS is an extension of the well known protection concept, called path diversity, to the case of partial multiple link failures. Path diversity assumes that when a certain subset of links fail, then their capacity is entirely lost and the nominal path-flows that are
Consider the transmission of complex-valued symbols over N parallell channels in additive white Gaussian noise. It is well known that linear precoding of the complex-valued data improves system performance (e. g. symbol error rate, information rate, MMSE, etc.) at a cost of increased decoding complexity at the receiver. This work constructs precoders that are constrained to have a decoding complex
A CMOS oscillator employing differential transistor pairs working in Class-C in push-pull configuration is presented. The oscillator exhibits the same advantages enjoyed by complementary topologies on oscillators based on a single differential pair, while yielding a substantial power consumption reduction thanks to the Class-C operation. The phase-noise performance and the fundamental conditions r
This paper compares the capacity improvement capability of spatial multiplexing and beamforming techniques for 60 GHz spatial transmissions in a multi-carrier radio system such as orthogonal frequency division multiplexing. The term beamforming in this paper refers to the conventional gain focusing, for the strongest propagation path, by narrow antenna beams. Our channel capacity metric depends on
Evaluation of Specific Absorption Rate (SAR) for multiple antenna systems is becoming important, with the upcoming deployment of LTE-Advanced. In this work, the influence of different antenna locations and antenna types was investigated for stand-alone SAR and simultaneous SAR, to provide some guidelines for antenna design in multi-antenna handsets. For simultaneous SAR, different phase shifts bet
This paper presents a 3rd-order, 3-bit continuous-time (CT) \Updelta\Upsigma Δ Σ modulator for an LTE radio receiver. A return-to-zero (RZ) pulse, centered in the sampling period by a quadrature clock, is used in the innermost DAC to reduce the sensitivity to loop-delay variations in the modulator, and omit implementing the additional loop delay compensation usually needed in CT modulators. The pe
Software failures in medical devices can lead to catastrophic situations. Therefore, it is crucial to handle software-related risks when developing medical devices, and there is a need for further analysis of how this type of risk management should be conducted. The objective of this paper is to collect and summarise experiences from conducting risk management with an organisation developing medic
Requirements communication plays a vital role in development projects in coordinating the customers, the business roles and the software engineers. Communication gaps represent a significant source of project failures and overruns. For example, misunderstood or uncommunicated requirements can lead to software that does not meet the customers’ requirements, and subsequent low number of sales or add
