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Massive Multiple-Input Multiple-Output (MIMO) systems have been shown to improve both spectral and energy efficiency one or more orders of magnitude by efficiently exploiting the spatial domain. Low-cost RF chains can be employed to reduce the Base Station (BS) cost, however this may require additional baseband processing to handle induced distortions due to the hardware impairments. In this artic

This paper presents a double directional analysis of vehicle-to-vehicle channel measurements conducted in two different traffic environments. Using a high-resolution algorithm, we derive channel parameters like angle-of- arrival, angle-of-departure, propagation delay and Doppler’s spread and identify underlying propagation mechanisms by combining these estimates with maps of the measurement sites.

Background. When delivering an embedded product, such as a mobile phone, third party products, like games, are often bundled with it in the form of Java MIDlets. To verify the compatibility be- tween the runtime platform and the MIDlet is a labour-intensive task, if input data should be manually generated for thousands of MIDlets. Aim. In order to make the verification more efficient, we investiga

With the advent of massive online encyclopedic corpora such as Wikipedia, it has become possible to apply a systematic analysis to a wide range of documents covering a significant part of human knowledge. Using semantic parsers, it has become possible to extract such knowledge in the form of propositions (predicate―argument structures) and build large proposition databases from these documents. Th

In this paper, multiple-input multiple-output (MIMO) channel measurements in an outdoor micro-cell environment are used to study the effect of base-station (BS) inter-element spacing on multi-user MIMO signal separation. Users with two dual-polarized patch antennas at the mobile station (MS), and four equally-spaced dual-polarized patch antennas at the BS are considered. At the BS, the inter-eleme

Measurements of a sub-threshold (sub-VT) decimation filter, composed of four half band digital (HBD) filters in 65 nm CMOS are presented. Different unfolded architectures are analyzed and implemented to combat speed degradation. The architectures are analyzed for throughput and energy efficiency over several threshold options. Reliability in the sub-VT domain is analyzed by Monte-Carlo simulations

A new architecture for Discrete Fourier Transform (DFT) based channel estimation has been analyzed, implemented and synthesized for ASIC. The core concept of the proposed esti- mation algorithm is to process the channel increments rather than the channel coefficients. With strong enough time correlation, we can reduce the wordlength of processing blocks compared to standard channel estimators and

Critical systems must comply with safety standards in many application domains. This involves gathering safety evidence in the form of artefacts such as safety analyses, system specifications, and testing results. These artefacts can evolve during a system’s lifecycle, and impact analysis might be necessary to guarantee that system safety and compliance are not jeopardised. Although extensive rese

In this paper we show a closed caption formula for the efficiency of the optimal sampling technique in the random S-box model. This formula is derived by analyzing the given model and sampling technique using statistical techniques. We further generalize the original random S-box model in two ways; allowing multiple-bit entries, xor of several random S-box outputs. For all cases we show the corres

This paper presents a double directional analysis of vehicle-to-vehicle channel measurements conducted in three different traffic scenarios. Using a high-resolution algorithm, we derive channel parameters like Angle-of-Arrival (AOA), Angle-of-Departure (AOD), propagation delay and Doppler shift and identify underlying propagation mechanisms by combining these estimates with maps of the measurement

Beamforming is an important feature of 60 GHz communications. We present an analysis of the influence of beamforming in indoor ultrawideband radio channels measured in the mm-wave 60 GHz band. The performance of narrowband and wideband direction-based beamformers is investigated in terms of improving channel metrics such as the delay spread, excess delay, and the signal-to-noise ratio (SNR). The p

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 and few devices is used. A simple but efficient technique is also used to improve the linearity of the filter without increasing its power consumption. The cutoff frequency of the sixth order Butterworth low-

This correspondence deals with the construction of minimum Euclidean distance precoders for multiple-input multiple-output (MIMO) systems with up to four transmit antennas. By making use of a state-of-the-art technique for optimization over the unitary group, we can numerically optimize the MIMO precoders. The correspondence then proceeds by identifying the obtained precoders as well-known lattice

This work studies the design of linear precoder codebooks for N-r x N-t MIMO channels with MMSE detection at the receiver. A natural split of precoder-design is unitary precoding and non-unitary precoding. Unitary precoding is only performing rotation of the data in a way beneficial for the channel. Non-unitary precoding additionally also uses power-loading to further improve the performance. Some

Increasing the number of persons working on quality assurance (QA) tasks, e.g., reviews and testing, increases the number of defects detected – but it also increases the total effort unless effort is controlled with fixed effort budgets. Our research investigates how QA tasks should be configured regarding two parameters, i.e., time and number of people. We define an optimization problem to answer

Realistic radio channel models are crucial for the success of vehicle-to-vehicle (V2V) system investigations. In this paper, we summarize the important parameters for V2V channel models and describe relevant measurement campaigns. Also, we develop and evaluate an ns-3 simulation model of a realistic V2V channel model that is based on measurements in Sweden. The channel model incorporates the effec

The use of duty-cycled ultralow-power wake-up receivers (WRxs) can significantly extend a node lifetime in low-power sensor network applications. In the WRx design, both the low-power operation of the WRx and the wake-up beacon (WB) detection performance are of importance. We present a system-level analysis of a duty-cycled WRx design, including an analog front end, a digital baseband, the WB stru

Vehicle-to-vehicle (V2V) communication is an enabler for improved traffic safety and congestion control. As for any wireless system, the ultimate performance limit is determined by the propagation channel. A particular point of interest is the shadowing effect of large vehicles such as trucks and buses, as this might affect the communication range significantly. In this paper we present measuremen