Simultaneous channel and symbol maximum likelihood estimation in Laplacian noise

This paper treats channel estimation and signal detection in Laplacian noise. The received signal is assumed to be a transmitted signal which has been corrupted by an unknown channel, modeled as a FIR filter, the output being further disturbed by additive independent Laplacian noise. The transmitted signal is assumed to depend on an unknown parameter belonging to a known finite set. The simultaneous maximum likelihood (ML) estimator of the unknown parameter, as well as of the FIR filter coefficients, is derived. The ML estimate of the channel can be obtained by using a linear programming approach and the decision about the parameter is based on the output from a set of generalized matched filters. Simulation results are included in order to illustrate the performance of the proposed receiver

Estimation in non-gaussian noise and classification of welding signals

Godkänd; 1991; 20080407 (ysko)</p

MMSE Estimation of Arrival Time with Application to Ultrasonic Signals Johan Jaap van de Beek ∗, † Per Ola Börjesson ∗ H˚akan

This paper deals with arrival time estimation of a narrow-band signal disturbed by white gaussian noise. In order to estimate the distance between a transmitting source and a reflecting target an estimator, based on the criterion of minimum mean square error (MMSE), is investigated. The MMSE-estimator is implemented in an experimental ultrasound pulse-echo system, and results of comparative simulations between the MAP-estimator and the MMSE-estimator are given. The results are compared to the theoretical Weiss-Weinstein lower bound. As expected, the MMSE-estimator has smaller mean square error than the MAP-estimator. For high SNRs, however, the mean square error obtained by the MAP-estimator manages to approach that of the MMSE-estimator. Other differences between the two estimators are revealed in additional experiments in which the range estimates are used to generate 3-dimensional surface pictures. Chapter

A simultaneous maximum likelihood estimator based on a generalized matched filter

The paper discusses parameter estimation and detection in Laplace distributed noise. The received signal is modeled as r(·)=As(·,&thetas;)+n(·), where A is an unknown amplitude, &thetas; is the parameter vector to be estimated and n(·) is independent Laplace distributed noise. The simultaneous maximum likelihood estimator of (A,&thetas;) is derived. The derived estimator is based on a combination of a weighted median filter [Astola and Nuevo, 1992] and a generalized form of the ordinary matched filter [Gustavsson and Borjesson, 1992]. Examples of performance for four different detectors are given for a case of binary detection, when the amplitude A or the signal shape s(·,&thetas;) are varied. Simulations indicate that the performance of detectors based on the generalized matched filter is not particularly dependent on either the estimate of the amplitude A or the signal shapeGodkänd; 1994; 20080222 (ysko

A generalized matched filter

Parameter estimation in additive independent identically distributed noise is treated. It is shown that there exists a generalized form of the matched filter which can be used for an arbitrary noise distribution to make e.g. ML-, MAP- or MMSE-estimates of a parameter vector. Simulations are presented to illustrate the performance.Godkänd; 1992; 20090306 (ysko

Development of Ultrafast Photodiodes for Microwave Photonics

Ultrafast photodiodes with high saturation current are under development. Current voltage characteristics and capacitance voltage characteristics will be presented. Estimated values of the RC-limited 3-dB bandwidth, as a function of area, will be discusse

MMSE Estimation of Arrival Time with Application to Ultrasonic Signals

This paper deals with arrival time estimation of a narrow-band signal disturbed by white gaussian noise. In order to estimate the distance between a transmitting source and a reflecting target an estimator, based on the criterion of minimum mean square error (MMSE), is investigated. The MMSE-estimator is implemented in an experimental ultrasound pulse-echo system, and results of comparative simulations between the MAP-estimator and the MMSE-estimator are given. The results are compared to the theoretical Weiss-Weinstein lower bound. As expected, the MMSE-estimator has smaller mean square error than the MAP-estimator. For high SNRs, however, the mean square error obtained by the MAP-estimator manages to approach that of the MMSE-estimator. Other di#erences between the two estimators are revealed in additional experiments in which the range estimates are used to generate 3-dimensional surface pictures

St\ue4ll tekniska egenskapskrav och anv\ue4nd deklarationerna

Ta bort energikraven i BBR och ers\ue4tt dem med \ue4ndam\ue5lsenliga egenskaps\uackrav. G\uf6r sedan energideklarationerna v\ue4rda namnet genom att inkludera hush\ue5lls- och verk\uacsam\uachets\uacel s\ue5 att de kan anv\ue4ndas f\uf6r att f\uf6lja upp energi\uacanv\ue4ndningen. I anslutning till Boverkets regeringsuppdrag (N2014/75/E) att definiera nya energihus\uach\ue5ll\uacningskrav, finns det all anledning att diskutera om vi \ue4r p\ue5 r\ue4tt v\ue4g med de krav p\ue5 bygg\uacnaders energi\uacprestanda som st\ue4lls i Boverkets Byggregler (BBR). Speciellt om dess uppfyllelse ska vara juridiskt bindande

Biofuels and land use in Sweden: an overview of land-use change effects

Supported by policies, biofuel production has been continuously increasing worldwide during recent years. However, concerns have been raised that biofuels, often advocated as the future substitute for greenhouse gas (GHG) intensive fossil fuels, may cause negative effects on the climate and the environment. When assessing GHG emissions from biofuels, the production phase of the biofuel crop is essential since this is the phase in which most of the GHG emissions occur during the life cycle of the fuel, often linked to land use and land management. Changes in land use can result from a wide range of anthropogenic activities including agriculture and forestry management, livestock and biofuel production. The report first presents a review of the literature in the different scientific areas related to land use change (LUC) and biofuel production. Knowledge gaps related to LUC is compiled and, a synthesis is developed highlighting major challenges and key findings. Main findings are that (i) deforestation, forest management, and climate change deforestation is a major contributor to GHG emissions and can contribute to soil erosion and carbon stock changes, (ii) albedo changes and the timing of emissions need to be better understood, (iii) to avoid degradation of biodiversity great care must be taken to develop sustainable biofuel production (iv) nutrient leakage and removal of forest residues can influence the biomass growth potential (v) to avoid fertility losses in agricultural soils during biofuel production, crops with low fertilizer needs, high nutrient use efficiency and high yields should be given priority (vi) indirect effects on land use are extremely complex to quantify without great uncertainty (vii) biofuels contribution to rising food prices and poverty even more challenging (viii) biofuel production can create jobs but also interfere with traditional ways of life and recreational values, (ix) to avoid negative effects, biofuel production should be developed in collaboration with the stakeholders involved: farmers, land owners, tourists, and industry. The literature review and synthesis presented in this report shows that land use on this planet is already placing high stress on ecosystems, atmosphere, soils and human life. Because of increased biofuel production, land use change is therefore at risk of aggravating these problems. Conclusions drawn are that the LUC caused by increasing use of biofuels can be negative to various degrees but that drawbacks can be mitigated through policy measures or technology developments. Examples include the cultivation of high-yielding crops, cultivation on abandoned arable land, and effective use of by-products and waste. To explore the opportunities that exist for beneficial land use change, continued responsible and sensitive collaboration between industry, policy-makers, researchers and local communities is a prerequisite