In aeronautical telemetry, the multipath interference usually causes significant performance degradation. As the bit rate of telemetry systems increases, the impairments of multipath interference are more serious. The constant modulus algorithm (CMA) blind equalizer is effective to mitigate the impairments of multipath interference. The CMA adapts the equalizer coefficients to minimize the deviation of the signal envelope from a constant level. This paper presents the performances of the CMA blind equalizer applied for PCM-FM, PCM-BPSK, SOQPSK-TG and ARTM CPM in aeronautical telemetry.

The objective of Diploma thesis is design of analysis tool for equalizers used in FMT modulation. The model of transmission channel was designed for simulations with FMT. The transmission path is modeled by test loop, which corresponds to DSL line. For this reason, some principles of DSL technology is described in the thesis. The principles of multicarrier modulation are introduced in first part. The multicarrier modulation with filter bank (FMT) is described in detail.The different methods of design the fiter bank are given and compared. Channel equalization are introduced in second part. The attention was focused on minimum mean square error filtering (MMSE). Decision feedback channel equalizer (DFE) is extended from linear MMSE equalizer. DFE equalizers were programmed in analysis tool. For computation of equalizer coeficients was used also equalizers based on adaptive algorithms and MMSE. The last part describes the results of DFE equalizers used in communication system with FMT modulation. Analysis tool was programmed in MATLAB with a graphical user interface. It allows to show mean square error, signal-to-noise ratio and transmission speed dependence on delay between original and distorted signal. Signal-to-noise ration is displayed also in individual subchannels and users can display mean square error dependence on different orders of DFE filters.

This thesis deals with analog bass guitar preamplifiers and related functional blocks such as equalizers and bass effects. The first part contains a theoretical analysis of individual functional blocks preamplifiers and principles as well as an outline of the design and construction principles. In the following section is presented a design of connection that involves a bass guitar preamplifier, including an equalizer, an integrated distortion effect and an amplifier for headphone output. The proposed connections are simulated in the PSpice program and the printed circuit boards design is carried out using the Eagle program. Based on previous results, the construction of a bass guitar preamplifier is realized. The parameters of the individual blocks are measured and compared with the simulations.

The paper deals with analysis of the problems of digital signal processing and with design of the control unit for DSP and audio signal distribution to active external loudspeakers. It describes function of delta-sigma AD converters, the most widely used digital filters and Fast Fourier Transform. The processed signal will be send to external loudspeakers using an Ethernet interface. The paper also covers the design of signal processing unit's hardware and software. Achieved functions and parameters of the unit are discussed in conclusion.

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This case study examined the extent to which the No Child Left Behind mandate has contributed to principal stress, specifically in middle schools who have achieved annual yearly progress through the use of confidence intervals when measuring sub-groups. A secondary question relating to how principals were coping with the law from an academic/personal point of view was also addressed. The primary data source were interviews with ten principals from urban, suburban and rural school districts surrounding the Philadelphia area. Review of data sources provided by the principals, use of educational databases as well as observations were used to study this phenomenon. The NCLB statute and it's myriad of consequences for schools that do not make AYP have created a more stressful, testing -driven environment for all stakeholders. Principals, teachers, parents, and most importantly, students have all been affected by this statute. Schools that are classified as corrective action 1 and 2 because of low sub-group scores continue to rise in Southeastern Pennsylvania; nowhere is this more dramatic than at the secondary schools level. Principals in these buildings face stiff pressure from internal and external forces. Nationally, recent research has borne out an increase in principal turnover across the country in the last 5 years. According to the statute, every student that attends public school in the United States will be proficient in math and reading, regardless of sub-group, by 2014. The purpose of this qualitative study was to illuminate an area of research pertaining to principals of schools whose subgroups achieved AYP through the use of a confidence interval, and to collect effective instructional data (interventions ) that could theoretically help student sub-groups achieve AYP. There is also an understanding among principals that if they do not meet the AYP goal each year, eventually they can be removed from the leadership positions at their schools. This punitive sanction does not take into effect a school's overall score, but is reflective of all its' subgroups. Results from this study show that principals, although aware of the law and its' sanctions, chose to focus on designing positive interventions that help all students achieve, while at the same time offering instructional supports to their respective staffs. The principals agreed that the NCLB law was good for public education, but stated that sub-group inclusion is unfair to the students it was designed to protect. All principals reported a moderate level of stress connected with the implementation of the statute, but not enough for them to consider leaving their jobs for another occupation. The premise that principals worried about losing their jobs as a result of AYP failure was refuted in this study. All principals reported major changes at their schools in curriculum delivery, interventions for sub-groups, and the use of data assessment systems to drive instruction. An emerging theme from this study is the concept that the NCLB statute over the past five years has become the " great equalizer" between urban and suburban school districts. As more suburban schools fall under NCLB sanctions, they no longer can dismiss AYP failures as a purely urban phenomenon, but actually look to partner with urban schools in order to create effective instructional programs for their students. The research about the impact of the NCLB law on principal stress remains inconclusive. As the law continues to move toward 2014, barring any dramatic changes all public schools in the United States will be under some type of corrective action. There is a large research gap about how principals will survive in this particular environment. This study has started to address that gap by focusing on what schools do when they are an under-performing sub-group away from NCLB sanctions. This study also begins to document the changes that have been occurring in schools as a result of NCLB, along with principal perceptions of stress since the law's advent in 2002. / Educational Administration

Considering the communication systems with cyclic prefix (CP), such as orthogonal frequency-division multiplexing (OFDM) modulation and single-carrier cyclic prefixed (SCCP) modulation, when the length of CP is longer than the channel length, the use of cyclic prefix (CP) does not only eliminate the inter-block interference, but also convert linear convolution of the transmitted signal with the channel into circular convolution. Unfortunately, the use of CP significantly decreases the bandwidth utilization. Therefore, to reduce the length of CP is a critical issue. The thesis investigates that how to design a channel-shortening equalizer (CSE) at receiver which forces the length of the effective channel response as short as the CP length. The thesis describes the signal model as a matrix form. The effect channel response after CSE is investigated and then the coefficient of channel shortening filter is obtained using singular value decomposition method under various criterions. We further propose a novel CSE maximizing the shortening signal-to-interference ratio. In addition, it is demonstrated that the proposed CSE has the same performance as the conventional scheme but a lower computation complexity.

International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada / The performance of novel experimental blind equalizers suitable for a large class of applications including telemetry systems and other wireless applications is described. Experimental hardware research of these adaptive patent pending Feher Equalizers (FE) confirms computer simulated data [1]. A two-ray RF selective faded telemetry channel has been simulated. A dynamically changing channel environment with a selective fade rate in the 1Hz to 50Hz range has been constructed by laboratory hardware. The Test and Evaluation (T&E) setup had RF frequency selective dynamic notch depth variations in the Power Spectral Density (PSD) within the band of the signal of up to 15dB. As an illustrative example of the adaptive equalizer capability we used a 1Mb/s rate Feher patented FQPSK [1] Commercially Of The Shelf (COTS) product. Both hardware experimental results as well as simulation indicate substantial performance improvement with the utilization of the FE. It is demonstrated that the FE improves for a large class of frequency selective faded systems the Bit Error Rate(BER) from 10^-2 to 10^-6. Similar performance improvements are presented for the Block Error Rate (BLER).

In this thesis the telecommunication problem known as inter-cell interference is examined. Inter-cell interference originates from users in neighboring cells and affects the users in the own cell. The reason that inter-cell interference is interesting to study is that it affects the maximum data-rates achievable in the 3G network. By knowing the inter-cell interference, higher data-rates can be scheduled without risking cell-instability. An expression for the coupling between cells is derived using basic physical principles. Using the expression for the coupling factors a nonlinear model describing the inter-cell interference is developed from the model of the power control loop commonly used in the base stations. The expression describing the coupling factors depends on the positions of users which are unknown. A quasi decentralized method for estimating the coupling factors using measurements of the total interference power is presented. The estimation results presented in this thesis could probably be improved by using a more advanced nonlinear filter, such as a particle filter or an Extended Kalman filter, for the estimation. Different expressions describing the coupling factors could also be considered to improve the result.