Performing Active Noise Control and Acoustic Experiments Remotely

I. Khan, D. Muthusamy, W. Ahmad, B. Sällberg, K. Nilsson, J. Zackrisson, I. Gustavsson, L. Håkansson International Journal of Online Engineering (iJOE), vol. 8, Special Issue 2: REV2012/2, pp. 65-74, 2012 This paper presents a novel and advanced remotely controlled laboratory for conducting Active Noise Control (ANC), acoustic and Digital Signal Processing (DSP) experiments. The laboratory facility, recently developed by Blekinge Institute of Technology (BTH) Sweden, supports remote learning through internet covering beginners level such as simple experimental measurements to…

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Adaptive Fingerprint Image Enhancement with Emphasis on Pre-processing of Data

J. Ström-Bartunek, M. Nilsson, B. Sällberg, I. Claesson IEEE Transactions on Image Processing, vol. 22, 2, pp. 644 – 656, 2012 This article proposes several improvements to an adaptive fingerprint enhancement method that is based on contextual filtering. The term adaptive implies that parameters of the method are automatically adjusted based on the input fingerprint image. Five processing blocks comprise the adaptive fingerprint enhancement method, where four of these blocks are updated in our proposed system. Hence, the proposed overall…

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Non-Coherent Fourth-Order Detector for Impulse Radio Ultra Wideband Systems: Empirical Evaluation Using Channel Measurements

M. Gufran Khan, B. Sällberg, J. Nordberg, F. Tufvesson, I. Claesson Springer Wireless Personal Communications, Vol. 68, No. 1, pp. 27-46, Jan. 2013 Low-complex and low-power non-coherent energy detectors (EDs) are interesting for low data rate impulse radio (IR) ultra wideband (UWB) systems, but suffer from a loss in performance compared to coherent receivers. The performance of an ED also strongly depends on the integration interval (window size) of the integrator and the window position. This paper presents a non-coherent…

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Energy efficient binary PPM/code-multiplexed transmitted-reference multi-user UWB system

M. Gufran Khan, B. Sällberg, J. Nordberg, I. Claesson IEEE International Conference on Ultra-Wideband, pp. 615-619, Sept. 2011 This paper presents a combined binary pulse position modulation (BPPM)/code-multiplexed transmitted-reference (CM-TR) ultra wideband (UWB) system. The low complexity CM-TR UWB is not energy efficient as one half of the energy is used to transmit reference pulses and, even at low-to-medium data rates, it suffers from strong multi-user interference (MUI) and inter-frame interference (IFI). Keeping the information rate constant, the combined BPPM/CM-TR…

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Modulation Domain Adaptive Gain Equalizer for Speech Enhancement

M. Shahid, R. Ishaq, B. Sällberg, N. Grbic, B. Lövström, I. Claesson IASTED International Conference on Signal and Image Processing and Applications, Aug. 2011 This paper evaluates speech enhancement by filtering in the modulation frequency domain, as an alternative to filtering in conventional frequency domain. Adaptive Gain Equalizer (AGE) is a commonly used single-channel speech enhancement algorithm. A recently introduced class of signal transformations called modulation transform has successfully made its place alongside classical time/frequency representations. This paper presents an…

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Source localization for multiple speech sources using low complexity non-parametric source separation and clustering

M. Swartling, B. Sällberg, N. Grbic Elsevier Journal of Signal Processing, vol. 91, No. 8, pp. 1781-1788, Aug. 2011 This article presents a new method for localization of multiple concurrent speech sources that relies on simultaneous blind signal separation and direction of arrival (DOA) estimation, as well as a method to solve the intersection point selection problem that arises when locating multiple speech sources using multiple sensor arrays. The proposed method is based on a low complexity non-parametric blind signal…

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Robust Weighted Non-Coherent Receiver for Impulse Radio UWB PPM Signals

M. Gufran Khan, B. Sällberg, J. Nordberg, I. Claesson IEEE Communication Letters, vol. 15, No. 6, pp. 614-616, June 2011 This letter proposes an energy detection based robust weight estimation scheme for pulse-position modulated (PPM) impulse radio ultra-wideband (IR-UWB) signals using weighted non-coherent receiver (WNCR). Conventional data-aided WNCR (DA-WNCR) scheme estimates the weighting coefficients, or channel state information (CSI), using a large number of training symbols over time-varying channels. In contrast, the proposed Robust WNCR (R-WNCR) scheme is non-data-aided (NDA),…

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