Lawrence Materum

Landmark-based audio fingerprinting algorithm for a transmitter-less alert recognition device for the hearing-impaired

Assistive devices for the hearing impaired have been developed to assist them through various techniques such as peripheral awareness and alerting systems. The disadvantage of presently available alerting systems is its fixed wired or wireless connection to the alert transmitter. This study focused on providing an alternative to these alerting systems in overcoming the transmitter dependence limitation. The researchers developed and integrated a real-time landmark-based audio fingerprinting and recognition algorithm for the implementation in a portable transmitter-less device which would notify the hearing impaired through combination of visual and vibrational cues when recognizing audio alert or warning signals.

Multipath Clustering and Cluster Tracking for Geometry-Based Stochastic Channel Modeling

This paper presents a clustering and tracking method that exploits the geometry of the scattering points (SPs) obtained from the measurement-based ray tracer. The multipath components (MPCs) were categorized into clusters by applying the KPowerMeans (KPM) framework to those SPs. The clusters were tracked by comparing the cluster-centroid SPs of the adjacent snapshots. The clusters were estimated based on the indoor environment geometry at 11 GHz, and their physical mechanisms were interpreted. The complexity and performance of this method was assessed and compared with that of conventional KPM by comparing the number of floating point operations (FLOPS) and the channel eigenvalues obtained from the reconstructed channel matrices, which were calculated by superposing the MPCs randomly generated from intracluster parameters. The verification of this method showed that most clusters were estimated and tracked according to the physical location of the scatterers in the environment with acceptable error. Moreover, the eigenvalues reconstructed from the proposed method were closer to the measured ones with less number of FLOPS, which indicates both accuracy and complexity improvement. The results also imply that multiple-input multiple-output performance is highly dependent on the radio propagation channel; therefore, it is imperative that clusters in the channel be determined accurately.

FPGA implementation of an indoor broadband power line channel emulator

Power line communication is an emerging technology in the field of communications that aims to use the power line as a medium to send and receive data. Several studies have been conducted to characterize the power lines [1], [2], [3], [4],. These studies guide PLC modem designers to create a more robust design. However, it is not practicable to test modems in a live power line network. This research aims to create an emulator capable of replicating the behavior of a typical indoor power line channel and use it as a test bed for PLC modem The emulator is implemented on Virtex 6 FPGA and FMC 151 for the analog front end. The power line channel model uses Zimmermans channel transfer function [5] as reference. Analysis are done by comparing theoretical results with the hardware results which are done in MATLAB and Xilinx respectively. Several features such as addition of noise are also within the emulator and can be selected by the user to improve the realism of the emulator. Lastly, channel parameters such as SNR (signal to noise ratio) and RMS (root mean square) delay spread are obtained to ensure the quality of the channel produced.