Utility based cross-layer collaboration for speech enhancement in wireless acoustic sensor networks

A wireless acoustic sensor network is considered that is used to estimate a desired speech signal that has been corrupted by noise. The application layer of the WASN derives an optimal filter in a linear MMSE sense. A utility function is then used in conjunction with the MMSE estimate in order to evaluate the most significant signal components from each node in the system. The utility values are used as a cross-layer link between the application layer and the network layer so the nodes transmit the signal components that are deemed most relevant to the estimate while adhering to the power constraints of the system. The simulation results show that a high signal-to-error and signal-to-noise ratio is still achievable while transmitting a subset of signal components

Energy aware greedy subset s election for speech enhancement in wireless acoustic sensor networks

Publication in the conference proceedings of EUSIPCO, Bucharest, Romania, 201

Demo abstract: Cross-technology TDMA synchronization using energy pattern beacons

When different technologies use the same frequency bands in close proximity, the resulting interference typically results in performance degradation. Coexistence methods exist, but these are often technology specific and require technology specific interference detection methods. To remove the root cause of the performance degradation, devices should be able to negotiate medium access even when using different technologies. To this end, an architecture that allows cross-technology medium access by means of a Time Division Multiple Access (TDMA) scheme was devised. In order to achieve cross-technology synchronization, which is required for the TDMA solution, an energy pattern beacon is transmitted. The use of energy patterns is sufficiently technology agnostic to allow multiple technologies to negotiate between each other. To showcase the feasibility of cross-technology synchronization a demo set-up, using IEEE802.15.4 and IEEE802.11 devices in the w-iLab.t testbed, has been created. It demonstrates that the TDMA solution can successfully divide the medium between the different technologies in order to minimize cross-technology interference