Ahmet G. Cepni

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— In this paper, we report a novel technique for inexpensive high-speed internet access in buildings. Our work shows that, one can use heating, ventilation, and air conditioning (HVAC) ducts for indoor wireless transmission systems and networks. Measurements and system calculations show that coverage distances in excess of 100 meters from the base station(More)
This paper presents the time reversal adaptive interferer can-celler (TRAIC), a novel algorithm that uses time reversal techniques to cancel the presence of interferers. TRAIC is developed for broadband signals and a single emitting antenna. Experimental tests in the electromagnetic domain show the viability and the power of TRAIC.
— In this paper, we report theoretical channel capac-cess of 1 Gbps are possible over distances up to 500 m in " matched " ducts (one can think of " matched " ducts as user-friendly ducts, since " matching " can, in principle, eliminate all the multi-path reflections in HVAC ducts). Our work also shows that data rates in excess of 300 Mbps are possible over(More)
—Heating, ventilation, and air conditioning (HVAC) ducts in buildings behave as multimode waveguides when excited at radio frequencies and thus, can be used to distribute radio signals. The channel properties of the ducts are different from the properties of a usual indoor propagation channel. In this paper, we describe physical mechanisms which affect the(More)
In this paper, we present a simple path loss prediction model for link budget analysis in indoor wireless local area networks (LANs) that use heating, ventilation, and air conditioning (HVAC) cylindrical ducts in 2.4-2.5 GHz frequency band. The model we propose predicts the average power loss between a transmitter-receiver pair in an HVAC duct network. This(More)
− Super-resolution focusing and nulling experiments are described based on multipath-enhanced time-reversal techniques. Using these techniques, two independent 2.45 GHz signals focused at locations separated by 5 cm at a distance of 6.7 m are successfully demodulated.
—In this paper, we report theoretical and experimental channel-capacity estimates of heating, ventilation, and air conditioning (HVAC) ducts based on multicarrier transmission that uses-ary quadrature amplitude modulation and measured channel responses at the 2.4-GHz industrial, scientific, and medical band. It is shown theoretically that data rates in(More)