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New methods of passive wireless communication are presented where no RF carrier is needed. Instead, data is wirelessly transmitted by modulating noise sources, from those found in electronic components to extraterrestrial noise sources. Any pair of noise sources with a difference in noise temperature can be used to enable communication. We discuss using the Earth, the Moon, the Sun, the coldness of space, and Active Cold Load circuits as sources of thermal contrast. We present Cosmic Backscatter and demonstrate that wireless connectivity can be enabled by switching an antenna connection between the "cold" Sky and a "hot" 50Ω resistor. Furthermore, we present Noise Suppression Communication, where data is transmitted by controlling an Active Cold Load to selectively reduce emitted noise below ambient temperature levels. 

In this work, we demonstrate that it is possible to read UHF RFID tags without a carrier. Specifically, we introduce an alternative reader design that does not emit a carrier and allows reading RFID tags intended for conventional carrier-based systems. While traditional RFID tags modulate a carrier, it is important to note that a modulation circuit used for backscatter also modulates the inherent noise of the tag circuitry, including the Johnson noise, irrespective of whether a carrier is present or not. Our Modulated Noise Communication (MNC) approach leverages recent work on Modulated Johnson Noise (MJN) and can be read by an alternative RFID reader design that enables simpler, more accessible RFID readings than a conventional backscatter reader by eliminating self-jamming obstructions. MNC is shown to support wireless transmission of data packets between 2 cm to 10 cm of separation between a standard UHF RFID tag and the proposed alternative reader for data rates of 1 bps and 2 bps.