Disclosed are systems, apparatus, devices, methods, media, products, and other implementations, including a method that includes controllably modifying, at a first wireless device, an original unmodified value of at least one PHY-layer signal parameter, such as amplitude, frequency, timestamp, gain, signal equalization, and/or any combination thereof, of a signal according to at least one pre-determined varying signal modification process. The method further includes transmitting to a second wireless device the signal with the controllably modified value of the at least one PHY-layer signal parameter, with the transmitted signal configured to facilitate position determination of the second wireless device when the original unmodified value of the at least one PHY-layer signal parameter is determined at the second wireless device from the controllably modified value of the at least one PHY-layer signal parameter.