Systems and methods include a kiosk that performs an electronic payment transaction based on instructions received from a portable device of a user. The system further includes a transmitting device electrically coupled to the kiosk. The transmitting device is configured to transmit a first signal to the portable device at a first direction. The system further includes a receiving device electrically coupled to the kiosk. The receiving device is configured to receive a second signal from the portable device at a second direction. The transmitting device and receiving device are positioned such that the first and second direction enable determination of a position of the user, where the processor enables the electronic payment transaction to be processed only when the portable device is at a location relative to the kiosk. The location is disposed within a transmission path coextensive with both the first direction and the second direction.