Internet of Things (IoT) is a topic of growing interest and intensive research in industry, technological centers and academy, where data communication is one of its most relevant aspects. Since IoT is an open field for new applications, it does not have yet a standard communication protocol. This paper presents the system level design of a WiFi receiver supporting the novel low power standard IEEE 802.11ah with focus on IoT applications. Theoretical performance analysis as well as system level design strategies are presented. Individual blocks of the receiver chain are specified as a condition for future circuit-level design. Simulation results validate the proposed system specifications attending the 802.11ah standard. The presented receiver provides 80.5dB maximum gain, 9 dB minimum noise figure and 69.4 dB of dynamic range. Those performance parameters lead to −99.4 dBm sensitivity, 21 dB and 51 dB for adjacent and non-adjacent maximum channel rejection.