Runtime Tunable Transmitting Power Technique in mm-Wave WiNoC Architectures

Emerging on-chip communication technologies, like wireless networks-on-chip (WiNoCs), have been recently proposed as candidate solutions for addressing the scalability limitations of conventional multihop network on chip (NoC) architectures. In a WiNoC, a subset of network nodes, namely, radio hubs, are equipped with a wireless interface that allows them to wirelessly communicate with other radio hubs. Thus, long-range communications, which would involve multiple hops in a conventional wireline NoC, can be realized by a single hop through the radio medium. Unfortunately, the energy consumed by the RF transceiver into the radio hub (ie, the main building block in a WiNoC), and in particular by its transmitter, accounts for a significant fraction of the overall communication energy. In order to alleviate such contribution, this paper presents a runtime tunable transmitting power technique for improving the energy efficiency of the transceiver in WiNoC architectures. The basic idea is tuning the transmitting power based on the physical location of the recipient of the current communication. Specifically, based on the destination address of the incoming packet, the radio hub tunes its transmitting power to a minimum level, but high enough to reach the destination antenna without exceeding a certain bit error ratio. The proposed technique is general and can be applied to any WiNoC architecture. Its application on different representative WiNoC architectures results in an average energy reduction up to 50% without any impact on performance and with a negligible overhead in terms of silicon area.