Digital energy detection for OOK demodulation in ultra-low power radios

A new technique for performing energy detection for ultra-low power OOK-modulated radio receivers is presented. This technique uses oversampling and digital averaging to reduce the excess noise contributions of wideband gain following the channel selection stage in these radios and helps to bring the noise performance closer to the expected value from communications theory. The proposed sampler effectively removes 10 dB of excess noise from such systems, bringing the minimum required IF SNR to achieve 10-3 bit error rate down as low as 0 dB. In addition, the oversampling technique provides added resolution in time to perform synchronization and clock extraction for the rest of the radio system. The energy detector was implemented in a 65 nm digital CMOS process, and consumes less than 10 μW under its nominal operating conditions providing a 200 kbps data rate.