A 3.52 Gb/s mmWave baseband with delayed decision feedback sequence estimation in 40 nm

We present a digital baseband ASIC for 60 GHz single-carrier (SC) transmission that is optimized for communication scenarios in which most of the energy is concentrated in the first few channel taps. Such scenarios occur for example in office environments with strong reflections. Our circuit targets close-to-optimum maximum-likelihood performance under such conditions. To this end, we show for the first time how a reduced-state-sequence-estimation algorithm can be realized for the 1760 MHz bandwidth of the IEEE 802.11ad standard. The equalizer is complemented in the frontend by a synchronization unit for frequency offset compensation as well as a Golay-sequence based channel estimator and in the backend by an low density parity check (LDPC) decoder. In 40nm CMOS we achieve a measured data rate of up to 3.52 Gb/s using QPSK modulation.