A mixed-signal 32-coefficient RX-FFE 100-coefficient DFE for an 8Gb/s 60GHz receiver in 65nm LP CMOS

The 60GHz band has opened the opportunity for multi-Gb/s wireless communications, and is being commercially supported by transceiver solutions utilizing the WirelessHD and/or WiGig standards. However, the hundreds of mWs of power consumption associated with today´s digital basebands (e.g. [1]) poses a significant barrier to adoption in mobile devices. Mixed-signal basebands have therefore been proposed and demonstrated [2] as an energy efficient (~50mW) solution for sample rates of up to 5GS/s. However, such mixed-signal designs have so far been incapable of handling non-line-of-sight (NLOS) channels with pre-cursor inter-symbol interference (ISI) and extended channel delay spreads of >10ns. This work therefore presents the design of an efficient receive-side feedforward equalizer (Rx-FFE) for pre-cursor ISI cancelation and a long decision feedback equalizer (DFE) that can efficiently handle NLOS interference profiles.