High-resolution ADCs are essential components in many biomedical and environmental sensing applications. As the demands for wearable, miniature and point-of-care systems keep increasing, the design requirements for high-resolution ADCs also get more stringent, with strong emphasis on energy efficiency, reliability, and low cost. Over the past few years, many design techniques have been developed to excel the figure-of-merit (FoM) of high-resolution ADCs, where the state-of-the-arts has gotten really close to the theoretical limit.

ESPRIT-based high-resolution parameter estimation algorithms in DFT beamspace have been proposed as efficient gridless channel estimation schemes for MIMO OFDM systems in the millimeter wave (mmWave) band. Compared to conventional ESPRIT-based algorithms in element space, the DFT beamspace approach can be applied to MIMO systems with hybrid analog-digital architectures. Moreover, this approach significantly reduces the training overhead for communication systems operating in the mmWave band. It involves coarse and fine estimation steps.