Yunning Li

1 Introduction In the big data and IoT (internet of things) era, while ubiquitous sensors are still rapidly growing in both their number and the rate of generating analog data, it has become too time and energy consuming to digitize all the analog data for processing.

We first configured the array to implement the discrete cosine transformation (DCT) as a typical example of a linear transformation. The DCT is a Fourier-related transform widely used in digital signal processing and image/video compression and processing13,46. Mathematically it can be expressed as The equation can also be written as a matrix operation: where x is the input signals vector, is the DCT matrix, and y is the output spectrum vector.