\documentclass{article} \usepackage{amsmath} \usepackage{amsfonts} \usepackage{graphicx} \usepackage{listings} \usepackage{caption} \usepackage{subcaption} \usepackage{float} \usepackage[margin=1in]{geometry} \title{} \author{Aidan Sharpe \& Elise Heim} \DeclareMathOperator{\sinc}{sinc} \begin{document} \begin{titlepage} \maketitle \end{titlepage} \section{Results \& Discussion} \subsection{The Discrete Fourier Transform (DFT)} Given a signal, $x[n]$, it's $N$-point DFT is given by \begin{equation} X_k = \sum_{n=0}^{N-1} x[n] W_N^{kn} \label{eqn:DFT_def} \end{equation} where $W_N = e^{-j2\pi/N}$. The discrete Fourier transform is the sampled version of the discrete time Fourier transform (DTFT), which is a continuous function. More specifically, the $N$-point DFT contains $N$ samples from the continuous DTFT. For example, consider the signal $x[n] = (-1)^n$ for $0 \le n \le N-1$. By evaluating the sum shown in equation \ref{eqn:DFT_def}, the $N$-point DFT of $x[n]$ is found to be \begin{equation} X_k = {1 + e^{-j2\pi k} \over 1 + e^{-j2\pi k / N}}. \label{eqn:DFT_ex} \end{equation} \subsection{The Z-Transform} Given a discrete signal, $x[n]$, its z-transform is given by \begin{equation} X(z) = \sum_n x[n] z^{-n} \end{equation} where $z$ is a complex variable. \subsection{The Inverse Z-Transform} \section{Conclusions} \end{document}