GATE ECE 2008 | Discrete Fourier Transform and Fast Fourier Transform Question 17 | Signals and Systems

{x(n)} is a real-valued periodic sequence with a period N. x(n) and X(k) form N-point. Discrete Fourier Transform (DFT) pairs. The DFT Y(k) of the sequence
y (n) = $${1 \over N}\,\sum\limits_{r = 0}^{N - 1} x \,\left( r \right)x\,(n + r\,)$$ is

$${\left| {X(k)} \right|^2}$$

$${1 \over N}\,\sum\limits_{r = 0}^{N - 1} X \,\left( r \right){X^*}\,(k + r\,)$$

$${1 \over N}\,\,\sum\limits_{r = 0}^{N - 1} X \,(r\,)X(k + r)$$

GATE ECE Subjects

Signals and Systems

Representation of Continuous Time Signal Fourier Series Discrete Time Signal Fourier Series Fourier Transform Discrete Time Signal Z Transform Continuous Time Linear Invariant System Transmission of Signal Through Continuous Time LTI Systems Discrete Time Linear Time Invariant Systems Sampling Continuous Time Signal Laplace Transform Discrete Fourier Transform and Fast Fourier Transform Transmission of Signal Through Discrete Time Lti Systems Miscellaneous Fourier Transform

Network Theory

State Equations For Networks Network Elements Network Theorems Two Port Networks Transient Response Sinusoidal Steady State Response Network Graphs Miscellaneous

Control Systems

Signal Flow Graph and Block Diagram Time Response Analysis Compensators Basic of Control Systems Frequency Response Analysis Stability Root Locus Diagram State Space Analysis

Digital Circuits

Number System and Code Convertions Boolean Algebra Logic Gates Combinational Circuits Sequential Circuits Semiconductor Memories Logic Families Analog to Digital and Digital to Analog Converters

General Aptitude

Numerical Ability Logical Reasoning Verbal Ability

Electronic Devices and VLSI

PN Junction Semiconductor Physics IC Basics and MOSFET BJT and FET

Analog Circuits

Diodes Bipolar Junction Transistor Frequency Response FET and MOSFET Oscillators Operational Amplifier Feedback Amplifier Power Amplifier 555 Timer

Engineering Mathematics

Linear Algebra Calculus Vector Calculus Complex Variable Probability and Statistics Differential Equations Numerical Methods Transform Theory

Microprocessors

Pin Details of 8085 and Interfacing with 8085 Instruction Set and Programming with 8085

Communications

Analog Communication Systems Digital Communication Systems Random Signals and Noise Fundamentals of Information Theory Noise In Digital Communication

Electromagnetics

Maxwell Equations Transmission Lines Uniform Plane Waves Waveguides Antennas Miscellaneous