Рет қаралды 43,739
Shows how Orthogonal Frequency Division Multiplexing (OFDM) is implemented with a Discrete Fourier Transform (DFT), and how it relates to single carrier digital communications.
Related videos: (see: www.iaincolling...)
• How are OFDM Sub Carrier Spacing and Time Samples Related? • How are OFDM Sub Carri...
• Why is the OFDM Symbol Prefix Shorter in 5G Mobile and 802.11ac WiFi? • Why is the OFDM Symbol...
• OFDM Waveforms: • OFDM Waveforms
• Why is Subcarrier Spacing Bigger in 5G Mobile Communications? • Why is Subcarrier Spac...
• What is a Cyclic Prefix in OFDM? • What is a Cyclic Prefi...
• How does OFDM Overcome ISI? • How does OFDM Overcome...
• Orthogonal Basis Functions in the Fourier Transform: • Orthogonal Basis Funct...
For a full list of Videos and Summary Sheets, goto: www.iaincolling...
** Note: I gave the continuous-time version of the Inverse Fourier Transform equation because it's more intuitive to show how the waveforms (at the different frequencies) add up. But if you substitute t=(n/N)T, then you get the standard IDFT equation (in terms of the discrete-time samples, indexed by the variable n). This is because in the IDFT, there are N time-domain samples, which is because there are N frequency-domain subcarriers. I also didn't show the usual scaling by a factor of 1/N (which I probably should have mentioned. ... but it's just a scaling, so it doesn't change any of the intuition, which is what I am trying to show in the video).