Waveform in 4G (OFDM) - Part IV — Lesson 7

This lesson covers the resilience of OFDM towards multi-path and the parameters of interest. It also discusses the concept of coherence time and bandwidth, sub-carrier spacing, and the guard interval. The lesson further elaborates on the impact of Doppler on signal strength and the role of vehicular mobility and carrier frequency in influencing Doppler. It also touches upon the concept of cyclic prefix and its benefits in OFDM.

Video Highlights

00:18 - Introduction and recap of previous lesson
04:46 - Frequency domain picture and the impact of channel impulse response on frequency
09:27 - Multi path propagation - wireless channel
14:49 - Cyclic prefix in OFDM and its benefits
18:16 - Time domain convolution operation
24:44 - Overall flow of the receiver in OFDM

Key Takeaways

- Understanding OFDM is crucial for 5G as it is used extensively in its parameterization.
- The resilience of OFDM towards multi-path is an important aspect of its analysis.
- Coherence time and bandwidth, sub-carrier spacing, and the guard interval are key parameters in OFDM.
- Doppler, influenced by vehicular mobility and carrier frequency, impacts signal strength.
- The concept of cyclic prefix in OFDM provides benefits such as avoiding inter-symbol interference and enabling low complexity processing.