Waveform in 4G (OFDM) - Part III — Lesson 6

This lesson covers the analytical representation of OFDM. It explains how OFDM signals are generated, transmitted, and received, and how they are affected by factors such as noise, channel coefficient, and residual carrier frequency. The lesson also delves into the concept of link adaptation in LTE systems, explaining how modulation and code rates can be dynamically adjusted based on the channel condition to maintain a certain quality of service. For instance, if the signal strength is low, a lower bit rate is used, and if the signal strength is high, a higher bit rate is used.

Video Highlights

00:18 - Analytical representation of OFDM
06:12 - Signal model under idealistic conditions at the receiver
10:15 - Parameters for downlink transmission in LTE
14:04 - Time frequency picture
20:43 - Link adaption system
25:25 - Error probability curve and SNR points
30:07 - Flow of signal

Key Takeaways

- OFDM is a key technology in the evolution of Air Interface towards 5G.
- The structure of OFDM involves the generation, transmission, and reception of signals.
- Factors such as noise, channel coefficient, and residual carrier frequency can affect OFDM signals.
- Link adaptation in LTE systems allows for dynamic adjustment of modulation and code rates based on channel condition.
- Maintaining a certain quality of service involves adjusting bit rates according to signal strength.