Software Defined Radio Architectures - Part IV — Lesson 6

This lesson covers the requirements and limitations of sampling directly at the RF frequency. It further discusses the impact of bandwidth on the performance of DAC and ADC, the Nyquist-Shannon theorem, and the concept of band-limited signals. The lesson also explains the benefits of over-sampling and under-sampling architectures, and how they can be applied in practical scenarios. For instance, the lesson uses the example of a 12-bit ADC with 16-time over-sampling to illustrate the improvement in SNR.

Video Highlights

00:18 - Architecture to alleviate imitations of DAC and ADC
04:51 - Concept of dynamic range in ADC or DAC
07:49 - Concept of sampling and its effects on architecture
10:07 - Nyquist frequency criteria and the benefits of over-sampling and under-sampling architectures
15:32 - Use of oversampling in practical implementation
24:14 - High speed sampling process
26:30 - Limitations of interleaving of ADCs and the future prospects of this technology

Key Takeaways

- The Nyquist-Shannon theorem is crucial in understanding the requirements for sampling frequency in relation to signal bandwidth.
- Over-sampling can increase the signal-to-noise ratio, improving the quality of the signal.
- Under-sampling or sub-sampling can also be used effectively, especially when dealing with high-frequency signals.
- Practical applications of these concepts include the use of over-sampling in a 16-bit DAC and under-sampling in RF sampling processes.
- Understanding these concepts is essential for designing advanced software defined radio architectures.