DigiCom

Prof: Raymond KNOPP

OFDM

Should be able to understand 3GPP documents

Lab Sessions are based on the 5G System

Typical Tranceiver (ptp)

| Message Source

 - Audio, Video
 - bits, samples 
 - labs sessions (10s of bits)

• Source Encoder

  - bits
  - minimize bandwith 
  - or the number of dimensions / Source bit/ sample
  - LASSI/LASSO
  

• Channel Encoder

  - bits
  - adds redundancy for noise immunity (find the right amount of redundancy)
  - linking the bits together (rope on a glacier metaphor)
  - Maximize probability of receiving the message
  

• Modulator

  • generates waveform

• Channel

  • Noise: emmited by amplifiers (Quantum effect, photons and electrons)
  • Propagation Medium: convolutive (linear)
  • Antenna: Radiation Pattern bringing
  • Amplifiers: non-linear
  • signal

$$y(t) \to y_n(t) = k Y(t) \to k_2 y^2(t) + k_3 y^3(t \dots$$

• Demodulator

  • degenerates waveform
  • Front-End processing
  • linear signal processing

• Channel Decoder

  • Non-linear algorithm
  • uses Graph based algorithm (not seen at Eurecom)

• Source Decoder

• Message Destination

Modulators

Simple system

• Pulse Position Modulation

25ns Optical System

Slide tcom1.pdf

Wiener-Khinchin theorem

$$| \int_J \theta_x(t + \tau) | < \infty$$ $$\begin{gather} \\\ {\color{Purple} \mathbf{ Sampling } } \\\ \\\ {\color{Green} \text{ Revisiting Dirac Delta } } \\\ \\\ x(t) = x(t) * \delta(t) = \sum x(\tau) \delta (t - \tau ) \mathrm{d}\tau \\\ \\\ {\color{Green} \text{ Take } x(t) = \delta (t) } \\\ \\\ \delta(t) = \delta(t) * \delta(t) \\\ \\\ r_{\Delta} (t) = \delta_{\Delta}(t) * \delta_{\Delta}(t) \\\ \\\ \end{gather}$$

References

• USRP B210 (Board Only)
• The global telecom industry seeks growth in the face of rising demands.
• Myrthe Scheepers - ASMLs Julia Journey
• Progressing from MATLAB to Julia