"Add real-time packet detection section to detection chapter"

[vishwaksen-1]

'Add Real-Time Packet Detection Section' & 'Add Full E2E QPSK Simulation to Sync Chapter'

Summary

Adds a comprehensive new section to the detection.rst chapter that demonstrates how to detect intermittent packets in continuous IQ streams from SDRs.

Adds a comprehensive end-to-end QPSK communication system simulation to the Synchronization chapter that demonstrates integration of all synchronization techniques.

Motivation

Closes #38
Closes #8

Changes

For #38

• New section: "Real-Time Packet Detection in Continuous IQ Streams"

  • Complete Python implementation combining correlation + CFAR + buffer management
  • Streaming simulation with realistic bursty packets
  • Performance evaluation metrics
  • Practical tuning guidelines

• New figure: detection_realtime.svg

• New script: figure-generating-scripts/detection_realtime.py

For #8

• New section: "Full E2E Communication System Simulation"
  • Complete Python implementation combining modulation + channel + synchronization + demodulation
  • ASCII message encoding/decoding with BER calculation
  • Realistic channel impairments (frequency offset, fractional delay, AWGN)
  • Mueller & Muller time synchronization with interpolation
  • Costas Loop frequency/phase synchronization
  • Phase ambiguity resolution
  • Constellation diagram visualization
  • Performance metrics and results display

[777arc]

Note I'm leaving out the sync part for now because 1) too much overlap with the next chapter and 2) the rotational symmetry being resolved by checking against the transmitting bits feels like cheating, without also mentioning the concept of pilot symbols, as the rx wouldn't have access to bits