Signal loss limits

atten

Path Loss With Frequency

rxnoise

Received Noise and sources vs. Frequency

e-field-noise-vs-freq

E field vs Frequency. Why HF receivers don't need a very low noise RF amp.

shannon

Bitrate/Bandwidth Limits  vs SNR for various signals

Shannon Limit is -1.6dB Eb/No no matter how the low the signal bitrate /bandwidth is

Basic parameters of signal:

  1. Transmitter power
  2. Transmitter aerial gain
  3. Transmission Information bandwidth (analogue) or Bitrate (digital)
  4. Transmission RF bandwidth
  5. Transmission coding (bits per symbol, CDMA, QAM, APSK etc) methods.
  6. Path losses
  7. Interfering signals
  8. Background Noise
  9. Receiver aerial gain
  10. Receiver Noise Figure
  11. Receiver Gain

Some Frequencies. Lower in list is worse for Rain

  1. Original GSM 900MHz
  2. Some GSM @ 1800MHz
  3. 3G/HSPA 2100MHz = 2.1 GHz
  4. WiFi based outdoor systems or Licence Free 2.4GHz, Some FWA
  5. MMDS 2.6GHz (should have big enough aerial for Rain)
  6. 3.6GHz Imagine WiMax, other FWALA, Breeze
  7. 5.8GHz registered but Licence free FWA (also WiFi). Some Breeze
  8. 10.6GHz. Various systems, inc Metro. Always only installed if has rain margin
  9. 12.3Ghz Defunct SCTV MMDS

Satellite

  1. GPS 1.57542 GHz (L1 signal) and 1.2276 GHz (L2 signal). Moving
  2. C band 4GHz
  3. Ku Band TV and Satellite Internet Downlink 10.7 .. 12.6GHZ
  4. K Band Satellite Internet Uplink14Ghz to 18GHz approx
  5. Ka Band 18GHz to 20GHz downlink. 22Ghz to 24GHz uplink

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