I have some questions regarding RSSI and LQI, here is the design notes:

 

http://e2e.ti.com/support/low_power_rf/w/design_notes/calculation-and-usage-of-lqi-and-rssi.aspx

 

There are four to five "extreme cases" that can be used to illustrate how RSSI and LQI work:
1. A weak signal in the presence of noise may give low RSSI and high LQI.
2. A weak signal in "total" absence of noise may give low RSSI and low LQI.
3. Strong noise (usually coming from an interferer) may give high RSSI and high LQI.
4. A strong signal without much noise may give high RSSI and low LQI.
5. A very strong signal that causes the receiver to saturate may give high RSSI and high LQI.

 

Regarding 1: weak signal with noise should indicate bad wireless environment, right? Why giving a high LQI?

 

Regarding 3 : Strong noise (usually coming from an interferer) may give high RSSI and high LQI. So high interference should point to a low LQI, but why high LQI?

 

 

Regarding 4 :A strong signal without much noise may give high RSSI and low LQI.  Strong signal without noise should indicate easy receiving, why low LQI?

 

 

Can you explain those reasons behind it?

 

Thanks

Rui