Communication link adjustments in wireless networks based upon composite LQI measurements
Methods and systems are disclosed to adjust communication links within wireless networks based upon composite link quality indicators (LQIs). Packet communications are received by a network node through a communication link from a separate network node within a wireless network. The network node can also be configured to transmit packet communications from the network node through the communication link to the separate network node. The network node generates composite LQI measurements for the received packet communications, and the composite LQI measurements are based upon signal strength measurements for the received packet communications and also based upon signal quality measurements for the received packet communications. The network node then adjusts the communication link based upon the composite LQI measurements.
1. A method to adjust a communication link for a network node in a wireless network, comprising:
receiving packet communications through a wireless communication link from a separate network node within a wireless network;
measuring signal strength for the received packets to produce signal strength measurements;
measuring signal quality for the received packets to produce signal quality measurements;
generating composite LQI (link quality indicator) measurements for the received packet communications based upon the signal strength measurements and the signal quality measurements, wherein each composite LQI is generated by applying a first weight to the signal strength measurement and a second weight to the signal quality measurement and combining the weighted signal strength measurement with the weighted signal quality measurement; and
adjusting the wireless communication link based upon the composite LQI measurements.
2. The method of claim 1 , further comprising adjusting the wireless communication link when the composite LQI measurement rises above a high threshold level or drops below a low threshold level.
3. The method of claim 1 , wherein the signal strength measurements comprise RSSI (receive signal strength indicator) measurements based upon a detected magnitude for the received packet communications.
4. The method of claim 1 , wherein the signal quality measurements comprise SNR (signal-to-noise ratio) measurements based upon a detected magnitude for the received packet communications and a detected magnitude for noise within the received packet communications.
5. The method of claim 1 , further comprising demodulating the received packet communications, and wherein the signal quality measurements comprise quality measurements associated with the demodulating.
6. The method of claim 1 , wherein the composite LQI measurements are further based upon LQI bias values.
7. The method of claim 1 , further comprising demodulating the received packet communications to generate demodulated digital symbols and generating symbol correlation magnitudes for the demodulated digital symbols.
8. The method of claim 7 , wherein the signal quality measurements comprise average symbol correlation magnitudes.
9. The method of claim 7 , further comprising derating the composite LQI measurements when demodulating quality falls below a threshold based upon the symbol correlation magnitudes.
10. A network node for a wireless network, comprising:
a receiver configured to receive packet communications through a wireless communication link from a separate network node within a wireless network and to generate composite LQI measurements for the received packet communications, the composite LQI measurements being based upon signal strength measurements for the received packet communications and signal quality measurements for the received packet communications, wherein each composite LQI is generated by applying a first weight to the signal strength measurement and a second weight to the signal quality measurement and combining the weighted signal strength measurement with the weighted signal quality measurement; and
one or more processors programmed to receive the composite LQI measurement as an input and to adjust the wireless communication link based upon the composite LQI measurement.
11. The network node of claim 10 , wherein the one or more processors are further programmed to adjust the communication link when the composite LQI measurement rises above a high threshold level or drops below a low threshold level.
12. The network node of claim 10 , wherein the signal strength measurements comprise RSSI (receive signal strength indicator) measurements based upon a detected magnitude for the received packet communications.
13. The network node of claim 10 , wherein the signal quality measurements comprise SNR (signal-to-noise ratio) measurements based upon a detected magnitude for the received packet communications and a detected magnitude for noise within the received packet communications.
14. The network node of claim 10 , further comprising a demodulator having as outputs demodulated digital symbols based upon the receive packet communications, and wherein the signal quality measurements comprise quality measurements associated with the demodulator outputs.
15. The network node of claim 10 , wherein the composite LQI measurements are further based upon LQI bias values.
16. The network node of claim 10 , further comprising a demodulator having as outputs demodulated digital symbols based upon the received packet communications and symbol correlation magnitudes associated with the demodulated digital symbols.
17. The network node of claim 16 , wherein the signal quality measurements comprise average symbol correlation magnitudes.
18. The network node of claim 16 , wherein the receiver is further configured to de-rate the composite LQI measurements when demodulating quality falls below a threshold based upon the symbol correlation magnitudes.