Table of Contents
To znamená, že se to děje, když se to děje.
Understanding Signal and Noise
To je důležité pro to, aby se poučit informace o tom, že se Wireless link, while noise includes all unwanted signals that interfere with thee communication. Noise sources can include thermal noise, interference from their devices, and environmental factors.
Measuring Signal Power
Signal power is typically measured in decibels- miliwatts (dBm). It can be dosaged using a spectrum analyzer or a receiver 's signal credith indicator. Te received signal credith indicator (RSSI) provides an estimate of te signal power at te receiver.
Měřicí systém Noise Power
Noise power is also measured in dBm. It can bee determinad by measuring thee background noise level when no signal is present or during idle periods. Noise figure and bandwidth influence thee noise measurement.
Calculating SNR
Te SNR is calculated by subtracting the noise power from the signal power:
CLANE1; CLANE1; CLANE3; CLANE3; CLANE3; CLANE3; CLANE3; CLANE3; CLANE3; CLANE3; CLANE3c; CLANE3c; CLANE3c; CLANE3c; CLANE3c; CLANE3c; CLANE3c; CLANE3c; CLANE3c; CLANE3c; CLANE3c; CLANE3c; CLANE3c; CLANE3c; CLANE3c; CLANE3c; CLANE3c; CLANE3c; CLANE3c; CCANE3c; CCANE3c)
Example Calculation
If the received signal power is -50 dBm and thoe noise power is -90 dBm, then the SNR is:
CLAS1; CLAS1; CLAS3; CLAS3; CLAS3; CLAS3; CLAS3; CLAS3c = -50 dBm - (-90 dBm) = 40 dB CLAS1; CLAS1; CLAS3d; CLAS3d;