Signal-to-noise ratio limits quality.
Noise (thermal N=kTB, shot, interference) limits receiver sensitivity. SNR=P_s/P_n; noise figure NF quantifies degradation by components; Friis cascade formula. Higher bandwidth admits more noise. Eb/N0 normalises digital performance.
A receiver with 10 MHz bandwidth and NF 5 dB has noise floor ≈ -99 dBm.
Bandwidth and noise limit how much information a channel can carry, so they determine the quality of every link.
Signal-to-noise ratio limits quality.
Bandwidth and noise limit how much information a channel can carry, so they determine the quality of every link.
The ratio of signal power to noise power, usually given in decibels, which sets the quality of the received signal.
A wider channel passes more noise power, so the SNR falls unless the signal power is increased.
Typical applications include estimating the signal to noise ratio needed for a given data rate, choosing the bandwidth of a channel for an audio link and checking whether a radio link has enough margin during rain fade.
Study "Analog modulation" first (topic 76 of 101 in Signals, Control & Comms). It covers the groundwork this topic builds on.
kTB = -174 dBm/Hz at room temperature. Noise temperature. Sensitivity calculation.
A receiver with 10 MHz bandwidth and NF 5 dB has noise floor ≈ -99 dBm.
The next topic is "Shannon capacity", which builds directly on this one.
It is classed as Advanced in Signals, Control & Comms (topic 77 of 101). It is an advanced topic. It assumes you are comfortable with the intermediate topics in Signals, Control & Comms.
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