The Receiver Thermal Noise block simulates the effects of thermal noise on a complex, baseband signal. You can specify the amount of thermal noise in three ways, according to which Specification method you select:
Noise temperature specifies the noise in degrees kelvin.
Noise factor specifies the noise as 1+(Noise temperature / 290).
Noise figure specifies the noise as 10*log10(1+(Noise temperature / 290)). This is the decibel equivalent of Noise factor.
The following scatter plot shows the effect of the Receiver Thermal Noise block, with Specification method set to Noise figure and Noise figure (dB) set to 3.01, on a signal modulated by 16-QAM.
This plot is generated by the model described in Illustrate RF Impairments That Distort a Signal with the following parameter settings:
Rectangular QAM Modulator Baseband
Normalization method set to Average Power
Average power (watts) set to 1e-12
Receiver Thermal Noise
Specification method set to Noise figure
Noise figure (dB) set to 3.01
The method by which you specify the amount of noise. The choices are Noise temperature, Noise figure, and Noise factor.
Scalar specifying the amount of noise in decibels relative to a noise temperature of 290 degrees kelvin. A Noise figure setting of 0 dB indicates a noiseless system.