Contents

Receiver Thermal Noise

Apply receiver thermal noise to complex baseband signal

Library

RF Impairments

Description

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

Dialog Box

Specification method

The method by which you specify the amount of noise. The choices are Noise temperature, Noise figure, and Noise factor.

Noise temperature (K)

Scalar specifying the amount of noise in degrees kelvin.

Noise figure

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.

Noise factor

Scalar specifying the amount of noise relative to a noise temperature of 290 degrees kelvin.

Initial seed

The initial seed value for the random number generator that generates the noise.

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