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Phase Noise - Apply receiver phase noise to complex baseband signal

Library

RF Impairments

Description

The Phase Noise block applies phase noise to a complex, baseband signal. The block applies the phase noise as follows:

Generates additive white Gaussian noise (AWGN) and filters it with a digital filter.
Adds the resulting noise to the angle component of the input signal.

The Phase Noise block generates phase noise over the entire spectral observation window, from 0 Hz (or as close as possible to 0 Hz) to , where F_s represents the sampling frequency. The noise is scaled so that it is at the block-specific phase noise level at the specified frequency offset. The block generates a phase noise with characteristic over the entire frequency range.

You can view the block's implementation of phase noise by right-clicking on the block and selecting Look under mask. This displays the following figure:

You can view the construction of the Noise Source subsystem by double-clicking it.

The effects of changing the block's parameters are illustrated by the following scatter plots of a signal modulated by 16-ary quadrature amplitude modulation (QAM). The usual 16-ary QAM constellation without distortion is shown in the first scatter plot:

The following figure shows a scatter plot of an output signal, modulated by 16-ary QAM, from the Phase Noise block with Phase noise level (dBc/Hz) set to -70 and Frequency offset (Hz) set to 100:

This plot is generated by the model described in Scatter Plot Examples with the following parameter settings for the Rectangular QAM Modulator Baseband block:

Normalization method set to Average Power
Average power (watts) set to 1e-12

Dialog Box

Phase noise level (dBc/Hz): Scalar specifying the phase noise level.
Frequency offset (Hz): Scalar specifying the frequency offset in Hertz.
Initial seed: Nonnegative integer specifying the initial seed for the random number generator the block uses to generate noise.

References

[1] Kasdin, N.J., "Discrete Simulation of Colored Noise and Stochastic Processes and 1/(f^alpha); Power Law Noise Generation," The Proceedings of the IEEE, May, 1995, Vol. 83, No. 5