Communications Blockset

Types of RF Impairments the Blocks Model

The blocks in the RF Impairments library can simulate the following types of signal impairments:

• Nonlinearity and I/Q imbalances
• Phase/frequency offsets and phase noise
• Receiver thermal noise and free space path loss

Nonlinearity and I/Q Imbalance

The following two blocks model signal impairments due to nonlinear devices or imbalances between the in-phase and quadrature components of a modulated signal:

• The Memoryless Nonlinearity block models the AM-to-AM and AM-to-PM distortion in nonlinear amplifiers.
• The I/Q Imbalance block models imbalances between the in-phase and quadrature components of a signal caused by differences in the physical channels carrying the separate components.

These blocks distort both the phase and amplitude of the signal.

Phase/Frequency Offsets and Phase Noise

The RF Impairments library contains two blocks that simulate phase/frequency offsets and phase noise:

• The Phase/Frequency Offset block applies phase and frequency offsets to a signal.
• The Phase Noise block models applies phase noise to a signal.

The Phase/Frequency Offset block and the Phase Noise block alter only the phase and frequency of the signal.

Receiver Thermal Noise and Free Space Path Loss

The RF Impairments Library contains two blocks that simulate signal impairments due to thermal noise and signal attenuation due to the distance from the transmitter to the receiver:

• The Receiver Thermal Noise block simulates the effects of thermal noise on a complex baseband signal.
• The Free Space Path Loss block simulates the loss of signal power due to the distance from the transmitter and signal frequency.

RF Impairments

Scatter Plot Examples