Engee documentation

Free Space Path Loss

Simulates signal power loss in free space.

free space path loss

Description

The Free Space Path Loss block adds free space loss to the complex signal. The block models the loss of signal power as a function of the distance between transmitter and receiver. The Mode parameter indicates whether the loss is specified explicitly in decibels or calculated based on the distance and frequency of the RF signal.

Ports

Input

In1 - input signal
scalar | vector-column

A complex input signal defined as a scalar or column vector.

Data types: Float16, Float32, Float64, Int8, Int16, Int32, Int64, Int128, UInt8, UInt16, UInt32, UInt64, UInt128.

Support for complex numbers: Yes

Output

Out1 - output signal
scalar | vector-column

Output signal returned as a scalar or column vector. The output signal has the same dimensionality and data type as the input signal.

Data types: Float64.

Parameters

Mode - loss calculation mode
Decibels (by default) | Distance and Frequency

Loss calculation mode set as one of these parameters.

  • Decibels - loss is defined using the Loss (dB) parameter.

  • Distance and Frequency - losses are calculated using the parameters Distance (km) and Carrier frequency (MHz).

Loss (dB) - power loss
10 (By default) | `scalar `

Power loss in decibels, specified as a scalar. The decibels displayed on the unit icon are rounded for demonstration purposes only.

Dependencies

To use this parameter, set the Mode parameter to Decibels.

Distance (km) is the distance between the transmitter and receiver
0.100 (By default) | scalar.

The distance between the transmitter and receiver in kilometres, specified as a scalar.

Dependencies

To use this parameter, set the Mode parameter to Distance and Frequency.

Carrier frequency (MHz) - Carrier frequency
1920 (By default) | scalar.

Carrier frequency in megahertz, specified as a scalar.

Dependencies

To use this parameter, set the Mode parameter to Distance and Frequency.

Read more

Algorithm

The free space loss, L, in decibels is:

πλ .

This formula assumes that the target is in the far zone of the transmitting element or antenna array. In the near zone, the free-space loss formula does not apply and may result in a loss less than 0 dB, which is equivalent to signal gain.