Wideband Two-Ray Channel
Libraries:
Radar Toolbox
Description
The Wideband Two-Ray Channel block propagates wideband signals from one point in space to multiple points or from multiple points back to one point via both the direct path and the ground reflection path. The block propagates wideband signals by (1) decomposing them into subbands, (2) propagating subbands independently, and (3) recombining the propagated subbands. The block models propagation time, propagation loss, and Doppler shift. The block assumes that the propagation speed is much greater than the object's speed in which case the stop-and-hop model is valid.
Ports
Input
Output
Parameters
Algorithms
When the origin and destination are stationary relative to each other, the block output can be written as y(t) = x(t – τ)/L. The quantity τ is the delay and L is the propagation loss. The delay is computed from τ = R/c where R is the propagation distance and c is the propagation speed. The free space path loss is given by
where λ is the signal wavelength.
This formula assumes that the target is in the far-field of the transmitting element or array. In the near-field, the free-space path loss formula is not valid and can result in losses smaller than one, equivalent to a signal gain. For this reason, the loss is set to unity for range values, R ≤ λ/4π.
When there is relative motion between the origin and destination, the processing also introduces a frequency shift. This shift corresponds to the Doppler shift between the origin and destination. The frequency shift is v/λ for one-way propagation and 2v/λ for two-way propagation. The parameter v is the relative speed of the destination with respect to the origin.
Extended Capabilities
Version History
Introduced in R2021a
See Also
Objects
phased.FreeSpace
|phased.LOSChannel
|twoRayChannel
|phased.WidebandFreeSpace
|phased.WidebandLOSChannel
|widebandTwoRayChannel
Functions
fogpl
|fspl
|gaspl
|rangeangle
|rainpl