DPCA Canceller
Displaced phase center array (DPCA) pulse canceller for a uniform linear array
Libraries:
Phased Array System Toolbox /
Space-Time Adaptive Processing
Description
The DPCA Canceller block filters clutter impinging on a uniform linear array using a displaced phase center array pulse canceller.
Ports
Input
X — Input signal
M-by-N-by-P
complex-valued matrix
Input signal, specified as an M-by-N-by-P complex-valued array. M is the number of range samples, N is the number of channels, and P is the number of pulses.
The size of the first dimension of the input matrix can vary to simulate a changing signal length. A size change can occur, for example, in the case of a pulse waveform with variable pulse repetition frequency.
Data Types: double
Complex Number Support: Yes
Idx — Index of range cells
positive integer
Index of range cells to compute processing weights.
Example: 1
Data Types: double
PRF — Pulse repetition frequency
positive scalar
Pulse repetition frequency of current pulse, specified as a positive scalar.
Dependencies
To enable this port, set the Specify PRF as
parameter to Input port
.
Data Types: double
Ang — Targeting direction
2
-by-1
real-valued
vector
Targeting direction, specified as a
2
-by-1 real-valued vector. The
vector takes the form of
[AzimuthAngle;ElevationAngle]
. Angle units are in
degrees. The azimuth angle must lie between –180° and 180°, inclusive,
and the elevation angle must lie between –90° and 90°, inclusive. Angles
are defined with respect to the local coordinate system of the
array.
Dependencies
To enable this port, set the Specify direction
as parameter to Input port
.
Data Types: double
Dop — Targeting Doppler frequency
scalar
Targeting Doppler frequency of current pulse, specified as a scalar.
Dependencies
This port appears when the Output pre-Doppler
result check box is cleared and the Specify
targeting Doppler as parameter is set to
Input port
.
Data Types: double
Output
Y — Beamformed output
M-by-1 complex-valued vector
Processing output, returned as an
M-by-1 complex-valued vector.
The quantity M is the number of range samples in the
input port X
.
Data Types: double
Complex Number Support: Yes
W — Processing weights
length N*P complex-valued
vector
Processing weights, returned as Length
N*P complex-valued vector. The
quantity N is the number of channels and
P is the number of pulses. When the
Specify sensor array as parameter is set to
Partitioned array
or Replicated
subarray
, N represents the number of
subarrays. L is the number of desired beamforming
directions specified in the Ang
input port or by the
Beamforming direction (deg) parameter. There is
one set of weights for each beamforming direction.
Dependencies
To enable this port, select the Enable weights output check box.
Data Types: double
Complex Number Support: Yes
Parameters
Signal propagation speed (m/s) — Signal propagation speed
physconst('LightSpeed')
(default) | real-valued positive scalar
Signal propagation speed, specified as a real-valued positive scalar. The default
value of the speed of light is the value returned by
physconst('LightSpeed')
. Units are in meters per second.
Example: 3e8
Data Types: double
Operating frequency (Hz) — System operating frequency
3e8
(default) | positive real scalar
System operating frequency, specified as a positive scalar. Units are in Hz.
Specify PRF as — Source of PRF value
Property
(default) | Input port
Source of PRF value, specified as Property
or
Input port
. When set to
Property
, the Pulse repetition frequency
(Hz) parameter sets the PRF. When set to Input
port
, pass in the PRF using the PRF
input
port.
Pulse repetition frequency (Hz) — Pulse repetition frequency
1
(default) | positive scalar
Pulse repetition frequency, PRF, specified as a positive scalar. Units are in Hertz.
Set this parameter to the same value set in any Waveform
library
block used in the simulation.
Dependencies
To enable this parameter, set the Specify PRF as parameter to
Property
.
Specify direction as — Specify source of targeting directions
Property
(default) | Input port
Specify whether the targeting direction for the STAP processor block comes from a block
parameter or from the ANG
input port. Values of this parameter
are
Property |
These parameters appear only when
the Specify direction as
parameter is set to
|
Input port | Enter the targeting directions using the |
Receiving mainlobe direction (deg) — Pointing direction of main lobe of array
[0;0]
(default) | real-valued 2-by-1 vector
Specify the direction of the main lobe of the receiving sensor array as a
real-valued 2-by-1 vector. The direction is specified in the format of
[AzimuthAngle; ElevationAngle]
. The azimuth angle
should be between –180° and 180° and the elevation angle should be between
–90° and 90°.
Example: [100;-45]
Dependencies
To enable this parameter, set Specify direction
as to Property
.
Number of bits in phase shifters — Number of phase shift quantization bits
0
(default) | nonnegative integer
The number of bits used to quantize the phase shift component of beamformer or steering vector weights. Specify the number of bits as a non-negative integer. A value of zero indicates that no quantization is performed.
Specify targeting Doppler as — Source of targeting Doppler
Property
(default) | Input port
Specify whether targeting Doppler values for the STAP processor comes from the
Targeting Doppler (Hz) parameter of this block or using the
DOP
input port. For the ADPCA Canceller and
DPCA Canceller blocks, the Specify targeting Doppler
as parameter appears only when the Output pre-Doppler
result check box is cleared. Values of this parameter are
Property | Specify targeting Doppler values using the Targeting
Doppler parameter of the block. The
Targeting Doppler parameter appears only
when Specify targeting Doppler as is set to
Property . |
Input port | Specify targeting Doppler values using the Dop
input port. This port appears only when Specify targeting
Doppler as is set to Input
port . |
Targeting Doppler (Hz) — Targeting Doppler of STAP processor
0
(default) | scalar
Targeting Doppler of STAP processor, specified as a scalar.
Dependencies
To enable this parameter for the SMI Beamformer block, set Specify targeting Doppler as to
Property
.To enable this parameter for the ADPCA Canceller and DPCA Canceller blocks, first clear the Output pre-Doppler result check box. Then set the Specify targeting Doppler as parameter to
Property
.
Enable weights output — Option to output beamformer weights
off (default) | on
Select this check box to obtain the beamformer weights from the output port,
W
.
Output pre-Doppler result — Output results before Doppler filtering
on (default) | off
Select this check box to output the results before Doppler filtering. Clear this check box to output the processing result after Doppler filtering. Selecting this check box will remove the Specify targeting Doppler as and Targeting Doppler (Hz) parameters.
Simulate using — Block simulation method
Interpreted Execution
(default) | Code Generation
Block simulation, specified as Interpreted Execution
or
Code Generation
. If you want your block to use the
MATLAB® interpreter, choose Interpreted Execution
. If
you want your block to run as compiled code, choose Code
Generation
. Compiled code requires time to compile but usually runs
faster.
Interpreted execution is useful when you are developing and tuning a model. The block
runs the underlying System object™ in MATLAB. You can change and execute your model quickly. When you are satisfied
with your results, you can then run the block using Code
Generation
. Long simulations run faster with generated code than in
interpreted execution. You can run repeated executions without recompiling, but if you
change any block parameters, then the block automatically recompiles before
execution.
This table shows how the Simulate using parameter affects the overall simulation behavior.
When the Simulink® model is in Accelerator
mode, the block mode specified
using Simulate using overrides the simulation mode.
Acceleration Modes
Block Simulation | Simulation Behavior | ||
Normal | Accelerator | Rapid Accelerator | |
Interpreted Execution | The block executes using the MATLAB interpreter. | The block executes using the MATLAB interpreter. | Creates a standalone executable from the model. |
Code Generation | The block is compiled. | All blocks in the model are compiled. |
For more information, see Choosing a Simulation Mode (Simulink).
Programmatic Use
Block
Parameter:SimulateUsing |
Type:enum |
Values:Interpreted
Execution , Code Generation |
Default:Interpreted
Execution |
Specify sensor array as — Method to specify array
Array (no subarrays)
(default) | MATLAB expression
Method to specify array, specified as Array (no subarrays)
or MATLAB expression
.
Array (no subarrays)
— use the block parameters to specify the array.MATLAB expression
— create the array using a MATLAB expression.
Expression — MATLAB expression used to create an array
Phased Array System Toolbox™ array System object
MATLAB expression used to create an array, specified as a valid Phased Array System Toolbox array System object.
Example: phased.URA('Size',[5,3])
Dependencies
To enable this parameter, set Specify sensor array as to
MATLAB expression
.
Element type — Array element types
Isotropic Antenna
(default) | Cosine Antenna
| Custom Antenna
| Omni Microphone
| Custom Microphone
Antenna or microphone type, specified as one of the following:
Isotropic Antenna
Cosine Antenna
Custom Antenna
Omni Microphone
Custom Microphone
Operating frequency range (Hz) — Operating frequency range of the antenna or microphone element
[0,1e20]
(default) | real-valued 1-by-2 row vector
Specify the operating frequency range of the antenna or microphone element as a 1-by-2
row vector in the form [LowerBound,UpperBound]
. The element has no
response outside this frequency range. Frequency units are in Hz.
Dependencies
To enable this parameter, set Element type to
Isotropic Antenna
, Cosine Antenna
, or
Omni Microphone
.
Operating frequency vector (Hz) — Operating frequency range of custom antenna or microphone elements
[0,1e20]
(default) | real-valued row vector
Specify the frequencies at which to set antenna and microphone frequency responses as a 1-by-L row vector of increasing real values. The antenna or microphone element has no response outside the frequency range specified by the minimum and maximum elements of this vector. Frequency units are in Hz.
Dependencies
To enable this parameter, set Element type to Custom
Antenna
or Custom Microphone
. Use
Frequency responses (dB) to set the responses at these
frequencies.
Baffle the back of the element — Set back response of an Isotropic Antenna
element or an Omni Microphone
element to
zero
off (default) | on
Select this check box to baffle the back response of the element. When back baffled, the responses at all azimuth angles beyond ±90° from broadside are set to zero. The broadside direction is defined as 0° azimuth angle and 0° elevation angle.
Dependencies
To enable this check box, set
Element type to
Isotropic Antenna
or
Omni Microphone
.
Exponent of cosine pattern — Exponents of azimuth and elevation cosine patterns
[1.5 1.5]
(default) | nonnegative scalar | real-valued 1-by-2 matrix of nonnegative values
Specify the exponents of the cosine pattern as a nonnegative scalar or a real-valued 1-by-2 matrix of nonnegative values. When Exponent of cosine pattern is a 1-by-2 vector, the first element is the exponent in the azimuth direction and the second element is the exponent in the elevation direction. When you set this parameter to a scalar, both the azimuth direction and elevation direction cosine patterns are raised to the same power.
Dependencies
To enable this parameter, set Element
type to Cosine
Antenna
.
Frequency responses (dB) — Antenna and microphone frequency response
[0,0]
(default) | real-valued row vector
Frequency response of a custom antenna or custom microphone for the frequencies defined by the Operating frequency vector (Hz) parameter. The dimensions of Frequency responses (dB) must match the dimensions of the vector specified by the Operating frequency vector (Hz) parameter.
Dependencies
To enable this parameter, set
Element type to
Custom Antenna
or
Custom
Microphone
.
Input Pattern Coordinate System — Coordinate system of custom antenna pattern
az-el
(default) | phi-theta
Coordinate system of custom antenna pattern, specified
az-el
or phi-theta
. When you
specify az-el
, use the Azimuth angles
(deg) and Elevations angles (deg) parameters to
specify the coordinates of the pattern points. When you specify
phi-theta
, use the Phi angles (deg)
and Theta angles (deg) parameters to specify the coordinates of the
pattern points.
Dependencies
To enable this parameter, set Element type to
Custom Antenna
.
Azimuth angles (deg) — Azimuth angles of antenna radiation pattern
[-180:180]
(default) | real-valued row vector
Specify the azimuth angles at which to calculate the antenna radiation pattern as a 1-by-P row vector. P must be greater than 2. Azimuth angles must lie between –180° and 180°, inclusive, and be in strictly increasing order.
Dependencies
To enable this parameter, set the Element type
parameter to Custom Antenna
and the
Input Pattern Coordinate System
parameter to az-el
.
Elevation angles (deg) — Elevation angles of antenna radiation pattern
[-90:90]
(default) | real-valued row vector
Specify the elevation angles at which to compute the radiation pattern as a 1-by-Q vector. Q must be greater than 2. Angle units are in degrees. Elevation angles must lie between –90° and 90°, inclusive, and be in strictly increasing order.
Dependencies
To enable this parameter, set the Element type
parameter to Custom Antenna
and the
Input Pattern Coordinate System
parameter to az-el
.
Phi Angles (deg) — Phi angle coordinates of custom antenna radiation pattern
0:360
| real-valued 1-by-P row vector
Phi angles of points at which to specify the antenna radiation pattern, specify as a real-valued 1-by-P row vector. P must be greater than 2. Angle units are in degrees. Phi angles must lie between 0° and 360° and be in strictly increasing order.
Dependencies
To enable this parameter, set the Element type parameter to
Custom Antenna
and the Input Pattern Coordinate
System parameter to phi-theta
.
Theta Angles (deg) — Theta angle coordinates of custom antenna radiation pattern
0:180
| real-valued 1-by-Q row vector
Theta angles of points at which to specify the antenna radiation pattern, specify as a real-valued 1-by-Q row vector. Q must be greater than 2. Angle units are in degrees. Theta angles must lie between 0° and 360° and be in strictly increasing order.
Dependencies
To enable this parameter, set the Element type parameter to
Custom Antenna
and the Input Pattern Coordinate
System parameter to phi-theta
.
Magnitude pattern (dB) — Magnitude of combined antenna radiation pattern
zeros(181,361)
(default) | real-valued Q-by-P matrix | real-valued Q-by-P-by-L
array
Magnitude of the combined antenna radiation pattern, specified as a Q-by-P matrix or a Q-by-P-by-L array.
When the Input Pattern Coordinate System parameter is set to
az-el
, Q equals the length of the vector specified by the Elevation angles (deg) parameter and P equals the length of the vector specified by the Azimuth angles (deg) parameter.When the Input Pattern Coordinate System parameter is set to
phi-theta
, Q equals the length of the vector specified by the Theta Angles (deg) parameter and P equals the length of the vector specified by the Phi Angles (deg) parameter.
The quantity L equals the length of the Operating frequency vector (Hz).
If this parameter is a Q-by-P matrix, the same pattern is applied to all frequencies specified in the Operating frequency vector (Hz) parameter.
If the value is a Q-by-P-by-L array, each Q-by-P page of the array specifies a pattern for the corresponding frequency specified in the Operating frequency vector (Hz) parameter.
Dependencies
To enable this parameter, set Element type to
Custom Antenna
.
Phase pattern (deg) — Custom antenna radiation phase pattern
zeros(181,361)
(default) | real-valued Q-by-P matrix | real-valued Q-by-P-by-L
array
Phase of the combined antenna radiation pattern, specified as a Q-by-P matrix or a Q-by-P-by-L array.
When the Input Pattern Coordinate System parameter is set to
az-el
, Q equals the length of the vector specified by the Elevation angles (deg) parameter and P equals the length of the vector specified by the Azimuth angles (deg) parameter.When the Input Pattern Coordinate System parameter is set to
phi-theta
, Q equals the length of the vector specified by the Theta Angles (deg) parameter and P equals the length of the vector specified by the Phi Angles (deg) parameter.
The quantity L equals the length of the Operating frequency vector (Hz).
If this parameter is a Q-by-P matrix, the same pattern is applied to all frequencies specified in the Operating frequency vector (Hz) parameter.
If the value is a Q-by-P-by-L array, each Q-by-P page of the array specifies a pattern for the corresponding frequency specified in the Operating frequency vector (
Dependencies
To enable this parameter, set Element type to
Custom Antenna
.
MatchArrayNormal — Rotate antenna element to array normal
on
(default) | off
Select this check box to rotate the antenna element pattern to align with the array normal. When not selected, the element pattern is not rotated.
When the antenna is used in an antenna array and the Input Pattern Coordinate System parameter is az-el
, selecting this check box rotates the pattern so that the x-axis of the element coordinate system points along the array normal. Not selecting uses the element pattern without the rotation.
When the antenna is used in an antenna array and Input Pattern Coordinate System is set to phi-theta
, selecting this check box rotates the pattern so that the z-axis of the element coordinate system points along the array normal.
Use the parameter in conjunction with the Array normal parameter of the URA
and UCA
arrays.
Dependencies
To enable this parameter, set Element type to Custom Antenna
.
Polar pattern frequencies (Hz) — Polar pattern microphone response frequencies
1e3 (default) | real scalar | real-valued 1-by-L row vector
Polar pattern microphone response frequencies, specified as a real scalar, or a real-valued, 1-by-L vector. The response frequencies lie within the frequency range specified by the Operating frequency vector (Hz) vector.
Dependencies
To enable this parameter, set Element type set to
Custom Microphone
.
Polar pattern angles (deg) — Polar pattern response angles
[-180:180]
(default) | real-valued -by-P row vector
Specify the polar pattern response angles, as a 1-by-P vector. The angles are measured from the central pickup axis of the microphone and must be between –180° and 180°, inclusive.
Dependencies
To enable this parameter, set Element type to
Custom Microphone
.
Polar pattern (dB) — Custom microphone polar response
zeros(1,361)
(default) | real-valued L-by-P matrix
Specify the magnitude of the custom microphone element polar patterns as an L-by-P matrix. L is the number of frequencies specified in Polar pattern frequencies (Hz). P is the number of angles specified in Polar pattern angles (deg). Each row of the matrix represents the magnitude of the polar pattern measured at the corresponding frequency specified in Polar pattern frequencies (Hz) and all angles specified in Polar pattern angles (deg). The pattern is measured in the azimuth plane. In the azimuth plane, the elevation angle is 0° and the central pickup axis is 0° degrees azimuth and 0° degrees elevation. The polar pattern is symmetric around the central axis. You can construct the microphone response pattern in 3-D space from the polar pattern.
Dependencies
To enable this parameter, set Element type to
Custom Microphone
.
Array Parameters
Specify sensor array as — Type of array
Array (no subarrays)
(default) | MATLAB expression
Specify a ULA sensor array directly or by using a MATLAB expression.
Types
Array (no subarrays) |
MATLAB expression |
Number of elements — Number of array elements in U
2
(default) | positive integer greater than or equal to two
The number of array elements for ULA arrays, specified as an integer greater than or equal to two.
Example: 11
Data Types: double
Element spacing — Distance between ULA elements
0.5
(default) | positive scalar
Distance between adjacent ULA elements, specified as a positive scalar. Units are in meters.
Example: 1.5
Array axis — Linear axis direction of ULA
y
(default) | x
| z
Linear axis direction of ULA, specified as y
,
x
, or z
. All ULA array
elements are uniformly spaced along this axis in the local array coordinate
system.
Dependencies
To enable this parameter, set Geometry to
ULA
.This parameter is also enabled when the block only supports ULA arrays.
Taper — ULA array taper
1
(default) | complex-valued vector
Tapers, also known as element weights, are applied to sensor elements in the array. Tapers are used to modify both the amplitude and phase of the transmitted or received data.
Specify element tapering as a complex-valued scalar or a complex-valued 1-by-N row vector. In this vector, N represents the number of elements in the array. If Taper is a scalar, the same weight is applied to each element. If Taper is a vector, a weight from the vector is applied to the corresponding sensor element. A weight must be applied to each element in the sensor array.
Example: [0.5;1;0.5]
Data Types: double
Complex Number Support: Yes
Expression — MATLAB expression used to create an array
Phased Array System Toolbox array System object
MATLAB expression used to create a ULA array, specified as a valid Phased Array System Toolbox array System object.
Example: phased.ULA('NumElements',13)
Dependencies
To enable this parameter, set Specify sensor array as to
MATLAB expression
.
Version History
Introduced in R2014b
See Also
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