Range Response

Range response.

blockType: RangeResponse

Path in the library:

/Phased Array Systems/Detection/Range Response

Description

Block Range Response performs data filtering in fast time (by range) using either a consistent filter or an FFT-based algorithm. The output signal is usually used as the input signal for the detector. Consistent filtering improves the signal-to-noise ratio (SNR) of pulse signals. For continuous FM signals, FFT processing allows you to select the beat frequency of FMCW signals. The beat frequency is directly related to the range.

Ports

Entrance

X — cube of input data
complex column vector K by 1 | complex matrix K by L | complex array K by N by L

An input data cube defined as a complex column vector K by 1, a complex-valued matrix K by L, or a complex-valued array K by N by L.

K is the number of range or time samples.
N is the number of independent channels, such as sensors or directions.
L is the number of pulses or sweeps in the input signal.

Each K-element column vector is processed independently.

For an FMCW signal with a triangular sweep, the sweeps alternate with a positive and negative slope. However, the block Range Response It is designed for processing consecutive sweeps with the same slope. To apply the block Range Response for a triangular scan system, use one of the following approaches:

Set a positive value for the Sweep slope parameter, and X will correspond only to the upward sweep. After getting the values of the Doppler speed or driving speed, divide them by 2.
Set a negative value for the Sweep slope parameter, and X will correspond only to the lowering speed. After getting the Doppler or velocity values, divide them by 2.

The number of samples for the first dimension of the input matrix can be changed to simulate a change in the length of the signal. A change in size can occur, for example, in the case of a pulse waveform with a variable pulse repetition rate.

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

Support for complex numbers: Yes

Coeff — coefficients of the matched pass filter:q[ ] complex column vector

Coefficients of the matched filter, specified as a complex column vector. The length of the vector must be less than or equal to the number of lines in the input data, K.

Dependencies

To use this port, set the Range processing method to Matched filter.

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

Support for complex numbers: Yes

XRef — pass reference signal:q[ ] complex column vector K by 1

The reference signal used to decrypt the input signal is specified as a complex-valued column vector (K-by-1). The number of lines must be equal to the length of the first dimension X.

Dependencies

To enable this port, set the Range processing method to `FFT' and select the Dechirp input signal parameter.

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

Support for complex numbers: Yes

Output

Range — pass range values:q[ ] the valid column vector is M by 1

The range values for the first measurement of the Resp data output port, specified as a real-valued column vector (M-by-1). This value determines the range values based on the first measurement of the output port data Resp. The units of measurement are meters.

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

Parameters

Range processing method — pass range processing method:q[ ] Matched filter (default) | FFT

The range processing method specified as Matched filter or `FFT'.

Matched filter — the block applies a matched filter to the incoming signal. This approach is usually used for pulsed signals, when the matched filter is a temporary feedback characteristic of the transmitted signal.
The 'FFT' block applies the FFT to the input signal. This approach is commonly used for FMCW and linear FM pulse signals.

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

Propagation speed (m/s) — speed of propagation of the pass signal:q[ ] 3e8 (default) | positive scalar

The propagation velocity of the signal, specified as a real positive scalar. The default value for the speed of light is `3e8'.

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

Inherit sample rate — inherit the sample rate of
enabled (by default) | disabled

Check the box to inherit the sampling rate from higher-level blocks. Otherwise, set the sampling rate using the Sample rate (Hz) parameter.

Sample rate — signal sampling rate, Hz
1e6 (default) | positive scalar

Set the sampling frequency of the signal as a positive scalar. The units of measurement are Hz.

Dependencies

To use this option, uncheck the Inherit sample rate checkbox.

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

FM sweep slope — FM band sweep slope, Hz/c
1e9 (default) | scalar

Set the slope of the FM linear sweep as a scalar. This parameter must correspond to the actual input data in port X.

Dependencies

To use this parameter, set the Range processing method parameter to FFT.

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

Dechirp input signal — enabling decryption of input signals
enabled (by default) | disabled

Select this option so that the block performs the decryption operation of the input signal. Uncheck this box to indicate that the input signal has already been decrypted and no decryption operation is required.

Dependencies

To use this parameter, set the Range processing method parameter to FFT.

Source of FFT length in range processing — FFT length source
Auto (default) | Property

The source of the FFT length used to process decrypted signals in the range is set as Auto or Property.

Auto — The length of the FFT is equal to the length of the fast time measurement of the input data cube.
Property — Specify the length of the FFT using the FFT length in range processing parameter.

Dependencies

To use this parameter, set the Range processing method parameter to FFT.

FFT length in range processing — length of the FFT processing range
Auto (default) | Property

The length of the FFT for range processing is set as a positive integer.

Dependencies

To use this parameter, set the Range processing method parameter to FFT and the Source of FFT length in range processing parameter to Property.

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

Specify the window used for range processing using one of the following values: None', `Hamming, Chebyshev, Hann, Kaiser, `Taylor'.

If you set this parameter to Taylor, the generated Taylor window will have four almost permanent side lobes adjacent to the main lobe.

Dependencies

To use this parameter, set the Range processing method parameter to FFT.

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

Range sidelobe attenuation level — attenuation level of the side lobes of the
30 (default) | scalar

The attenuation level of the side lobes in the form of a positive scalar.

This attenuation applies only to Chebyshev, Kaiser, or Taylor windows. The units of measurement are dB.

Dependencies

To use this parameter, set the Range processing method parameter to FFT, and the Range processing window parameter to Chebyshev, Kaiser, or `Taylor'.

Set reference range at center — setting the reference range in the center of the grid
enabled (by default) | disabled

Sets the reference range in the center of the grid, set as on or off. By checking this box, you can set the reference range in the center of the grid. Otherwise, the reference range is set to the beginning of the grid.

Dependencies

To use this property, set the Range processing method parameter to FFT.

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

Reference range — grid reference range, m
0.0 (default) | non-negative scalar

The reference range of the range grid, set as a non-negative scalar.

If the Range processing method parameter is set to Matched filter, the reference range is set to the beginning of the range grid.
If you set the Range processing method parameter to FFT, the reference range depends on the Set reference range at center checkbox.
- If the Set reference range at center checkbox is selected, the reference range will be set in the center of the range grid.
- If the Set reference range at center checkbox is not checked, the reference range is set to the beginning of the range grid. The units of measurement are meters.

Example: 1000.0

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