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Transmitter

Amplify and transmit signal

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  • Transmitter block icon

Libraries:
Phased Array System Toolbox / Transmitters and Receivers

Description

The Transmitter block amplifies and transmits waveform pulses. The transmitter can either maintain coherence between pulses or insert phase noise.

Examples

Simulating a Bistatic Radar with Two Targets

Simulating a Bistatic Radar with Two Targets

Simulate a bistatic radar system with two targets. The transmitter and the receiver of a bistatic radar are not co-located and move along different paths.

Ports

Input

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Input waveform, specified as a complex-valued matrix.

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

Output

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Transmitted signal, output as a complex-value matrix. Y is the amplified input waveform where the amplification is based on the characteristics of the transmitter, such as the peak power and the gain.

Data Types: double

Transmitter on-off status, output as a 0 or 1. A 1 indicates that the transmitter is on, and a 0 indicates that the transmitter is off.

Dependencies

To enable this port, select the Enable transmitter status output check box.

Data Types: double

Phase noise, output as a scalar.

Dependencies

To enable this port, select the Enable pulse phase noise output check box.

Data Types: double

Parameters

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Main

Peak power, specified as a positive scalar. Units are in Watts.

Data Types: single | double

Method for applying gain to the transmitted signal, specified as Linear, Cubic polynomial or Lookup table.

  • When set to Linear, linear gain is applied.

  • When set to Cubic polynomial, a cubic polynomial model is used to apply non-linear gain.

  • When set to Lookup table, a lookup table is defined to directly specify output power and phase shift as a function of input power.

Data Types: char | string

Linear transmitter gain, specified as a real scalar or length-N vector of real values. N is the number of channels. If the Gain (dB) parameter is a scalar, the same value is applied to all channels. Units are in dB.

Dependencies

To enable this property, set the Gain method parameter to Linear or Cubic polynomial.

Data Types: single | double

Output IP3, specified as a scalar or length-N vector of real values. N is the number of channels. OIP3 expresses the non-linearity of the transmitter or receiver. OIP is also called the third-order intercept point. If OIP3 is a scalar, the same value is applied to all channels. See Nonlinearities and Noise in Idealized Baseband Amplifier Block (RF Blockset) for a detailed discussion of OIP3. Units are in dBm.

Dependencies

To enable this property, set the Gain method parameter to Cubic polynomial.

Data Types: single | double

AM/AM-AM/PM lookup table, specified as a 3-by-M-by-N real-valued array. The lookup table specifies amplifier power characteristics. M is the number of table entries and N is the number of channels. Each row in the table expresses the relationship between output power or phase change as a function of input power. Specify AM/AM (in dB/dB) and AM/PM (in deg/dB) characteristics in a [Pin(dBm),Pout(dBm),Phase shift(degrees)]-by-M matrix or [Pin(dBm),Pout(dBm),Phase shift(degrees)]-by-M-by-N array. Use the table to linear interpolate or extrapolate power values. The column 1 input power must increase monotonically. There must be at least 3 rows in the table. The power output can be written as:

uout=TAM−AM(|u|)eTAM−PM(|u|+∠u)

Dependencies

To enable this property, set the Gain method parameter to Lookup table.

Data Types: single | double

Transmit loss factor, specified as a nonnegative scalar or length-N vector of nonnegative values. N is the number of channels. If Loss factor (dB) parameter is a scalar, the same value is applied to all channels.

Dependencies

To enable this property, set the Gain method parameter to Linear.

Data Types: double | single

Select this check box to output the transmitter-in-use status for each output sample from the output port TR.

Data Types: Boolean

Select this check box to preserve coherence among transmitted pulses.

  • When you select this check box, the transmitter does not add random phase to the output pulse.

  • When you deselect this check box, the transmitter adds random phase noise to each transmitted pulse. The random phase noise is introduced by multiplying the pulse value by ejϕ where ϕ is a uniformly-distributed random variable on the interval [0,2π].

Data Types: Boolean

Select this check box to create an output port, Ph, with the output sample random phase noise introduced if Preserve coherence among pulses is cleared. The output port can be directed to a receiver to simulate coherent-on-receive systems.

Dependencies

This check box appears only when Preserve coherence among pulses is not selected.

Data Types: Boolean

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 SimulationSimulation Behavior
NormalAcceleratorRapid Accelerator
Interpreted ExecutionThe block executes using the MATLAB interpreter.The block executes using the MATLAB interpreter.Creates a standalone executable from the model.
Code GenerationThe 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
Noise

Selected this check box to add noise it the input signal prior to applying receiver effects. The Input noise temperature (K) parameter determines the power of the added noise. The Sample rate (Hz) parameter determines the noise bandwidth.

Example: true

Data Types: Boolean

Input noise temperature, specified as a positive scalar or length-N vector of positive values where N is the number of receiver channels. If the Input noise temperature (K) parameter is a scalar, the same value is applied to all channels. Units are in Kelvin degrees.

Example: 300

Dependencies

To enable this parameter, select the Input noise temperature (K) check box.

Data Types: single | double

Method for defining the system noise, specified as None, Noise figure, Noise factor or Noise temperature.

  • When set to None, no noise is applied.

  • When set to Noise figure, the Noise figure (dB) parameter determines the noise level.

  • When set to Noise temperature, the Input noise temperature (K) parameter determines the noise level.

  • When set to Noise factor, the Noise factor parameter determines the noise level.

The noise bandwidth is derived from the input signal sample rate.

Example: Noise figure

Data Types: char | string

Receiver noise figure, specified as a real scalar or length-N vector of real values. N is the number of channels. If Noise figure (dB) is a scalar, the same value is applied to all channels. Noise is generated with respect to the temperature defined by the Reference temperature (K) parameter.

Dependencies

To enable this property, set the Noise method parameter to Noise figure.

Data Types: single | double

Receiver noise factor, specified as a positive scalar or length-N vector of positive values. N is the number of channels. If the Noise factor parameters is a scalar, the same value is applied to all channels. Noise is generated with respect to the temperature defined by the Reference temperature (K) parameter.

Dependencies

To enable this property, set the Noise method parameter to Noise factor.

Data Types: single | double

Reference temperature, specified as a positive scalar or a length-N vector of positive values. N is the number of channels. If the Reference temperature (K) parameter is a scalar, the same value is applied to all channels.

Dependencies

To enable this property, set the Noise method parameter to Noise figure or Noise factor.

Data Types: single | double

Sample rate of the input signal, specified as a positive scalar. Use this parameter to add noise to the signal. The Sample rate (Hz) parameter is only used to derive the noise bandwidth of the signal.

Dependencies

To enable this property, select the Add noise to input signal check box or set the Noise method parameter to Noise figure, Noise factor, or Noise temperature.

Data Types: single | double

Select this parameter to inherit the sample rate from upstream blocks. Otherwise, specify the sample rate using the Sample rate (Hz) parameter.

Data Types: Boolean

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 SimulationSimulation Behavior
NormalAcceleratorRapid Accelerator
Interpreted ExecutionThe block executes using the MATLAB interpreter.The block executes using the MATLAB interpreter.Creates a standalone executable from the model.
Code GenerationThe 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
PhaseOffset

Phase offset, specified as a real scalar or length-N vector of real values. N is the number of channels. If Phase offset (degrees) is a scalar, the same value is applied to all channels. Units are in degrees.

Data Types: single | double

Randomization

Source of seed for random number generator, specified as Auto or Property. When source is Auto, the seed if generated automatically. When the source is Property, seed is set using the Seed for random number generator parameter.

Example: Property

Data Types: char | string

Seed for random generator, specified as a positive integer.

Data Types: single | double

Version History

Introduced in R2014b

See Also

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