Engee documentation

EngeePhased.ReceiverPreamp

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The receiver’s preamp.

Library

EngeePhased
Block

Receiver Preamp

Description

The ReceiverPreamp system object implements the receiver’s preamplifier model. The object receives incoming signals, multiplies them by the gain of the amplifier and divides them by the losses in the system. Then Gaussian white noise is added to the signal.

To simulate the receiver’s preamp, follow these steps:

  1. Create an object EngeePhased.ReceiverPreamp and set its properties.

  2. Call an object with arguments as if it were a function.

To learn more about how to work with system objects, see Engee System Objects.

Syntax

Creation

  • receiver = phased.ReceiverPreamp() — Creates a receiver preamp object with by default property values.

  • receiver = phased.ReceiverPreamp(Name=Value) — creates a preamp object with specified properties in the form of a pair Name=Value, where Name — the name of the property, and Value — the corresponding value. You can specify multiple pairs «name-value» the order of the pairs does not matter. Unspecified properties retain their by default values.

Usage

  • Y = receiver(X) — Applies receiver gain and noise to the input signal X and returns the resulting output signal Y.

  • Y = receiver(X,EN_RX) — uses the input argument EN_RX as an enabling signal when for the property EnableInputPort set to true.

  • Y = receiver(_,PHNOISE) — uses the input argument PHNOISE as phase noise for each sample in X when for PhaseNoiseInputPort value set true. The phase noise is the same for all channels in X. The elements in PHNOISE are random phases that the transmitter adds to the transmitted pulses. The receiver preamplifier object removes these random phases from all received samples returned within the corresponding pulse intervals. This setting is often called coherent reception.

Arguments

Input arguments

X — input signal

+ vector | the matrix

Details

An input signal specified as a vector or matrix.

The size of 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 signal with a variable pulse repetition rate.

EN_RX — enabling signal

+ column vector

Details

A resolution signal specified in the form of a column vector, the length of which is equal to the number of rows in X. Each element of EN_RX, equal to 0 or false, indicates that the receiver is turned off and no input signal is passing through it. Each element of EN_RX that is not equal to zero or true, indicates that the receiver is turned on and an input signal is passing through it.

Dependencies

To use this argument, set the property to EnableInputPort value true.

Типы данных

Float64, Bool

PHNOISE — phase noise

+ column vector

Details

Phase noise for each sample in X, specified as a column vector whose length is equal to the number of rows in X. The PHNOISE argument can be obtained as an optional output argument from an object EngeePhased.Transmitter.

Dependencies

To use this argument, set the property to PhaseNoiseInputPort value true.

Output arguments

Y — output signal

+ vector | the matrix

Details

An input signal returned as a vector or matrix.

The argument Y has the same dimensions as X.

Properties

# LossFactor — receiver preamp loss factor
Real number

Details

The loss coefficient in dB, set as a scalar.

Default value — 0.

# NoiseFigure — receiver preamp noise factor
Real number

Details

The noise factor in dB, set as a scalar. If the receiver has multiple channels or sensors, the noise factor is applied to each channel or sensor.

Default value — 0.

Dependencies

To use this property, set the NoiseMethod value "Noise temperature".

# Seed — the initial value for the random number generator
Real number

Details

The initial number for the random number generator, set as a non-negative integer, is less than 232.

Dependencies

To use this property, set the SeedSource value "Property".

# EnableInputPort — using a permissive signal
Logical

Details

The possibility of using the input resolution signal, set as false (by default) or true.

To use the receiver’s on signal, set this property to true and use the input argument EN_RX. If you do not want to use the receiver power-on signal, set this property to false.

# PhaseNoiseInputPort — using phase noise
Logical

Details

The possibility of using input phase noise, defined as false (by default) or true.

To set the phase noise for each input sample, set this property to true and use the input argument PHNOISE. You can use this information to simulate coherent reception systems. If you do not want to specify phase noise, set this property to false.

# ReferenceTemperature — The receiver’s preamp reference temperature
Real number

Details

The reference temperature of the receiver in kelvins, set as a scalar. If the receiver has multiple channels or sensors, a reference temperature is applied to each channel or sensor.

Default value — 290.

Dependencies

To use this property, set the NoiseMethod value "Noise temperature".

# NoiseMethod — the method of determining the noise level
String

Details

A method for calculating the noise power, given as "Noise power" or "Noise temperature" (by default).

If you set this property to "Noise temperature", a complex base noise is added to the input signal with a power calculated based on the properties ReferenceTemperature, NoiseFigure and SampleRate. If you set this property to "Noise power", noise is added to the signal with the power specified in the NoisePower.

# NoisePower — noise power
Real number

Details

The noise power in watts, set as a positive scalar.

Default value — 1.

Dependencies

To use this property, set the NoiseMethod value "Noise power".

# Gain — receiver preamp gain
Real number

Details

Gain factor in dB, set as a scalar.

Default value — 20.

# SampleRate — sampling rate
Real number

Details

The sampling frequency in hertz, set as a positive scalar. The SampleRate property also determines the noise bandwidth.

Default value — 1.0e6.

Dependencies

To use this property, set the NoiseMethod value "Noise temperature".

# SeedSource — the source of the initial value for the random number generator
String

Details

The source of the initial value for the random number generator, set as "Auto" (by default) or "Property".

When setting the value for this property "Auto" The system object generates random numbers using the default random number generator.

When setting the value for this property "Property", you can specify the initial value of the random number generator using the property Seed.

Methods

Common to all system objects

step!

Run the algorithm of the system object
release!

Allow changing the value of the system object property
reset!

Resetting the internal states of the system object

Literature

  1. Richards, M. A. Fundamentals of Radar Signal Processing. New York: McGraw-Hill, 2005.

  2. Skolnik, M. Introduction to Radar Systems, 3rd Ed. New York: McGraw-Hill, 2001.

Examples