Engee documentation

EngeeComms.RaisedCosineReceiveFilter

Generates a pulse by decimating the signal using an FIR filter with an elevated cosine.

Library

EngeeComms

Block

Raised Cosine Receive Filter

Description

To generate an impulse by decimating the signal using an FIR filter with an elevated cosine, follow these steps:

  1. Create an object EngeeComms.RaisedCosineReceiveFilter 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

  • rxfilter = EngeeComms.RaisedCosineReceiveFilter() — returns the system object of the receiving FIR filter with a raised cosine, which decimates the input signal using the FIR filter with a raised cosine. The filter uses an effective polyphase structure of the FIR filter decimation and has a unit energy.

    Example:

    rxfilter = EngeeComms.RaisedCosineReceiveFilter()
  • rxfilter = EngeeComms.RaisedCosineReceiveFilter(Name=Value) — creates a system object EngeeComms.RaisedCosineReceiveFilter with the specified properties as a pair Name=Value, where Name — the name of the property, and Value — appropriate value. You can specify multiple pairs «name-value» the order of the pairs does not matter. Unspecified properties retain their by default values. For example, comm.RaisedCosineReceiveFilter(RolloffFactor=0.3) configures the system object reception filter with a raised cosine with a smoothing coefficient set to 0.3.

    Example:

    rxfilter = EngeeComms.RaisedCosineReceiveFilter(RolloffFactor=0.3)

Usage

  • Y = rxfilter(X) — applies pulse generation by decimating the input signal using an elevated cosine FIR filter. Decimated signal values are obtained at the output.

Y = rxfilter(X)

Arguments

Input arguments

X — input signal

+ column vector | the matrix

Details

An input signal specified as a column vector or matrix on , where i is the number of input samples per signal channel, and — number of signal channels.

For the input signal in the form of a matrix i on the object treats the columns of the input matrix as independent channels.

This system object accepts input data of variable size. After locking the system object, you can change the size of each input channel, but you cannot change the number of channels.

Типы данных

Float64, Float32

Support for complex numbers

Yes

Output arguments

Y — output signal

+ column vector | the matrix

Details

The output signal returned as a column vector or matrix on . equal to / DecimationFactor, where — the number of input samples per signal channel, and — number of signal channels.

The system object filters each channel by time and generates a matrix on at the exit. The output signal has the same data type as the input signal.

Properties

# InputSamplesSymbol — input counts per character
Real number

Details

Input counts per character, specified as a positive integer.

# DecimationOffset — decimation bias
Real number

Details

The decimation offset, specified as an integer in the range [0, (DecimationFactor - 1)]. This property defines the number of filtered samples that the object discards before downsampling.

# RolloffFactor — smoothing factor
Real number

Details

A smoothing factor specified as a scalar in the range [0, 1].

# DecimationFactor — decimation factor
Real number

Details

The decimation factor specified as an integer in the range [1, InputSamplesPerSymbol]. This value must be evenly divisible by InputSamplesPerSymbol. The sampling rate of the output signal is reduced by the decimation factor so that length(Y)/length(X) is equal to DecimationFactor. For a matrix input signal, the number of input rows must be a multiple of the decimation factor.

# LinearAmplitudeFilterGain — linear filter gain
Real number

Details

The linear filter gain factor of a filter, specified as a positive scalar. The system object designs the raised cosine of the filter having unit energy, and then applies the linear filter gain to obtain the final tap ratio values.

# FilterSpanSymbols — filter range in characters
Real number

Details

The range of the filter in symbols, specified as a positive integer. The system object truncates the infinite impulse response (IIR) of an ideal raised cosine filter to an impulse response that spans the number of symbols specified by this property.

Methods

Common to all system objects

step!

Run the algorithm of the system object