Raised Cosine Transmit Filter
The block collapses the input signal with an impulse response, represented as a function of the raised cosine.
blockType: SubSystem
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Path in the library: |
Description
Block Raised Cosine Transmit Filter It increases sampling and filters the input signal using a conventional FIR filter with a raised cosine.
Filter Characteristics
Since the ideal cosine filter has an infinite impulse response, the block truncates the impulse response to the number of characters that the parameter specifies. Filter span in symbols. The filter range in symbols N and the number of output samples per symbol L determine the length of the filter’s impulse response, which is the filter range in characters .
Parameter Rolloff factor — this is the smoothing coefficient of the filter. It must be a real number from 0 before 1. The smoothing coefficient of the filter determines the excess bandwidth of the filter. For example, the smoothing coefficient of the filter 0.5 means that the bandwidth of the filter is in 1.5 is twice the input sampling rate.
The unit normalizes the filter coefficients to a unit of energy. If you have specified a linear amplitude filter gain other than 1, then the block scales the normalized filter coefficients using the gain value you specify.
Ports
Input
#
IN_1
—
The input signal
scalar | column vector | the matrix
Details
Input signal in the form of a scalar, column vector or matrix on , where is the number of input samples per signal channel, and — the number of signal channels.
| Data types |
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| Complex numbers support |
No |
Output
#
OUT_1
—
The output signal
scalar | column vector | the matrix
Details
The output signal is in the form of a scalar, column vector, or matrix on :
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;
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— number of signal channels;
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— the number of input samples per signal channel;
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— parameter value Output samples per symbol.
The block filters each channel by time and generates an output matrix. on . The output signal has the same data type as the input signal.
| Data types |
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| Complex numbers support |
No |
Parameters
Main group
# Rolloff factor — smoothing ratio
Details
Set the smoothing coefficient of the filter. Use a real number between 0 and 1.
| Default value |
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| Program usage name |
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| Tunable |
No |
| Evaluatable |
Yes |
# Filter span in symbols — filter length in characters
Details
Set the number of characters that the filter covers as an even, positive integer scalar. Default value 10. Since the ideal raised cosine filter has an infinite impulse response, the block truncates the impulse response to the number of characters that this parameter specifies.
| Default value |
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| Program usage name |
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| Tunable |
No |
| Evaluatable |
Yes |
# Output samples per symbol — output samples per character
Details
Set the number of output samples for each input character. The default value is 8. This property takes on a positive integer scalar value. The number of taps for the raised cosine filter is equal to the value of this parameter multiplied by the value of the parameter Filter span in symbols.
| Default value |
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| Program usage name |
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| Tunable |
No |
| Evaluatable |
Yes |
# Linear amplitude filter gain — the linear gain of the filter
Details
The linear gain coefficient of the filter.
| Default value |
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| Program usage name |
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| Tunable |
No |
| Evaluatable |
Yes |