| Getting Started |
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Setting Parameters in the FSK Model
Make the following changes to the default parameter settings in the masks for the blocks:
- Double-click the Bernoulli Binary Generator block and make the following changes to the default parameters in the block's mask:
- Set Probability of a zero to
0.5.
- Set Sample time to
1/1200.
- Double-click the M-FSK Modulator Passband block and make the following changes to the default parameters in the block's mask:
- Set M-ary number to
2. This specifies the number of frequencies in the modulated signal.
- Set Frequency separation to
1000. This specifies the separation between the two frequencies of the modulated signal.
- Set Symbol period to
1/1200 to match the Sample time in the Bernoulli Binary Generator block.
- Set Baseband samples per symbol to
5. This causes the block to oversample the incoming signal. Oversampling increases the sampling rate by a factor of 5, thereby raising the sampling rate above the Nyquist rate. This enables the Spectrum Scope block to generate a more accurate picture.
- Set Carrier frequency to
10000. This specifies the frequency of the carrier.
- Set Output sample time to
1/30000.
- Double-click the M-FSK Demodulator Passband block and make the same changes to the block's default parameters as for the M-FSK Modulator Passband block. Set Input sample time to
1/30000 to match the Output sample time of the M-FSK Modulator Passband block.
- Double-click the AWGN Channel block and set Symbol period to
1/1200, to match the Symbol period in the M-FSK Modulator Passband block.
- Double-click the Spectrum Scope block and make the following changes to the default parameters in the block's mask:
- Check the box next to Buffer input. This converts the input into frames so that the block can calculate the FFT.
- Set Buffer size to
1024.
- Set Buffer overlap to
256.
- Set Number of spectral averages to
20.
- Check the box next to Axis properties.
- Set Minimum Y-limit to
-40.
- Set Maximum Y-limit to
20.
- Double-click the Integer Delay block and change Delay to
6 in the block's mask. The Integer Delay block delays the transmitted signal by the number of sample periods specified by the Delay parameter. For more information about delays, see the section Delays in the Model.
- Double-click the Error Rate Calculation block and make the following changes to the default parameters in the block's mask:
- Set Receive delay to
6.
- Set Output data to Port.
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