NI 5441
Amplitude Modulation (AM) or Double Sideband
You can generate an AM radio signal with the OSP block. To generate an AM signal, complete the following steps.
- Enable onboard signal processing by setting the OSP Enabled property or the NIFGEN_ATTR_OSP_ENABLED attribute.
- Specify the use of real numbers for the waveform data by setting the Data Processing Mode property or the NIFGEN_ATTR_OSP_DATA_PROCESSING_MODE attribute.
- Set the IQ Rate property or the NIFGEN_ATTR_OSP_IQ_RATE attribute to the sample rate of the baseband data.
- Set the Pre-Filter Gain I property or the NIFGEN_ATTR_OSP_PRE_FILTER_GAIN_I attribute to 0.5.
- Set the Pre-Filter Offset I property or the NIFGEN_ATTR_OSP_PRE_FILTER_OFFSET_I attribute to 0.5. Steps 4 and 5 ensure that all interpolated data is positive when it is mixed with the carrier.
- Enable the carrier by setting the Carrier Enabled property or the NIFGEN_ATTR_OSP_CARRIER_ENABLED attribute.
- Set the Carrier Frequency property or the NIFGEN_ATTR_OSP_CARRIER_FREQUENCY attribute to the station frequency.
- Specify a flat FIR filter by setting the FIR Filter Type property or the NIFGEN_ATTR_OSP_FIR_FILTER_TYPE attribute.
- Set the Flat Filter Passband property or the NIFGEN_ATTR_OSP_FIR_FILTER_FLAT_PASSBAND attribute to 0.4.
- Download the waveform data to the signal generator.