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131 lines
4.7 KiB
Markdown
131 lines
4.7 KiB
Markdown
<h1>Test source input plugin</h1>
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<h2>Introduction</h2>
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This input sample source plugin is an internal continuous wave generator that can be used to carry out test of software internals.
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<h2>Build</h2>
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The plugin is present in the core of the software and thus is always present in the list of sources.
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<h2>Interface</h2>
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<h3>1: Common stream parameters</h3>
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<h4>1.1: Frequency</h4>
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This is the center frequency of reception in kHz.
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<h4>1.2: Start/Stop</h4>
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Device start / stop button.
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- Blue triangle icon: device is ready and can be started
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- Green square icon: device is running and can be stopped
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- Magenta (or pink) square icon: an error occurred. In the case the device was accidentally disconnected you may click on the icon, plug back in and start again.
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<h4>1.4: Stream sample rate</h4>
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Baseband I/Q sample rate in kS/s. This is the device to host sample rate (3) divided by the decimation factor (4).
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<h3>2: Various options</h3>
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<h4>2.1: Auto corrections</h4>
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This combo box control the local DSP auto correction options:
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- **None**: no correction
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- **DC**: auto remove DC component
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- **DC+IQ**: auto remove DC component and correct I/Q balance.
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<h4>2.2: Decimation factor</h4>
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The I/Q stream from the generator is downsampled by a power of two before being sent to the passband. Possible values are increasing powers of two: 1 (no decimation), 2, 4, 8, 16, 32. This exercises the decimation chain.
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This exercises the decimation chain.
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<h4>2.3: Baseband center frequency position relative the center frequency</h4>
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- **Cen**: the decimation operation takes place around the center frequency Fs
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- **Inf**: the decimation operation takes place around Fs - Fc.
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- **Sup**: the decimation operation takes place around Fs + Fc.
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With SR as the sample rate before decimation Fc is calculated as:
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- if decimation n is 4 or lower: Fc = SR/2^(log2(n)-1). The device center frequency is on the side of the baseband. You need a RF filter bandwidth at least twice the baseband.
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- if decimation n is 8 or higher: Fc = SR/n. The device center frequency is half the baseband away from the side of the baseband. You need a RF filter bandwidth at least 3 times the baseband.
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<h3>2.4: Sample size</h3>
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This is the sample size in number of bits. It corresponds to the actual sample size used by the devices supported:
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- **8**: RTL-SDR, HackRF
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- **12**: Airspy, BladeRF, LimeSDR, PlutoSDR, SDRplay
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- **16**: Airspy HF+, FCD Pro, FCD Pro+
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<h3>3: Sample rate</h3>
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This controls the generator sample rate in samples per second.
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<h3>4: Modulation</h4>
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- **No**: No modulation
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- **AM**: Amplitude modulation (AM)
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- **FM**: Frequency modulation (FM)
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- **P0**: Pattern 0 is a binary pattern
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- Pulse width: 150 samples
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- Sync pattern: 010 at full amplitude
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- Binary pattern LSB first on 3 bits from 0 to 7 at 0.3 amplitude
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- **P1**: Pattern 1 is a sawtooth pattern
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- Pulse width: 1000 samples
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- Starts at full amplitude then amplitude decreases linearly down to zero
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- **P2**: Pattern 2 is a 50% duty cycle square pattern
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- Pulse width: 1000 samples
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- Starts with a full amplitude pulse then down to zero for the duration of one pulse
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<h3>5: Modulating tone frequency</h3>
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This controls the modulating tone frequency in kHz in 10 Hz steps.
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<h3>6: Carrier shift from center frequency</h3>
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Use this control to set the offset of the carrier from the center frequency of reception.
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<h3>7: AM modulation factor</h3>
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This controls the AM modulation factor from 0 to 99%
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<h3>8: FM deviation</h3>
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This controls the frequency modulation deviation in kHz in 100 Hz steps. It cannot exceed the sample rate.
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<h3>9: Amplitude coarse control</h3>
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This slider controls the number of amplitude bits by steps of 100 bits. The total number of amplitude bits appear on the right.
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<h3>10: Amplitude fine control</h3>
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This slider controls the number of amplitude bits by steps of 1 bit. The signal power in dB relative to the maximum power (full bit range) appear on the right.
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<h3>11: DC bias</h3>
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Use this slider to give a DC component in percentage of maximum amplitude.
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<h3>12: I bias</h3>
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Use this slider to give an in-phase (I) bias in percentage of maximum amplitude.
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<h3>13: Q bias</h3>
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Use this slider to give an quadrature-phase (Q) bias in percentage of maximum amplitude.
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<h3>14: Phase imbalance</h3>
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Use this slider to introduce a phase imbalance in percentage of full period (continuous wave) or percentage of I signal injected in Q (AM, FM).
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