What is meant by "direct sampling" in software defined radios?

1. A Software is converted from source code to object code during operation of the receiver
2. B I and Q signals are generated by digital processing without the use of RF amplification
3. C Incoming RF is digitized by an analog-to-digital converter without being mixed with a local oscillator signal
4. D A switching mixer is used to generate I and Q signals directly from the RF input

What kind of digital signal processing audio filter is used to remove unwanted noise from a received SSB signal?

1. A An adaptive filter
2. B A crystal-lattice filter
3. C A Hilbert-transform filter
4. D A phase-inverting filter

What type of digital signal processing filter is used to generate an SSB signal?

1. A An adaptive filter
2. B A notch filter
3. C A Hilbert-transform filter
4. D An elliptical filter

Which method generates an SSB signal using digital signal processing?

1. A Mixing products are converted to voltages and subtracted by adder circuits
2. B A frequency synthesizer removes unwanted sidebands
3. C Varying quartz crystal characteristics are emulated in digital form
4. D Signals are combined in quadrature phase relationship

How frequently must an analog signal be sampled to be accurately reproduced?

1. A At least half the rate of the highest frequency component of the signal
2. B At least twice the rate of the highest frequency component of the signal
3. C At the same rate as the highest frequency component of the signal
4. D At four times the rate of the highest frequency component of the signal

What is the minimum number of bits required to sample a signal with a range of 1 volt at a resolution of 1 millivolt?

1. A 4 bits
2. B 6 bits
3. C 8 bits
4. D 10 bits

What function is performed by a Fast Fourier Transform?

1. A Converting analog signals to digital form
2. B Converting digital signals to analog form
3. C Converting signals from the time domain to the frequency domain
4. D Converting signals from the frequency domain to the time domain

What is the function of decimation?

1. A Converting data to binary-coded decimal form
2. B Reducing the effective sample rate by removing samples
3. C Attenuating the signal
4. D Removing unnecessary significant digits

Why is an anti-aliasing filter required in a decimator?

1. A It removes high-frequency signal components that would otherwise be reproduced as lower frequency components
2. B It peaks the response of the decimator, improving bandwidth
3. C It removes low-frequency signal components to eliminate the need for DC restoration
4. D It notches out the sampling frequency to avoid sampling errors

What aspect of receiver analog-to-digital conversion determines the maximum receive bandwidth of a direct-sampling software defined radio (SDR)?

1. A Sample rate
2. B Sample width in bits
3. C Integral non-linearity
4. D Differential non-linearity

What sets the minimum detectable signal level for a direct-sampling software defined receiver in the absence of atmospheric or thermal noise?

1. A Sample clock phase noise
2. B Reference voltage level and sample width in bits
3. C Data storage transfer rate
4. D Missing codes and jitter

Which of the following is generally true of Finite Impulse Response (FIR) filters?

1. A FIR filters can delay all frequency components of the signal by the same amount
2. B FIR filters are easier to implement for a given set of passband rolloff requirements
3. C FIR filters can respond faster to impulses
4. D All these choices are correct

What is the function of taps in a digital signal processing filter?

1. A To reduce excess signal pressure levels
2. B Provide access for debugging software
3. C Select the point at which baseband signals are generated
4. D Provide incremental signal delays for filter algorithms

Which of the following would allow a digital signal processing filter to create a sharper filter response?

1. A Higher data rate
2. B More taps
3. C Lower Q
4. D Double-precision math routines