Flashcards
Sampling: Discrete-time baseband model
Cards in this deck (14)
- 1If an input waveform is restricted to a bandwidth W, what is the restriction on the baseband equivalent wave?W/2
- 2Describe an 'Impulse Train' or 'Dirac Delta function'
- 3If a function x(t) contains no frequencies higher than B hertz, it is completely determined by giving its ordinates at a series of points spaced ________ seconds apart.1/2B
- 4If a function x(t) contains no frequencies higher than B hertz, a sufficient sample-rate is......given by 2B samples/second, or anything larger.
- 5For a given sample rate fs, perfect reconstruction is guaranteed possible for what set of bandlimits B?B < fs/2.
- 6Aliasing occurs when...... the bandlimit of a signal is too high (greater than half the sampling rate)
- 7Nyquist RateTwice the bandwidth of a bandlimited function (ie. the lower bound for the sample rate required to reproduce the signal accurately).
- 8Nyquist FrequencyHalf the sampling rate fs of a discrete-time system (ie. the maximum frequency that can be recovered by sampling at a rate of fs).
- 9What are represented by x[n]The discrete samples taken of a signal at time intervals 1/W. (For a baseband signal bandlimited to bandwidth of W/2).
- 10Explicitly, x[n] is defined asx[n]=x_b(n/W) the value of the (baseband) signal at time t=n/W.
- 11What is the Sampling TheoremAny waveform band-limited to W/2 can be expanded in terms of the orthogonal basis:
sinc(Wt−n),
with coefficients given by the samples (taken at integer multiples of 1/W). - 12Define sinc(t)
- 13Using sampling theory, the baseband equivalent of an input waveform of a signal with bandwidth W can be represented as
- 14—
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- PhD Comms (The Wireless Channel) Flashcards on Sampling: Discrete-time baseband model, created by L H on 16/01/2018.
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- L H
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