DSP LEC - P2

a programmable device, with its own native instruction code. Designed specifically to meet numerically-intensive requirements of DSP. It is capable of carrying out millions of floating point operations per second.

• - we only take samples of the signals at intervals and don't know what happens in between
  - cannot distinguish between higher and lower frequencies

most signals are analog in nature, and have to be sampled

we only take samples for a limited period of time

To avoid aliasing, sampling rate must be at least twice the maximum frequency component ('bandwidth') of the signal.

• True

• False

Sampling theorem says there is not enough information to reconstruct the signal, which does not mean sampled signal looks like original one.

• True

• False

correct reconstruction is not just connection samples with straight lines it needs anti-alias filter (to filter out all high frequency components before sampling) and the same for reconstruction - it does remove information though.

• True

• False

we only take samples for a limited period of time

does not pick up "relatively" slow changes

limited (by the number of bits available) precision in data storage and arithmetic

smoothly varying signal represented by "stepped" waveform

Reconfiguring analog system means hardware redesign, testing, and verification

• Digital system can be simply reprogrammed for other applications / ported to different hardware / duplicated

• DSP provides better control of accuracy requirements

• Digital signals can be easily stored without deterioration

• More sophisticated signal processing algorithms can be implemented