#### Example 5.1 | #### Question 5.1

## Spectral occupancy of ASK: ASK data spectrum

If we now include all the components in the baseband stream which will mix with the carrier to generate a sum and difference component, the resulting spectrum is again symmetrical about the carrier frequency, and is in fact a positive and reversed image of the baseband 'sinc' spectrum for an unfiltered binary data stream. This ASK spectrum is sometimes referred to as a double sideband spectrum, with an upper and lower sideband with respect to the carrier. It is immediately evident that the bandwidth occupied by the ASK modulation is twice that occupied by the source baseband stream with a maximum bandwidth efficiency of: |

#### Bandwidth efficiency of binary ASK = 1 bit/second/Hz