Chapter 13 - Spead Spectrum

Question 1

WRT Spread Spectrum Techniques briefly explain the operation of a Frequency Hopping system.

Answer 1

The signal is rapidly switched or “hopped” among many frequency channels in a predetermined sequence. Each hop typically occurs within a fraction of a second, spreading the signal over a wider bandwidth. This technique reduces interference and increases security, as an unintended receiver would need to know the hopping pattern to successfully intercept the signal.

Question 2

WRT Spread Spectrum Techniques briefly explain the operation of a Direct Sequence system.

Answer 2

This process takes the baseband signal and then spreads this power over a much wider bandwidth.

This ‘spread’ signal is then used to phase shift key a sub-carrier.

This sub-carrier would be then up-converted to a higher frequency before being amplified and transmitted.