Certified Network Defender (CND) — Question 23

Identify the spread spectrum technique that multiplies the original data signal with a pseudo random noise spreading code.

Answer options

• A. ISM
• B. FHSS
• C. DSSS
• D. OFDM

Correct answer: C

Explanation

The correct answer is C, DSSS (Direct Sequence Spread Spectrum), which uses a pseudo noise sequence to spread the signal over a wider bandwidth. FHSS (Frequency Hopping Spread Spectrum) changes frequencies rapidly to transmit data, while ISM (Industrial, Scientific, and Medical) refers to frequency bands rather than a specific technique. OFDM (Orthogonal Frequency Division Multiplexing) is a method of encoding digital data on multiple carrier frequencies but does not involve spreading codes.