Certified Wireless Design Professional (CWDP) 2025 – 400 Free Practice Questions to Pass the Exam

In 802.11a, the modulation technique used is Orthogonal Frequency Division Multiplexing (OFDM). This method involves dividing the wireless signal into multiple smaller sub-signals, which can be transmitted simultaneously over different frequencies. The advantage of OFDM is its resilience to interference and multipath fading, making it particularly suitable for high-data-rate transmissions in environments with potential obstructions and varying distances.

OFDM efficiently utilizes the available bandwidth by allowing different subcarriers to overlap while remaining orthogonal, which minimizes interference between them. This modulation technique is capable of supporting higher data rates and improved overall performance in wireless networks compared to other methods.

DSSS (Direct Sequence Spread Spectrum), QPSK (Quadrature Phase Shift Keying), and CDMA (Code Division Multiple Access) are modulation techniques used in other standards or contexts, but they do not apply to the specific modulation scheme utilized by 802.11a. The choice of OFDM in 802.11a is one of the key reasons for its success in providing robust, high-speed wireless communication.