What is Orthogonal Frequency Division Multiplexing (OFDM) primarily used for?

Orthogonal Frequency Division Multiplexing (OFDM) is a method used primarily for splitting a single data stream into multiple smaller streams that can be transmitted simultaneously over different frequencies. This technique takes advantage of the properties of orthogonal signals, meaning that the different frequency channels do not interfere with each other, which allows for a more efficient use of the bandwidth.

By dividing the available spectrum into many closely spaced sub-carriers that are orthogonal to each other, OFDM can effectively mitigate issues such as inter-symbol interference and improve the robustness of the communication, especially in environments with multipath propagation. This is particularly beneficial in wireless communications, broadband data transmission, and digital television broadcasting.

In contrast, the other options focus on different aspects of data transmission and communication. Converting analog signals to digital concerns the process of digitizing signals rather than transmission methods. Encrypting wireless communications involves securing the data being transmitted but does not address the modulation techniques used. Transmitting video signals relates to the type of content rather than the method of splitting the signals for efficient delivery. Therefore, the primary function of OFDM is best described by the concept of splitting a signal into multiple orthogonal frequencies for better transmission efficiency.