Orthogonal frequency division multiplexing (OFDM) is a communications
technique that divides a communications channel into a number of equally spaced
frequency bands. A subcarrier carrying a portion of the user information is transmitted
in each band. Each subcarrier is orthogonal (independent of each other) with every
other subcarrier, differentiating OFDM from the commonly used frequency division
multiplexing (FDM). It is important that the overall system design be well matched to
the service profiles to maximize the performance of the system and balance the ultimate
user experience it provides relative to the cost to the operator. OFDM enables the
creation of a very flexible system architecture that can be used efficiently for a wide
range of services, including voice and data. For any mobile system to create a rich user
experience, it must provide ubiquitous, fast, and user-friendly connectivity. OFDM has
several unique properties that make it especially well suited to handle the challenging
environmental conditions experienced by mobile wireless data applications