How OFDMA Transmitter in LTE ?
In the downlink, OFDM is selected to efficiently meet E-UTRA performance requirements. With OFDM, it is straightforward to exploit frequency selectivity of the multi-path channel with lowcomplexity
receivers. This allows frequency selective in addition to frequency diverse scheduling and one cell reuse of available bandwidth.
Furthermore, due to its frequency domain nature, OFDM enables flexible bandwidth operation with low complexity. Smart antenna technologies are also easier to support with OFDM, since each sub-carrier becomes flat faded and the antenna weights can be optimized on a per sub-carrier (or block of sub-carriers) basis.
In addition, OFDM enables broadcast services on a synchronized single frequency network (SFN) with appropriate cyclic prefix design.
This allows broadcast signals from different cells to combine over the air, thus significantly increasing the received signal power and supportable data rates for broadcast services.
OFDMA Transmitter in LTE
When you look at the LTE transmitter, one of its core components is the OFDMA transmitter. I think of it as the system that breaks up data into smaller pieces and then sends it out across multiple frequencies at once. This is crucial for the downlink, as it allows LTE to send data to multiple users simultaneously, without interference.
The OFDMA transmitter works by first taking the data and splitting it into smaller subcarriers. These subcarriers are then mapped onto the available frequency spectrum. What’s key here is that these subcarriers are orthogonal, meaning they won’t interfere with each other, even if they’re close together. This orthogonality maximizes efficiency and ensures clear signal transmission.
For you, this means the transmitter has to handle the complexities of allocating the correct amount of bandwidth to each user, adjusting based on their data needs and channel conditions. It’s a dynamic process where the system continuously adjusts to provide the best possible service to each user in the cell.