Mobile WiMAX frame structure Unlike Fixed WiMAX, which uses OFDM frames, Mobile WiMAX uses OFDMA frames. OFDMA allows multiple users to receive data from the base station at the same time. In this type of system, the downlink bursts from the base station are divided by a time offset and a frequency offset (sub-channel offset). … Read more
For channel estimation different types of reference signals are in use: – Cell specific reference signals. – MBSFN reference signals. – UE specific reference signals CELL-SPECIFIC REFERENCE SIGNALS These signals are transmitted for all non-MBSFN subframes only where subcarrier spacing is 15 kHz. In MBSFN subframes only the first 2 OFDM symbols can be used. … Read more
One of the advantages of using LTE TDD is that it is possible to dynamically change the up and downlink balance and characteristics to meet the load conditions. In order that this can be achieved in an ordered fashion, a total of seven up / downlink configurations have been set within the LTE standards, in … Read more