A Survey of Adaptive Modulation and Cyclic Prefixes Over WiMAX Environment
The wireless medium has limited bandwidth, higher packet error rate and higher packet overheads that altogether limit the capacity of the network to offer guaranteed QoS. Orthogonal Frequency-Division Multiplexing (OFDM) systems also referred as multi-carrier systems are known to be the basis of 3G and 4G technology, for example in LTE (Long Term Evolution) 4G cellular standards, WiMAX standards, 802.11 a/g/n microwave standards, etc. Thus, OFDM is a key wireless broadband technology which supports high data rates. The WiMAX forums network working group is responsible for developing the end-to-end network requirements, architecture and protocols for WiMAX using IEEE 802.16e 2005 as the air interface.