The World Academy of Research in Science and Engineering (WARSE)
In this paper, Adaptive Active Constellation Extension (AACE) is implemented for Peak to Average Power Ratio (PAPR) reduction of OFDM systems with spectral diversity of Space Time Block Coding (STBC). The Adaptive Active Constellation Extension (A-ACE) is more simple and attractive for practical downlink implementation purpose. With the combination of MIMO and OFDM, grater channel capacities could be realized with robustness to channel impairments like ISI and multipath fading through Cyclic Prefix (CP). To overcome the disadvantage of normal constellation method i.e. minimum PAR value cannot be achieved if the target clipping level is much below than the initial optimum value, the authors envisaged ACE algorithm with adaptive clipping control to STBC MIMOOFDM systems.