Adaptive resource allocation in OFDMA with insufficient guard interval under fractional load

Orthogonal frequency division multiple access (OFDMA), which is known as one of the most promising physical techniques for advanced wireless communications system, generally has a guard interval (GI) to mitigate the inter-symbol interference (ISI) and inter-carrier interference (ICI) caused by delay paths. However, the intra-cell interference (ISI and ICI) may be severe, when GI becomes insufficient in an execrable radio environment. Under fractional load (FL), resource allocator doesn´t have to occupy entire system bandwidth due to the lack of traffic in the network, that is, the flexibility of allocator is increased for resource management. Instead of the complicated interference reduction algorithms at the receiver, in this paper we proposed a novel adaptive resource allocation (ARA) scheme, which utilizes the flexibility of radio resource management under FL, to efficiently avoid intra-cell interference in insufficient GI scenario. System-level simulations show that, the proposed ARA improves system performance than the conventional resource allocation (CRA) under FL, whereas the performance of proposed ARA approaches the CRA under the full load.