A novel half-overlap FMT system using CIC filter in cognitive radio

Cognitive radio (CR) is a dynamic spectrum access technology as a solution to spectrum under-utilization problem in some licensed bands. Operating over an exceedingly wide spectrum, CR systems usually adopt multi-carrier modulation to implement flexible channelization. Due to small sideband power leakage, filter bank multi-carrier (FBMC) techniques are considered as interesting alternatives to traditional OFDM for spectrum pooling CR. Non-overlap and half-overlap Filtered Multi-Tone (FMT) is two kinds of FBMC system. Half-overlap FMT has higher spectrum utilization than non-overlap FMT but introduces inter-carrier interference (ICI) due to loss of orthogonality which may degrade system performance. In this paper, an improved Half-overlap FMT (CICFB-FMT) system with orthogonal sub-carriers will be proposed and a comparison on anti-ICI performance when frequency offset occurs in OFDM, CICFB-FMT and Half-overlapped FMT will be conducted. Both the simulation and measure results show that the proposed modulation technique has the best anti-ICI performance and is a good candidate for physical layer of CR.