The affine Fourier transform (AFT), a general formulation of chirp transforms, has been recently proposed for use in multicarrier\r\ncommunications. The AFT-basedmulticarrier (AFT-MC) system can be considered as a generalization of the orthogonal frequency\r\ndivision multiplexing (OFDM), frequently used in modern wireless communications. AFT-MC keeps all important properties\r\nof OFDM and, in addition, gives a new degree of freedom in suppressing interference caused by Doppler spreading in timevaryingmultipath\r\nchannels.We present a general interference analysis of the AFT-MC system that models both time and frequency\r\ndispersion effects. Upper and lower bounds on interference power are given, followed by interference power approximation that\r\nsignificantly simplifies interference analysis. The optimal parameters are obtained in the closed form followed by the analysis of\r\nthe effects of synchronization errors and the optimal symbol period. A detailed interference analysis and optimal parameters are\r\ngiven for different aeronautical and land-mobile satellite (LMS) channel scenarios. It is shown that the AFT-MC system is able to\r\nmatch changes in these channels and efficiently reduce interference with high-spectral efficiency.
Loading....