Frequency division multi-service researches for next generation broadcasting system

With advances in technology，wireless communication shows two trends of high data rates and mobile support.The newly developed advanced terrestrial digital multimedia broadcasting（DTMB-A) system faces the poor performance in the mobile environment because of its high order modulation.This article proposes a frequency division multi-service method with the variable sub-carrier spacing and the time-frequency-domain structure to improve the performance.According to the ability of anti-inter carrier interference（ICI) and the channel characteristics，the most appropriate fast Fourier transform（FFT) size is chosen.Virtual subcarriers and time-domain windowing are further used to reduce the interference from the mobile service to the fixed one.Simulation results show that the interference in fixed service is less than -30dB through the virtual sub-carrier and the pulse shaping methods in mobile part.So the DTMB-A system will well meet the mobile support trend as well as high data rate transmission.