广义加权分数傅里叶变换两分量组合抗衰落技术

To improve the anti-fading ability of the classical single carrier system (SC) and multi-carrier system (MC) without changing the carrier scheme, a double-component combination anti-fading scheme based on generalized weighted fractional Fourier transform (GWFRFT) is proposed in this paper, taking the advantage of the high flexibility of the generalized hybrid carrier (GHC) system. As for the SC system, the proposed double-component scheme contains time domain component and time domain reverse component, which enhances the ability to resist time-selective fading; while as for the MC system, the scheme contains frequency domain component and frequency domain reverse component, which possesses higher anti-frequency-selective fading ability. To fully dig out the potential of double-component combined signal form, mechanism of the characteristic advantage is analyzed. Results show that the power allocation between two components and the fading independence of the same symbol in the two components are the key factors affecting the performance of the double-component combination signal. In view of this, equal power allocation scheme and half-block inversion scheme are proposed to further optimize the performance of the double-component combination signal. In that case, generation method of double-component combined signal is proposed and the implementation complexity as well as spectral characteristics are also analyzed. Simulation results illustrate the improvement on anti-fading ability of proposed scheme without occupying extra time and frequency resources, compared with that of classic single-carrier and multi-carrier system. In addition, equal power allocation scheme and half-block inversion scheme enable a further improvement on the anti-fading ability.