针对传统调制方式难以满足人们对高速通信的要求,结合Hartley变换与离散多音调制(DMT)提出一种用于可见光通信的多载波调制方式。为了实现DMT,采用Harltey变换来代替傅里叶变换,然后对调制信号进行非对称式限幅来降低LED的发射功率。仿真结果表明,相比于直流偏置调制模式,非对称限幅调制模式更为节能。
Traditional modulations can not meet the requirements of high-speed communication,thus in this paper,a multi-carrier modulation schema was proposed,which combines Hartley transform with the discrete multi-tone modulation(DMT)for visible light communication.The system with DMT adopts Hartley transform instead of Fourier transform and then the asymmetrically clipping technique is applied to reduce the transmitting power of LED.Simulation results show that, compared to the DC-bias modulation mode,the asymmetrically clipping modulation mode is more power efficient.