针对强度调制直接检测-滤波器组多载波(IMDD-FBMC)系统中低比特位数数字模拟转换器(DAC)量化性能较差的问题，提出一种基于信号分布估计的非均匀量化方案。该方案采用基于FBMC信号分布的非线性规划方法获得量化误差最小时的量化阶距，进而提升基于低比特位数DAC的IMDD-FBMC系统性能。仿真结果表明:与均匀量化方式相比，该方案在3~5位量化比特位数的情况下可以使IMDD-FBMC系统的误码率(BER)性能提升15.9~60.7倍，且在保证系统性能的情况下，基于信号分布的量化方案可以减少1~2位量化比特位数，降低系统成本。

Aiming at the poor quantization performance of low bit digital analog converter(DAC) in intensity modulation direct detection-filter bank multi-carrier(IMDD-FBMC) system, a non-uniform quantization scheme based on signal distribution estimation is proposed. The scheme uses the non-linear programming method based on FBMC signal distribution to obtain the quantitative step when the quantization error is minimum, and then improves the performance of IMDD-FBMC system based on low bit DAC. The simulation results show that the proposed scheme can improve the BER performance of the IMDD-FBMC system by 15.9~60.7 times under the condition of 3~5 bit quantization number compared with the uniform quantization scheme, and the quantization scheme based on signal distribution can reduce 1~2 bit quantization number and reduce the system cost under the condition of ensuring the system performance.