提出一种用于单载波数字相干光通信系统的自适应色散补偿方法.在发射机端，利用强度光调制器在光信号两侧加入脉冲幅度调制导频光信号.搜索信号谱的峰值确定光信号两侧的PAMPTs线状谱.在色散估计之前，通过其中一个PAMPTs的频率漂移来估计激光器发射频偏，并将信号谱线沿着频率轴反向平移，补偿发射频偏，实现信号谱频域均衡.在接收机端，利用幅度脉冲调制导频信号脉冲时延估计色散大小，在色散补偿之前通过幅度脉冲调制导频信号频移补偿，并消除接收机本振频偏对频域色散补偿的影响.最终，幅度脉冲调制导频的光场信息被充分用来精确进行色散估计和色散补偿.数值仿真表明：每次色散估计的误差小于±65 ps/nm，而且距离从200 km到1 000 km之间的平均色散估计误差小于±10 ps/nm.该方法色散补偿精度高，计算量小.

A novel adaptive chromatic dispersion (CD) compensation method was proposed for digital coherent single carrier systems. Two pulse amplitude modulated pilot tones (PAMPTs) were inserted at both sidebands of the signal in the transmitter. The two line spectra of the PAMPTs can be found by searching the spectrum peaks in the upper and lower sideband. Before CD estimation (CDE), the laser frequency offset (LFO) can be directly estimated from the frequency drift of one of the PAMPTs. Then the signal spectrum was shifted on the reverse of the frequency axis to adjust the received spectrum of OFDE and compensate LFO. After that, the relative time delay between the two line spectra of the PAMPTs was recovered at the receiver and used for CD estimation, while the frequency of the PAMPT recovered was used for spectrum preadjustment of frequency domain CD equalization, Therefor by using this method, the field information of the PAMPTs was fully utilized for accurate CDE and CDC. Numerical simulations show that the CDE error is less than ±65 ps/nm for single time CDE and the averaged error is below ±10 ps/nm for all the distances from 200 to 1 000 km. The method enables much faster and more accurate CD adaptive compensation and reduces computational complexity.