非均匀采样系统的修正与补偿

Correction and Compensation Method for Sampling Waveforms with Time Interleaved ADC Systems

提出一种针对非均匀采样失真的修正补偿方法。用正弦波激励与波形拟合,获得各子A/D的增益、直流偏移和相对于参考子A/D的延迟时间差。将各子A/D的采样序列叠加直流偏移修正因子使各直流偏移一致,补偿偏移采样失真,将各子A/D的样本序列乘以增益修正因子使各增益一致,补偿增益采样失真,通过等间隔采样插值运算,补偿采样延迟失真,获得均匀采样结果。在一组16个子A/D的仿真数据上的补偿实验验证了方法的正确性。在具有8个子A/D的一个数据采集系统的实测数据上的补偿实验,验证了方法的可行性。

In nonuniformity sampling data acquisition systems with multi-ADC of time inter- leaved, due to the differences of gains, offsets, and the sampling delays among different sub- ADCs, the sampling distortions can be created. For this distortion, a compensation and correc- tion method is presented by using sinusoidal stimulation and curve-fitting, all the gains, off- sets. And the sampling delays of each sub-ADC are obtained. By moving different offsets of sub-ADC series into identical to correct the offset distortion, by multiplying different gain fac- tors, modifying different gains of sub-ADC into identical to compensate the sampling distortion of gains, then by using insert value algorithm on uniformity sampling periods, the different sampling delays of sub-ADCs are compensated and the uniformity sampling series are obtained. In simulation test with 16 sub-ADCs, the correctness of the method is validated in the experi- ment on a data acquisition system with 8 sub-ADCs. Finally, the effective results are obtained and the feasibility of the method is proved.