The Research And Design Of Multi-channel Data Acquisition System

The analog to digital converter is the foundation in digital signal proceesing, higher-performance ADCs are required with the development of software radio in today’s communication systems. How to improve the sampling rate with necessary accuracy become the key technique. Time-interleaved ADC can be a reasonable solution to prove the performance of the single ADC and become one of the future direction.This dissertation focused on the method of error estimation and calibration base on TI-ADC system. The primary works are as follows:1. Investigate the spectrum of the nonuniformly sampling data, analyse the spectrum distortion caused by mismatches.2. A method base on frequency domain to estimate the mismatchs is proposed, use FFT to pick up the mismatch signals in spectrum can estimate the errors accuracy.3. Combined methods base on time domain to estimate the mismatchs is proposed, Provide a structure of LMS combined with a structure of filters to estimate the errors, it can estimate the errors at the same time, this method is improved to estimate all the erros in one iterative.4. Farrow structure is introduced to calibration the time error, use the symmetry coefficient in Farrow structure can reduce the consumption of resources in FPGA and improve the operation efficiency.5. Design a FPGA structure for TI-ADC, complete the software design for error estimation and calibration6. Verify the feasibility of the relevant method through the system simulations.