An Optimal Decimation Filter for a Very Large band Signal in Radioastronomy. Application to the ALMA Digital Filtering System: the Tunable Filter Bank (TFB)
Pascal Camino
This study was initiated in the frame of the digital filter of the large Correlator System of the ALMA (Atacama Large Millimetre Array) interferometer project. The main goal of this work was to reduce the power consumption of the mathematical processing implemented in large FPGAs by optimizing the amount of logic elements. Different architectures have been discussed and compared in terms of performances (complexity, power consumption). We have demonstrated that a multistage architecture based on a modified structure of the CIC (Cascaded Integrator Comb) filter for a time demultiplexed input format significantly improves the power dissipation. In addition to this, the potential use of IIR filters in radio astronomy project has been considered.