Accuracy Loss in Multi-Rate Processing of Biomedical Signals

The problem of multi-rate biomedical signal filtration is considered in this paper. If a signal can be processed with a reduced sampling frequency, the number of computational operations during signal processing can be significantly reduced and a restoration of the signal samples with the original sampling frequency can be carried out using the interpolation operation. In the paper the mathematical dependences of the upper limits of the decimation coefficients are obtained. These limits make it possible to restore the original sequence of discrete samples of the signal after processing with an error not exceeding the specified level. The process of decimation of the initial sequence of samples of the signal and the subsequent restoration of the missed samples using linear interpolation are simulated. The simulation results confirm the possibility of using the polynomial interpolation operation at the last stage of processing instead of the filtering operation.