The present disclosure provides methods for accurate base calling of sequences using molecular barcodes. A method for sequencing nucleic acid molecules may comprise: (a) using barcode molecules to barcode nucleic acid molecules from a sample, to generate barcoded nucleic acid molecules comprising barcode sequences; (b) sequencing the barcoded nucleic acid molecules to generate sequencing signals comprising signals corresponding to the barcode sequences, wherein the sequencing signals are not sequencing reads; (c) using the signals corresponding to the barcode sequences to group the sequencing signals into groups, wherein sequencing signals of a given group comprise signals corresponding to a barcode sequence that is (i) identical for the given group and (ii) different from barcode sequences of other groups; (d) processing the sequencing signals within the given group to generate sets of aggregated signals which are not sequencing reads; and (e) combining the sets of aggregated signals to generate a consensus sequence.