A method of performing quadrature mirror filter, QMF, synthesis filtering, the method comprising: determining positions of samples to be discarded from a first memory bank that comprises modulated QMF sub-band samples by performing a first modulo operation based on sample recording positions in a previous time slot; recording, at the determined positions, samples corresponding to a current time slot by replacing the samples recorded at the determined positions in the previous time slot with the samples corresponding to the current time slot; extracting samples from the first memory bank, wherein positions of the samples to be extracted are determined according to whether the current time slot is an even number or an odd number; determining filter coefficients corresponding to the extracted samples by performing a second modulo operation, according to the current time slot; and synthesizing a time domain sample by using the extracted samples and the filter coefficients, wherein positions of the samples extracted from the first memory bank when the current time slot is an even number, and positions of the samples extracted from the first memory bank when the current time slot is an odd number, are mutually exclusive, wherein the determining of the filter coefficients comprises: performing the second modulo operation by using the current time slot and a degree of a synthesis filter; and selecting the filter coefficients from a second memory bank based on a result of the second modulo operation, characterized in that an identical filter coefficient is recorded twice in the second memory bank and positions where the identical filter coefficient is recorded are separated from each other by the degree of the synthesis filter. determining positions of samples to be discarded from a first memory bank that comprises modulated QMF sub-band samples by performing a first modulo operation based on sample recording positions in a previous time slot; recording, at the determined positions, samples corresponding to a current time slot by replacing the samples recorded at the determined positions in the previous time slot with the samples corresponding to the current time slot; extracting samples from the first memory bank, wherein positions of the samples to be extracted are determined according to whether the current time slot is an even number or an odd number; determining filter coefficients corresponding to the extracted samples by performing a second modulo operation, according to the current time slot; and synthesizing a time domain sample by using the extracted samples and the filter coefficients, wherein positions of the samples extracted from the first memory bank when the current time slot is an even number, and positions of the samples extracted from the first memory bank when the current time slot is an odd number, are mutually exclusive, wherein the determining of the filter coefficients comprises: performing the second modulo operation by using the current time slot and a degree of a synthesis filter; and selecting the filter coefficients from a second memory bank based on a result of the second modulo operation, characterized in that an identical filter coefficient is recorded twice in the second memory bank and positions where the identical filter coefficient is recorded are separated from each other by the degree of the synthesis filter. performing the second modulo operation by using the current time slot and a degree of a synthesis filter; and selecting the filter coefficients from a second memory bank based on a result of the second modulo operation, characterized in that an identical filter coefficient is recorded twice in the second memory bank and positions where the identical filter coefficient is recorded are separated from each other by the degree of the synthesis filter. <EOS>