Abstract: The invention describes a simple and efficient codeword degrouping algorithm which can be applied in an MPEG audio decoder, in which a codeword is degrouped into three samples. According to the proposed algorithm, the division and modulo computations applied in the original degrouping method can be fully substituted into the addition and subtraction computations by using the mode selection and iterative decompositions, and thus largely reduces the overhead and complexity for the decoder. Also, an efficient architecture for the proposed algorithm includes one special adder, two subtractors, and two adders. The architecture generates the quotient and remainder simultaneously with fix-rate throughput.