Abstract: There is disclosed a base station apparatus having a cloud radio access network (CRAN) structure. The base station apparatus includes a digital unit (DU) that includes a baseband processing unit for processing signals of a baseband, a Fast Fourier Transform (FFT) operation unit that converts baseband signals of a time domain into signals of a frequency domain, an Inverse FFT (IFFT) operation unit that converts signals of a frequency domain into signals of a time domain, and a radio unit (RU) that processes radio signals with respect to a terminal, and transmits and receives the processed signals, wherein the FFT operation unit and the IFFT operation unit are provided in the RU to reduce an amount of transmission and reception data between the DU and the RU.

Abstract: A method of compressing In-phase/Quadrature (I/Q) data transmitted and received between a Digital Unit (DU) and a Radio Unit (RU) in a Cloud Radio Access Network (CRAN) structure is disclosed. The method includes (a) calculating a minimum value DiMSB among meaningless higher-order bit digits Di,jMSB with respect to each of j-th I/Q samples having a predetermined resolution among i-th unit blocks that are units of compression, and (b) transmitting each of the samples after each of the samples is converted into a binary number and DiMSB number of higher-order bits, excluding a sign bit, are removed.