Patent ID: 8687675

Claim:
A method for transmitting data by a transmitter in a communication system, the method comprising the steps of: grouping transmission signals in units of transmission signals according to a transmission coding matrix having a t/k size; multiplying each of the units of the transmission signals by the transmission coding matrix; Inverse Discrete Fourier Transform (IDFT) processing the units of the multiplied transmission signals at one time according to a size of IDFT; and transmitting to a receiver the IDFT processed units of the multiplied transmission signals; where t is a number of transmission signals included in each unit of the transmission signals, and k is a number of multiplied transmission signals included in each unit of the multiplied transmission signals; wherein, when a channel formed between the transmitter and the receiver is a time-varying Rayleigh channel, the transmission coding matrix is a matrix to maximize a channel capacity lower bound, wherein the channel capacity lower bound is determined based on interference information of the channel, noise information and a maximum transmission power of the transmitter, and wherein the interference information and the noise information are used to calculate a covariance of interference and noise to be received by the receiver.