Provided is a decoding apparatus and method using orthogonal space-time block codes (OSTBCs) robust against timing errors. The decoding apparatus may include: a cyclic prefix removal unit to receive a signal, and to remove a cyclic prefix in the signal; an inverse discrete Fourier transform (IDFT) unit to apply an IDFT to the signal with the removed cyclic prefix; a guard band removal unit to remove a guard band in the inverse discrete Fourier transformed signal, and to generate a complex matrix; a channel estimation unit to transmit a carrier corresponding to the complex matrix and channel status information associated with transmit and receive antennas; and a decoder to calculate a channel status vector with respect to a complex symbol included in the complex matrix, using the channel status information, and to calculate an inner product between the channel status vector and the complex matrix, to restore the complex symbol.