A new multicarrier transceiver based on the discrete cosine transform

We derive conditions on the impulse response and input signal of a frequency-selective FIR channel to be diagonalized by the DCT into parallel, decoupled, and memoryless subchannels. We show how these conditions can be satisfied in a practical multi-carrier transceiver through a novel design of the guard sequence and the front-end prefilter. This DCT-based design completely eliminates inter-block and inter-carrier interference at a lower complexity and without incurring any additional guard sequence overhead compared to DFT-based multicarrier transceivers. Extensions to multi-input multi-output frequency-selective channels are also described.