An apparatus for processing data symbols in a multi-carrier transmitter, includes a transmit pulse shaper and a transmit sub-band filter. The transmit pulse shaper is adapted to filter a plurality of data pulses with respective transmit pulse shaping filters. Each of the data pulses is associated with a respective carrier of the multi-carrier communication system. The transmit sub-band filter is adapted to perform sub-band filtering of the pulse-shaped data pulses. The sub-band filter and at least one of the transmit pulse shaping filters are correlated. This correlation may be achieved by jointly designing the sub-band filter and the pulse shaping filter(s).