The present invention relates to a method and corresponding apparatus of transmitting and receiving broadcast signals. One aspect of the present invention relates to time-interleave the FEC-encoded L1 signaling data by serially writing the FEC-encoded L1 signaling data into a memory in a diagonal direction and serially reading the written L1 signaling data from the memory in a row direction according to L1 TI, Time Interleaving, mode information that indicates a time interleaving depth, wherein a number of rows of the memory is equal to the time interleaving depth, wherein a number of columns of the memory is equal to a quotient resulting from dividing a number of cells corresponding to the L1 signaling data by the time interleaving depth, and wherein the time interleaving depth is equal or larger than a minimum number of OFDM symbols required for carrying an L1 block including the L1 signaling data.