Apparatus for time interleaving and method using the same

An apparatus for time interleaving, comprising a processor and a memory storing at least one instruction to be executed by the processor, wherein the at least one instruction is configured to:

• perform twisted block interleaving corresponding to intra-subframe interleaving;
• and
• perform inter-subframe interleaving using an output of the twisted block interleaving,
• wherein the inter-subframe interleaving is performed by using a convolutional delay line, and the convolutional delay line reads only data cells except for virtual cells corresponding to the twisted block interleaving,
• wherein after each row of the data cells is written from the output of the twisted block interleaving, the convolutional delay line generates new virtual cells prior to switches moving to a next branch, and
• wherein the number of the new virtual cells corresponds to a number obtained by subtracting a number (NFEC_TI) of FEC blocks in a time interleaving block of an interleaving frame from a maximum number (NFEC_TI_MAX) of the FEC blocks corresponding to the time interleaving block of the interleaving frame for each branch.