A convolutional interleaver included in a time interleaver, which performs convolutional interleaving includes: a first switch that switches a connection destination of an input of the convolutional interleaver to one end of one of a plurality of branches; a FIFO memories provided in some of the plurality of branches except one branch, wherein a number of FIFO memories is different among the plurality of branches; and a second switch that switches a connection destination of an output of the convolutional interleaver to another end of one of the plurality of branches. The first and second switches switch the connection destination when the plurality of cells as many as the codewords per frame have passed, by switching a corresponding branch of the connection destination sequentially and repeatedly among the plurality of branches.