increment the row index register n reg and the column index register i reg the circuitry effectively maintains the same column until each sequential row value has been used and then increments the column to the next column in the interleaver vector starting at the initial row of that column this is accomplished through the use of a unit incrementer 80 associated with the row register n reg to increment the row value by one for each cycle of first stage processing the output of register n reg is also compared in comparator 81 against a maximum row value determined by a multiplexer 83 the maximum row value for the particular column is either the maximum row value row of the entire matrix or row 1 the multiplexer 83 generates an output in response to a comparator 84 which compares the column value currently being output by the register file 78 with the largest column value having the maximum row size row if the comparator 81 determines that the maximum row number has been reached by the output value of register n reg the comparator 81 issues a signal to reset n reg to 0 and to operate a multiplexer mux 86 associated with the index register i reg a unit incrementer 88 is also associated with the index register i reg and the mux 86 permits incrementation of the i reg value by one via the incrementer 88 when a.