Sub-carrier to symbol de-interleaver for DVB-T2 using odd interleaving

摘要

DVB-T and DVB-H receivers deinterleave symbols from sub-carriers using a pseudo random sequence generated using an LFSR (linear feedback shift register) 200 whose bits are fed through a permutation matrix 210 to generate the write address for a partitioned de-interleaver memory. The invention provides improved separation between symbols by using an odd interleaving process only (fig 9) for successive sets of data symbols, when the number of data symbols which can be carried per OFDM symbol is less than half the maximum that can be carried. Received data symbols are written using a generated address into the memory and sequentially read out. Applying a cyclic offset to the address that changes from symbol to symbol reduces the likelihood that successive data bits which are close in order are mapped onto the same sub-carrier of an OFDM symbol.