SYMBOL SELF SYNCHRONOUS INTERLEAVING METHOD AND APPARATUS FOR OFDM-BASED COMMUNICATION SYSTEM

摘要

An interleaving method and apparatus is disclosed for an in-band on-chann el (IBOC) digital audio broadcasting (DAB) system. The disclosed interleaver method and apparatus utilize a convolutional interleaver having a row size equal to one OFDM symbol and a time span of arbitrary size. A structured memory block is utilized in the de-interleaver at the receiver having a row size of one OFDM symbol (the number of active sub-carriers in the applicable sub-band of the IBOC system). The self - synchronizing nature of the present invention permits a receiver in an OFDM- based IBOC system to sort the scrambled blocks and descramble the received symbo ls according to its own frame count, without regard to the frame count of the transmitter. The disclosed interleaver method and apparatus does not require interleav er synchronization between the transmitter and receiver. In one implementation, separate convolutional encoders and convolutional interleavers are applied to each su b- band in a multi-stream structure to provide independent error spreading for each sub- band.