Incremental Redundancy for LDPC Codes of 2nd Generation DVB Systems

In 2
^nd
generation Digital Video Broadcasting (DVB) systems, low-density parity-check codes (LDPCCs) are applied. In this paper, we propose extension of the standardized LDPCCs to allow for additional incremental redundancy (IR). Several use-cases of IR in broadcasting systems are outlined. We derive an algorithm to extend a given LDPCC with optimized degree sequences. The extended LDPCC yields both original codeword and additional IR. We suggest to transmit IR part at later instances as the standard LDPC codewords. If the receiver fails to decode the standard LDPCC, it can use in addition the IR part. However, in all other cases, the receiver can fall into sleep mode during transmission of IR, allowing for power saving. Examples are given to indicate both coding gain and power saving capabilities of IR.