Multi-rate LDPC decoder implementation for CMMB

In this paper, a multi-rate Low Density Parity Check (LDPC) decoder for China Mobile Multimedia Broadcasting (CMMB) is proposed. The architecture of proposed decoder only utilizes a parallel with 2 for ½ rate and 1 for ¾ rate can meet the throughput requirements for the CMMB standard. Various techniques are employed to significantly reduce memory and logic resources, including a special quantization scheme, solution for memory collision, the reuse properties of layered decoding, compressing of check-to-variable messages and the layered algorithm, which lead to a reduction of memory and logic resources by a half.