State Key Laboratory of ASIC & System, Fudan university
Xiaofang Zhou
State Key Laboratory of ASIC & System, Fudan university
Gerald E. Sobelman
Dept. of Electrical and Computer Engineering, University of Minnesota
Xinxin Li
State Key Laboratory of ASIC & System, Fudan university State Key Lab of Transducer Technology, Shanghai Institue of microsystem and Information Technology, Chinsese Academy of Science
A novel compression technique for modulo-normalized state metrics in turbo decoder is presented. This technique performs the compression dynamically according to the range of state metrics. The framework of the compression circuit is given. BER performances for several turbo decoders are simulated. Implementation results show that the proposed technique needs only 25.2% logic gates and 77.5% memory bits of the existing method with same BER performance loss and much shorter critical path for eight state turbo codes. For four state turbo codes, 30.1% logic gates and 75% memory bits are required.
