Title :
Turbo codes on the fixed point DSP TMS320C55x
Author :
Ngo, Tri ; Verbauwhede, Ingrid
Author_Institution :
Philips Semicond., Irvine, CA, USA
Abstract :
Turbo codes are introduced in 3rd generation wireless cellular standards for their superior coding gain. The MIPS requirements of turbo codes are however extremely high. This paper describes the implementation of a turbo-decoding algorithm on the TMS320C55x processor. The coding performance is evaluated with fixed-point arithmetic. A method to optimize the memory is also introduced to address the large data storage problem. The effect of finite word lengths is carefully examined to reduce the state metric normalization time and to achieve at the same time an acceptable bit error rate (BER). The coding gain of 5.8 dB for a BER of 10-3 in 6 iterations is achieved with a frame size of 1 K bits and 50 Hz frame rate. Total MIPS estimate when using the max Log-MAP algorithm is 46 MIPS
Keywords :
cellular radio; decoding; digital signal processing chips; fixed point arithmetic; telecommunication standards; turbo codes; 3rd generation wireless cellular standards; 46 MIPS; 50 Hz; BER; MIPS requirements; bit error rate; coding gain; coding performance; finite word lengths; fixed point DSP TMS320C55x processor; fixed-point arithmetic; frame rate; frame size; large data storage problem; max Log-MAP algorithm; memory optimisation; state metric normalization time; turbo codes; turbo-decoding algorithm; Bit error rate; Block codes; Code standards; Digital signal processing; Fixed-point arithmetic; Iterative decoding; Multiaccess communication; Optimization methods; Throughput; Turbo codes;
Conference_Titel :
Signal Processing Systems, 2000. SiPS 2000. 2000 IEEE Workshop on
Conference_Location :
Lafayette, LA
Print_ISBN :
0-7803-6488-0
DOI :
10.1109/SIPS.2000.886724
