The binary parallel concatenated codes called turbo codes provide relatively large coding gains with reasonable computation complexity. The application of turbo codes to a coherent DS-CDMA mobile radio link with antenna diversity and coherent RAKE combining is considered. A soft-in/soft-out Viterbi decoder that requires less computation complexity is employed instead of maximum a posteriori probability (MAP) decoder. The effect of turbo codes on the achievable bit error rate (BER) performance in frequency selective multipath fading channels is evaluated by computer simulation. It is demonstrated that turbo codes can achieve better BER performance than convolutional codes having the same code rate for the relatively large interleaver size. How the coding gains are impacted by the interleaver size and constraint length of the turbo codes and by the propagation channel condition (power delay profile, the number of resolvable propagation paths, and the maximum Doppler frequency) is discussed.
|ジャーナル||IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences|
|出版ステータス||Published - 1998|
ASJC Scopus subject areas
- Signal Processing
- Computer Graphics and Computer-Aided Design
- Electrical and Electronic Engineering
- Applied Mathematics