Turbo Code Based Interleave Division Multiple Access

• Main Authors: Yen, Yi-Hsiu, 顏義修
• Other Authors: Su, Yu-Ted
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/79619312632963425040

碩士 === 國立交通大學 === 電信工程研究所 === 104 === Interleave division multiple access (IDMA) is a multiple access scheme that employs user-specific interleavers to differentiate users. It uses a simple chip by chip multiuser detection method which requires a constant per-user computational complexity, independent of number of system users. Compared with the coded division multiple access (CDMA) method, IDMA scheme can provide single-user performance by using simple repetition coding and random interleaving in addition to a common forward error correcting (FEC) code while CDMA requires a family of low cross-correlation spreading codes. In this thesis, we first consider IDMA systems that use either a turbo or convolutional code as the common FEC code. An alternative system structure replaces BPSK modulator by a DPSK modulator and insert an interleaver after the DPSK modulator. The combined repletion (unit) interleaver and DPSK modulator is equivalent to a repetition-accumulation (RA) encoder. Numerical results show that our turbo code based IDMA (TC-IDMA) scheme is able to outperform the conventional (convolutional code based) IDMA system and the DPSK-based system yields much lower error floor.