Improving the performance of BICM-ID and MLC systems with different FEC codes

[摘要] In bandwidth limited communication systems, the high data rate transmissionwith performance close to capacity limits is achieved by applying multilevelmodulation schemes in association with powerful forward error correction(FEC) coding, i.e. coded modulation systems. The most important practicalapproaches to coded modulation systems are multilevel coding with multistagedecoding (MLC/MSD) and bit interleaved coded modulation with iterativedemapping and decoding (BICM-ID).

Multilevel modulation formats such as M-QAM, which can be used as a part ofcoded modulation systems, have the capability of multilevel protection. Basedon this fact, we investigate the methods to improve the performance ofBICM-ID using multiple interleavers with different binary channel codingschemes such as convolutional codes, turbo codes and low-densityparity-check (LDPC) codes. Moreover, an MLC system with parallel decoding onlevels (PDL) at the receiver is considered. In our contribution, we proposeto design the individual coding schemes using the extrinsic informationtransfer (EXIT) charts for individual bit levels in the constellation. Oursimulation results show that the BICM-ID systems, taking into accountdifferent bit-level protections, can provide an improvement of 0.65 dB,1.2 dB and 1.5 dB for 256-QAM with turbo, LDPC and convolutional codes,respectively. On the other hand, MLC systems with PDL designed using EXITcharts for individual bit levels can slightly improve the performance andeliminate the error floor compared to the systems with MSD.

[学科分类] 电子、光学、磁材料