For Full-Text PDF, please login, if you are a member of IEICE,|
or go to Pay Per View on menu list, if you are a nonmember of IEICE.
Iterative Multiuser Detection with Soft Decision-Directed Channel Estimation for MC-IDMA and Performance Comparison with Chip-Interleaved MC-CDMA
IEICE TRANSACTIONS on Communications
Publication Date: 2009/05/01
Online ISSN: 1745-1345
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Section on Radio Access Techniques for 3G Evolution)
mobile communication, MIMO-OFDM, IDMA, MC-IDMA, channel estimation, MC-CDMA,
Full Text: PDF>>
This paper applies iterative multiuser detection employing a new channel estimation scheme to multicarrier interleave-division multiple access (MC-IDMA), called OFDM-IDMA, which is expected to offer improved spectral efficiency in mobile communications. The MC-IDMA transmitter uses both a low-rate channel code and an individual chip interleaver for each user. The MC-IDMA receiver, which this paper focuses upon, repeats the iterative multiuser detection and soft decision-directed channel estimation (SDCE) by exploiting log-likelihood ratios (LLRs) of the coded bits which the maximum a posteriori (MAP)-based channel decoders for all users provide. SDCE estimates channel impulse responses of all users by the least-mean-square (LMS) algorithm, which aims to minimize the mean squared error between the received signal and its replica. This paper investigates the performance of MC-IDMA employing SDCE and compares it with those of three MC-CDMA techniques. Computer simulations demonstrate that MC-IDMA employing SDCE outperforms time-spread MC-CDMA and frequency-spread MC-CDMA, and that it can achieve almost the same bit error rate performance as chip-interleaved MC-CDMA while requiring lower complexity.