Efficient Soft Demodulation in MIMO-OFDM Systems with BICM and Constant Modulus Alphabets

Author

Seethaler, Dominik ; Matz, Gerald ; Hlawatsch, Franz

Author_Institution

Inst. of Commun. & Radio-Frequency Eng., Vienna Technol. Univ.

Volume

4

fYear

2006

fDate

14-19 May 2006

Abstract

MIMO-OFDM using bit-interleaved coded modulation (BICM) is an attractive scheme for wireless communications in frequency-selective fading channels. The BICM decoder requires log-likelihood ratios (LLRs) whose exact computation is extremely costly. In this paper, we present a novel method termed soft sphere-projection algorithm (SSPA) that provides approximate LLRs for the case of constant modulus symbol alphabets. The SSPA has very low computational complexity and performs nearly as well as the list sphere decoder. These properties are demonstrated by numerical simulations using synthetic and measured MIMO channels

Keywords

MIMO systems; OFDM modulation; computational complexity; decoding; demodulation; fading channels; modulation coding; wireless channels; BICM decoder; MIMO-OFDM systems; bit-interleaved coded modulation; computational complexity; constant modulus symbol alphabets; frequency-selective fading channels; log-likelihood ratios; measured MIMO channels; multiple input multiple output systems; orthogonal frequency division multiplexing; soft demodulation; soft sphere-projection algorithm; synthetic MIMO channels; wireless communications; Computational complexity; Decoding; Demodulation; Fading; Frequency; Interleaved codes; MIMO; Modulation coding; Receiving antennas; Wireless communication;

fLanguage

English

Publisher

ieee

Conference_Titel

Acoustics, Speech and Signal Processing, 2006. ICASSP 2006 Proceedings. 2006 IEEE International Conference on

Conference_Location

Toulouse

ISSN

1520-6149

Print_ISBN

1-4244-0469-X

Type

conf

DOI

10.1109/ICASSP.2006.1660916

Filename

1660916