文档介绍：348 IEEE TRANSACTIONS ON SIGNAL PROCESSING, VOL. 52, NO. 2, FEBRUARY 2004
Performance Analysis and Design Optimization of
LDPC-Coded MIMO OFDM Systems
Ben Lu, Member, IEEE, Guosen Yue, Student Member, IEEE, and Xiaodong Wang, Member, IEEE
Abstract—We consider the performance analysis and de- check (LDPC) coded wireless multiple-input multiple-output
sign optimization of low-density parity check (LDPC) coded (MIMO) orthogonal frequency-division multiplexing (OFDM)
multiple-input multiple-output (MIMO) orthogonal frequency-di- communications. In the considered systems, different users
vision multiplexing (OFDM) systems for high data rate wireless
transmission. The tools of density evolution with mixture Gaussian access the downlink channels in a time-division multiple
approximations are used to optimize irregular LDPC codes and to accessing (TDMA) manner, dynamic with a certain scheduling
compute minimum operational signal-to-noise ratios (SNRs) for scheme [1]. Compared with other alternative solutions, the
ergodic MIMO OFDM channels. In particular, the optimization MIMO-OFDM-TDMA downlink transmission proposed here
is done for various MIMO OFDM system configurations, which attempts to balance between high rate transmission and low
include a different number of antennas, different channel models,
and different demodulation schemes; the optimized performance plexity of mobile devices, where the former pri-
pared with the corresponding channel capacity. It is shown marily counts on the LDPC-coded MIMO techniques, and the
that along with the optimized irregular LDPC codes, a turbo iter- latter is owing to the orthogonal structure of OFDM-TDMA.
ative receiver that consists of a soft maximum a posteriori (MAP) A large number of works on the physical-layer study of
demodulator and a belief-propagation LDPC decoder can per- MIMO techniques has been done in the past decade. Various
form within 1 dB from the ergodic capacity of the MIMO OFDM
systems und