文档介绍：74 IEEE TRANSACTIONS MUNICATIONS, VOL. 50, NO. 1, JANUARY 2002
LDPC-Based Space–Time Coded OFDM Systems
Over Correlated Fading Channels: Performance
Analysis and Receiver Design
Ben Lu, Student Member, IEEE, Xiaodong Wang, Member, IEEE, and Krishna R. Narayanan, Member, IEEE
Abstract—We consider a space–time coded (STC) orthogonal systems integrate the techniques of antenna array spatial diver-
frequency-division multiplexing (OFDM) system with multiple sity and channel coding and can provide significant capacity
transmitter and receiver antennas over correlated frequency- gains in wireless channels. However, many wireless channels
and time-selective fading channels. It is shown that the product
of the time-selectivity order and the frequency-selectivity order are frequency-selective in nature, for which the STC design
is a key parameter to characterize the outage capacity of the problem es plicated issue. On the other hand, the
correlated fading channel. It is also observed that STCs with large orthogonal frequency-division multiplexing (OFDM) technique
effective lengths and ideal built-in interleavers are more effective transforms a frequency-selective fading channel into parallel
in exploiting the natural diversity in multiple-antenna correlated
fading channels. We then propose a low-density parity-check correlated flat-fading channels. Hence, in the presence of fre-
(LDPC)-code-based STC-OFDM system. Compared with the quency selectivity, it is natural to consider STC in the OFDM
conventional space–time trellis code (STTC), the LDPC-based context. The first STC-OFDM system was proposed in [4]. In
STC can significantly improve the system performance by ex- this paper, we provide system performance analysis and receiver
ploiting both the spatial diversity and the selective-fading diversity
in wireless channels. Compared with the recently proposed design for a new STC-OFDM system over correlated frequency-
turbo-code-based STC scheme, LDPC-b