5 research outputs found
Bit-Interleaved Coded Multiple Beamforming with Perfect Coding
When the Channel State Information (CSI) is known by both the transmitter and
the receiver, beamforming techniques employing Singular Value Decomposition
(SVD) are commonly used in Multiple-Input Multiple-Output (MIMO) systems.
Without channel coding, there is a trade-off between full diversity and full
multiplexing. When channel coding is added, both of them can be achieved as
long as the code rate Rc and the number of employed subchannels S satisfy the
condition RcS<=1. By adding a properly designed constellation precoder, both
full diversity and full multiplexing can be achieved for both uncoded and coded
systems with the trade-off of a higher decoding complexity, e.g., Fully
Precoded Multiple Beamforming (FPMB) and Bit-Interleaved Coded Multiple
Beamforming with Full Precoding (BICMB-FP) without the condition RcS<=1.
Recently discovered Perfect Space-Time Block Code (PSTBC) is a full-rate
full-diversity space-time code, which achieves efficient shaping and high
coding gain for MIMO systems. In this paper, a new technique, Bit-Interleaved
Coded Multiple Beamforming with Perfect Coding (BICMB-PC), is introduced.
BICMB-PC transmits PSTBCs through convolutional coded SVD systems. Similar to
BICMB-FP, BICMB-PC achieves both full diversity and full multiplexing, and its
performance is almost the same as BICMB-FP. The advantage of BICMB-PC is that
it can provide a much lower decoding complexity than BICMB-FP, since the real
and imaginary parts of the received signal can be separated for BICMB-PC of
dimensions 2 and 4, and only the part corresponding to the coded bit is
required to acquire one bit metric for the Viterbi decoder.Comment: accepted to conference; Proc. IEEE ICC 201
Multiple Beamforming with Perfect Coding
Perfect Space-Time Block Codes (PSTBCs) achieve full diversity, full rate,
nonvanishing constant minimum determinant, uniform average transmitted energy
per antenna, and good shaping. However, the high decoding complexity is a
critical issue for practice. When the Channel State Information (CSI) is
available at both the transmitter and the receiver, Singular Value
Decomposition (SVD) is commonly applied for a Multiple-Input Multiple-Output
(MIMO) system to enhance the throughput or the performance. In this paper, two
novel techniques, Perfect Coded Multiple Beamforming (PCMB) and Bit-Interleaved
Coded Multiple Beamforming with Perfect Coding (BICMB-PC), are proposed,
employing both PSTBCs and SVD with and without channel coding, respectively.
With CSI at the transmitter (CSIT), the decoding complexity of PCMB is
substantially reduced compared to a MIMO system employing PSTBC, providing a
new prospect of CSIT. Especially, because of the special property of the
generation matrices, PCMB provides much lower decoding complexity than the
state-of-the-art SVD-based uncoded technique in dimensions 2 and 4. Similarly,
the decoding complexity of BICMB-PC is much lower than the state-of-the-art
SVD-based coded technique in these two dimensions, and the complexity gain is
greater than the uncoded case. Moreover, these aforementioned complexity
reductions are achieved with only negligible or modest loss in performance.Comment: accepted to journa
Diversity Analysis of Bit-Interleaved Coded Multiple Beamforming with Orthogonal Frequency Division Multiplexing
For broadband wireless communication systems, Orthogonal Frequency Division
Multiplexing (OFDM) has been combined with Multi-Input Multi-Output (MIMO)
techniques. Bit-Interleaved Coded Multiple Beamforming (BICMB) can achieve both
spatial diversity and spatial multiplexing for flat fading MIMO channels. For
frequency selective fading MIMO channels, BICMB with OFDM (BICMB-OFDM) can be
applied to achieve both spatial diversity and multipath diversity, making it an
important technique. However, analyzing the diversity of BICMB-OFDM is a
challenging problem. In this paper, the diversity analysis of BICMB-OFDM is
carried out. First, the maximum achievable diversity is derived and a full
diversity condition RcSL <= 1 is proved, where Rc, S, and L are the code rate,
the number of parallel steams transmitted at each subcarrier, and the number of
channel taps, respectively. Then, the performance degradation due to the
correlation among subcarriers is investigated. Finally, the subcarrier grouping
technique is employed to combat the performance degradation and provide
multi-user compatibility.Comment: accepted to journa