49 research outputs found
A Low-Complexity, Full-Rate, Full-Diversity 2 X 2 STBC with Golden Code's Coding Gain
This paper presents a low-ML-decoding-complexity, full-rate, full-diversity
space-time block code (STBC) for a 2 transmit antenna, 2 receive antenna
multiple-input multiple-output (MIMO) system, with coding gain equal to that of
the best and well known Golden code for any QAM constellation. Recently, two
codes have been proposed (by Paredes, Gershman and Alkhansari and by Sezginer
and Sari), which enjoy a lower decoding complexity relative to the Golden code,
but have lesser coding gain. The STBC presented in this paper has
lesser decoding complexity for non-square QAM constellations, compared with
that of the Golden code, while having the same decoding complexity for square
QAM constellations. Compared with the Paredes-Gershman-Alkhansari and
Sezginer-Sari codes, the proposed code has the same decoding complexity for
non-rectangular QAM constellations. Simulation results, which compare the
codeword error rate (CER) performance, are presented.Comment: Submitted to IEEE Globecom - 2008. 6 pages, 3 figures, 1 tabl
Full Diversity Space-Time Block Codes with Low-Complexity Partial Interference Cancellation Group Decoding
Partial interference cancellation (PIC) group decoding proposed by Guo and
Xia is an attractive low-complexity alternative to the optimal processing for
multiple-input multiple-output (MIMO) wireless communications. It can well deal
with the tradeoff among rate, diversity and complexity of space-time block
codes (STBC). In this paper, a systematic design of full-diversity STBC with
low-complexity PIC group decoding is proposed. The proposed code design is
featured as a group-orthogonal STBC by replacing every element of an Alamouti
code matrix with an elementary matrix composed of multiple diagonal layers of
coded symbols. With the PIC group decoding and a particular grouping scheme,
the proposed STBC can achieve full diversity, a rate of and a
low-complexity decoding for transmit antennas. Simulation results show that
the proposed codes can achieve the full diversity with PIC group decoding while
requiring half decoding complexity of the existing codes.Comment: 10 pages, 3 figures
Low ML-Decoding Complexity, Large Coding Gain, Full-Rate, Full-Diversity STBCs for 2 X 2 and 4 X 2 MIMO Systems
This paper (Part of the content of this manuscript has been accepted for
presentation in IEEE Globecom 2008, to be held in New Orleans) deals with low
maximum likelihood (ML) decoding complexity, full-rate and full-diversity
space-time block codes (STBCs), which also offer large coding gain, for the 2
transmit antenna, 2 receive antenna () and the 4 transmit antenna, 2
receive antenna () MIMO systems. Presently, the best known STBC for
the system is the Golden code and that for the system is
the DjABBA code. Following the approach by Biglieri, Hong and Viterbo, a new
STBC is presented in this paper for the system. This code matches
the Golden code in performance and ML-decoding complexity for square QAM
constellations while it has lower ML-decoding complexity with the same
performance for non-rectangular QAM constellations. This code is also shown to
be \emph{information-lossless} and \emph{diversity-multiplexing gain} (DMG)
tradeoff optimal. This design procedure is then extended to the
system and a code, which outperforms the DjABBA code for QAM constellations
with lower ML-decoding complexity, is presented. So far, the Golden code has
been reported to have an ML-decoding complexity of the order of for
square QAM of size . In this paper, a scheme that reduces its ML-decoding
complexity to is presented.Comment: 28 pages, 5 figures, 3 tables, submitted to IEEE Journal of Selected
Topics in Signal Processin
Space-time coding techniques with bit-interleaved coded modulations for MIMO block-fading channels
The space-time bit-interleaved coded modulation (ST-BICM) is an efficient
technique to obtain high diversity and coding gain on a block-fading MIMO
channel. Its maximum-likelihood (ML) performance is computed under ideal
interleaving conditions, which enables a global optimization taking into
account channel coding. Thanks to a diversity upperbound derived from the
Singleton bound, an appropriate choice of the time dimension of the space-time
coding is possible, which maximizes diversity while minimizing complexity.
Based on the analysis, an optimized interleaver and a set of linear precoders,
called dispersive nucleo algebraic (DNA) precoders are proposed. The proposed
precoders have good performance with respect to the state of the art and exist
for any number of transmit antennas and any time dimension. With turbo codes,
they exhibit a frame error rate which does not increase with frame length.Comment: Submitted to IEEE Trans. on Information Theory, Submission: January
2006 - First review: June 200
An Algebraic Coding Scheme for Wireless Relay Networks With Multiple-Antenna Nodes
We consider the problem of coding over a half-duplex wireless relay network where both the transmitter and the receiver have respectively several transmit and receive antennas, whereas each relay is a small device with only a single antenna. Since, in this scenario, requiring the relays to decode results in severe rate hits, we propose a full rate strategy where the relays do a simple operation before forwarding the signal, based on the idea of distributed space-time coding. Our scheme relies on division algebras, an algebraic object which allows the design of fully diverse matrices. The code construction is applicable to systems with any number of transmit/receive antennas and relays, and has better performance than random code constructions, with much less encoding complexity. Finally, the robustness of the proposed distributed space-time codes to node failures is considered
Explicit Space-Time Codes Achieving The Diversity-Multiplexing Gain Tradeoff
A recent result of Zheng and Tse states that over a quasi-static channel,
there exists a fundamental tradeoff, referred to as the diversity-multiplexing
gain (D-MG) tradeoff, between the spatial multiplexing gain and the diversity
gain that can be simultaneously achieved by a space-time (ST) block code. This
tradeoff is precisely known in the case of i.i.d. Rayleigh-fading, for T>=
n_t+n_r-1 where T is the number of time slots over which coding takes place and
n_t,n_r are the number of transmit and receive antennas respectively. For T <
n_t+n_r-1, only upper and lower bounds on the D-MG tradeoff are available.
In this paper, we present a complete solution to the problem of explicitly
constructing D-MG optimal ST codes, i.e., codes that achieve the D-MG tradeoff
for any number of receive antennas. We do this by showing that for the square
minimum-delay case when T=n_t=n, cyclic-division-algebra (CDA) based ST codes
having the non-vanishing determinant property are D-MG optimal. While
constructions of such codes were previously known for restricted values of n,
we provide here a construction for such codes that is valid for all n.
For the rectangular, T > n_t case, we present two general techniques for
building D-MG-optimal rectangular ST codes from their square counterparts. A
byproduct of our results establishes that the D-MG tradeoff for all T>= n_t is
the same as that previously known to hold for T >= n_t + n_r -1.Comment: Revised submission to IEEE Transactions on Information Theor