Abstract
In the near future, the 5th generation (5G) of wireless systems will be well established. They will consist of an integration of different techniques, including distributed antenna systems and massive multiple-input multiple-output (MIMO) systems, and the overall performance will highly depend on the channel coding techniques employed. Due to the nature of future wireless networks, space–time codes are no longer merely an object of choice, but will often appear naturally in the communications setting. However, as the involved communication devices often exhibit a modest computational power, the complexity of the codes to be utilised should be reasonably low for possible practical implementation. Fast-decodable codes enjoy reduced complexity of maximum-likelihood (ML) decoding due to a smart inner structure allowing for parallelisation in the ML search. The complexity reductions considered in this chapter are entirely owing to the algebraic structure of the considered codes, and could be further improved by employing non-ML decoding methods, however yielding suboptimal performance. The aim of this chapter is twofold. First, we provide a tutorial introduction to space–time coding and study powerful algebraic tools for their design and construction. Secondly, we revisit algebraic techniques used for reducing the worst-case decoding complexity of both single-user and multiuser space-time codes, alongside with general code families and illustrative examples.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Notes
- 1.
By discrete, we mean that the metric on \(\mathbb {R}^n\) defines the discrete topology on Λ, i.e., any bounded region of \(\mathbb {R}^n\) contains only finitely many points of the subgroup.
- 2.
The practical reason behind this choice is that the popular modulation alphabets, referred to as pulse amplitude modulation (PAM) and quadrature amplitude modulation (QAM), correspond to the rings of integers of these fields.
- 3.
The smallest Frobenius norms correspond to the shortest Euclidean norms of the vectorised matrices. Directly, this would mean spherical constellation shaping. However, it is often more practical to consider a slightly more relaxed cubic shaping. This is the case in particular when the lattice in question is orthogonal, as then the so-called Gray-mapping [13] will give an optimal bit labelling of the lattice points.
- 4.
In the literature, the code rate is often defined in complex symbols per channel use. We prefer using real symbols, as not every code admits a Gaussian basis, while every lattice has a \(\mathbb {Z}\)-basis.
- 5.
This is a usual trick to balance the average energies of the codeword entries more evenly. See [3, Ex. 1] for more details.
- 6.
As remarked in Sect. 3.4.1, the property of fast decodability is independent of the channel. Hence, we omit details on the structure of the effective channel.
References
Alamouti, S.: A simple transmitter diversity scheme for wireless communications. IEEE J. Sel. Areas Commun. 16(8), 1451–1458 (1998)
Amani, E., Djouani, K., Kurien, A.: Low complexity decoding of the 4 × 4 perfect space–time block code. In: International Conference on Ambient Spaces, Networks and Technologies (2014)
Barreal, A., Hollanti, C., Markin, N.: Fast-decodable space–time codes for the n-relay and multiple-access MIMO channel. IEEE Trans. Wirel. Commun. 15(3), 1754–1767 (2016)
Belfiore, J.-C., Rekaya, G.: Quaternionic lattices for space–time coding. In: Proceedings of the IEEE Information Theory Workshop (2003)
Belfiore, J-C., Rekaya, G., Viterbo, E.: The Golden code: a 2 × 2 full-rate space–time code with non-vanishing determinants. IEEE Trans. Inf. Theory 51(4), 1432–1436 (2005)
Berhuy, G., Oggier, F.: An introduction to central simple algebras and their applications to wireless communication. In: Mathematical Surveys and Monographs. American Mathematical Society, New York (2013)
Berhuy, G., Markin, N., Sethuraman, B.A.: Fast lattice decodability of space–time block codes. In: Proceedings of the IEEE International Symposium on Information Theory (2014)
Berhuy, G., Markin, N., Sethuraman, B.A.: Bounds on fast decodability of space–time block codes, skew-Hermitian matrices, and Azumaya algebras. IEEE Trans. Inf. Theory 61(4), 1959–1970 (2015)
Biglieri, E., Hong, Y., Viterbo, E.: On fast-decodable space–time block codes. IEEE Trans. Inf. Theory 55(2), 524–530 (2009)
Conway, J.H., Sloane, N.J.A.: Sphere Packings, Lattices and Groups, 3rd edn.. Springer, Berlin (1999)
Ebeling, W.: Lattices and Codes, 3rd edn. Spektrum, Heidelberg (2013)
Elia, P., Sethuraman, B.A., Kumar, P.V.: Perfect space–time codes for any number of antennas. IEEE Trans. Inf. Theory 53(11), 3853–3868 (2007)
Gray, F.: Pulse Code Communication (1953). US Patent 2,632,058
Hollanti, C., Lahtonen, J.: A new tool: Constructing STBCs from maximal orders in central simple algebras. In: Proceedings of the IEEE Information Theory Workshop (2006)
Hollanti, C., Lahtonen, J., Lu, H.f.: Maximal orders in the design of dense space–time lattice codes. IEEE Trans. Inf. Theory 54(10), 4493–4510 (2008)
Hollanti, C., Lahtonen, J., Ranto, K., Vehkalahti, R.: On the algebraic structure of the silver code: a 2 × 2 perfect space–time block code. In: Proceedings of the IEEE Information Theory Workshop (2008)
Howard, S.D., Sirianunpiboon, S., Calderbank, A.R.: Low complexity essentially maximum likelihood decoding of perfect space-time block codes. In: IEEE International Conference on Acoustics, Speech, and Signal Processing (2009)
Jäämeri, E.: Tila-aikakoodien nopea pallodekoodaus (2016). Bachelor’s thesis
Jithamithra, G.R., Rajan, B.S.: A quadratic form approach to ML decoding complexity of STBCs. arXiv:1004.2844v2 (2010)
Jithamithra, G.R., Rajan, B.S.: Minimizing the complexity of fast sphere decoding of STBCs. IEEE Trans. Wirel. Commun. 12(12), 6142–6153 (2013)
Jithamithra, G.R., Rajan, B.S.: Construction of block orthogonal STBCs and reducing their sphere decoding complexity. IEEE Trans. Wirel. Commun. 13(5), 2906–2919 (2014)
Lu, H.f., Vehkalahti, R., Hollanti, C., Lahtonen, J., Hong, Y., Viterbo, E.: New space–time code constructions for two-user multiple access channels. IEEE J. Sel. Top. Sign. Proces. 3(6), 939–957 (2009)
Lu, H.f., Hollanti, C., Vehkalahti, R., Lahtonen, J.: DMT optimal codes constructions for multiple-access MIMO channel. IEEE Trans. Inf. Theory 57(6), 3594–3617 (2011)
Luzzi, L., Vehkalahti, R.: Almost universal codes achieving ergodic MIMO capacity within a constant gap. IEEE Trans. Inf. Theory 63(5) (2017)
Markin, N., Oggier, F.: Iterated space–time code constructions from cyclic algebras. IEEE Trans. Inf. Theory 59(9), 5966–5979 (2013)
Mejri, A., Khsiba, M.-A., Rekaya, G.: Reduced-complexity ML decodable STBCs: Revisited design criteria. In: Proceedings of the International Symposium on Wireless Communication Systems (2015)
Milne, J.: Class Field Theory (2013). Graduate course notes, v4.02
Milne, J.: Algebraic Number Theory (2014). Graduate course notes, v2.0
Neukirch, J.: Algebraic Number Theory. Springer, Berlin (2010)
Oggier, F., Rekaya, G., Belfiore, J.-C., Viterbo, E.: Perfect space–time block codes. IEEE Trans. Inf. Theory 52(9), 3885–3902 (2006)
Oggier, F., Viterbo, E., Belfiore, J.-C.: Cyclic Division Algebras: A Tool for Space-Time Coding, vol. 4(1). Foundations and Trends in Communications and Information Theory (2007)
Paredes, J.M., Gershman, A.B., Gharavi-Alkhansari, M.: A new full-rate full-diversity space–time block code with nonvanishing determinants and simplified maximum-likelihood decoding. IEEE Trans. Signal Process. 56(6) (2008)
Ren, T.P., Guan, Y.L., Yuen, C., Shen, R.J.: Fast-group-decodable space–time block code. In: Proceedings of the IEEE Information Theory Workshop (2010)
Sethuraman, B.A., Rajan, B.S., Shashidhar, V.: Full-diversity, high-rate space–time block codes from division algebras. IEEE Trans. Inf. Theory 49(10), 2596–2616 (2003)
Sirinaunpiboon, S., Calderbank, A.R., Howard, S.D.: Fast essentially maximum likelihood decoding of the Golden code. IEEE Trans. Inf. Theory 57(6), 3537–3541 (2011)
Srinath, K.P., Rajan, B.S.: Low ML-decoding complexity, large coding gain, full-rate, full-diversity STBCs for 2 × 2 and 4 × 2 MIMO systems. IEEE J. Sel. Top. Sign. Proces. 3(6), 916–927 (2009)
Srinath, K.P., Rajan, B.S.: Fast-decodable MIDO codes with large coding gain. IEEE Trans. Inf. Theory 60(2), 992–1007 (2014)
Tarokh, V., Seshadri, N., Calderbank, A.R.: Space–time codes for high data rate wireless communication: performance criterion and code construction. IEEE Trans. Inf. Theory 44(2), 744–765 (1998)
Vehkalahti, R., Hollanti, C., Lahtonen, J., Ranto, K.: On the densest MIMO lattices from cyclic division algebras. IEEE Trans. Inf. Theory 55(8), 3751–3780 (2009)
Vehkalahti, R., Hollanti, C., Oggier, F.: Fast-decodable asymmetric space–time codes from division algebras. IEEE Trans. Inf. Theory 58(4), 2362–2385 (2012)
Viterbo, E., Boutros, J.: A universal lattice code decoder for fading channels. IEEE Trans. Inf. Theory 45(7), 1639–1642 (1999)
Yang, S., Belfiore, J.-C.: Optimal space–time codes for the MIMO amplify-and-forward cooperative channel. IEEE Trans. Inf. Theory 53(2), 647–663 (2007)
Zheng, L., Tse, D.: Diversity and multiplexing: A fundamental tradeoff in multiple-antenna channels. IEEE Trans. Inf. Theory 49(5), 1073–1096 (2003)
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2020 Springer Nature Switzerland AG
About this chapter
Cite this chapter
Barreal, A., Hollanti, C. (2020). On Fast-Decodable Algebraic Space–Time Codes. In: Beresnevich, V., Burr, A., Nazer, B., Velani, S. (eds) Number Theory Meets Wireless Communications. Mathematical Engineering. Springer, Cham. https://doi.org/10.1007/978-3-030-61303-7_3
Download citation
DOI: https://doi.org/10.1007/978-3-030-61303-7_3
Published:
Publisher Name: Springer, Cham
Print ISBN: 978-3-030-61302-0
Online ISBN: 978-3-030-61303-7
eBook Packages: EngineeringEngineering (R0)