4 research outputs found
Signal Set Design for Full-Diversity Low-Decoding-Complexity Differential Scaled-Unitary STBCs
The problem of designing high rate, full diversity noncoherent space-time
block codes (STBCs) with low encoding and decoding complexity is addressed.
First, the notion of -group encodable and -group decodable linear STBCs
is introduced. Then for a known class of rate-1 linear designs, an explicit
construction of fully-diverse signal sets that lead to four-group encodable and
four-group decodable differential scaled unitary STBCs for any power of two
number of antennas is provided. Previous works on differential STBCs either
sacrifice decoding complexity for higher rate or sacrifice rate for lower
decoding complexity.Comment: 5 pages, 2 figures. To appear in Proceedings of IEEE ISIT 2007, Nice,
Franc
Noncoherent Low-Decoding-Complexity Space-Time Codes for Wireless Relay Networks
The differential encoding/decoding setup introduced by Kiran et al, Oggier et
al and Jing et al for wireless relay networks that use codebooks consisting of
unitary matrices is extended to allow codebooks consisting of scaled unitary
matrices. For such codebooks to be used in the Jing-Hassibi protocol for
cooperative diversity, the conditions that need to be satisfied by the relay
matrices and the codebook are identified. A class of previously known rate one,
full diversity, four-group encodable and four-group decodable Differential
Space-Time Codes (DSTCs) is proposed for use as Distributed DSTCs (DDSTCs) in
the proposed set up. To the best of our knowledge, this is the first known low
decoding complexity DDSTC scheme for cooperative wireless networks.Comment: 5 pages, no figures. To appear in Proceedings of IEEE ISIT 2007,
Nice, Franc
Algebraic Distributed Differential Space-Time Codes with Low Decoding Complexity
The differential encoding/decoding setup introduced by Kiran et al,
Oggier-Hassibi and Jing-Jafarkhani for wireless relay networks that use
codebooks consisting of unitary matrices is extended to allow codebooks
consisting of scaled unitary matrices. For such codebooks to be usable in the
Jing-Hassibi protocol for cooperative diversity, the conditions involving the
relay matrices and the codebook that need to be satisfied are identified. Using
the algebraic framework of extended Clifford algebras, a new class of
Distributed Differential Space-Time Codes satisfying these conditions for power
of two number of relays and also achieving full cooperative diversity with a
low complexity sub-optimal receiver is proposed. Simulation results indicate
that the proposed codes outperform both the cyclic codes as well as the
circulant codes. Furthermore, these codes can also be applied as Differential
Space-Time codes for non-coherent communication in classical point to point
multiple antenna systems.Comment: To appear in IEEE Transactions on Wireless Communications. 10 pages,
5 figure