An Algebraic Coding Scheme for Wireless Relay Networks With Multiple-Antenna Nodes

Abstract

Abstract-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.

Distributed GABBA space-time codes in amplify-and-forward relay networks

“…In addition, suboptimal linear decoder can be used to decrease the complexity, while the full diversity order is achievable. Other DSTCs have also been proposed in [42,48] to improve the bandwidth efficiency of cooperative.…”

“…For example, in [42], the destination was assumed to have perfect knowledge of all the channel fading gains from the source to the relays and those from the relays to the destination. To overcome the need for channel knowledge, distributed differential space time coding was studied in [48][49][50][51], which is essentially an extension of differential unitary space time coding for point to point MIMO systems to the relay network case. In [52], a A&F DSTC involving a combination of training, channel estimation and detection in conjunction with existing coherent distributed STBCs is proposed for non-coherent communication in A&F relay networks.…”

Cyclic Division Algebras: A Tool for Space-Time Coding

“…Adaptation of perfect Space-Time codes have been used for wireless networks for example in [19,37,42]. Furthermore, since in wireless networks, the number of relay nodes correspond to the number of antennas, it is useful to have general code constructions, as given in [21].…”

Orthogonal code design for MIMO amplify-and-forward cooperative networks

“…the appropriate space-time codes is not investigated in [4]. In [6], an algebraic coding scheme is introduced for A&F DSTC. Note that in decode-and-forward (D&F) based spacetime codes, we can simply use the same space-time codes in the context of MIMO in multiple antenna source and relays [7].…”