Design of delay-tolerant linear dispersion codes

Wenjin Wang*, Fuchun Zheng, Alister Burr, Michael Fitch

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


In cooperative communication networks, owing to the nodes' arbitrary geographical locations and individual oscillators, the system is fundamentally asynchronous. This will damage some of the key properties of the space-time codes and can lead to substantial performance degradation. In this paper, we study the design of linear dispersion codes (LDCs) for such asynchronous cooperative communication networks. Firstly, the concept of conventional LDCs is extended to the delay-tolerant version and new design criteria are discussed. Then we propose a new design method to yield delay-tolerant LDCs that reach the optimal Jensen's upper bound on ergodic capacity as well as minimum average pairwise error probability. The proposed design employs stochastic gradient algorithm to approach a local optimum. Moreover, it is improved by using simulated annealing type optimization to increase the likelihood of the global optimum. The proposed method allows for flexible number of nodes, receive antennas, modulated symbols and flexible length of codewords. Simulation results confirm the performance of the newly-proposed delay-tolerant LDCs.

Original languageEnglish
Article number6241380
Pages (from-to)2560-2570
Number of pages11
JournalIEEE Transactions on Communications
Issue number9
Early online date16 Jul 2012
Publication statusPublished - Sept 2012


  • Asynchronous relay network
  • Cooperative communication
  • Delay-tolerant space-time code
  • Linear dispersion code

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