Abstract
Cooperative communication protocols are generally assumed to be synchronous in nature, which is not always possible in distributed wireless networks. Lack of synchronisation may cause space time codes to lose their property of being full rank. The solution proposed, thus far, increase the size of the codes in the temporal that in turn increases the energy consumption and complexity of the receiver. In addition, the channel is required to be static over the length of codes, which is a hard condition when the size of the ST code increases. In order to mitigate these issues, we have proposed delay tolerant codes in this paper that do not increase receiver complexity and require less circuit energy. The simulation results for various delay profiles show that the proposed codes require less total energy per bit when relays are within a small range. Therefore, the proposed scheme is better suited to short-range applications such as sensor networks. Copyright (C) 2014 John Wiley & Sons, Ltd.