In this article, a novel two-way double-relay selection strategy with its bit error rate (BER) performance analysis is proposed. In this novel strategy, as a first step we choose two relays out of a set of relay-nodes in a way to maximize the system performance in terms of BER and complexity. In the second step, the selected relays apply orthogonal space-time coding scheme using the three-phase protocol to establish a two-way communication between the transceivers, which will lead to a significant improvement in the achievable diversity and coding gain with a very low decoding complexity by using a symbol-wise decoder. Furthermore, the performance of the overall system is further enhanced through the use of a network coding method at the selected relay-nodes. Moreover, this paper proposes the analytical approximation of the BER performance. As well, we show that the analytical results match perfectly the simulated ones. In addition, we prove that our strategy outperforms the current state-of-the-art ones by proposing a better cooperative communication system in terms of BER.

在本文中，提出了一种新颖的双向双向中继选择策略，并对其误码率（BER）性能进行了分析。在这种新颖的策略中，第一步，我们从一组中继节点中选择两个中继，以最大程度地提高BER和复杂度的系统性能。在第二步中，选定的中继使用三相协议应用正交空时编码方案，以在收发器之间建立双向通信，这将在非常低的情况下显着提高可实现的分集和编码增益通过使用基于符号的解码器来解码复杂度。此外，通过在所选择的中继节点处使用网络编码方法，进一步增强了整个系统的性能。此外，本文提出了BER性能的解析近似。同样，我们表明分析结果与模拟结果完全匹配。此外，我们通过提出一种基于BER的更好的协作通信系统，证明了我们的策略优于当前的最新技术。