Adaptive Transmission Scheme Based on Channel State in Dual-Hop System

In this paper, a dual-hop relay based on channel state is studied. In the conventional relay scheme, a relay uses the same modulation method without reference to channel state. But, a relay uses an adaptive modulation method with reference to channel state. If the channel state is poor, a relay eliminates latter 2 bits and uses Quadrature Phase Shift Keying (QPSK) modulation. If channel state is good, a relay modulates the received symbols with 16-QAM symbols by using 4 bits. The performance of the proposed scheme for Symbol Error Rate (SER) and throughput is analyzed.

Authors:

• Seung-Jun Yu
• Yong-Jun Kim
• Jung-In Baik
• Hyoung-Kyu Song

Keywords:

• Adaptive transmission
• channel state
• dual-hop
• hierarchical modulation
• relay.

References:

[1] D. P. Palomar, J. M. Cioffi and M. A. Lagunas, Joint Tx-Rx beamforming design for multicarrier MIMO channels: A unified framework for convex optimization, IEEE Trans. Signal Process., vol. 51, no. 9, pp. 2381–2401, Sep. 2003.
[2] Y. Fan and J. Thompson, MIMO configurations for relay channels: theory and practice, IEEE Trans. Wireless Commun., vol. 6, no. 5, pp. 1774–1786, May 2007.
[3] L. Sanguinetti, A. A. D’Amico and Y. Rong, A tutorial on the optimization of amplify-and-forward MIMO relay system, IEEE J. Sel. Areas Commun., vol. 30, no. 8, pp. 1331–1346, Sep. 2012.
[4] J. N. Laneman, G. W. Wornell and D. N. C, An efficient protocol for realizing cooperative diversity in wireless networks, in Proc. IEEE International Symposium on Information Theory, pp. 294, June 2001.
[5] J. N. Laneman and G. W. Wornell, Exploiting distributed spatial diversity in wireless networks, in Proc. Allerton Conference on Communication, Control, and Computing, pp. 1–10, Oct. 2000.
[6] G. Kramer, M. Gastpar and P. Gupta, Cooperative strategies and capacity theorem for relay networks, IEEE Trans. Inf. Theory, vol. 51, no. 9, pp. 3037–3063, Sep. 2005.
[7] Shin, J.-C., Song, J.-H., Kim, J.-H. and Song, H.-K, Dual-hop transmission scheme based on hierarchical modulation in wireless networks, IEICE Trans. Commun., vol. E93-B, no.6, pp.1645-1648, June 2010.
[8] Yu, S.-J., Kim, Y.-J., and Song, H.-K, Adaptive relay scheme based on channel state in dual-hop system, IJERA, vol. 6, no.2, pp.20-23, Jan. 2016.