Bandwidth Efficient Three-User Cooperative Diversity Scheme Based on Relaying Superposition Symbols
- 1
- 2
- 3
Abstract
Recently, Cooperative diversity in wireless communication systems has gained much attention. A simple two-user cooperative diversity scheme called decode-and-forward cooperation scheme has been presented by Laneman (2004). Each user has one partner to decode its information and retransmit it by employing repeti-tion coding. This scheme can offer diversity order of two. But the bandwidth efficiency is low. In this paper, we propose a bandwidth efficient three-user cooperative diversity scheme based on relaying superposition symbols. Each user has two partners and each partner relays superposition symbols of the other two users instead of repetition. Thus, the bandwidth efficiency is improved compared to the baseline decode- and-forward cooperative diversity scheme presented by Laneman. Moreover, the proposed scheme can also offer diversity order of two. Then, in order to improve the system performance, a new constellation labeling for the superposition 8PSK modulation is designed. It is a simple way to exploit the symbol mapping diver-sity and a gain of about 2 dB can be obtained. Furthermore, the performance improvement comes at no addi-tional power or bandwidth expense.
- G. J. Foschini and M. J. Gans, “On limits of wireless communications in a fading environment when using multiple antennas,” Wireless Personal Communications, Vol. 6, No. 3, pp. 311-335, 1998.
- E. Telatar, “Capacity of multi-antenna Gaussian channels,” European Transactions on Telecommuni- cations, Vol. 10, No. 6, pp. 585-596, 1999.
- S. M. Alamouti, “A simple transmit diversity technique for wireless communications,” IEEE Journal on Selected Areas in Communications, Vol. 16, No. 8, pp. 1451-1458, 1998.
- A. Sendonaris, E. Erkip, and B. Aazhang, “User cooperation diversity Part I: System description,” IEEE Transactions on Communications, Vol. 51, No. 11, pp. 1927-1938, November 2003.
- A. Sendonaris, E. Erkip, and B. Aazhang, “User cooperation diversity Part II: Implementation aspects and performance analysis,” IEEE Transactions on Communications, Vol. 51, No. 11, pp. 1939-1948, November 2003.
- A. Nosratinia, T. E. Hunter, and A. Hedayat, “Co- operative communication in wireless networks,” IEEE Communications Magazine, Vol. 42, No. 10, pp. 74-80, October 2004.
- J. N. Laneman, D. N. C. Tse, and G. W. Wornell, “Cooperative diversity in wireless networks: Efficient protocols and outage behavior,” IEEE Transactions on Information Theory, Vol. 50, No. 12, pp. 3062-3080, December 2004.
- J. N. Laneman and G. W. Wornell, “Distributed space- time-coded protocols for exploiting cooperative diversity in wireless networks,” IEEE Transactions on Information Theory, Vol. 49, No. 10, pp. 2415-2425, October 2003.
- O. Shalvi, “Multiple source cooperation diversity,” IEEE Communications Letters, Vol. 8, No. 12, pp. 712-714, December 2004.
- R. Q. Wang, W. L. Zhao, and G. B. Giannakis, “Multi-source cooperative networks with distributed convolutional coding,” 2005 Conference Record of the Thirty-Ninth Asilomar Conference on Signals, Systems and Computers, pp. 1056-1060, 2005.
- R. Q. Wang, W. L. Zhao, and G. B. Giannakis, “Distributed trellis coded modulation for multi-source cooperative networks,” Radio and Wireless Symposium, 2006 IEEE, San Diego, CA, pp. 271-274, January 2006.
- R. Q. Wang and G. B. Giannakis, “Complex field coding in multi-source cooperative networks for full diversity,” 2006 IEEE International Conference on Communications, Vol. 10, pp. 4485-4488, June 2006.
- E. G. Larsson and B. R. Vojcic, “Cooperative transmit diversity based on superposition modulation,” IEEE Communications Letters, Vol. 9, No. 9, pp. 778-780, September 2005.