Bit error rate (BER) and outage probability for amplify-and-forward (AF) relaying systems with two different channel estimation methods, disintegrated channel estimation and cascaded channel estimation, using pilot-aided maximum likelihood method in slowly fading Rayleigh channels are derived. Based on the BERs, the optimal values of pilot power under the total transmitting power constraints at the source and the optimal values of pilot power under the total transmitting power constraints at the relay are obtained, separately. Moreover, the optimal power allocation between the pilot power at the source, the pilot power at the relay, the data power at the source and the data power at the relay are obtained when their total transmitting power is fixed. Numerical results show that the derived BER expressions match with the simulation results. They also show that the proposed systems with optimal power allocation outperform the conventional systems without power allocation under the same other conditions. In some cases, the gain could be as large as several dB's in effective signal-to-noise ratio.
Wang, K., Chen, Y., Alouini, M.-S., & Xu, F. (2014). BER and Optimal Power Allocation for Amplify-and-Forward Relaying Using Pilot-Aided Maximum Likelihood Estimation. IEEE Transactions on Communications, 62(10), 3462–3475. doi:10.1109/tcomm.2014.2358219
The work of Y. Chen was supported in part by the Open Research Project of the State Key Laboratory of Industrial Control Technology, Zhejiang University, China (Grant IC14T40). Part of this paper has been submitted for publication to the IEEE 80th Vehicular Technology Conference. The associate editor coordinating the review of this paper and approving it for publication was M. Uysal.