TY - GEN
T1 - Opportunistic cooperation with receiver-based ratio combining strategy
AU - Wang, Qian
AU - Ren, Kui
AU - Zhang, Yanchao
AU - Zhu, Bo
PY - 2008
Y1 - 2008
N2 - In cooperative wireless communication systems, many combining techniques could be employed at the receiver, such as maximal ratio combining (MRC), equal gain combining (EGC), etc. To address the effect of receiver diversity combining on optimum energy allocation, we analyze the problem of minimizing average total transmit energy under a SNR constraint when different ratio combining methods are utilized at destination. For maximal ratio combining (MRC), based on the explicit analytical solution an asymptotic solution for normalized optimum total energy in terms of μ and η was derived in the high-SNR scenario. For fixed ratio combining (FRC), we find that there does not exist an explicit analytical solution to the optimum energy allocation problem. However, the convexity proof for the energy function provides a way of using numerical convex optimization methods to find the unique solution. Our results also show that, while direct transmission (r* = 0) is optimum for certain channel states when the destination uses MRC, the relay should always transmit, i.e. r* > for all channel states, when the combining ratio β is a fixed number.
AB - In cooperative wireless communication systems, many combining techniques could be employed at the receiver, such as maximal ratio combining (MRC), equal gain combining (EGC), etc. To address the effect of receiver diversity combining on optimum energy allocation, we analyze the problem of minimizing average total transmit energy under a SNR constraint when different ratio combining methods are utilized at destination. For maximal ratio combining (MRC), based on the explicit analytical solution an asymptotic solution for normalized optimum total energy in terms of μ and η was derived in the high-SNR scenario. For fixed ratio combining (FRC), we find that there does not exist an explicit analytical solution to the optimum energy allocation problem. However, the convexity proof for the energy function provides a way of using numerical convex optimization methods to find the unique solution. Our results also show that, while direct transmission (r* = 0) is optimum for certain channel states when the destination uses MRC, the relay should always transmit, i.e. r* > for all channel states, when the combining ratio β is a fixed number.
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U2 - 10.1007/978-3-540-88582-5_35
DO - 10.1007/978-3-540-88582-5_35
M3 - Conference contribution
AN - SCOPUS:56749150948
SN - 3540885811
SN - 9783540885818
T3 - Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
SP - 361
EP - 372
BT - Wireless Algorithms, Systems, and Applications - Third International Conference, WASA 2008, Proceedings
PB - Springer Verlag
T2 - 3rd International Conference on Wireless Algorithms, Systems, and Applications, WASA 2008
Y2 - 26 October 2008 through 28 October 2008
ER -