We consider the optimization of a two-hop relay network based on an amplify-and-forward Multiple-Input Multiple-Output (MIMO) relay. The relay is assumed to derive the output signal by a Relay Transform Matrix (RTM) applied to the input signal. Assuming perfect channel state information about the network at the relay, the RTM is optimized according to two different criteria: {\bf\em i)} network capacity; {\bf\em ii)} network capacity based on Orthogonal Space--Time Block Codes. The two assumptions have been addressed in part in the literature. The optimization problem is reduced to a manageable convex form, whose KKT equations are explicitly solved. Then, a parametric solution is given, which yields the power constraint and the capacity achieved with uncorrelated transmitted data as functions of a positive indeterminate. The solution for a given average power constraint at the relay is amenable to a \emph{water-filling-like} algorithm, and extends earlier literature results addressing the case without the direct link. Simulation results are reported concerning a Rayleigh relay network and the role of the direct link SNR is precisely assessed.
翻译:我们认为,基于超前和超前多输入多输出(MIIMO)中继的双速中继网络最优化。 中继假设通过对输入信号应用的中继变换母体(RTM)获得输出信号。 假设关于中继网络的完美频道状态信息, RTM则根据两个不同标准优化: {bf\em( i)}网络能力; \bf\em( ii)}基于Orthognal空间- 时空区块代码的网络能力。 两种假设已在文献中部分述及。 优化问题被简化为可控的 convex 格式, 其KKT方程式得到明确解决。 然后, 给出了一个参数解决方案, 产生能量限制和用未电源相关传输数据所实现的能力, 作为正不确定的函数。 中继中继器的平均电力限制的解决方案可适用于\emph{ water- like} 运算法, 并扩展了处理该案件的早期文献结果, 而没有直接链接。 Simulting 的结果被精确地评估。