A key aspect of many resource allocation problems is the need for the resource controller to compute a function, such as the max or arg max, of the competing users' metrics. Information must be exchanged between the competing users and the resource controller in order for this function to be computed. In many practical resource controllers, the competing users' metrics are communicated to the resource controller, which then computes the desired extremization function. However, in this paper, it is shown that information rate savings can be obtained by recognizing that the controller only needs to determine the result of this extremization function. If the extremization function is to be computed losslessly, the rate savings are shown in most cases to be at most 2 b independent of the number of competing users. Motivated by the small savings in the lossless case, simple achievable schemes for both the lossy and interactive variants of this problem are considered. It is shown that both of these approaches have the potential to realize large rate savings, especially in the case where the number of competing users is large. For the lossy variant, it is shown that the proposed simple achievable schemes are in fact close to the fundamental limit given by the rate distortion function.

The effect of a power amplifier nonlinearity on multi-antenna orthogonal frequency division multiplexing (OFDM) transmitters utilizing subcarrier beamforming is investigated. Theoretical analysis and simulation shows that such systems can exhibit significant performance degradation due to the power amplifier nonlinearity when there are channel state feedback errors. The SINR degradation under solely channel mismatch is shown to be significantly better than when power amplifier nonlinearity effects are included. The ultimate conclusion is that power amplifier nonlinearity effects should be considered when designing per subcarrier transmit beamformers.