In this paper, we consider the interference rejection combining (IRC) receiver, which improves the cell-edge user throughput via suppressing inter-cell interference and requires estimating the covariance matrix including the inter-cell interference with high accuracy. In order to solve the problem of sample covariance matrix estimation with limited samples, a regularization parameter optimization based on the minimum eigenvalue criterion is developed. It is different from traditional methods that aim at minimizing the mean squared error, but goes straight at the objective of optimizing the final performance of the IRC receiver. A lower bound of the minimum eigenvalue that is easier to calculate is also derived. Simulation results demonstrate that the proposed approach is effective and can approach the performance of the oracle estimator in terms of the mutual information metric.

翻译：本文研究干扰抑制合并（IRC）接收机，该接收机通过抑制小区间干扰来提升小区边缘用户吞吐量，且需要高精度地估计包含小区间干扰的协方差矩阵。为解决有限样本下样本协方差矩阵估计问题，提出一种基于最小特征值准则的正则化参数优化方法。该方法不同于传统以最小化均方误差为目标的方法，而是直接以优化IRC接收机最终性能为目标。此外，还推导了更易计算的最小特征值下界。仿真结果表明，所提方法有效，且能在互信息度量上接近"理想估计器"的性能。