Hybrid Selection and Maximum-Ratio Combining without Excessive Channel Estimation

In the paper, we investigate the selection algorithm of hybrid selection and maximum-ratio combining systems. Most existing algorithms require channel coefficients of all receive antennas. It is difficult to satisfy for reduced number of RF chains. Therefore, a new selection algorithm is proposed so that the number of required channel coefficients equals that of RF chains. The presented algorithm uses the remainder antenna to substitute the worse one whose channel coefficient is estimated. Simulation results show that the performance of proposed algorithm is greatly close to that of optimal selection, especially for larger number of RF chains. The proposed algorithm is asymptotic-optimal in performance; moreover, it doesn´t need excessive channel estimation.