Irregular Antenna Arrays Research Articles

Pattern Synthesis of 4-D Irregular Antenna Arrays Based on Maximum-Entropy Model

The 4-D antenna arrays with the irregular array topology have great advantages in simplifying the beamforming network and reducing the cost. However, the complexity of such synthesis problems limited their development. An effective joint optimization approach based on the maximum-entropy model is proposed for the pattern synthesis of 4-D irregular arrays. By introducing the entropy concept into 4-D irregular arrays, the original synthesis problem is simplified into two problems, which can be solved in two steps separately. In the first step, the optimization of the topology of 4-D irregular arrays characterized by domino-shaped tiles is performed, based on the principle of entropy maximization. The genetic algorithm is introduced to solve the pure integer optimization problem. Then, the differential evolution algorithm is used to synthesize the desired radiation pattern based on the optimized array topology. Consequently, the joint optimization approach significantly improves the overall synthesis efficiency. Three numerical examples are presented to demonstrate the effectiveness of the proposed approach. Moreover, the numerical results show that the 4-D irregular arrays designed by the proposed approach have the excellent beam scanning ability.

Multi-User Massive MIMO Communication Systems Based on Irregular Antenna Arrays

In practical mobile communication engineering applications, surfaces of antenna array deployment regions are usually uneven. Therefore, massive multi-input–multi-output (MIMO) communication systems usually transmit wireless signals by irregular antenna arrays. To evaluate the performance of irregular antenna arrays, the matrix correlation coefficient and the ergodic received gain are defined for massive MIMO communication systems with mutual coupling effects. Furthermore, the lower bound of the ergodic achievable rate, symbol error rate, and average outage probability is first derived for multi-user massive MIMO communication systems using irregular antenna arrays. Asymptotic results are also derived when the number of antennae approaches infinity. Numerical results indicate that there exists a maximum achievable rate when the number of antennae keeps increasing in massive MIMO communication systems using irregular antenna arrays. Moreover, the irregular antenna array outperforms the regular antenna array in the achievable rate of massive MIMO communication systems when the number of antennae is larger than or equal to a given threshold.