In the heterogeneous networks (HetNets), the downlink-uplink decoupled (DUDE) user association is a very promising technology that can employ different association strategies for uplink and downlink. The DUDE mode has great potential for improving system capacity and frequency efficiency. However, interference between the DUDE user equipment (DUDE UE), macro user equipment (MUE) and small user equipment (SUE) still needs to be considered and properly tackled. Therefore, this paper presents an optimization scheme of frequency allocation and power control to improve the communication quality of users. Firstly, the multiple region frequency allocation (MRFA) scheme is proposed for non-uniform user distribution to alleviate interference among users and allocate spectrum resources equally to dense users. This scheme is modelled as a sub-region partition problem with maximum sum rate, which can disperse densely distributed users to different sub-bands for transmission. Secondly, the convergent power control (CPC) algorithm is considered to improve the transmission performance of each user. It can converge the transmit power to the optimal transmit power for reducing interference among co-channel users when there is no disturbance in the network. The CPC algorithm can also make the signal-to-interference-plus-noise-ratio (SINR) of each active user always greater than the target threshold until the end of communication by dynamically adjusting the transmit power of users. Simulation results show that the joint scheme of MRFA and CPC achieves a higher system throughput and better user performance than existing frequency allocation schemes or power control schemes.

中文翻译：

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具有非均匀用户分布的下行-上行解耦 HetNet 的上行性能改进

在异构网络（HetNets）中，下行-上行解耦（DUDE）用户关联是一种非常有前景的技术，可以对上下行采用不同的关联策略。DUDE模式在提高系统容量和频率效率方面具有巨大潜力。然而，DUDE用户设备（DUDE UE）、宏用户设备（MUE）和小用户设备（SUE）之间的干扰仍然需要考虑和妥善处理。因此，本文提出了一种频率分配和功率控制的优化方案，以提高用户的通信质量。首先，针对非均匀用户分布提出了多区域频率分配（MRFA）方案，以减轻用户之间的干扰，并将频谱资源平均分配给密集用户。该方案被建模为具有最大和速率的子区域划分问题，可以将密集分布的用户分散到不同的子带进行传输。其次，考虑收敛功率控制（CPC）算法来提高每个用户的传输性能。它可以在网络没有干扰的情况下将发射功率收敛到最佳发射功率，以减少同信道用户之间的干扰。CPC算法还可以通过动态调整用户的发射功率，使每个活跃用户的信干噪比(SINR)始终大于目标门限，直到通信结束。