A user cooperation aided device-centric clustering approach for large-scale distributed antenna systems

Large-scale distributed antenna systems (LS-DASs) are gaining increasing momentum and emerging as highly promising candidates for future wireless communications. To improve the user's quality of service (QoS) in that systems, in the present study, we propose a user cooperation aided clustering approach based on device-centric architectures and enable the multi-user multiple-input multiple-output transmissions with non-reciprocal setups. We actively use device-to-device communication techniques to achieve the sharing of user information and try to form clusters on user side instead of the traditional way that performs clustering on base station (BS) side in data offloading. We further adopt a device-centric architecture to break the limits of the classical BS-centric cellular structure. Moreover, we derive an approximate expression to calculate the user rate for LS-DASs with employment of the zero-forcing precoding and consideration of inter-cluster interference. Simulated and numerical results indicate that the approximate expression predicts the user rate with a lower computational cost, and the proposed approach provides better user experience for, in particular, the users who have unacceptable QoS.