On the Energy Efficiency-Spectral Efficiency Trade-Off of the 2BS-DMIMO System

In this paper, we propose a novel closed-form approximation of the Energy Efficiency vs. Spectral Efficiency (EE-SE) trade-off for the uplink/downlink of distributed multiple-input multiple-output (DMIMO) system with two cooperating base stations. Our closed-form expression can be utilized for evaluating the idealistic and realistic EE-SE performances of various antenna configurations as well as assessing how DMIMO compares against MIMO system in terms of EE. Results show a tight match between our closed-form approximation and the Monte-Carlo simulation for both idealistic and realistic EESE trade-off. Our results also show that given a target SE requirement, there exists an optimal antenna setting that maximizes the EE. In addition, DMIMO scheme can offer significant improvement in terms of EE over the MIMO scheme

Distributed Cooperative Multicell Precoding Based on Local Channel State Information

Cooperative multicell precoding is an attractive way of improving the performance in multicell downlink scenarios especially for terminals at cell edges. Multiple base stations in a given area serve each terminal after precoding, which can coordinate the inter-cell interference and achieve higher performance. Most previous work in the area has focus on centralized precoding which requires gathering all transmitters’ channel state information (CSI) at central station (CS) through backhaul and then precoding at CS. However, the requirements on backhaul signaling and computational power scales rapidly in large and dense networks, which usually make such fully centralized approaches impractical. In this paper, we study two practical precoding strategies with only local CSI under a relatively realistic scenario. Performance is finally illustrated through numerical simulations

A practical semi-dynamic clustering scheme using affinity propagation in cooperative picocells

Coordinated multipoint (CoMP) is corroborated to be an effective technology in mitigating cochannel interference (CCI) and enhancing system performance in picocell systems, which consist of a large number of pico base stations (BSs). In picocell systems, effective CoMP clustering schemes could provide significant gains of system performance such as throughput and cell-edge spectrum efficiency (SE). Moreover, an intrinsic problem of densely deployed networks is the cost of signaling overhead and data exchange between BSs in clusters. In this paper, a novel semidynamic clustering scheme based on affinity propagation for CoMP-Pico is presented to maximize user SE and throughput under the constraint of backhaul cost. Our proposed scheme consists of online and offline stages that can achieve good performance and low complexity. Simulation results show that the proposed scheme yields significant gains of SE and throughput and low running time compared with the existing clustering schemes