Performance Analysis And Optimization Strategies Study In Distributed Wireless Communication System

Distributed Wireless Communication System (DWCS) is a novel wireless communication system, which is proposed by Tsinghua University and Beijing University of Posts and Telecommunications. DWCS is based on distributed antennas. It substitutes the "visual cell" and "visual base-station" for the traditional cell and base-station, and can enhance the system capacity greatly in comparison with traditional centralized multi-antenna systems. Furthermore, with a simple architecture, DWCS can be facilitated into all-IP realization.This dissertation focuses on studying and analyzing the performance and optimization technologies in DWCS.The main innovations of this dissertation are as follows:1. An exact reverse-link E_b/I₀ expression for multi-cell GDAS (Generalized Distributed Antenna System) is derived. And the performance of various antenna architectures derived from GDAS model is analyzed.2. The impacts of imperfect channel estimation on the forward-link and reverse-link performance in DWCS in multi-path fading environment are investigated, and the related analytical results are derived. The signals transmit and combine methods adapted in such environment are also proposed.3. The scheme of quality-of-service (QoS) guaranteed forward-link transmission optimization for multi-service DWCS is investigated. The design of the scheme involves balancing a number of conflicting requirements, including QoS provision, throughput maximization, and low system cost. A novel uni-access scheme combined with transmit beamforming algorithm is proposed.4. Based on the idea of dynamic radio resource management, a class of antenna dynamic selection algorithms based on E_b/I₀ is proposed. Simulation results demonstrate effectiveness of the proposed algorithms, which can guarantee the system capacity while reducing antenna costs in DWCS significantly.