LTE系統下感知式Femtocell之優先次序資源管理機制

Abstract

由於宏細胞(macrocell)無法提供足夠的服務給室內用戶，家庭基站(femtocell)被提出來改善室內用戶的服務效能。然而，家庭基站的佈建會對宏細胞系統造成無法預期的感擾，並降低周遭室外用戶的服務效能。為了解決這個難題，混合式接取技術被視為一個大有可為的解決方法。混合式接取技術使家庭基站能夠去服務周遭的室外用戶，並卸載宏細胞的電信業務。 在本篇論文中，我們提出感知優先次序資源分配(cognitive priority-based resource management, CPRM)機制，意圖最大化感知式家庭基站的傳輸量，並保證滿足各種電信業務的服務品質要求。CPRM機制會動態調整感測時間以達到準確的感測結果、設計優先次序來表明用戶需要服務的緊急程度、決定用戶的最小傳輸位元數來滿足用戶的服務品質要求。然後，CPRM機制會依照優先次序分配資源以避免違反緊急用戶的服務品質要求。模擬結果顯示我們提出的CPRM機制能達到比傳統機制高的系統傳輸量，並保證滿足各種電信業務的服務品質需求。

Since macrocells cannot provide enough services to indoor users, femtocell is proposed to improve the service performance of indoor users. However, the deployment of femtocell would cause unexpected interference to the macrocell system, and degrade the performance of the nearby outdoor users. To overcome this challenge, hybrid access policy is envisioned as a promising solution. Hybrid access policy enables femtocell to serve the nearby outdoor users and offload the traffic of macrocell system. In this thesis, we propose a cognitive priority-based resource management (CPRM) scheme to maximize the throughput of cognitive femtocells with guaranteeing the quality-of-service (QoS) requirements of all traffic types. The CPRM scheme adapts the sensing duration to achieve accurate sensing result, designs the priority function to indicate the degree of urgency of users, and determines the minimum transmission bits to satisfy the QoS requirements of each user. Then, the CPRM scheme would allocate resource based on the priority to avoid violating the QoS requirements of urgent users. Simulation results show that the proposed CPRM scheme achieves higher system throughput than the conventional schemes with guaranteeing the QoS requirements of all traffic types.