Search Space Design of Enhanced Physical Downlink Control Channel forrnLong Term Evolution Advanced System

摘要

This paper focuses on investigating the search space design of Enhanced Physical Downlink Control CHannel (EPDCCH),whicn is introduced in Long Term Evolution-Advanced (LTE-A) system to increase the capacity of the downlink control channel. Since EPDCCH is frequency-division-multiplexed with downlink data channel, resource utilization efficiency is a very important issue in addition to blocking probability. This paper proposes the innovative methods of locating the search spaces of EPDCCH with different transmission schemes, i.e. distributed transmission and localized transmission, considering the UE complexity, the capacity of control channel and the impacts on Physical Downlink Shared CHannel (PDSCH). By simulation results, it is proven that the proposed methods could get higher resource utilization and lower blocking probability while maintain the same UE complexity in blind decoding.%本稿では，LTE-Advanced (Release 11)において検討されている拡張型下り制御チャネル(EPDCCH: Enhanced Physical Downlink Control Channel)におけるサーチスペース構成について検討している.EPDCCHでは，下り制御情報（DCI: downlink control information)を複数のPRB (Physical Resource Block)にマッピングするため，DCIが少ない場合，DCIが離散的に配置され，リソースの利用効率が低下してしまう.本稿では，ブロッキング確率を低 減しつつ，リソース利用効率を改善することを目的に，分散マッピングおよび局所マッピングを用いるEPDCCHに おける最適なサーチスペース構成を提案し，提案法の適用効果を，シミュレーション評価により明らかにしている.