| 抄録（和） |
W-CDMAシステムに,閉ループ型の送信ダイバーシチ(Mode1)を適用した場合の所要送信電力削減効果を,計算機シミュレーションを用いて定量的に評価する.アンテナベリフィケーション,受信SIR推定,及びRake合成について,本検討で用いた方法の詳細を述べた後,シミュレーションによる評価結果を示す.アンテナ間のフェージング相関や受信タイミングずれがない場合は,1アンテナ送信に比べ,低速で1.7dB程度の送信電力削減効果があり,フェージング相関が大きくなると,特性は低速で劣化し,高速では逆に改善することを示す.また,受信タイミングのずれの大きさが1/4chipの時には0.5dB程度,1/2chipの時には1.0dB程度,0chipの場合に比べ,特性が劣化することを示す. |
| 抄録（英） |
This paper evaluates to what degree required transmit power can be reduced by applying closed loop mode transmit diversity (Model) to W-CDMA systems. The algorithms of antenna verification, received signal-to-interference ratio (SIR) estimation and rake combining employed are described first, then the simulation results are presented. The results shows that the required transmit power of the Model can be decreased by approximately 1.7dB in a low-mobility case as compared with one-antenna transmission when both fading correlation between two antennas and received time difference from them are 0, and that the performance is degraded in low-mobility case and is, in contrast, improved in high-mobility case when correlation is large as against the case when correlation is small. It also indicates that the performance is degraded by about 0.5dB and 1.0dB, when received time difference from two antennas is 1/4 chip and 1/2 chip respectively by comparison with the case of O chip-time. |