翻訳と辞書 Words near each other ・ Zero-configuration networking ・ Zero-copy ・ Zero-coupon bond ・ Zero-Coupon Inflation-Indexed Swap ・ Zero-crossing rate ・ Zero-curtain effect ・ Zero-day (computing) ・ Zero-defects mentality ・ Zero-dimensional space ・ Zero-dispersion wavelength ・ Zero-drag satellite ・ Zero-emissions vehicle ・ Zero-energy building ・ Zero-energy universe ・ Zero-Force Evolutionary Law ・ Zero-forcing precoding ・ Zero-fuel weight ・ Zero-G (disambiguation) ・ Zero-G Ltd ・ Zero-hour contract ・ Zero-inflated model ・ Zero-intelligence trader ・ Zero-K ・ Zero-knowledge password proof ・ Zero-knowledge proof ・ Zero-length launch ・ Zero-level elevation ・ Zero-lift drag coefficient ・ Zero-load ・ Zero-marking in English Dictionary Lists mini英和辞書 mini和英辞書 Webster 1913 Latin-English FOLDOC Wikipedia English ウィキペディア

翻訳と辞書　辞書検索 [ 開発暫定版 ] スポンサード リンク Zero-forcing precoding ： ウィキペディア英語版 Zero-forcing precoding Zero-forcing (or Null-Steering) precoding is a method of spatial signal processing by which the multiple antenna transmitter can null multiuser interference signals in wireless communications. Regularized zero-forcing precoding is enhanced processing to consider the impact on a background noise and unknown user interference, where the background noise and the unknown user interference can be emphasized in the result of (known) interference signal nulling. In particular, Null-Steering is a method of beamforming for narrowband signals where we want to have a simple way of compensating delays of receiving signals from a specific source at different elements of the antenna array. In general to make better use of the antenna arrays, we sum and average the signals coming to different elements, but this is only possible when delays are equal. Otherwise, we first need to compensate the delays and then sum them up. To reach this goal, we may only add the weighted version of the signals with appropriate weight values. We do this in such a way that the frequency domain output of this weighted sum produces a zero result. This method is called null steering. The generated weights are of course related to each other and this relation is a function of delay and central working frequency of the source. ==Performance of Zero-forcing Precoding== If the transmitter knows the downlink channel state information (CSI) perfectly, ZF-precoding can achieve almost the system capacity when the number of users is large. On the other hand, with limited channel state information at the transmitter (CSIT) the performance of ZF-precoding decreases depending on the accuracy of CSIT. ZF-precoding requires the significant feedback overhead with respect to signal-to-noise-ratio (SNR) so as to achieve the full multiplexing gain. Inaccurate CSIT results in the significant throughput loss because of residual multiuser interferences. Multiuser interferences remain since they can not be nulled with beams generated by imperfect CSIT. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Zero-forcing precoding」の詳細全文を読む スポンサード リンク 翻訳と辞書 : 翻訳のためのインターネットリソース Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.