著者らは，これまでアナログ部で素子数と同数のマルチビームから電力が大きいビームを選択し，選択したビームを出力としてディジタル信号処理でConstant Modulus Algorithm (CMA) を適用するmassive MIMO 伝送法を提案してきた．本手法は，伝搬チャネル応答(Channel State Information : CSI) 推定を不要とするため，MassiveMIMO を適用したシステムで大きく伝送効率を改善できる．これまで，上り回線における提案方法の有効性を明らかにしてきた．しかしながら，次世代移動通信では下り回線の伝送速度高速化が不可欠である．本報告では，簡易なビーム制御で提案方法の下り回線におけるmassive MIMO の性能評価を行った結果を示す．
（英）
Multi-beam massive MIMO configuration has proposed that utilizes the beam selection with high powerin analog part and blind algorithm such as constant modulus algorithm (CMA) which does not need channel state information (CSI) is applied in digital part. The proposed configuration obtains high transmission efficiency because the CSI estimation itself is eliminated by the proposed method. We have evaluated the performance in the uplink by the proposed method. However, it is essential to enhance the transmission rate of downlink in future wireless communication systems. In this report, we evaluate the transmission performance in the downlink with simple beamforming by the proposed massive MIMO transmission.