Yupeng Liu Ling Qiu Impact of Channel Estimation Error on the Sum-Rate in MIMO Broadcast Channels with User Selection. 955-958 2008 91-B IEICE Transactions 3 http://dx.doi.org/10.1093/ietcom/e91-b.3.955 db/journals/ieicet/ieicet91b.html#LiuQ08