Wei Wang 0020 Gang Shen 0001 Shan Jin Dongyao Wang Jiming Chen Approximate minimum SER precoding for spatial multiplexing over Ricean channels. 2360-2364 2009 PIMRC https://doi.org/10.1109/PIMRC.2009.5450205 conf/pimrc/2009 db/conf/pimrc/pimrc2009.html#WangSJWC09