{"id":559,"date":"2007-08-01T03:30:26","date_gmt":"2007-08-01T03:30:26","guid":{"rendered":"http:\/\/network.ee.tsinghua.edu.cn\/niulab\/?p=559"},"modified":"2010-08-24T11:37:05","modified_gmt":"2010-08-24T11:37:05","slug":"adaptive-orthonormal-random-beamforming-and-multi-beam-selection-for-cellular-systems","status":"publish","type":"post","link":"https:\/\/network.ee.tsinghua.edu.cn\/niulab\/?p=559","title":{"rendered":"Adaptive Orthonormal Random Beamforming and Multi-beam Selection for Cellular Systems"},"content":{"rendered":"<p><a href=\"http:\/\/network.ee.tsinghua.edu.cn\/papers\/zhangkai_ieicetrans07_2.pdf\" target=\"_blank\"><img loading=\"lazy\" decoding=\"async\" class=\"alignright size-full wp-image-117\" title=\"pdf\" src=\"https:\/\/network.ee.tsinghua.edu.cn\/niulab\/wp-content\/uploads\/2010\/08\/pdf.gif\" alt=\"\" width=\"95\" height=\"50\" \/><\/a><br \/>\n<span class=\"paper_subtitle\">LANGUAGE<\/span><br \/>\nEnglish<br \/>\n<span class=\"paper_subtitle\">SOURCE<\/span><br \/>\nIEICE Trans. on Comm., Vol.E90-B, No.8, 2007<br \/>\n<span class=\"paper_subtitle\">Published Date<\/span>:2007-08-01<br \/>\n<span class=\"paper_subtitle\">ABSTRACT<\/span><br \/>\nChannel state information (CSI) at transmitter plays an important role for multiuser MIMO broadcast channels, but full CSI at transmitter is not available for many practical systems. Previous work has proposed orthonormal random beamforming (ORBF) [16] for MIMO broadcast channels with partial channel state information (CSI) feedback, and shown that ORBF achieves the optimal sum-rate capacity for a large number of users. However, for cellular systems with moderate number of users, i.e., no more than 64, ORBF only achieves slight performance gain. Therefore, we analyze the performance of ORBF with moderate number of users and total transmit power constraint and show that ORBF scheme is more e\u00b1cient under low SNR. Then we propose an adaptive ORBF scheme that selects the number of random beams for simultaneous transmission according to the average signal-to-noise ratio (SNR). Moreover, a multi-beam selection (MBS) scheme that jointly selects the number and the subset of the multiple beams is proposed to further improve the system performance for low SNR cases. The simulation results show that the proposed schemes achieve significant performance improvement when the number of users is moderate.<br \/>\n<span class=\"paper_subtitle\">KEYWORDS<\/span><br \/>\nMIMO, Broadcast Channels, Random beamforming, Multi-beam selection<\/p>\n","protected":false},"excerpt":{"rendered":"<p><a href=\"http:\/\/network.ee.tsinghua.edu.cn\/papers\/zhangkai_ieicetrans07_2.pdf\" target=\"_blank\"><img loading=\"lazy\" decoding=\"async\" class=\"alignleft size-full wp-image-117\" title=\"pdf\" src=\"https:\/\/network.ee.tsinghua.edu.cn\/niulab\/wp-content\/uploads\/2010\/08\/pdf.gif\" alt=\"\" width=\"95\" height=\"50\" \/><\/a>Kai ZHANG and Zhisheng NIU, <span class=\"papertitle\">Adaptive Orthonormal Random Beamforming and Multi-beam Selection for Cellular Systems<\/span>, <span class=\"papersource\">IEICE Trans. on Comm., Vol.E90-B, No.8, 2007<\/span><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[7],"tags":[100,45,18],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/network.ee.tsinghua.edu.cn\/niulab\/index.php?rest_route=\/wp\/v2\/posts\/559"}],"collection":[{"href":"https:\/\/network.ee.tsinghua.edu.cn\/niulab\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/network.ee.tsinghua.edu.cn\/niulab\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/network.ee.tsinghua.edu.cn\/niulab\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/network.ee.tsinghua.edu.cn\/niulab\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=559"}],"version-history":[{"count":3,"href":"https:\/\/network.ee.tsinghua.edu.cn\/niulab\/index.php?rest_route=\/wp\/v2\/posts\/559\/revisions"}],"predecessor-version":[{"id":963,"href":"https:\/\/network.ee.tsinghua.edu.cn\/niulab\/index.php?rest_route=\/wp\/v2\/posts\/559\/revisions\/963"}],"wp:attachment":[{"href":"https:\/\/network.ee.tsinghua.edu.cn\/niulab\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=559"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/network.ee.tsinghua.edu.cn\/niulab\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=559"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/network.ee.tsinghua.edu.cn\/niulab\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=559"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}