# Multiuser Transmit Precoding Design for Dimming Compatible Visible Light Communications
[PERSON]  
1 Jiangsu Provincial Engineering Laboratory of Pattern Recognition and Computational Intelligence, Jiangnan University, Wuxi 214122, China; 2 [EMAIL_ADDRESS] (B.L. ); 1 [EMAIL_ADDRESS] (X.X. ); 1 [EMAIL_ADDRESS] (Q.W. ); [EMAIL_ADDRESS] (Y.L. ); 1 [EMAIL_ADDRESS] (G.W.) [PERSON]  
1 Jiangsu Provincial Engineering Laboratory of Pattern Recognition and Computational Intelligence, Jiangnan University, Wuxi 214122, China; 2 [EMAIL_ADDRESS] (B.L. ); 1 [EMAIL_ADDRESS] (X.X. ); 1 [EMAIL_ADDRESS] (Q.W. ); [EMAIL_ADDRESS] (Y.L. ); 1 [EMAIL_ADDRESS] (G.W.) [PERSON]  
1 Jiangsu Provincial Engineering Laboratory of Pattern Recognition and Computational Intelligence, Jiangnan University, Wuxi 214122, China; 2 [EMAIL_ADDRESS] (B.L. ); 1 [EMAIL_ADDRESS] (X.X. ); 1 [EMAIL_ADDRESS] (Q.W. ); [EMAIL_ADDRESS] (Y.L. ); 1 [EMAIL_ADDRESS] (G.W.) [PERSON]  
1 Jiangsu Provincial Engineering Laboratory of Pattern Recognition and Computational Intelligence, Jiangnan University, Wuxi 2141222, China; 2 [EMAIL_ADDRESS] (B.L. ); 1 [EMAIL_ADDRESS] (X.X. ); 1 [EMAIL_ADDRESS] (Q.W. ); [EMAIL_ADDRESS] (Y.L. ); 1 [EMAIL_ADDRESS] (G.W.) [PERSON]  
1 Jiangsu Provincial Engineering Laboratory of Pattern Recognition and Computational Intelligence, Jiangnan University, Wuxi 214122, China; 2 [EMAIL_ADDRESS] (B.L. ); 1 [EMAIL_ADDRESS] (X.X. ); 1 [EMAIL_ADDRESS] (Q.W. ); [EMAIL_ADDRESS] (Y.L. ); 1 [EMAIL_ADDRESS] (G.W.) [PERSON]  
1 Jiangsu Provincial Engineering Laboratory of Pattern Recognition and Computational Intelligence, Jiangnan University, Wuxi 214122, China; 2 [EMAIL_ADDRESS] (B.L. ); 1 [EMAIL_ADDRESS] (X.X. ); 1 [EMAIL_ADDRESS] (Q.W. ); [EMAIL_ADDRESS] (Y.L. ); 1 [EMAIL_ADDRESS] (G.W.) [PERSON]  
1 Jiangsu Provincial Engineering Laboratory of Pattern Recognition and Computational Intelligence, Jiangnan University, Wuxi 2141222, China; 2 [EMAIL_ADDRESS] (B.L. ); 1 [EMAIL_ADDRESS] (X.X. ); 1 [EMAIL_ADDRESS] (Q.W. ); [EMAIL_ADDRESS] (Y.L. ); 1 [EMAIL_ADDRESS] (G.W.) [PERSON]  
1 Jiangsu Provincial Engineering Laboratory of Pattern Recognition and Computational Intelligence, Jiangnan University, Wuxi 2141222, China; 2 [EMAIL_ADDRESS] (B.L. ); 1 [EMAIL_ADDRESS] (X.X. ); 1 [EMAIL_ADDRESS] (Q.W. ); [EMAIL_ADDRESS] (Y.L. ); 1 [EMAIL_ADDRESS] (G.W.) [PERSON]  
1 Jiangsu Provincial Engineering Laboratory of Pattern Recognition and Computational Intelligence, Jiangnan University, Wuxi 214122, China; 2 blong@[EMAIL_ADDRESS] (B.L. ); 1 [EMAIL_ADDRESS] (B.L. ); 1 [EMAIL_ADDRESS] (B.L. ); 1 [EMAIL_ADDRESS] (B.L. ); 1 [EMAIL_ADDRESS] (B.L. ); 1 [EMAIL_ADDRESS] (B.L. ); 1 [EMAIL_ADDRESS] (B.L. ); 1 [EMAIL_ADDRESS] (B.L. ); 1 [EMAIL_ADDRESS] (B.L. ); 1 [EMAIL_ADDRESS] (B.L. ); 1 [EMAIL_ADDRESS] (B.L. ); 1 [EMAIL_ADDRESS] (B.L. ); 1 xugl@[EMAIL_ADDRESS] (B.  
interference arises, which may severely degrade the system performance if it is not carefully handled. In a multiuser scenario, transmit precoding (TPC) is an effective technique to suppress inter-user interference and improve attainable link performance [10]. The TPC techniques have been extensively studied in RF communications. However, these algorithms cannot be directly applied to VLC due to some specific features of VLC. More specifically, the LED-based indoor lighting infrastructure of VLC is used for simultaneously providing both illumination and communications [11]. Therefore, dimming control is critical and of high priority in practical applications in order to maintain the target illumination level [12; 13]. Furthermore, in the context of intensity modulation and direct detection (IM/DD), the signal transmitted by LEDs is restricted to be non-negative [14]. Both distinctive features have inspired us to develop specific signal processing algorithms for the multiuser VLC system. Recently, there have been several contributions to the multiuser TPC in VLC [15; 16; 17; 18; 19; 20; 21]. The authors of [15; 16; 17; 18] investigated the zero-forcing (ZF) TPC strategies under various design criteria for multiuser VLC systems.