 per full system bandwidth when the system bandwidth (or subset of resource blocks [RBs]) is smaller than or equal to 12 RBs and per five adjacent resource blocks or the full system bandwidth (or subset of resource blocks) when the system bandwidth is larger than 12 RBs; and rank adaptation with single rank feedback referring to full system band- width; node B can override rank report. 5.2 SU-MIMO 5.2.1 Layer Mapping for Spatial Multiplexing The complex-valued modulation symbols for each of the code words to be trans- mitted are mapped onto one or several layers. Complex-valued modulation sym- bols (M ( 1) for code word q are mapped onto the layers x(i) = [x(0) 1, where V is the number of layers and M symb layer is the number of modulation symbols per layer. For spatial multiplexing, the layer mapping is done according to Table 5.1. The number of layers V is less than or equal to the number of antenna ports P used for transmission of the physical channel. 5.2.2 Layer Mapping for Transmit Diversity For transmit diversity, the layer mapping is done according to Table 5.2. There is only one code word, and the number of layers V is equal to the number of antenna ports P used for transmission of the physical channel. © 2009 by Taylor & Francis Group, LLC Long Term Evolution: 3GPP LTE Radio and Cellular Technology Table 5.1 Code-Word-to-Layer Mapping for Spatial Multiplexing Number of Number of Layers Code Words Code-Word-to-Layer Mapping i = 0,1, M layer = d(0) (i) X(0)(i)=d(0) = (i) X(0)(i)=d(0) = (i) x(1) (i) = d(¹) (2i) x(2) = d(1) (2i 1) x(0) (i) = d(0) (2i) x(1) (i) = d(0) (2i+1) x(2) (i) = d(¹) (2i) x(3) (i) = d(1) (2i+1) 5.2.3 Precoding The precoder takes as input a block of vectors x(i) = 0, - 1 from the layer mapping and generates a block of .]T, - 1 to be mapped onto resources on each of the antenna ports, where y(p) (i) represents the signal for antenna port p. 5.2.3.1 Precoding for Transmission on a Single Antenna Port For transmission on a single antenna port, precoding is defined by Table 5.2 Code-Word-t