es to provide the peak data rate, average throughput, and system per- formance in 3GPP LTE. Based on the function of the multiple transmission symbol streams in MIMO, the operation modes of multiple transmit antennas at the cell site (denoted as MIMO mode) are spatial division multiplexing (SDM), precoding, and transmit diversity (TD). Based on the allocation of the multiple transmission streams in MIMO, the MIMO mode is denoted as single user (SU)-MIMO if the multiple transmission symbol streams are solely assigned to a single UE and multiuser (MU)-MIMO if the spatial division multiplexing of the modulation symbol streams for differ- ent UEs uses the same time-frequency resource. Because the LTE downlink is an OFDM system, the MIMO modes proposed in LTE are MIMO-OFDM schemes. Chapter 5 ("MIMO OFDM Schemes for 3GPP LTE") introduces the two main categories of MIMO-OFDM schemes in LTE-SU-MIMO and MU-MIMO- and the related physical channel procedures. The performance of selected code- books is provided to show their advantages. Uplink transmission in the LTE of the UMTS terrestrial radio access system (UTRA LTE) has numerous physical layer advantages in comparison to UTRA WCDMA, mainly to achieve two to three times better spectral efficiency. These include flexible channel bandwidth up to 20 MHz, flexible user resource alloca- tion in both time and frequency domains, and a shorter time transmission interval (TTI) of 1 ms. Specifically challenging for the uplink is that these enhancements are to be achieved, preferably, with reduced power consumption to extend the bat- tery life and cell coverage. The radio access technique is one of the key issues in the LTE uplink air interface. In LTE, OFDMA has been selected as the multiple- access scheme for downlink and single-carrier frequency division multiple access (SC-FDMA) for uplink. OFDM is an attractive modulation technique in a cellular environment to combat frequency selective fading channels with a relatively low- © 2009 by Taylor & Francis Group, LLC Introduction co