Mobile communications are penetrating into society at a high rate. The demand for new services to support Internet and video presents technical challenges. Mobility requires adaptation to time varying channel conditions, and portability imposes constraints on receiver size and power consumption. This book presents techniques that improve the performance of the system. All the techniques described here are classified as block transmission systems. The first system described in this book aims to reduce the complexity of the receiver by moving the qualization done in the receiver to the transmitter. This technique results in a 2 dB enhancement in performance in comparison with the normal Block Linear Equalizer where all the equalization is done at the receiver. In the second system, a sharing strategy was applied on the precoding system in order to increase the performance of the system. This makes the system more immune toward additive noise, and results in 2dB enhancement more than the precoder, and 4 dB more than BLE. The third system is proposed to reduce the bandwidth with a performance similar to the precoding system proposed.