Firstly, we define a set of transmit beamforming (TxBF) transceiver architectures in the framework of IEEE 802.11n systems. In the following, assuming frequency selective spatially correlated TGn D channels, we carry out a comparative performance analysis taking into accounting the effects of realistic time synchronization and channel estimation schemes and practical feedback issues (i.e., delay, quantization and subcarrier grouping) on the throughput gains of the TxBF schemes over the Vertical Bell lab Layered Space Time (V-BLAST) spatial division multiplexing (SDM) scheme.