Downlink Beamforming
In wireless communications, either more spectrum or higher spectral efficient communication technologies can increase the data rate, which enables to service various multimedia contents. Since frequency spectrum is a natural resource, it is inherently limited so that it costs very high. Therefore, it is very important to find highly spectral efficient communication technologies. However, new good technologies requires higher complexity in terms of development, installation and so on. Therefore, our research goal is either to optimize the current technology and to find a new innovative technology. Beamforming is a scheme to overcome the limitation of the spectrum resource. Beamforming is used for spatial division multiple access which increases the system throughput by spatially diving multiple user signals. Spatially diving let multiple users communicate simultaneously in a same frequency band. When beamforming is applied for the downlink transmission, we call it as downlink beamform