Downlink Beamforming

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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 beamforming.

Downlink beamforming requires feedback signaling of downlink channel information from each user to the transmitter. The performance of a downlink beamforming depends on the accuracy of feedback signaling. Hence we need new scheme which breaks the current tradeoff curve between the performance of the systems and the requirement of feedback signaling.

Comments

  1. AnonymousMarch 8, 2008 at 9:39 PM

    This is more understandable than before. Thank for your kind explanation.

    ReplyDelete

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