Partial update adaptive transmit beamforming with limited feedback

This work proposes a new partial update filtering technique tailored for adaptive transmit beamforming with low feedback rate. A signal dependent selection rule is derived that singles out one component of the beamforming vector to be updated. This provides an efficient way to perform the update, which escalates the performance with the number of available feedback bits without increasing the computational complexity. An operation count for the proposed algorithm and existing solutions is provided. Simulations show that the proposed scheme outperforms the tracking capabilities of existing code-book solutions in low mobility scenarios, while having comparable bit error probability performance and a computational complexity reduction of 90%.