作者: Omar Mehanna , Nicholas D. Sidiropoulos
关键词: Communication channel 、 Pilot signal 、 Telecommunications link 、 Maximum a posteriori estimation 、 Duplex (telecommunications) 、 Transmitter 、 Precoding 、 Control theory 、 Computer science 、 Beamforming 、 Many antennas 、 Electronic engineering
摘要: Channel state feedback is a serious burden that limits deployment of transmit beamforming systems with many antennas in frequency-division duplex (FDD) mode. Transmit limited estimate the channel at receiver and send quantized or beamformer information to transmitter. A different approach exploits spatio-temporal correlation proposed here. The transmitter periodically sends beamformed pilot signal downlink, while quantizes corresponding received feeds back bits Assuming an autoregressive (AR) model, Kalman filtering (KF) based on sign innovations (SOI) for tracking, closed-form expressions estimation mean-squared error (MSE) are derived under certain conditions. For more general models, novel tracking quantization maximum posteriori (MAP) formulation. Simulations show close optimum performance can be attained only 2 per dwell time block, even antennas. This clears hurdle FDD mode—which was almost impossible prior state-of-art.