Channel Tracking and Transmit Beamforming With Frugal Feedback

作者: Omar Mehanna , Nicholas D. Sidiropoulos

DOI: 10.1109/TSP.2014.2365762

关键词: Communication channelPilot signalTelecommunications linkMaximum a posteriori estimationDuplex (telecommunications)TransmitterPrecodingControl theoryComputer scienceBeamformingMany antennasElectronic 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.