METHOD AND APPARATUS FOR COMPRESSING CHANNEL STATE INFORMATION BASED ON PATH LOCATION INFORMATION

摘要

Methods and apparatus are described for compressing channel state information (CSI) in time-domain based on path location information for CSI feedback. Downlink (DL) CSI is compressed in the time domain and fed back by not sending the multipath location information, or sending at a very low rate. In one method, a wireless transmit/receive unit (WTRU) selects the strongest multipath components based on channel characteristics. The multipath components are quantized in the time domain via direct or vector based quantization. The base station reconstructs a channel impulse response from the fed back quantized multipath components and applies same to precoding processing. In another method, the WTRU feeds back information associated with a narrowband portion(s) of a system spectrum. The selected narrowband portion(s) have sufficient density over time to allow good precoding per subband or across the system spectrum. Short term feedback may be augmented with long term channel information.