2014/02/19 by SaiDhiraj Amuru, Amuru, SaiDhiraj, Ravi Tandon +3
Engineering · #Advanced MIMO Systems Optimization #Energy Harvesting in Wireless Networks #Advanced Wireless Network Optimization
paper · pdf · doi:10.48550/arxiv.1402.4729
The 3-user multiple-input single-output (MISO) broadcast channel (BC) with\nhybrid channel state information at the transmitter (CSIT) is considered. In\nthis framework, there is perfect and instantaneous CSIT from a subset of users\nand delayed CSIT from the remaining users. We present new results on the\ndegrees of freedom (DoF) of the 3-user MISO BC with hybrid CSIT. In particular,\nfor the case of 2 transmit antennas, we show that with perfect CSIT from one\nuser and delayed CSIT from the remaining two users, the optimal DoF is 5/3. For\nthe case of 3 transmit antennas and the same hybrid CSIT setting, it is shown\nthat a higher DoF of 9/5 is achievable and this result improves upon the best\nknown bound. Furthermore, with 3 transmit antennas, and the hybrid CSIT setting\nin which there is perfect CSIT from two users and delayed CSIT from the third\none, a novel scheme is presented which achieves 9/4 DoF. Our results also\nreveal new insights on how to utilize hybrid channel knowledge for multi-user\nscenarios.\n