Network Control Without CSI Using Rateless Codes for Downlink Cellular Systems
Wireless network scheduling and control techniques (e.g., opportunistic scheduling) rely heavily on access to Channel State Information (CSI). However, obtaining this information is costly in terms of bandwidth, time, and power, and could result in large overhead. Therefore, a critical question is how to optimally manage network resources in the absence of such information. To that end, the authors develop a cross-layer solution for downlink cellular systems with imperfect (and possibly no) CSI at the transmitter. They use rateless codes to resolve channel uncertainty. To keep the decoding complexity low, they explicitly incorporate time-average block-size constraints, and aim to maximize the system utility.