Wireless communication channelsInformation theory of underspread WSSUS channelsIn this project, we developed the theory of communication over timefrequency varying wireless channels, taking into account the cost of acquiring the channel state information (CSI) 7,8. The theory leads to a new criterion on how to choose a good signal set for communication. Mathematically, this work relies on analyzing the action of the timefrequency varying channel operator upon the highlystructured WeylHeisenberg signal set. Materials:
Capacity of multiantenna noncoherent channelsIn this project, we discovered that one additional antenna at the receiver device can substantially reduce the cost of acquiring the CSI. With this idea the resources that normally would be spent learning the CSI, can now be used to transmit useful information, thus increasing the data rate in the channel. Mathematically, this work relies on understanding the manifold geometry corresponding to the communication channel. Materials:
