Abstract of the Lecture 2 [Dr. S. Kashyap, IIT Guwahati]

Title: Role of Channel State Information in Adaptation and Resource Allocation in Next Generation Wireless Systems

Abstract: Motivated by the ever-increasing demand for higher data rates, coverage, and spectral efficiency, current and next generation wireless systems must adapt their transmission parameters and perform resource allocation based on the variations in the instantaneous channel states. However, adaptation and/or resource allocation requires knowledge of channel state information (CSI), which might not be available a priori at the node or nodes that are adapting or allocating resources and must be estimated through channel training.

In the first part, we will present examples to elucidate the role of CSI in adaptation and resource allocation in the context of a next generation wireless technology, namely, Massive MIMO (Multiple Input Multiple Output) systems. In these systems, hundreds of antennas at the base station serve tens of users over the same time and frequency through spatial multiplexing. The second part will focus on another next generation technology, namely, Cognitive radio (CR), which itself is a form of adaptation in which secondary users (SUs) adapt their transmissions to avoid interfering with the licensed primary users (PUs), who own the spectrum. We will present examples of symbol error probability (SEP)-optimal transmit power adaptation policies when the SUs are subject to different kinds of interference and transmit power constraints.