This book explores the different strategies regarding limited feedback information. The book analyzes the impact of quantization and the delay of CSI on the performance. The author shows the effect of the reduced feedback information and gives an overview about the feedback strategies in the standards. This volume presents theoretical analysis as well as practical algorithms for the required feedback information at the base stations to perform adaptive resource algorithms efficiently and mitigate interference coming from other cells.
During the past decade, many wireless communication techniques have been
developed to achieve various goals such as higher data rate, more robust link quality,
and higher number of users in a given bandwidth. For wireless communication
systems, depending on the availability of a feedback link, two approaches can be
considered: namely open and closed loop. Open loop communication system that
does not exploit the channel knowledge at the transmitter is now well understood
from both a theoretical and practical point of view. On the other hand, closed loop
based communication systems have emerged as a promising solution to increase
the data rate and the robustness of the communication links by using channel
state information. The performance of single input single output (SISO) closed
loop wireless communication systems can be improved with adaptive modulation
and coding and power allocation by exploiting channel state information at the
transmitter. The potential gains are tremendous in the case of multiuser multiple
input multiple output (MIMO) systems where it can be possible to communicate
to more than one user. Furthermore, cooperative multicell transmission is a recent
solution to increase data rate and reduces outage in wireless networks by mitigating
intercell interference caused by the other cells. The channel state information at
the transmitter can be obtained through the feedback link. Since it is important
to limit the amount of information to feed back, different strategies have been
considered up to now. This book will address all these feedback strategies to design
efficient wireless communication systems from both theoretical and practical issues
including the study of the quantization of the channel state information on the
performance.
