TY - GEN
T1 - Adaptive rate transmission for spectrum sharing system with quantized channel state information
AU - Abdallah, Mohamed
AU - Salem, Ahmed
AU - Alouini, Mohamed Slim
AU - Qaraqe, Khalid A.
PY - 2011
Y1 - 2011
N2 - The capacity of a secondary link in spectrum sharing systems has been recently investigated in fading environments. In particular, the secondary transmitter is allowed to adapt its power and rate to maximize its capacity subject to the constraint of maximum interference level allowed at the primary receiver. In most of the literature, it was assumed that estimates of the channel state information (CSI) of the secondary link and the interference level are made available at the secondary transmitter via an infinite-resolution feedback links between the secondary/primary receivers and the secondary transmitter. However, the assumption of having infinite resolution feedback links is not always practical as it requires an excessive amount of bandwidth. In this paper we develop a framework for optimizing the performance of the secondary link in terms of the average spectral efficiency assuming quantized CSI available at the secondary transmitter. We develop a computationally efficient algorithm for optimally quantizing the CSI and finding the optimal power and rate employed at the cognitive transmitter for each quantized CSI level so as to maximize the average spectral efficiency. Our results give the number of bits required to represent the CSI sufficient to achieve almost the maximum average spectral efficiency attained using full knowledge of the CSI for Rayleigh fading channels.
AB - The capacity of a secondary link in spectrum sharing systems has been recently investigated in fading environments. In particular, the secondary transmitter is allowed to adapt its power and rate to maximize its capacity subject to the constraint of maximum interference level allowed at the primary receiver. In most of the literature, it was assumed that estimates of the channel state information (CSI) of the secondary link and the interference level are made available at the secondary transmitter via an infinite-resolution feedback links between the secondary/primary receivers and the secondary transmitter. However, the assumption of having infinite resolution feedback links is not always practical as it requires an excessive amount of bandwidth. In this paper we develop a framework for optimizing the performance of the secondary link in terms of the average spectral efficiency assuming quantized CSI available at the secondary transmitter. We develop a computationally efficient algorithm for optimally quantizing the CSI and finding the optimal power and rate employed at the cognitive transmitter for each quantized CSI level so as to maximize the average spectral efficiency. Our results give the number of bits required to represent the CSI sufficient to achieve almost the maximum average spectral efficiency attained using full knowledge of the CSI for Rayleigh fading channels.
UR - http://www.scopus.com/inward/record.url?scp=79957799788&partnerID=8YFLogxK
U2 - 10.1109/CISS.2011.5766156
DO - 10.1109/CISS.2011.5766156
M3 - Conference contribution
AN - SCOPUS:79957799788
SN - 9781424498475
T3 - 2011 45th Annual Conference on Information Sciences and Systems, CISS 2011
BT - 2011 45th Annual Conference on Information Sciences and Systems, CISS 2011
T2 - 2011 45th Annual Conference on Information Sciences and Systems, CISS 2011
Y2 - 23 March 2011 through 25 March 2011
ER -