Computer Science – Information Theory
Scientific paper
2008-06-27
Computer Science
Information Theory
To appear in IEEE Transactions on Information Theory
Scientific paper
This paper studies the information-theoretic limits of a secondary or cognitive radio (CR) network under spectrum sharing with an existing primary radio network. In particular, the fading cognitive multiple-access channel (C-MAC) is first studied, where multiple secondary users transmit to the secondary base station (BS) under both individual transmit-power constraints and a set of interference-power constraints each applied at one of the primary receivers. This paper considers the long-term (LT) or the short-term (ST) transmit-power constraint over the fading states at each secondary transmitter, combined with the LT or ST interference-power constraint at each primary receiver. In each case, the optimal power allocation scheme is derived for the secondary users to achieve the ergodic sum capacity of the fading C-MAC, as well as the conditions for the optimality of the dynamic time-division-multiple-access (D-TDMA) scheme in the secondary network. The fading cognitive broadcast channel (C-BC) that models the downlink transmission in the secondary network is then studied under the LT/ST transmit-power constraint at the secondary BS jointly with the LT/ST interference-power constraint at each of the primary receivers. It is shown that D-TDMA is indeed optimal for achieving the ergodic sum capacity of the fading C-BC for all combinations of transmit-power and interference-power constraints.
Cui Shuguang
Liang Ying-Chang
Zhang Rui
No associations
LandOfFree
On Ergodic Sum Capacity of Fading Cognitive Multiple-Access and Broadcast Channels does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with On Ergodic Sum Capacity of Fading Cognitive Multiple-Access and Broadcast Channels, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and On Ergodic Sum Capacity of Fading Cognitive Multiple-Access and Broadcast Channels will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-692613