Showing papers by "Gam D. Nguyen published in 2015"
25 May 2015
TL;DR: This work considers a wireless network consisting of source-destination pairs, in which each source is required to transmit a given bit volume to its destination, and shows that TDMA scheduling is appropriate for this goal, in the sense thatTDMA is asymptotically optimal when the time constraint approaches infinity.
Abstract: We consider a wireless network consisting of source-destination pairs, in which each source is required to transmit a given bit volume to its destination. The goal is for all the sources to transmit the given bit volumes, under a time constraint, so that the total transmission energy is minimized. Our approach is the joint optimization of link scheduling and power control for minimum energy. We show that TDMA scheduling is appropriate for this goal, in the sense that TDMA is asymptotically optimal when the time constraint approaches infinity. When the time constraint is strictly bounded, we show that TDMA is also optimal for the case of equal channel gains.
5 citations
TL;DR: Cognitive radio networking methods for a heavy-traffic model in which the channel is always occupied by primary users are developed, using an “underlay” approach to cognitive radio networking by allowing secondary users to share the channel with simultaneously transmitting primary users.
Abstract: We develop cognitive radio networking methods for a heavy-traffic model in which the channel is always occupied by primary users. This contrasts with the interference-avoidance approach for the non-heavy-traffic model, in which primary users have idle times, and secondary users are allowed to use the channel at those idle times. We use an “underlay” approach to cognitive radio networking by allowing secondary users to share the channel with simultaneously transmitting primary users. Thus, secondary users can degrade the performance of primary users, and our goal is to ensure that the level of performance degradation is acceptable. This is accomplished by scheduling and coordinating the transmissions among users, as well as providing a safeguard for controlling the level of additional interference caused by transmissions from secondary users. We show that our methods can provide additional throughput for secondary users, while maintaining the performance of primary users at the specified level.
2 citations