Elements of information theory
Elements of information theory
Convex Optimization
Analysis of iterative waterfilling algorithm for multiuser power control in digital subscriber lines
EURASIP Journal on Applied Signal Processing
Joint multiuser detection and optimal spectrum balancing for digital subscriber lines
EURASIP Journal on Applied Signal Processing
IEEE Transactions on Signal Processing
IEEE Transactions on Signal Processing
Dynamic spectrum management for next-generation DSL systems
IEEE Communications Magazine
Distributed multiuser power control for digital subscriber lines
IEEE Journal on Selected Areas in Communications
Cognitive radio: brain-empowered wireless communications
IEEE Journal on Selected Areas in Communications
Duality gap estimation and polynomial time approximation for optimal spectrum management
IEEE Transactions on Signal Processing
Optimal spectrum management in multiuser interference channels
ISIT'09 Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 4
Noisy-interference sum-rate capacity of parallel Gaussian interference channels
ISIT'09 Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 4
Robust IWFA for open-spectrum communications
IEEE Transactions on Signal Processing
MIMO cognitive radio: a game theoretical approach
IEEE Transactions on Signal Processing
Cognitive MIMO radio: incorporating dynamic spectrum access in multiuser MIMO network
GLOBECOM'09 Proceedings of the 28th IEEE conference on Global telecommunications
IEEE Transactions on Signal Processing
A class of convergent algorithms for resource allocation in wireless fading networks
IEEE Transactions on Wireless Communications
Near-optimal power control in wireless networks: a potential game approach
INFOCOM'10 Proceedings of the 29th conference on Information communications
Dynamic power allocation under arbitrary varying channels - the multi-user case
INFOCOM'10 Proceedings of the 29th conference on Information communications
Hi-index | 754.85 |
Consider a multiuser communication system in a frequency selective environment whereby users share a common spectrum and can interfere with each other. Assuming Gaussian signaling and no interference cancelation, we study optimal spectrum sharing strategies for the maximization of sum-rate under separate power constraints for individual users. Since the sum-rate function is nonconcave in terms of the users' power allocations, there can be multiple local maxima for the sum-rate maximization problem in general. In this paper, we show that, if the normalized crosstalk coefficients are larger than a given threshold (roughly equal to 1/2), then the optimal spectrum sharing strategy is frequency division multiple access (FDMA). In case of arbitrary positive crosstalk coefficients, if each user's power budget exceeds a given threshold, then FDMA is again sum-rate optimal, at least in a local sense. In addition, we show that the problem of finding the optimal FDMA spectrum allocation is NP-hard, implying that the general problem of maximizing sum-rate is also NP-hard, even in the case of two users. We also propose several simple distributed spectrum allocation algorithms that can approximately maximize sum-rates. Numerical results indicate that these algorithms are efficient and can achieve substantially larger sum-rates than the existing Iterative Waterfilling solutions, either in an interference-rich environment or when the users' power budgets are sufficiently high.