SPC10-2: Iterative Water-filling for Optimal Resource Allocation in OFDM Multiple-Access and Broadcast Channels

A class of optimal resource allocation problems in linear Gaussian multiple-access and broadcast channels (MAC and BC) can be summarized as weighted sum power minimization problem. In this paper an iterative water-filling algorithm is proposed to solve this problem efficiently. It is shown that by formulating an explicit rate expression for MAC, though non-convex of power spectral densities, the optimality conditions demonstrate a strong water-filling flavor. By iteratively solving the optimality conditions, whereas in each iteration a slightly modified single-user margin adaptive water-filling(MAWF) algorithm is applied to update the dual variable in a greedy manner, the power spectral density of each user converges to the optimal solution very fast. Simulations verify convergence and optimality. The problem in BC can be solved in its dual MAC.

[1]  David Tse,et al.  Multiaccess Fading Channels-Part II: Delay-Limited Capacities , 1998, IEEE Trans. Inf. Theory.

[2]  Andrea J. Goldsmith,et al.  On the duality of Gaussian multiple-access and broadcast channels , 2002, IEEE Transactions on Information Theory.

[3]  Sergio Verdú,et al.  Gaussian multiaccess channels with ISI: Capacity region and multiuser water-filling , 1993, IEEE Trans. Inf. Theory.

[4]  Wei Yu,et al.  Iterative water-filling for Gaussian vector multiple-access channels , 2001, IEEE Transactions on Information Theory.

[5]  Stephen P. Boyd,et al.  Convex Optimization , 2004, Algorithms and Theory of Computation Handbook.

[6]  Andrea J. Goldsmith,et al.  Outage capacities and optimal power allocation for fading multiple-access channels , 2005, IEEE Transactions on Information Theory.

[7]  John M. Cioffi,et al.  Optimum power allocation and control for OFDM in multiple access channels , 2004, IEEE 60th Vehicular Technology Conference, 2004. VTC2004-Fall. 2004.

[8]  David Tse,et al.  Multiaccess Fading Channels-Part I: Polymatroid Structure, Optimal Resource Allocation and Throughput Capacities , 1998, IEEE Trans. Inf. Theory.

[9]  Andrea J. Goldsmith,et al.  Duality, achievable rates, and sum-rate capacity of Gaussian MIMO broadcast channels , 2003, IEEE Trans. Inf. Theory.

[10]  John M. Cioffi,et al.  Optimized transmission for fading multiple-access and broadcast channels with multiple antennas , 2006, IEEE Journal on Selected Areas in Communications.

[11]  David Tse,et al.  Optimal power allocation over parallel Gaussian broadcast channels , 1997, Proceedings of IEEE International Symposium on Information Theory.