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Iterative Water-filling for Gaussian Vector Multiple Access Channel. Wei Yu, Wonjong Rhee, Stephen Boyd and John M. Cioffi IEEE Trans. Inform ., 2002 Presenters: Xingkai Bao and Zhenlei Shen. Outline. Introduction Multiple Access Channel Rate region for 2 user MAC goal
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Iterative Water-filling for Gaussian Vector Multiple Access Channel Wei Yu, Wonjong Rhee, Stephen Boyd and John M. Cioffi IEEE Trans. Inform., 2002 Presenters: Xingkai Bao and Zhenlei Shen
Outline • Introduction • Multiple Access Channel • Rate region for 2 user MAC • goal • Optimization for Sum Capacity • Singer-user Water-filling • Multi-user Water-filling • Iterative Water-filling • Conclusion
Introduction-- Multiple Access Channel • Multiple uncoordinated transmitters send independent information to a common receiver
Introduction-- Rate region for 2 user MAC • Constraint • Total power • Changing • Pentagon • Hull • Convex • Intersection • Water filling
Introduction--Goal Find a numerical algorithm that can be used to efficiently compute the sum capacity achieving input distribution for a Gaussian vector multiple access channel
Optimization for sum capacity--Single-user water-filling • Solve where Orthogonal matrix
Optimization for sum capacity--Single-user water-filling • Step 1: We can rewrite the problem as
Optimization for sum capacity--Single-user water-filling • Step 2:
Optimization for sum capacity--Single-user water-filling • Results
Optimization for sum capacity--Multi-user water-filling • Solve where is the covariance matrix of the i’th user • Result
Thank you Welcome Zhenlei to present The numerical algorithm of iterative waterfilling