Degree-of-Freedom Based Transmission Protocol Design with Optimization for Multi-Cell Multi-User Green Systems

Chunguo LI
Yongping ZHANG

IEICE TRANSACTIONS on Communications   Vol.E97-B    No.12    pp.2784-2789
Publication Date: 2014/12/01
Online ISSN: 1745-1345
DOI: 10.1587/transcom.E97.B.2784
Type of Manuscript: PAPER
Category: Wireless Communication Technologies
multi-cell,  interference cancellation,  degree of freedom,  energy efficiency,  power allocation,  

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The joint power allocation (PA) issue is studied in multi-user three-cell systems under the degree-of-freedom (DoF) based transmission protocol. This protocol makes all the interferences received at each user orthogonal to the useful signal at the same user by Jafar's topological interference management through index coding, which is proved to offer full DoF. Under this protocol, we formulate the joint power allocations problem based on the objective of energy efficiency under the required quality-of-service constraint. Due to the highly complicated Lagrangian equation, the properties of Lambert function are widely exploited to solve the problem using a closed-form expression. It is discovered that the relationship among the optimal power coefficients are completely different from that of the well-known water-filling method. Simulations demonstrate the energy efficiency of the designed scheme.