Sum Spectral Efficiency Optimization for Rate Splitting in Downlink MU-MISO: A Generalized Power Iteration Approach

Jeonghun Park, Jinseok Choi, Namyoon Lee, Wonjae Shin, H. Vincent Poor

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

In this paper, we consider a downlink multiple-input multiple-output (MIMO) system, where a rate splitting approach is applied to serve multiple users more efficiently. We formulate a sum spectral efficiency maximization problem with respect to precoders when noisy channel state information is available at the transmitter. Finding even a suboptimal solution is a very challenging task by its non-convexity and non-smoothness. To resolve this challenge, we first approximate the non-smooth minimum function by using a LogSumExp technique, and reformulate the problem as a form of the product of Rayleigh quotients, considering channel estimation error. Then we derive the first-order optimality condition. A key observation of the obtained condition is that it can be cast as a nonlinear eigenvector-dependent eigenvalue problem so that finding a leading eigenvector is equivalent to finding a local optimal solution. To this end, we propose an algorithm inspired by a power iteration method, referred to as a generalized power iteration for rate splitting. Simulation results show that the proposed method enhances the achievable performance when channel acquisition error exists.

Original languageEnglish (US)
Title of host publication2021 IEEE Wireless Communications and Networking Conference Workshops, WCNCW 2021
PublisherInstitute of Electrical and Electronics Engineers Inc.
ISBN (Electronic)9781728195070
DOIs
StatePublished - Mar 29 2021
Event2021 IEEE Wireless Communications and Networking Conference Workshops, WCNCW 2021 - Nanjing, China
Duration: Mar 29 2021 → …

Publication series

Name2021 IEEE Wireless Communications and Networking Conference Workshops, WCNCW 2021

Conference

Conference2021 IEEE Wireless Communications and Networking Conference Workshops, WCNCW 2021
CountryChina
CityNanjing
Period3/29/21 → …

All Science Journal Classification (ASJC) codes

  • Hardware and Architecture
  • Computer Networks and Communications
  • Computer Science Applications

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