Unlike the general concept of eliminating or avoiding inter-user interference in the downlink multi-user multiple-input single-output (MISO) system, the data-Aided precoding scheme attempts to exploit the constructive interference at symbol level. Positive interference can be constructed to enhance the received signal gain by predicting the phase and magnitude of the inter-user interference. In this paper, we formulate a constructive interference optimization problem that minimizes a sum of minimum mean square error (MMSE) for all users, while ensuring the minimum required constructive interference gain with a fixed total power constraint. As opposed to the existing scheme, such as constructive zero-forcing precoding or minimum power precoding subject to strict phase conservation for phase-shift keying (PSK), our proposed scheme exploits a full range of relaxation for the constructive interference region, while ensuring the link performance by minimizing the sum of mean-square error (MSE) for all users. In fact, the relaxed requirements lead to more degrees of freedom for improving the cumulative constructive interference gain (CCIG) under the varying channel conditions. Furthermore, our MMSE-based optimization approach allows for a semi-closed-form optimal solution to the data-Aided precoding scheme, providing a more CCIG without incurring unacceptable complexity than other state-of-The-Art schemes.
Bibliographical noteFunding Information:
Manuscript received September 22, 2017; revised May 20, 2018; accepted December 11, 2018. Date of publication January 4, 2019; date of current version February 11, 2019. This work was supported in part by the Institute for Information and communications Technology Promotion (IITP) Grant funded by the Korea Government (MSIT) under Grant 2014-0-00282, and in part by the Development of 5G Mobile Communication Technologies for Hyperconnected smart services, in part by The Cross-Ministry Giga KOREA Project Grant funded by the Korea Government (MSIT) (Grant GK18S0400, Research and Development of Open 5G Reference Model). The associate editor coordinating the review of this paper and approving it for publication was N. Gonzalez-Prelcic. (Corresponding author: Chung G. Kang.) Y. Choi was with the School of Electrical Engineering, Korea University, Seoul 02841, South Korea. He is now with Samsung Electronics Co., Ltd., Suwon 16678, South Korea (e-mail: email@example.com).
© 2002-2012 IEEE.
- KKT conditions
- Multi-user MISO downlink system
- constructive interference gain
- constructive interference optimization (CIO)
- data-Aided precoding
- minimum mean square error (MMSE)
ASJC Scopus subject areas
- Computer Science Applications
- Electrical and Electronic Engineering
- Applied Mathematics