### Abstract

Conjugate beamforming (CB) and zero-forcing (ZF) are well-known linear precoders, which have optimized hardware implementations. In this work, a linear precoder is proposed based on switching between CB and ZF for line-of-sight propagation environments. The proposed idea is to predict and use the precoder, which results in the highest sum-rate for a given channel. To this end, three regimes are introduced for the ratio of power per user at the base station (BS) over noise power at a user receiver. For low values of this ratio, CB and for high values, ZF result in the highest sum-rate. For moderate values, a precoding strategy is proposed to switch to the best precoder. The switching mechanism is based on an upper bound for the ZF sum-rate, which we introduced in this work. The proposed precoding strategy achieves a sum-rate higher than both CB and ZF. Simulation results for a massive MIMO system including a l00-antenna BS, show up to 8% improvement on the sum-rate compared to CB and ZF. In addition, the proposed precoder reduces computational complexity up to 16.5% compared to the ZF precoding.

Language | English |
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Title of host publication | 2018 25th International Conference on Telecommunications, ICT 2018 |

Publisher | Institute of Electrical and Electronics Engineers |

Pages | 121-126 |

Number of pages | 6 |

ISBN (Print) | 9781538623213 |

DOIs | |

State | Published - 13 Sep 2018 |

Event | 25th International Conference on Telecommunications, ICT 2018 - Saint Malo, France Duration: 26 Jun 2018 → 28 Jun 2018 |

### Conference

Conference | 25th International Conference on Telecommunications, ICT 2018 |
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Country | France |

City | Saint Malo |

Period | 26/06/18 → 28/06/18 |

### Fingerprint

### Cite this

*2018 25th International Conference on Telecommunications, ICT 2018*(pp. 121-126). [8464908] Institute of Electrical and Electronics Engineers. DOI: 10.1109/ICT.2018.8464908

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*2018 25th International Conference on Telecommunications, ICT 2018.*, 8464908, Institute of Electrical and Electronics Engineers, pp. 121-126, 25th International Conference on Telecommunications, ICT 2018, Saint Malo, France, 26/06/18. DOI: 10.1109/ICT.2018.8464908

**A reduced-complexity linear precoding strategy for massive MIMO base stations.** / Farsaei, Amirashkan; Willems, Frans; Alvarado, Alex; Gustavsson, Ulf.

Research output: Chapter in Book/Report/Conference proceeding › Conference contribution › Academic › peer-review

TY - GEN

T1 - A reduced-complexity linear precoding strategy for massive MIMO base stations

AU - Farsaei,Amirashkan

AU - Willems,Frans

AU - Alvarado,Alex

AU - Gustavsson,Ulf

PY - 2018/9/13

Y1 - 2018/9/13

N2 - Conjugate beamforming (CB) and zero-forcing (ZF) are well-known linear precoders, which have optimized hardware implementations. In this work, a linear precoder is proposed based on switching between CB and ZF for line-of-sight propagation environments. The proposed idea is to predict and use the precoder, which results in the highest sum-rate for a given channel. To this end, three regimes are introduced for the ratio of power per user at the base station (BS) over noise power at a user receiver. For low values of this ratio, CB and for high values, ZF result in the highest sum-rate. For moderate values, a precoding strategy is proposed to switch to the best precoder. The switching mechanism is based on an upper bound for the ZF sum-rate, which we introduced in this work. The proposed precoding strategy achieves a sum-rate higher than both CB and ZF. Simulation results for a massive MIMO system including a l00-antenna BS, show up to 8% improvement on the sum-rate compared to CB and ZF. In addition, the proposed precoder reduces computational complexity up to 16.5% compared to the ZF precoding.

AB - Conjugate beamforming (CB) and zero-forcing (ZF) are well-known linear precoders, which have optimized hardware implementations. In this work, a linear precoder is proposed based on switching between CB and ZF for line-of-sight propagation environments. The proposed idea is to predict and use the precoder, which results in the highest sum-rate for a given channel. To this end, three regimes are introduced for the ratio of power per user at the base station (BS) over noise power at a user receiver. For low values of this ratio, CB and for high values, ZF result in the highest sum-rate. For moderate values, a precoding strategy is proposed to switch to the best precoder. The switching mechanism is based on an upper bound for the ZF sum-rate, which we introduced in this work. The proposed precoding strategy achieves a sum-rate higher than both CB and ZF. Simulation results for a massive MIMO system including a l00-antenna BS, show up to 8% improvement on the sum-rate compared to CB and ZF. In addition, the proposed precoder reduces computational complexity up to 16.5% compared to the ZF precoding.

UR - http://www.scopus.com/inward/record.url?scp=85054526703&partnerID=8YFLogxK

U2 - 10.1109/ICT.2018.8464908

DO - 10.1109/ICT.2018.8464908

M3 - Conference contribution

SN - 9781538623213

SP - 121

EP - 126

BT - 2018 25th International Conference on Telecommunications, ICT 2018

PB - Institute of Electrical and Electronics Engineers

ER -