# Hybrid Beamforming for Millimeter-Wave Heterogeneous Networks

## Abstract

**:**

## 1. Introduction

## 2. System Model

#### 2.1. Access Link

#### 2.2. Backhaul Link

#### 2.3. End-to-End SINR and Channel Capacity

- ${S}_{k,{l}_{s}}^{}={H}_{k,MBS}{w}_{T,k}{w}_{R,k,{l}_{s}}^{H}{\mathbf{g}}_{k,{l}_{s}}{x}_{{l}_{s}}^{s}$ is the ${l}_{s}^{\mathrm{th}}\text{}$user signal of the ${k}^{\mathrm{th}}$ SBS,
- ${S}_{k,I}^{\mathrm{SU}}={H}_{k,MBS}{w}_{T,k}{w}_{R,k,{l}_{s}}^{H}{{\displaystyle \sum}}_{i=1,i\ne {l}_{s}}^{{L}_{s}}{\mathit{g}}_{k,i}{x}_{i}^{s}$ is the interference from the ${L}_{s}-1$ other SUs of ${k}^{\mathrm{th}}$ SBS,
- ${S}_{I}^{SBS}={{\displaystyle \sum}}_{i=1,\text{}i\ne k}^{K}\left({H}_{i,MBS}{w}_{T,i}{w}_{R,i,{l}_{s}}^{H}{\mathit{y}}_{i,SBS}\right)$ is the interference from the $K-1$ other SBSs.
- ${S}_{I}^{\mathrm{PU}}=\text{}{H}_{k,MBS}{w}_{T,k}{w}_{R,k,{l}_{s}}^{H}{\mathit{G}}_{k,PU}{\mathit{x}}_{p}+{\mathit{c}}_{k}^{H}{H}_{PU,MBS}{\mathit{x}}_{p}$
- ${\mathit{N}}_{MBS}=\left({H}_{k,MBS}{w}_{T,k}{w}_{R,k,{l}_{s}}^{H}{\mathit{n}}_{k,SBS}+{\mathit{n}}_{MBS}\right)$

#### 2.4. Channel Model

## 3. Proposed Hybrid Beamforming

#### 3.1. Access Link

#### 3.2. Backhaul Link

## 4. Simulation Results

## 5. Conclusions

## Funding

## Acknowledgments

## Conflicts of Interest

## References

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**Figure 2.**The architecture of analog beamformers: (

**a**) Fully-connected structure; (

**b**) partially-connected structure.

**Figure 5.**Beampattern of the access link: (

**a**) Proposed HBF, 4 RF chains; (

**b**) fully-digital beamforming (optimal).

**Figure 6.**Beampattern of the backhaul link: (

**a**) Proposed HBF, 4 RF chains; (

**b**) fully-digital beamforming (optimal).

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**MDPI and ACS Style**

Hefnawi, M.
Hybrid Beamforming for Millimeter-Wave Heterogeneous Networks. *Electronics* **2019**, *8*, 133.
https://doi.org/10.3390/electronics8020133

**AMA Style**

Hefnawi M.
Hybrid Beamforming for Millimeter-Wave Heterogeneous Networks. *Electronics*. 2019; 8(2):133.
https://doi.org/10.3390/electronics8020133

**Chicago/Turabian Style**

Hefnawi, Mostafa.
2019. "Hybrid Beamforming for Millimeter-Wave Heterogeneous Networks" *Electronics* 8, no. 2: 133.
https://doi.org/10.3390/electronics8020133