# Joint Resource Allocation for Frequency-Domain Artificial Noise Assisted Multiuser Wiretap OFDM Channels with Finite-Alphabet Inputs

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## Abstract

**:**

## 1. Introduction

## 2. System Model and Problem Formulation

## 3. Optimal Solution

#### 3.1. Update of ${p}_{k,i}$ with Given ${\sigma}_{a,i}^{2}$

#### 3.2. Update of ${\sigma}_{a,i}^{2}$ with Given ${p}_{k,i}$

Algorithm 1: Joint power allocation of artificial noise and information signals for solving Equation (9). |

#### 3.3. Computational Complexity Analysis

## 4. Numerical Results

## 5. Conclusions

## Author Contributions

## Funding

## Acknowledgments

## Conflicts of Interest

## References

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**Figure 1.**Illustration of a multiuser wiretap orthogonal frequency-division multiplexing (OFDM) system, including one legitimate transmitter (LT), K legitimate receivers (LRs) and one passive eavesdropper (PE).

**Figure 2.**Block diagram of an OFDM transmitter and receiver with artificial noise (AN) addition and cancellation procedure in a wiretap channel.

**Figure 3.**The convergence of the proposed algorithm, $K=10,P=25\phantom{\rule{3.33333pt}{0ex}}\mathrm{dB}$.

**Figure 4.**(

**a**) Sum secrecy rate for both Gaussian and Quadrature Phase Shift Keying (QPSK) inputs. (

**b**) Sum secrecy rate of various LRs’ number for QPSK inputs. (

**c**) Sum secrecy rate of 10 LRs for Gaussian and QPSK inputs. The SC assignment scheme in Equation (8).

**Figure 5.**(

**a**) Sum secrecy rate for both Gaussian and QPSK inputs. (

**b**) Low sum secrecy rate for both Gaussian and QPSK inputs. The fixed subcarrier (SC) assignment scheme.

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**MDPI and ACS Style**

Fan, L.; Tang, B.; Jiang, Q.; Liu, F.; Yin, C.
Joint Resource Allocation for Frequency-Domain Artificial Noise Assisted Multiuser Wiretap OFDM Channels with Finite-Alphabet Inputs. *Symmetry* **2019**, *11*, 855.
https://doi.org/10.3390/sym11070855

**AMA Style**

Fan L, Tang B, Jiang Q, Liu F, Yin C.
Joint Resource Allocation for Frequency-Domain Artificial Noise Assisted Multiuser Wiretap OFDM Channels with Finite-Alphabet Inputs. *Symmetry*. 2019; 11(7):855.
https://doi.org/10.3390/sym11070855

**Chicago/Turabian Style**

Fan, Linhui, Bo Tang, Qiuxi Jiang, Fangzheng Liu, and Chengyou Yin.
2019. "Joint Resource Allocation for Frequency-Domain Artificial Noise Assisted Multiuser Wiretap OFDM Channels with Finite-Alphabet Inputs" *Symmetry* 11, no. 7: 855.
https://doi.org/10.3390/sym11070855