TY - GEN
T1 - Downlink Non-Orthogonal Multiple Access Systems with an Untrusted Relay
AU - Arafa, Ahmed
AU - Shin, Wonjae
AU - Vaezi, Mojtaba
AU - Poor, H. Vincent
N1 - Funding Information:
This work was supported in part by the U.S. National Science Foundation under Grant CNS-1702808.
Publisher Copyright:
© 2018 IEEE.
PY - 2019/2/19
Y1 - 2019/2/19
N2 - A downlink single-input single-output (SISO) non-orthogonal multiple access (NOMA) system in which a base station (BS) is communicating with two users is considered. An untrusted half-duplex relay node is available to assist with the BS's transmission. The BS uses superposition coding to transmit its messages, and the relay employs either a compress-and-forward or an amplify-and-forward scheme to communicate with the users. Two modes of operation are considered: passive user mode, and active user mode. In the passive user mode, the users receive data from both a direct link from the BS and the relay's forwarding link, and use that to decode their messages. In the active user mode, the users send a cooperative jamming signal simultaneously with the BS's transmission to confuse the relay. The focus is on half-duplex nodes, and hence the users cannot receive data from the BS's direct link in the active user mode while transmitting the cooperative jamming signal; they receive it only through the relay's forwarding link. For each mode, and under each relaying scheme, achievable secrecy rate regions are developed. Results show that the best relaying scheme and user mode depend on relative distances among the nodes, and on which part of the secrecy region the system is operating at.
AB - A downlink single-input single-output (SISO) non-orthogonal multiple access (NOMA) system in which a base station (BS) is communicating with two users is considered. An untrusted half-duplex relay node is available to assist with the BS's transmission. The BS uses superposition coding to transmit its messages, and the relay employs either a compress-and-forward or an amplify-and-forward scheme to communicate with the users. Two modes of operation are considered: passive user mode, and active user mode. In the passive user mode, the users receive data from both a direct link from the BS and the relay's forwarding link, and use that to decode their messages. In the active user mode, the users send a cooperative jamming signal simultaneously with the BS's transmission to confuse the relay. The focus is on half-duplex nodes, and hence the users cannot receive data from the BS's direct link in the active user mode while transmitting the cooperative jamming signal; they receive it only through the relay's forwarding link. For each mode, and under each relaying scheme, achievable secrecy rate regions are developed. Results show that the best relaying scheme and user mode depend on relative distances among the nodes, and on which part of the secrecy region the system is operating at.
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U2 - 10.1109/ACSSC.2018.8645185
DO - 10.1109/ACSSC.2018.8645185
M3 - Conference contribution
AN - SCOPUS:85062955742
T3 - Conference Record - Asilomar Conference on Signals, Systems and Computers
SP - 1689
EP - 1693
BT - Conference Record of the 52nd Asilomar Conference on Signals, Systems and Computers, ACSSC 2018
A2 - Matthews, Michael B.
PB - IEEE Computer Society
T2 - 52nd Asilomar Conference on Signals, Systems and Computers, ACSSC 2018
Y2 - 28 October 2018 through 31 October 2018
ER -