TY - JOUR
T1 - Covert communication in downlink NOMA systems with random transmit power
AU - Tao, Liwei
AU - Yang, Weiwei
AU - Yan, Shihao
AU - Wu, Dan
AU - Guan, Xinrong
AU - Chen, Dechuan
PY - 2020/11
Y1 - 2020/11
N2 - This letter considers covert communication in downlink NOMA systems, where a public action (communication from Alice to the NOMA-weak user U1) is used to provide a cover for a secret action (communication from Alice to the NOMA-strong user U2). To aid system design, we first derive the detection error probability (DEP) at Willie and the connect outage probabilities (COPs) at U1 and U2. Then, considering the covertness and outage constraints, the optimization of power allocation factor ratio between U1 and U2 is tackled in order to maximize the effective covert rate. The results demonstrate that the minimum DEP is the power allocation factor for U1. In addition, for a given covert constraint, relaxing the outage constraint will effectively increase the maximum effective covert rate within a certain range of the maximum transmit power of U1.
AB - This letter considers covert communication in downlink NOMA systems, where a public action (communication from Alice to the NOMA-weak user U1) is used to provide a cover for a secret action (communication from Alice to the NOMA-strong user U2). To aid system design, we first derive the detection error probability (DEP) at Willie and the connect outage probabilities (COPs) at U1 and U2. Then, considering the covertness and outage constraints, the optimization of power allocation factor ratio between U1 and U2 is tackled in order to maximize the effective covert rate. The results demonstrate that the minimum DEP is the power allocation factor for U1. In addition, for a given covert constraint, relaxing the outage constraint will effectively increase the maximum effective covert rate within a certain range of the maximum transmit power of U1.
UR - http://www.scopus.com/inward/record.url?scp=85096197111&partnerID=8YFLogxK
U2 - 10.1109/LWC.2020.3011191
DO - 10.1109/LWC.2020.3011191
M3 - Article
AN - SCOPUS:85096197111
VL - 9
SP - 2000
EP - 2004
JO - IEEE Wireless Communications Letters
JF - IEEE Wireless Communications Letters
SN - 2162-2337
IS - 11
ER -