The Degrees-of-Freedom in Monostatic ISAC Channels: NLoS Exploitation Vs. Reduction

Shihang Lu1; Fan Liu1; Lajos Hanzo2

2022

10.1109/TVT.2022.3210307

IEEE Transactions on Vehicular Technology   Impact Factor & Quartile

1939-9359

1939-9359

The degrees of freedom (DoFs) attained in monostatic integrated sensing and communications (ISAC) are analyzed. Specifically, monostatic sensing aims for extracting target-orientation information from the line of sight (LoS) channel between the transmitter and the target, since the Non-LoS (NLoS) paths only contain clutter or interference. By contrast, in wireless communications, typically, both the LoS and NLoS paths are exploited for achieving diversity or multiplexing gains. Hence, we shed light on the NLoS exploitation vs. reduction tradeoffs in a monostatic ISAC scenario. In particular, we optimize the transmit power of each signal path to maximize the communication rate, while guaranteeing the sensing performance for the target. The non-convex problem formulated is firstly solved in closed form for a single-NLoS-link scenario, then we harness the popular successive convex approximation (SCA) method for a general multiple-NLoS-link scenario. Our simulation results characterize the fundamental performance tradeoffs between sensing and communication, demonstrating that the available DoFs in the ISAC channel should be efficiently exploited in a way that is distinctly different from that of communication-only scenarios.

ISAC Power Allocation Parameter Estimation Target Detection Spatial Degrees Of Freedom

SCI

English

First ; Corresponding

Special Funds for the Cultivation of Guangdong College Students' Scientific and Technological Innovation "Climbing Program"[pdjh2022c0028] ; National Natural Science Foundation of China["62101234","U20B2039"] ; CAST through Young Elite Scientist Sponsorship Program[YESS20210055] ; Engineering and Physical Sciences Research Council["EP/W016605/1","EP/P003990/1"] ; European Research Council's Advanced Fellow Grant QuantCom[789028]

Engineering ; Telecommunications ; Transportation

Engineering, Electrical & Electronic ; Telecommunications ; Transportation Science & Technology

WOS:000944202400100

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC

IEEE

1.Department of Electronic and Electrical Engineering, Southern University of Science and Technology, Shenzhen, China
2.Department of Electronics and Computer Science, University of Southampton, Southampton, U.K.

Shihang Lu,Fan Liu,Lajos Hanzo. The Degrees-of-Freedom in Monostatic ISAC Channels: NLoS Exploitation Vs. Reduction[J]. IEEE Transactions on Vehicular Technology,2022,PP(99):1-6.

Shihang Lu,Fan Liu,&Lajos Hanzo.(2022).The Degrees-of-Freedom in Monostatic ISAC Channels: NLoS Exploitation Vs. Reduction.IEEE Transactions on Vehicular Technology,PP(99),1-6.

Shihang Lu,et al."The Degrees-of-Freedom in Monostatic ISAC Channels: NLoS Exploitation Vs. Reduction".IEEE Transactions on Vehicular Technology PP.99(2022):1-6.