Self-Interference Cancellation (SIC) for Simultaneous Transmit and Receive

Authors

Md Nurul Anwar TarekFollow

Document Type

Dissertation

Degree

Doctor of Philosophy (PhD)

Major/Program

Electrical and Computer Engineering

First Advisor's Name

Elias Alwan

First Advisor's Committee Title

Committee chair

Second Advisor's Name

Jean H. Andrian

Second Advisor's Committee Title

Committee member

Third Advisor's Name

Shubhendu Bhardwaj

Third Advisor's Committee Title

Committee member

Fourth Advisor's Name

Stephen Secules

Fourth Advisor's Committee Title

Committee member

Keywords

Simultaneous Transmit and receive, Full duplex, Antenna, Self Interference cancellation, Wideband, Isolation, Coupling suppression, Cancellation Filter

Date of Defense

6-12-2023

Abstract

Microwave communication requires simultaneous transmit and receive (STAR) systems, but isolating the transmit and receive radio chains can be challenging. The most common practice is using a single antenna and a circulator, which provides insufficient isolation for full-duplex communication. Practical STAR systems need additional cancellation stages to prevent receiver desensitization caused by high power transmit signals. To address this challenge, a novel STAR system that includes two circulators, a hybrid coupler, and a self-interference cancellation (SIC) circuit based on a Finite Impulse Response (FIR) topology was developed. This design achieved an average Tx/Rx port isolation of about 37 dB over a 25 MHz bandwidth in simulations. A prototype was fabricated and tested, showing an average cancellation of 36 dB with a cancellation range of 33 dB to 42 dB and good agreement with the simulations. In-band full-duplex (IBFD) systems can double spectral efficiency by enabling simultaneous transmission and reception within the same band. However, SI suppression becomes more challenging across broader bandwidths, and conventional SIC circuits require a filter bank with at least two FIR filters to achieve wide bandwidths. A wideband and low-profile SIC circuit based on a hybrid FIR and resonator filter topology has been developed to address this challenge. The design achieved vi an average cancellation of 22 dB across 800 MHz in the L-band, with simulations showing a minimum cancellation of 15 dB and a maximum cancellation of 45 dB. A prototype was fabricated and tested, offering an average of around 20 dB cancellation, with a minimum cancellation of 15 dB and maximum cancellation of 27 dB. A two-stage SIC system has been developed that includes transmit and receive antenna isolation and RFSIC filter stages. The isolation between the transmit and receive antennas is based on a novel symmetric suppression technique, and the RFSIC filter is based on a hybrid FIR filter and resonator architecture. The design achieved an average isolation of around 52 dB across a 500 MHz bandwidth, with simulations showing a minimum cancellation of 41 dB and a maximum cancellation of 65 dB. A prototype was fabricated and tested, showing an average of around 44 dB cancellation, with good agreement with the simulations. These novel STAR and SIC systems offer practical solutions for full duplex communication and SI suppression, enabling enhanced spectrum access and doubled spectral efficiency. These advancements can improve the efficiency of microwave communication systems and open up new possibilities for communication technology.

Identifier

FIDC011166

ORCID

0000-0002-7105-0983

Previously Published In

1. M. N. A. Tarek, R. Hokayem, S. R. Govindarajulu, M. H. Novak and E. A. Alwan, (2022). A Two-Stage Wideband RF Cancellation of Coupled Transmit Signal for Bi-Static Simultaneous Transmit and Receive System. IEEE Journal of Microwaves, vol. 2, no. 3, pp. 429-441.

2. M. N. A. Tarek, M. R. Guerra, A. Nunez, M. N. Uddin and E. A. Alwan, (2023). Improving Isolation in Monostatic Simultaneous Transmit and Receive Systems Using a Quasi-Symmetrical Self-Interference Cancellation Architecture. IEEE Journal of Microwaves, vol. 3, no. 2, pp. 655-664.

3. M. N. A. Tarek, E. A. Alwan, (2022). Wideband, Low Profile Coupling Suppression Circuit for Simultaneous Transmit and Receive System Based on Hybrid Finite Impulse Response and Resonator Topology. IEEE Access, vol. 10, pp. 126508- 126515.

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 License.

Recommended Citation

Tarek, Md Nurul Anwar, "Self-Interference Cancellation (SIC) for Simultaneous Transmit and Receive" (2023). FIU Electronic Theses and Dissertations. 5403.
https://digitalcommons.fiu.edu/etd/5403