Method and system for interference cancellation in MIMO wireless system

Technology: Transceiver system in MIMO full duplex communication system;
Industry: LTE Advance, LTE Advance Pro, 5G Network technology, ICT;
Applications: System for cross talk/interference cancellation in MIMO full duplex system
Market: The global MIMO market is projected to reach $15.79B by 2027, growing at a CAGR of 35% during the forecast period (2020-2027).

In the wireless communication system, self-interference from the transmitter is major challenge in same channel full duplex (SCFD) front end circuit.
In multiple input multiple output (MIMO) SCFD system, signal leakage from another transmitting stream makes the interference even worse.
The electrical balance based duplexer(EBD) can suppress the self-interference, but suffers from insertion loss in transmitter(Tx) & receiver(Rx) paths. Many prior arts method discussed, however handling disadvantages like power consumption, robustness, reliability, integrity issues, complex design & other issues. Hence, there is a need to address the above disadvantages/other shortcomings.

Present patent claimed a transceiver system for full duplex communication (Refer FIG.2).
Further the patent describes a method implemented by an electrical balance based duplexer (EBD) for interference cancellation using a at least one circulators in full-duplex communication.
Further the invention is directed to transmitting & receiving two independent signals at the same time enabling a MIMO Full-duplex communication.
There are only an interconnection of EBD and circulators in the way shown in the figure, which helps to achieve claimed system without causing cross-talk.

Technical Perspective:

The EBD is configured to pass the first signal at a first port from the plurality of ports through the at least one circulator, & pass the second signal at a second port from the plurality of ports through the at least one circulator, shown in figure.
The reciprocal nature of the antenna coupling ensures that equal and same phase signal couples to the two antennas, & therefore, the coupled signal is cancelled at the difference port & appear only at a receiver connected to the sum port which can be treated as self-interference.
The signal from Tx2 during couples back to the antennas, only appears at the receiver connected to the difference port & since, the two antennas will have closely matched input impedance, this configuration results a wide band isolation between the two Tx/Rx pair under a balanced condition.

Industrial Perspective:

Present patent provides the claimed EBD configuration which solves cross-talk problems by using circulator in a MIMO full duplex system.
The EBD is configured in such a manner which provides an isolation between the transmitting signals & the receiving signals in a same channel full duplex (SCFD) front end circuit using the at least one circulators.
Provides a cost-effective system in simple design, reliable, & mitigate other issues in efficient manner.

Prof. Aniruddhan S,

Prof. Radhakrishna Ganti,

Department of Electrical Engineering

TRL – 3

Proof of Concept ready & validated

Technology Transfer