As the demand for frequency spectrum resources increases rapidly, research to obtain higher frequency efficiency has been advanced. Data traffic increases exponentially, and it is expected that it will be difficult for the current communication system to withstand the enormous amount of data transfer that is required in the future.
One of the technologies that is receiving the most attention in this situation is just full-duplex communication. In full-duplex communication, by using the same frequency resource at the same time and simultaneously performing transmission and reception between nodes, frequency efficiency can be doubled compared to conventional half-duplex communication.
However, in the full-duplex communication technology, since the echo of the transmitted signal is received as it is via the receiver, the problem of self-interference arises. It is essential to lower the self-interference signal to the white noise level in order to obtain frequency efficiency nearly twice that of half duplex communication.
Research Results and Evaluation Methods
In order to improve resource utilization efficiency, the aim is to design a flexible duplex system that variably applies Half / Full Duplex communication according to the uplink / downlink traffic to which self-interference cancellation algorithm is applied. Therefore, we study as follows.
· Self-interference control technique using digital filter
· Adaptive design technique of time-frequency filter for multiple time-frequency resources
· Channel prediction-based time-frequency filter adaptive design technique
· Utilizing the OP map, research available bandwidth-aware Flexible duplex transmission / reception technology
· Study on techniques to minimize the complexity by applying interference control techniques to other parts where the bands do not overlap and others overlap
· Optimization of performance and complexity when applying heterogeneous self-interference control technology
· System level simulation SW test bed implements a channel model based on the methodology of the standardization organization’s recommendations and developed Flexible Duplex technology in MATLAB.