General Principles and Basic Algorithms for Full-duplex Transmission

This chapter studies full-duplex technology from the perspective of signal-processing algorithms and implementation. It explains full-duplex system requirements, self-interference, and self-interference cancellation (SIC) techniques and the related algorithms and implementation challenges. The chapter also shows the current achievements, from SISO, in order to treat the problem from the basics, to MIMO, which still needs further development. SIC techniques in a full-duplex SISO system are classified into four main categories: passive SI suppression in the propagation domain, active SIC in the analog domain, active SIC in the digital domain and auxiliary chain SIC. The required cancellation has to meet certain requirements related to the system specifications, such as the full scale of the analog-to-digital converter (ADC) and noise-floor level. Full-duplex technology offers the potential to participate in the evolution of 5G, and it leads the way toward new mobile generations that have higher capacity, more efficiency and optimal performance.