Multi-Service System: An Enabler of Flexible 5G Air Interface

A multi-service system is an enabler to flexibly support diverse communication requirements for the next generation wireless communications. In such a system, multiple types of services coexist in one baseband system with each service having its optimal frame structure and low out-of-band emission waveforms operating on the service frequency band to reduce the ISvcBI. In this article, a framework for a multi-service system is established, and the challenges and possible solutions are studied. The multi-service system implementation in both the time and frequency domains is discussed. Two representative SFMC waveforms, F-OFDM and UFMC, are considered in this article. Specifically, the design methodology, criteria, orthogonality conditions, and prospective application scenarios in the context of 5G are discussed. We consider both SR and MR signal processing methods. Compared to the SR system, the MR system has significantly reduced computational complexity at the expense of performance loss due to ISubBI in MR systems. The ISvcBI and ISubBI in MR systems are investigated with proposed low-complexity interference cancellation algorithms to enable multi-service operation in low interference level conditions.