LTE-compatible 5G PHY based on generalized frequency division multiplexing

The soft transition between generations of mobile communication systems is a desirable feature for telecommunication operators and device manufacturers. Looking to the past, clock compatibility between WCDMA and LTE allowed manufacturers to build inexpensive multi-standard devices. In this paper it is shown that GFDM, a candidate waveform for the 5G PHY layer, is able to use the LTE master clock and the same time-frequency structure as employed in today´s generation of cellular systems. Two approaches for coexistence of 4G/5G waveforms are presented in the paper. The first GFDM setting is aligned with the LTE grid; in the other one GFDM acts as a secondary system to the primary LTE. The second approach introduces a new way of positioning subcarriers that further enhances the flexibility of GFDM. In addition, the paper also considers low latency aspects for autonomous and human controlled device communication in future application scenarios.