5GNOW: Intermediate frame structure and transceiver concepts

Abstract

This paper reports intermediate transceiver and frame structure concepts and corresponding results from the European FP7 research project 5GNOW. The core is the unified frame structure concept which supports an integrated 5G air interface, capable of dealing both with broadband data services and small packet services within the same band. It is essential for this concept to introduce waveforms which are more robust than OFDM, e.g., with respect to time-frequency misalignment. Encouraging candidate waveform technologies are presented and discussed with respective results. This goes along with the corresponding multiple access technologies using multi-layered signals and advanced multi-user receivers. In addition we introduce new (compressive) random access strategies to enable 'one shot transmission' with greatly reduced control signaling particularly for sporadic traffic by orders of magnitude. Finally, we comment on the recent results on the 5GNOW networking interface. The intermediate results of 5GNOW lay the ground for the standardization path towards a new 5G air interface beyond LTE-A

On the time-frequency localisation of 5G candidate waveforms

“…A stringent URLLC target being standardised is 99 Such protocols are also themselves prone to errors, impacting reliability.…”

“…Consider a connectionless, "one-shot" random access scenario, as in [94,99,100], where many users access a limited number of physical resources In such a contention-based access scheme, collisions resulting in ISI and ICI will occur when time-and frequency-adjacent access packets overlap in the phase space. The likelihood that packets partially or even fully overlap in the phase space depends on the arrival process.…”

Evaluation and Analysis of FBMC/OQAM Systems Based on Pulse Shaping Filters

“…broadband systems. OFDM has significant limitations, such as high OoB emissions, which causes interfering between the neighboring channels, CP overhead, which causes a reduction in spectral efficiency, and orthogonality, which requires stringent time and frequency synchronization to avoid frequency and timing offsets, that make it not the most suitable waveform for all targeted application scenarios [3], [4].…”

Seven fundamental rethinking for next-generation wireless communications

“…A unified frame structure concept is proposed in [15] which is capable of dealing both with broadband data services and small packet services within the same band. In order to realize SDAI, the frame structure should be flexible enough.…”