A future radio-access framework

This paper discusses the requirements on future radio access and, based on the requirements, proposes a framework for such a system. The proposed system based on orthogonal frequency-division multiplexing supports very low latencies and data rates up to 100 Mb/s with wide area coverage and 1 Gb/s with local area coverage. Spectrum flexibility is identified as one main requirement for future systems, and the proposed framework can be deployed in a wide range of spectrum allocations with bandwidths ranging from 2.5 to 100 MHz. Multihop relaying, useful to extend the range for the high data rates, and multiple-antenna configurations are integral parts of the framework. A packet-centric approach is taken for the dataflow processing, implying that the scheduling mechanism and the retransmission protocol operate on complete packets rather than segments thereof, thus allowing for cross-layer optimization. Finally, numerical evaluations are provided, illustrating the feasibility of future very wideband radio access.