On-the-fly hardware acceleration for protocol stack processing in next generation mobile devices

In this paper we present a new on-the-fly hardware acceleration approach, based on a smart Direct Memory Access (sDMA) controller, for the layer 2 (L2) downlink protocol stack processing in Long Term Evolution (LTE) and beyond mobile devices. We use virtual prototyping in order to simulate an ARM1176 processor based hardware platform together with the executed software comprising an LTE protocol stack model. The sDMA controller with diff erent hardware accelerator units for the time critical algorithms in the protocol stack is implemented and integrated in the hardware platform. We prove our new hardware/software partitioning concept for the LTE L2 by measuring the average execution time per transport block in the protocol stack at di fferent activated on-the-fly hardware acceleration stages in the sDMA controller. At LTE data rates of 100 Mbit/s, we achieve a speedup of 24% compared to a pure software implementation by enabling the sDMA hardware support for header processing in the protocol stack. Furthermore, an activation of the complete on-the-fly hardware acceleration in the sDMA controller, including on-the-fly deciphering, leads to a speedup of more than 50 %. Finally, at transmission conditions with more computational demands and data rates up to 320 Mbit/s, we obtain acceleration ratios of almost 80 %. Investigations show that our new sDMA on-the-fly hardware acceleration approach in combination with a single-core processor off ers the required computational power for next generation mobile devices.