Håkan Andersson

Hardware acceleration of the robust header compression (RoHC) algorithm

In LTE base-stations, RoHC is a processing-intensive algorithm that may limit the system from serving a large number of users when it is used to compress the VoIP packets of mobile traffic. In this paper, a hardware-software and a full-hardware solution are proposed to accelerate the RoHC compression algorithm in LTE base-stations and enhance the system throughput and capacity. Results for both solutions are discussed and compared with respect to design metrics like throughput, capacity, power consumption, and hardware resources. This comparison is instrumental in taking architectural level trade-off decisions in-order to meet the present day requirements and also be ready to support a future evolution. In terms of throughput, a gain of 20% (6250 packets/sec) is achieved in the HW-SW implementation by accelerating the Cyclic Redundancy Check (CRC) and the Least Significant Bit (LSB) encoding in hardware. The full-HW implementation leads to a throughput of 45 times (244000 packets/sec) compared to the SW-Only implementation. The full-HW solution consumes more Adaptive Look-Up Tables (7477 ALUTs) compared to the HW-SW solution (2614 ALUTs) when synthesized on Alteras Arria II GX FPGA.