LTE Physical Layer Implementation Based on GPP Multi-core Parallel Processing and USRP Platform

Software defined radio (SDR) is characterized by its flexibility and convenience of modification, because significant amounts of signal processing are handed over to the general-purpose processor (GPP), rather than being done in special-purpose hardware. In the long term, software-defined radios work well in low data transmission rate systems such as 2G/3G cellular systems and other wireless radio systems. With rapid development of GPP power, more complex algorithms and higher data rate wireless communication systems can be implemented with GPP processor and general purpose RF front end. In this paper we propose a LTE physical layer parallel system architecture based on multicore GPP to match up the high capacity requests of LTE air interface. Firstly, we analyzed the complexity of each LTE physical layer module and made a statistics of their processing time. And then we used Linux CPU affinity to allocate each LTE module to particular CPU core carefully based on the statistics. CPU utilization rate shows that using multi-core makes the system to have enough capacity. Our system can only match up 2M bandwidth when the LTE physical layer procedures are running on single CPU core, while it can match up 5M bandwidth when it's running on multi-core.