The Design And Realization Of Software Platform For The Baseband Processing

To meet the serious challenges of high cost,high energy consumption and low spectrum utilization faced by mobile operator with the current,Institute of Computing Technology,C hinese Academy of Sciences has proposed a centralized Super Base Station architecture levelly pooling the resources such as radio frequency,baseband and computing,to achieve the goals of high capacity,low power consumption and high resource utilization.The super base station requires the baseband resource pool to adopt the hardware statistical multiplexing technology based on the software radio thought.The different waveform application can reuse the baseband processing resou rces according to the requirements.The baseband processing unit proposes two aspects: 1)adopting the high performance general processing architecture supports the physical layer real-time signal processing;2)to achieve hardware and software decoupling,waveform software is needed to support the flexible loading.This paper aims at baseband processing requirements for super base stations.In the hardware,a high-performance baseband processing architecture based on heterogeneous multi-core processor "ARM(Acorn RISC Machine)+ DSP(Digital Signal Processing)" is proposed.DSP supports in real-time signal processing of baseband data streams,and ARM supports physical layer control of timing,state and interface.It can take into account the platform's real-timing and versatility.In the software,it proposes a platform architecture of hiding the underlying hardware details and heterogeneous processor differences.The architecture is divided into the driver layer,operating system layer and middleware abstraction layer.This paper focuses on the design of the underlying driver software and the "SMP Linux(Symmetrical Multi Processing)+ SYS/BIOS" operating system.The specific content is summarized as follows:1.Design and implementation of driver layer.To meet the demand of LTE's large amount of baseband data,high rate and low uplink and downlink switching delay,the baseband pool transmits baseband data by supporting 1-16 Gbps SRIO(Serial Rapid IO).And the physical layer control is relatively low requirement in rate and delay,it can transfer the baseband control tasks over Ethernet.In this paper,the Ethernet driver is designed and implemented under the Linux driver model.The SRIO driver is designed and implemented under the SYS/BIOS system.The maximum Ethernet speed is 935 Mbps and the SRIO is 12.7Gbps.Comparison of two kinds of interface technology verifies the platform resolution.2.Design and implementation of operating system layer.To meet the demand of ARM physical layer control,DSP computing tasks and data exchange,operating system needs to achieve the decoupling of heterogeneous processors and provide file system interfaces for hardware operating.And Boot Loader is the primary condition of system start-up,shortening the start-up time can effectively reduce the possibility of communication failure,and it is conducive to software's upgrades.In this paper,the boot loader of operating system is designed and implemented by ARM boot DSP.The Boot Loader is optimized by multi-level guide and phased operation,which makes the loading time decrease significantly.It successfully builds and transplants the kernel and file system,and also realizes distribution of the DSP tasks by ARM,thus it protects the baseband control tasks computing and information exchange.