Wireless Wideband Code Division Multiplexing Transmission System And Study On The Technology Of Double - Star Positioning In The User's Machine CPU Development And Implementation

Many high technologies has been widely used in the fields of communications and information processings ,which may give a higher demand for the design of a more harmonic software and hardware in complicated communication systems .As software and hardware are classified in two way, one is based on ASIC design as its solution and the other is on optimizing the ability of processor. This paper describes in detail two different schemes for the control module in communication systems.The technology of direct sequence spread spectrum/code division multipul access (DSSS/CDMA) are applied in the broadband code division multiplex wireless communication systems,which means transmitting data at the rate of 2.048Mbps using four E1 lines within the band of 20MHz .In this paper, the theory of the whole debice is first analysized specified for the system ASIC design and optimizing its performance. Then a modified plan for initial operation and monitoring the El line alarring which is performed by the E1 interface module controlled by FPGA.The double-start positioning system is an all-weather and regional satellite positioning system, developed independently by our country. This paper discusses the CPU implementation of the dispread subsystem in the double-start positioning system to carry out the main control of the system and to finish the information frame processing .The hardware platform we used is based on Cirrus Logic's EP7312 develop board. Maverick?EP7312 Processor is designed for high-performance ultra-low-power system on chip application,enables flexible interface devices ,such as Led conroler, touch screen,SPI,usb.The core-logic functionality of the CPU is built around an ARM720T processor. The device is so powerful that it can perform primary control in double-start positioning system.Then we analyze the key technologies both hardware driver divice and software development in the embedded system design.The most important program run on the CPU is real time operation system (RTOS). Meanwhile,the BlueCat Linux of Lynuxworks' is applied in our system In detail .we describe the advanced power management (APM) and flash filesystem (FFS), in order to complete process management and acess the flash rom area in EP7312.Further we introduce the implementation of embedded GUI and board support package (BSP).The system we developed is efficiency ,as well as easy to transplant to other communication systems,so it has a bright future with widely usedIt has been verified that the methods and plans mentioned in this paper are of great correctness in the practical applications.