高分悬赏英文翻译

Communications modernization of human society into the information age, an important indicator. Encountered in modern communication is an important issue in the interference problem. Spread spectrum technology as a result of anti-jamming, anti-interception, anti-multipath multiple access capability, secure location is good and a number of advantages of high precision for use in communications systems, communications systems can greatly enhance the quality of communication.
In this paper, starting from the theory of spread spectrum communication, spread spectrum signal generator design. The signal generator to achieve such a major feature - the use of DDS technology will be useful information and pseudo-code sequence modulation, the carrier signal with BPSK modulation, the final amplification by filtering out fired by the antenna. Signal generator hardware realization of the program include: single-chip control circuit, circuit carrier, pseudo-code Generation Circuit, BPSK modulation circuit, filter circuit, amplifier circuit. One single-chip chip ATMEL Corporation AT89S52 chip carrier using Analog Devices have a circuit of the AD9854 chip company to achieve, the main circuit pseudo-code generated by CPLD family MAX Ⅱ of EPM240T100C. Software mainly consists of two parts: First, using Keil software program for single-chip, to achieve single-chip control of the AD9854: The second is the use of Quartus Ⅱ software CPLD chip to program the device to

Modern communications when human society entered the era of information is the important symbol. In the modern communication is an important problem of interfering problems. Because of spread spectrum technology with strong anti-jamming capability, interception, anti-multipath multi-access ability, good secrecy and the ranging accuracy of a series of advantages, it will be used for communication system, can greatly improve the quality of communication.
From the spread spectrum communication theory, design of spread spectrum signal generator. This signal generator main achieve such a function - using DDS technology will be useful information and the sequence of pn code modulation, and carrier BPSK modulation signal, through the filter and amplification emitted by antenna. Signal generator implementation scheme of hardware mainly include: the single-chip microcomputer control circuit, carrier happen circuit, pn code generated BPSK modulation circuit, circuit and filter circuits, amplifying circuit. One of the chip ATMEL company adopts chip AT89S52 chip, carrier with Analog to produce stats Devices produced circuit chip to achieve the company AD9854 pn code, the main produce circuit with CPLD Ⅱ MAX EPM240T100C series. Software parts mainly includes two parts: one is to use Keil software, chip microcontroller program, to AD9854 control: 2 is Quartus, using the device of CPLD Ⅱ software programming, chip causes pn code sequences.