The Technology Of Frequency Hopping Use In Ship Communication Equipment

In modern wireless communications and anti-interference in the growing confrontation,the first single-frequency or frequency of communication have been more vulnerable to jamming to interfere with or interfere with tracking,a new means of communication to combat Communications interference is an inevitable trend.The use of frequency hopping communication mode,constant frequency, random hopping,is a pro-active manner to avoid interference,will be able to effectively avoid interference and increase anti-interference capability,modern electronic communications to combat the use of more Way,is the focus of discussion in this article.By comparing the frequency-hopping technology at home and abroad and the use of the status quo,as well as the combination of existing equipment is being used in a variety of circumstances,the use of frequency hopping technology to determine the modification of existing fixed-frequency equipment,and equipment modified to meet frequency hopping can be Use.This article on the spread-spectrum technology,equipment to achieve the function of frequency-hopping technology to achieve the three areas were studied.The main functions of the device,to achieve the function of frequency hopping is the focus of the discussion.Equipment in the main functions of the study,based on the characteristics of frequency-hopping communication network and communication requirements of the actual conduct of the hopping parameter programming,networks called the election and call functions,features jump-speed traction,not later than after the network function,to respond to radio frequency Call functions calibration function,and so on a timely extension of the function of the realization;in the function of frequency hopping to achieve,by the frequency-hopping technology requirements,first of all to improve the frequency synthesizer,and then determine the frequency-hopping pseudo-random sequence,the modem as well as frequency-hopping rate,The frequency-hopping pattern,the frequency-hopping radio and network synchronization;in accordance with technical requirements and then choose the main components:CPU,DDS,pseudo-random sequence generator and a modem;Finally,in accordance with the need to improve control of part of the complete control of the machine.This article from the analysis of the frequency-hopping technology elements of the year,based on the performance of existing equipment,and as much as possible to retain the shape of the original equipment and accessories, used to increase the frequency stability,to change the frequency synthesizer,as well as control over part of the increase in the frequency-hopping Modules such as frequency hopping to achieve the various functions,after the pilot testing, satisfactory results,mainly carried out as follows:1.By the definition of frequency hopping communication,the theoretical basis,principle,the main indicator of performance and technical characteristics, such as a brief introduction and analysis,selection of equipment for frequency-hopping technology to lay a theoretical foundation.The frequency-hopping radio at home and abroad,Bluetooth and so on the brief, modified existing equipment to determine the performance and features,such as the provision of great help.2.Electrical equipment has been on the performance of the main functions of a simple,clear device to be improved to achieve the various functions and to be changed,modified for the equipment specified in the right direction.3.The completion of the frequency synthesizer part of the improvement and replacement of the main vibration crystal,increased the frequency of equipment accuracy and stability,has been a high degree of stability of the main vibration frequency hopping and control the clock frequency.According to the DDS and analog synthesizer technology features,using FPGA(PLD) to complete the DDS, at the same time take full advantage of the existing co-frequency analog equipment,will be mixing with DDS output frequency to generate the desired frequency hopping mixer.At the same time,by the increase in the V11,V12 (1N4148) and R28,R29(10K) constitute a fast lock circuit to ensure that the frequency hopping to keep up with fast.4.According to the unit of frequency hopping signals sent from the various requirements of the computer control module to improve the relevant part of the completion of the jump master and control the exchange of information,control of frequency hopping.5.The indicators of detection equipment,machines display modified to receive sensitivity,transmit power,frequency stability,the frequency-hopping capabilities,frequency of the main design parameters are in line with the requirements of the desired effect.After these steps,the device can be very good to complete the function of frequency hopping.After the pilot testing,equipment designed to meet the technical requirements,the basic completion of the conversion task.