Foreign research started on simulator technology earlier, technology is relatively mature, the developed simulator can simulate L1, the frequency of L2 C/A code and P code signal, also can simulate the modernization of GPS after L1C, L2C, L5C and L1M in the L2M civil signal, [6] code signal, some products can also simulate the GLONASS system frequency division multiple access (FDMA) binary offset carrier modulation signal and Galileo system (BOC) modulation signal, even analog differential signal and the signal of [7]. attitude measurement for domestic satellite navigation signal simulator of a late start, coupled with foreign technology blockade on the simulator, technology and the gap between foreign countries, in recent years with the steady construction of BDS system in our country, domestic satellite navigation industry has been considerable development, many scientific research units and companies to carry out research on the navigation signal simulator, some companies have pushed A mature market [8]. products abroad there are a number of manufacturers to provide navigation signal mode of multiple series of quasi products, such as [7] series simulator GSS British Spirent company, 100020005000 series of [9] simulator of CAST company in the United States and Germany IFEN company NCS series simulator [10] and so on. This paper introduces the Spirent company's GSS series of navigation signal simulator, to illustrate the current high-end navigation signal simulator development the latest international level is.GSS9000 navigation signal simulator's new Spirent, [7].GSS9000 system is composed of signal generator and computers running SimGEN software adopts modular design, can support one or more radio channel unit in a single signal generator. Each radio channel unit supports up to 16 satellite channel. If you need more signal output, can use multiple RF links Single element consists of a.SimGEN signal generator is a mathematical simulation software developed by Spirent, a powerful, standard of its functions include simulated gas effect, multipath, terrain obstacles, antenna gain and phase diagram, differential error generation software [11].SimGEN real-time correction data and vehicle / air / sea / space vector path and complete, according to the user set the scene to generate corresponding configuration parameters, different demand driven modular design signal generator generates satellite navigation signals,.GSS9000 can support the receiver test, but also can be extended by GSS9000 configuration, to support GPS, Galileo, GLONASS and SBAS and BDS composite signal in order to meet the requirement of user testing.

The domestic research on simulator technology mainly concentrated in universities, research institutes and companies, such as the Beihang University, in 54, in Shenzhen City, Hebei East Lianxing, United Technology Limited by Share Ltd, which introduces in Hebei joint satellite navigation signal simulator, said to the development level of domestic Ming simulator technology in Hebei joint. GNSS-5000B multi constellation navigation signal simulator can simulate the Beidou / two generation, GPS, GLONASS and Galileo four satellite navigation system, each frequency point supports up to 16 satellite channels, through multiplexing mode, multipath channel per frequency point can also support 1~4 Road, by upgrading the components, can also support the interference signal generation and navigation simulation function [8]. the simulator supporting closed-loop evaluation software support receiver and simulator closed loop assessment test, can be used for navigation terminal equipment R & d, Production, testing, acceptance and inspection.