CN201387485Y

CN201387485Y - Compass navigation satellite system receiver module

Info

Publication number: CN201387485Y
Application number: CN200920040622U
Authority: CN
Inventors: 刘波; 张北江
Original assignee: COMPASS NAVIGATION JIANGSU COMMUNICATION TECHNOLOGY Co Ltd; PLA University of Science and Technology
Current assignee: COMPASS NAVIGATION JIANGSU COMMUNICATION TECHNOLOGY Co Ltd; PLA University of Science and Technology
Priority date: 2009-04-21
Filing date: 2009-04-21
Publication date: 2010-01-20
Anticipated expiration: 2019-04-21

Abstract

The utility model discloses a compass navigation satellite system receiver module, which comprises an inverter, a bandpass filter, a GPS radio frequency chip and a digital receiver processor which are connected in turn; the inverter conducts frequency conversion to compass satellite signals outputted by a low-noise amplifier, and obtains signals and the carrier frequency of the obtained signals is at GPS L1 frequency; the bandpass filter allows the compass satellite signals whose carrier frequency is transformed to GPS L1 frequency to pass, and filters other frequency signals outputted by the inverter and out-of-band noises; the GPS radio frequency chip conducts amplification, double conversion, wave filtering and AD conversion to compass signals whose carrier frequency is GPS L1 frequency, and obtains digital baseband signals or digital IF signals; the digital receiver processor conducts digital quadrature downconversion, dispreading, demodulation, decoding and other handlings to the signals outputted by the GPS radio frequency chip, and realizes positioning, time service and other functions. The compass navigation satellite system receiver module can significantly reduce the cost, power consumption and size of the compass navigation satellite receiver module.

Description

A kind of Beidou satellite navigation system receiving module

Technical field

The utility model relates to a kind of receiver module of satellite navigation system, is a kind of Beidou satellite navigation system receiving module specifically.

Background technology

" No. one, the Big Dipper " satellite navigation system is satellite navigation location, the time dissemination system of China's independent development, utilizes this system can realize location, navigation, accurately time service.Receiver module and receiver are the important component parts of big-dipper satellite system.The user utilizes receiver module can position and time service, in the location, navigation and the communications field have a wide range of applications.Receiver module can embed other and need locate or the device interior of time service, also can install with antenna and low noise amplifier (LNA) one.Existing receiver module mainly is made up of radio-frequency channel and digital received processing section, and as shown in Figure 1, the radio-frequency channel comprises radio frequency amplification, frequency conversion for the first time, AGC amplification, frequency conversion for the second time, low-pass filtering, AD converter etc.Because Beidou I navigation system uses dedicated frequency to transmit, existing receiver module generally will use a plurality of general-purpose devices to realize the radio-frequency channel, this just causes the existing receiver module cost of triones navigation system, power consumption higher, and the volume of receiver module is bigger.Though existing special-purpose receiving cable chip of the Big Dipper has reduced the volume of radio-frequency channel, but still there is the problem of big (about 600 milliwatts), cost higher (more than 800 yuan) of power consumption.

Summary of the invention

Goal of the invention: the purpose of this utility model is the problem at existing Beidou satellite navigation system receiving module existence, and the Beidou satellite navigation system receiving module of a kind of low cost, low-power consumption, small size is provided.

Technical scheme: a kind of Beidou satellite navigation system receiving module, it comprises frequency converter, bandpass filter, GPS radio frequency chip and the digital received processor that is electrically connected successively; Frequency converter carries out frequency conversion to satellite-signal of the Big Dipper of low noise amplifier output, obtains the signal of carrier frequency in GPS L1 frequency; Bandpass filter allows carrier frequency shift pass through to satellite-signal of the Big Dipper of GPS L1 frequency, other frequency signal and the out-of-band noise of the output of the frequency converter of filtering simultaneously; The GPS radio frequency chip to carrier frequency be that the Big Dipper signal of GPS L1 frequency amplifies, double conversion, filtering, AD conversion, obtain digital baseband signal or digital medium-frequency signal; The digital received processor carries out digital quadrature down coversion, despreading, demodulation again, deciphers, resolves processing the digital baseband signal or the digital medium-frequency signal of the output of GPS radio frequency chip, realizes location, time service function.

Wherein, described GPS L1 frequency is 1574.92～1575.92MHz.

Wherein, the input end of frequency converter is electrically connected with amplifier, and this amplifier is looked the concrete condition setting.

Wherein, described bandpass filter is a GPS L1 frequency bandpass filter.

Receiver module of the present utility model adopts a kind of new Beidou satellite navigation system receiving module radio-frequency channel to realize.Promptly use the general frequency conversion chip that volume is little, cost is low, earlier the Big Dipper satellite signal carrier frequency shift is arrived in the GPS L1 frequency range; Use the bandpass filter of GPS L1 frequency to carry out filtering then, with the GPS radio frequency chip to the Big Dipper signal that is converted to the GPS frequency amplify, frequency conversion, filtering, AD conversion, obtain digital baseband signal or digital medium-frequency signal; Receive processing by the digital received processor again, processing such as realize digital quadrature down coversion, despreading, demodulation, decipher, resolve, realize functions such as location, time service, reduce the radio-frequency channel number of devices and then reduce the module volume, reduce the purpose of module cost and power consumption to reach.

Beneficial effect: (1) Beidou satellite navigation system receiving module of the present utility model compared with prior art, only use 1 frequency conversion chip and 1 GPS radio frequency chip in the radio-frequency channel part, the device that uses significantly reduces, shared board area can be reduced to below 2 square centimeters, thereby the volume of whole receiver module is reduced.(2) since the GPS radio frequency chip specially at the low-power consumption GPS Terminal Design, its power consumption adds upconverter and amplifier less than 100 milliwatts, the power consumption of whole radio-frequency channel part can be reduced to below 300 milliwatts.(3) because the output of frequency converter and GPS radio frequency chip is all very big, its price is all at several dollars, and the cost of the radio-frequency channel part of big-dipper satellite system receiving module can be reduced to about 150 yuan thereby make in batches.

Description of drawings

Below in conjunction with accompanying drawing the utility model is done further explanation.

Fig. 1 is the structured flowchart of existing Beidou satellite navigation system receiving module.

Fig. 2 is the structured flowchart of Beidou satellite navigation system receiving module of the present utility model.

Fig. 3 is a MAX2769 chip theory diagram.

Embodiment:

As shown in Figure 1, general main first frequency mixer, first if bandpas filter, first intermediate frequency variable gain amplifier, second frequency mixer, second if bandpas filter, second intermediate frequency amplifier and the analog to digital converter that is electrically connected successively that comprise in the radio-frequency channel of existing Beidou satellite navigation system receiving module.The digital received processor is generally by realizing digital quadrature down coversion, spread spectrum code acquisition and tracking, separate and be in harmonious proportion the programmable logic array (FPGA) of functions such as decoding, and the microprocessor composition of the information processing function such as is resolved in realization position, time.At first frequency mixer, carrier frequency is the satellite-signal of the Big Dipper and the first local oscillation signal mixing of 2491.75MHz, and obtaining frequency is first intermediate-freuqncy signal (the concrete frequency of first intermediate frequency can have multiple choices) of 200～900MHz; After the first if bandpas filter filtering, first intermediate-freuqncy signal is given first intermediate frequency variable gain amplifier of back, this amplifier amplifies to received signal, and its gain is generally adjusted automatically according to the size of received signal power, and this grade amplifier is called the AGC amplifier usually again; First intermediate-freuqncy signal after AGC amplifies obtains second intermediate-freuqncy signal that frequency is about 12.24MHz in second frequency mixer and the second local oscillation signal mixing; Second if bandpas filter is generally low-pass filter, it filter out that second frequency mixer produces with frequency component and high frequency noise; Second intermediate-freuqncy signal obtains digital medium-frequency signal by analog to digital converter again after second intermediate frequency amplifier further amplifies, analog to digital converter generally adopts 8 bit converter.

Principle of the present utility model is that GPS L1 frequency is arrived in the frequency transformation of a satellite-signal of the Big Dipper, realizes the receiving RF channel function with the GPS chip then, and the digital processing part still adopts prior art.Receiver module of the present utility model can be applicable to that receiver or other need to locate, in the equipment of time service, present embodiment is that example is illustrated to be applied to receiver.Receiver module is installed in the receiver, and receiver also includes receiving antenna and low noise amplifier etc.

As shown in Figure 2, embodiment comprises amplifier 5, frequency converter 1, bandpass filter 2, GPS radio frequency chip 3 and the digital received processor 4 that is electrically connected successively.Satellite-signal of the Big Dipper that the receiving antenna of receiver receives is after low noise amplifier amplifies, giving amplifier 5 amplifies, when the difference of low noise amplifier gain and the radio-frequency cable loss that is connected low noise amplifier and this receiver module during, can not use amplifier 5 greater than 40dB.Signal of the Big Dipper after amplifier 5 amplifies is given frequency converter 1, and frequency converter 1 can adopt the built-in frequency synthesizer frequency conversion chip of RF Micro Devices company (RFMD company), as RF2051, RF2052, RF2053.Frequency converter 1 is that the satellite-signal of the Big Dipper of 2491.75MHz and local oscillation signal that frequency is 916.33MHz carry out mixing with carrier frequency, obtains the signal that carrier frequency is a GPS L1 frequency.According to actual conditions, can the appropriate change local frequency, obtain carrier frequency at 1574.92～1575.92MHz, i.e. signal in 1575.42 ± 0.5MHz scope, but optimum frequency is 1575.42MHz.Bandpass filter 2 is a GPS L1 frequency bandpass filter, can adopt Surface Acoustic Wave Filter such as TRIQUINT company 856561.Bandpass filter 2 allows the satellite-signal of the Big Dipper that is converted to 1575.42MHz pass through, and gives the GPS radio frequency chip 3 of back.GPS radio frequency chip 3 can adopt the MAX2769 of Maxim company, Figure 3 shows that the circuit theory diagrams of MAX2769, and this chip is made up of low noise amplifier, orthogonal mixer, variable gain amplifier, AD converter and frequency synthesizer.The satellite-signal of the Big Dipper that is converted to GPS L1 frequency can be given chip internal low noise amplifier (LNA) by the 25th pin or the 27th pin and amplify, and the signal after the amplification is exported from the 2nd pin, gives the quadrature frequency changer of chip internal then from the 5th pin; In quadrature frequency changer, carrier frequency is the signal of GPS L1 frequency and the orthogonal local oscillation signal mixing that chip internal VCO exports through phase shifter; Orthogonal mixer output after wave filter (FILTER) filtering, obtains the quadrature base-band analog signal in sheet; The quadrature base-band analog signal amplifies through the chip internal variable gain amplifier, and after the analog to digital conversion (ADC), obtains the digital baseband signal of bit quantization, exports from the 20th, 21,17,18 pin.Thereby realize the radio-frequency channel function of a receiver module of the existing Big Dipper.4 pairs of digital baseband signals of digital received processor or digital medium-frequency signal receive processing, realize the reception to Big Dipper signal, and then realize location, time service.

The utility model use be widely used in communicating by letter, the general frequency conversion chip of radio and television, and the GPS radio frequency chip that is used for the GPS receiver in a large number, comparing with the receiver module of existing Beidou satellite navigation system can be on the basis of realizing identical function, reduce the volume of receiver module greatly, significantly reduce the cost and the power consumption of receiver module.

The above only is a preferred implementation of the present utility model; should be pointed out that for those skilled in the art, under the prerequisite that does not break away from the utility model principle; can also make some improvements and modifications, these improvements and modifications also should be considered as protection domain of the present utility model.

Claims

1, a kind of Beidou satellite navigation system receiving module is characterized in that: it comprises frequency converter (1), bandpass filter (2), GPS radio frequency chip (3) and the digital received processor (4) that is electrically connected successively;

Frequency converter (1): the Big Dipper satellite signal to low noise amplifier output carries out frequency conversion, obtains the signal of carrier frequency in GPS L1 frequency;

Bandpass filter (2): allow carrier frequency shift pass through, other frequency signal and the out-of-band noise of the output of the frequency converter of filtering simultaneously to the Big Dipper satellite signal of GPS L1 frequency;

GPS radio frequency chip (3): to carrier frequency be that the Big Dipper signal of GPS L1 frequency amplifies, double conversion, filtering, AD conversion, obtain digital baseband signal or digital medium-frequency signal;

Digital received processor (4): digital baseband signal or digital medium-frequency signal to the output of GPS radio frequency chip carry out digital quadrature down coversion, despreading, demodulation again, decipher, resolve processing, realize location, time service function.

2, Beidou satellite navigation system receiving module according to claim 1 is characterized in that: described GPS L1 frequency is 1574.92～1575.92MHz.

3, Beidou satellite navigation system receiving module according to claim 1 is characterized in that: the input end of frequency converter (1) is electrically connected with amplifier (5).

4, Beidou satellite navigation system receiving module according to claim 1 is characterized in that: described bandpass filter (2) is a GPS L1 frequency bandpass filter.