CN204103915U - A kind of airborne CPE radio system based on LTE FDD technology - Google Patents

Abstract

The utility model discloses a kind of airborne CPE radio system based on LTE FDD technology, comprise processor, fpga logic circuit module, CLOCK circuit module, digital-to-analogue/analog to digital conversion circuit module, local oscillation circuit module, transceiver circuit module, processor is connected with fpga logic circuit module and upper PC respectively, fpga logic circuit module and digital-to-analogue/analog to digital conversion circuit model calling, CLOCK circuit module respectively with processor, digital-to-analogue/analog to digital conversion circuit module, local oscillation circuit module is connected with fpga logic circuit module, transceiver circuit module respectively with local oscillation circuit module, digital-to-analogue/analog to digital conversion circuit module is connected.The utility model effectively can complete the modulation from baseband carrier data to radiofrequency signal, and from radiofrequency signal to the demodulation of baseband carrier data, for the speed that aircraft is surfed the Net is fast and the high guarantee provided of quality of video.

Description

A kind of airborne CPE radio system based on LTE FDD technology

Technical field

The utility model relates to communication technical field, especially relates to a kind of airborne CPE radio-frequency (RF) circuit module system based on LTE FDD technology.

Background technology

For many years, closing hand phone and wireless device before flight takeoff, fastening seat belts, is the topic of aviation safety prompting invariability.Being on the one hand to prevent wireless signal countermeasure aircraft to take off landing, is also because upper-air route cannot cover this awkward fact on the other hand.The aircraft of term of voyage is that civilian mobile communication is difficult to arrive " blind area " always.Along with the fast development of science and technology, smart mobile phone and mobile communications network are day by day popularized in China, domestic passenger, and especially long-distance business visitor, the demand for on-air radio network promotes just day by day.Can at term of voyage, realize at any time with the communication in the external world, day by day become the demand that busy business people urgently thirsts for.Along with the development of technology, this demand becomes possibility gradually.

At present, civil aviation realizes mobile communication, comparatively feasible resolving ideas has two kinds: adopt satellite link to be connected with terrestrial communication networks, or utilize ground private base station to aerial covering.Satellite communication Method compare is ripe, and strong security, disturbs little, and capacity is large, and wide coverage is stable.Concerning boat enterprise, disposing the course line that satellite communication facility realizes voice-and-data aboard and cover, is a newly-increased non-boat business profit direction, however due to the repacking cost of satellite communication system very high, can cost-recovering be effectively also an individual unknown number.Meanwhile, the bandwidth critical constraints of satellite communication, costly, be difficult to for passenger provides scale service, this is the obstacle that satellite communication is difficult to promote in civil aviation course line covering.If adopt the mode that base station covers sky, user can obtain the communication bandwidth that can reach up to a hundred million fully, expense also can be accepted by users, can solve the problem that multi-modulation scheme (GSM, CDMA, TD-SCDMA, WCDMA etc.) uses simultaneously aboard simultaneously.Therefore, although this communication mode based on ground base station limits by region to a certain extent, comparatively satellite mode is low generally for its cost, has more and more become the first-selection that course line covers.

The airborne CPE (Customer Premise Equipment) that the utility model relates to is a LTE FDD type UE equipment on aircraft for oceangoing voyage associating Duo Jia supplier of nation develops for CAAC, is mainly used in as aerial passenger provides online and VOD service.In whole aviation communication system, realize the access of internal passenger's voice, 2G/3G and Wi-Fi data service, externally realize the exchanges data with course line special LTE base station eNodeB chain group along the line.The utility model relates to radio-frequency apparatus wherein, it acts on the protocol requirement of being mainly correlated with based on LTE and completes bottom from baseband carrier data to the modulation of radiofrequency signal, and from radiofrequency signal to the demodulation of baseband carrier data, realize the communication with upper strata Base Band Unit.

Utility model content

For realizing above object, the technical solution of the utility model is:

A kind of airborne CPE radio system based on LTEFDD technology, comprise processor, fpga logic circuit module, CLOCK circuit module, digital-to-analogue/analog to digital conversion circuit module, local oscillation circuit module and transceiver circuit module, processor respectively with fpga logic circuit module, upper PC connects, fpga logic circuit module and digital-to-analogue/analog to digital conversion circuit model calling, CLOCK circuit module respectively with processor module, digital-to-analogue/analog to digital conversion circuit module, local oscillation circuit module is connected with fpga logic circuit module, transceiver circuit module respectively with local oscillation circuit module, digital-to-analogue/analog to digital conversion circuit module is connected.

Described processor, controls and information interaction for back-up system, comprises configuration fpga logic circuit module and clock circuit module, and accepts the monitoring of upper PC;

Described fpga logic circuit module, for completing framing or the demodulation of I/Q data and C & M data according to upper-layer protocol, realizes following the mutual of receiving-transmitting chain signal simultaneously;

Described clock circuit module, for providing clock to processor, fpga logic circuit module, digital-to-analogue/analog to digital conversion circuit module, local oscillation circuit module;

Described digital-to-analogue/analog to digital conversion circuit module is for completing the conversion between digital signal and analog signal;

Described local oscillation circuit module is for providing the bridge of the conversion between intermediate-freuqncy signal and radiofrequency signal;

Described transceiver circuit module is for completing conversion and the transmitting-receiving of middle radiofrequency signal.

And described processor, comprises cpu chip, the memory cell be connected with cpu chip, interface circuit.

Cpu chip is the core of processor circuit module, can realize, adopt Vxworks operating system with POWER PC, for completing configuration and the monitoring of each business chip, produces and interactive controlling, management information.And realize the access to external memory storage (FLASH and SDRAM) by local data bus and address bus, the function that completion system self-starting, program load.

Memory cell comprises FLASH and SDRAM chip, for accepting the operation of CPU, stores data.The data stored comprise system program, FPGA code, I/Q data source and other log informations.

Described interface circuit comprises Ethernet interface and RS-232 interface, for outer computer interactive information.

And described CLOCK circuit module comprises two parts, a part provides 50M clock by external crystal-controlled oscillation, for the work clock of cpu chip and FPGA; Another part realizes primarily of special clock chip, produces the synchronised clock of 122.88M to FPGA.

The utility model has highly versatile, and framework realizes simple, and the advantage that resource is few, cost is low, effectively can realize the conversion of base band and radiofrequency signal, establishes the basis that whole airborne equipment normally provides service.And follow test by doing repetitious temperature, verify this radio-frequency (RF) circuit module performance.

Accompanying drawing explanation

Fig. 1 is structured flowchart of the present utility model.

embodiment

Below in conjunction with drawings and Examples, the utility model is described in further detail.

Refer to as shown in figure, the utility model is made up of following part based on LTE baseband circuit blocks radio-frequency unit: processor, fpga logic circuit module, clock circuit module, digital-to-analogue/analog to digital conversion circuit module, local oscillation circuit module, transceiver circuit module.As shown in figure, processor circuit module, application of logic circuit module are electrically connected successively, transmit up-downgoing data and C & M data by the interface of catching up with layer baseband equipment.Wherein:

Described processor for core, completes configuration and the monitoring of each business chip with CPU MPC852T, and can by FPGA with the mode of control word and upper-level BTS interactive controlling, management information.Meanwhile, control section provides the instruction of debug serial port, debugging serial interface, LED, board resetting etc. for debugging single board and fault location.

Described application of logic circuit module take FPGA as core, and its GTX unit receives the downlink data of baseband circuit blocks by SMA mouth, through IR interface protocol, extracts I/Q data and CM data, by I/Q data through DUC algorithm, carries out follow-up CFR and DPD process; Obtain two-way digital medium-frequency signal by ADC sampling, become baseband signal through DDC, deliver to IR agreement framing; The CM data that down link extracts deliver to CPU through SCC mouth, and the CM data returned also deliver to FPGA inside by SCC mouth, finally deliver in IR protocol analysis circuit module and become RRU upstream data with I/Q data together framing; PPC852 is communicated with FPGA by three buses (CBUS, DBUS and ABUS), monitors the state information of each circuit module of FPGA internal circuit blocks and the parameter of each circuit module of configuration in the mode of register file; The configuration of FPGA to be downloaded by the mode of serial by CPU and in the renewal of sequence of threads; CPU completes the control of SPI device on this plate by the mode of FPGA expansion I/O port, comprises the chips such as CLK, ADC, DAC, LO, VGA, realizes the access to different I 2C device on board simultaneously.

Described modulus/D/A converting circuit module with ADC and DAC for core, between transceiver circuit module and FPGA.Wherein analog-to-digital conversion part mainly realizes digital uplink function, and namely analog if signal is sampled by ADC, forms digital signal, exports FPGA process to; And digital-to-analogue conversion part is by converting the analog if signal of specific frequency after the Digital Up Convert of DAC to transmitting chain process by the I/Q signal obtained from FPGA from base band.

In described transceiver circuit module, the major function of down link exports to power amplifier unit after the signal that digital-to-analogue conversion exports being carried out filtering, up-conversion, radio frequency amplification; There is provided the gain-adjusted function of certain limit, the change in gain that uncertain and variations in temperature causes with the gain realizing rate of static power and control, compensate power amplifier and radio-frequency devices simultaneously; And the function of up link is amplified and filtering at the radiofrequency signal after LNA process, again by carrying out analog-to-digital conversion after down-conversion, filtering, amplification process, gain-adjusted function is provided simultaneously, compensates the change in gain that LNA unit and radio-frequency devices gain uncertainty and variations in temperature cause.

Described clock circuit module is respectively each circuit module and provides work clock.It comprises two parts, a part provide each circuit module work with road clock, realize primarily of professional clock core; Another part provides 50M system clock to processor chips, is produced by external crystal-controlled oscillation.Part I has two kinds of working methods, a kind of be 122.88M clock to recover from baseband signal as with reference to clock, produce clock for logical block and UFIU UMSC Fiber Interface Unit work; Another kind of mode provides reference clock by Sub-miniature B from the reference signal of outside introducing 10M.

By configuring the I/Q data source file of baseband circuit blocks, radio-frequency (RF) circuit module of the present invention is applicable to multiple types and comprises the service condition that TDD-LTE and FDD-LTE and various bandwidth comprise 5M, 10M, 20M.

Specific embodiment described herein is only to the explanation for example of the present invention's spirit.The utility model person of ordinary skill in the field can make various amendment or supplements or adopt similar mode to substitute to described specific embodiment, but can't depart from spirit of the present utility model or surmount the scope that appended claims defines.

Claims (3)

1. based on an airborne CPE radio system for LTE FDD technology, it is characterized in that: comprise processor, fpga logic circuit module, CLOCK circuit module, digital-to-analogue/analog to digital conversion circuit module, local oscillation circuit module and transceiver circuit module,

Processor is connected with fpga logic circuit module, upper PC respectively, fpga logic circuit module and digital-to-analogue/analog to digital conversion circuit model calling, CLOCK circuit module is connected with fpga logic circuit module with processor, digital-to-analogue/analog to digital conversion circuit module, local oscillation circuit module respectively, and transceiver circuit module is connected with local oscillation circuit module, digital-to-analogue/analog to digital conversion circuit module respectively.

2. a kind of airborne CPE radio system based on LTE FDD technology according to claim 1, is characterized in that: described processor comprises cpu chip, the memory cell be connected with cpu chip, interface circuit.

3. a kind of airborne CPE radio system based on LTE FDD technology according to claim 2, is characterized in that: described interface circuit comprises Ethernet interface and RS-232 interface, by interface circuit and PC interactive information.