CN103595497A

CN103595497A - System and method for utilizing delay forwarding to shield cell phone signals

Info

Publication number: CN103595497A
Application number: CN201310596518.1A
Authority: CN
Inventors: 曹永福; 王利强; 周亚良
Original assignee: Sunwave Communications Co Ltd
Current assignee: Zhejiang Sanwei Communication Technology Co., Ltd.
Priority date: 2013-11-21
Filing date: 2013-11-21
Publication date: 2014-02-19
Anticipated expiration: 2033-11-21
Also published as: CN103595497B

Abstract

The invention discloses a system and method for utilizing delay forwarding to shield cell phone signals. The system comprises a receiving antenna, a sending antenna, a power amplifier, a low noise amplifier module, a frequency mixing module, an analog-digital conversion module, a digital-analog conversion module, and a field programmable gate array (FPGA). Received signals are delayed for one frame (or several frames) and then are amplified and forwarded. Due to the fact that forwarded signals and normal coverage signals are aligned in frame, the same in frequency and the same in modulation technology, self-disturbance is adopted to exquisitely enable the link reinforcement technology, of mobile communication, used for resisting to disturbance not to work, and the purpose of effectively shielding cell phone signals is achieved as long as repeated-sent signals are larger than original signals. Due to the fact that signals in the position of the receiving antenna basically are signals capable of being received by a cell phone nearby, the system and method can shield received air signals of all signal systems, and can be applied to various signals systems (GSM, CDMA, WCDMA, TD-SCDMA, TD-LTE and FDD-LTE).

Description

A kind of employing postpones to forward the system and method for realizing mobile phone signal shielding

Technical field

The present invention relates to the mobile phone signal shielding system of moving communicating field, more specifically, it relates to a kind of employing and postpones to forward the system and method for realizing mobile phone signal shielding.

Background technology

Mobile phone signal shielding system bans use of the place of mobile phone mainly for all kinds of examination halls, school, gas station, church, court, library, conference centre (chamber), cinema, hospital, government, finance, prison, public security, place of military importance etc.Mobile communication covers the complex situations that signal exists multi-modulation scheme ,Duo community, multicarrier etc., and traditional mobile phone signal shielding technology adopts high-power or adopts pseudo-base station to reach the object of shielding.

For using powerful mode, such as for WCDMA system spread-spectrum, gain is 21db, the shielded signal that so traditional high-power WCDMA mobile phone signal shielding Technology Need transmission is greater than normal signal 21db just can reach the object of effective shielding, not only power consumption is large, radiation is large, large to human body animal injury, and can produce to base station the consequences such as interference.And for the mode that adopts pseudo-base station, system complex volume is large, realizes cost higher, the use in inconvenient some place.

Summary of the invention

The object of the invention is to overcome deficiency of the prior art, provide a kind of employing to postpone to forward the system and method for realizing mobile phone signal shielding.

The object of the invention is to be achieved through the following technical solutions.This employing postpones to forward the system that realizes mobile phone signal shielding, this system comprises reception antenna, transmitting antenna, power amplifier, LNA module, frequency mixing module, analog-to-digital conversion module, D/A converter module and on-site programmable gate array FPGA, receiver: reception antenna receives aerial mobile communication wireless signal, after signal being amplified by LNA module, through frequency mixing module, be downconverted into analog if signal, after sampling becomes digital medium-frequency signal through AD, give FPGA, the DDC module of FPGA inside becomes the digital signal of the low rate of zero intermediate frequency after signal is carried out digital mixing and extracted, then the ram memory cell of giving FPGA inside carries out signal storage, send link: the ram memory cell signal of FPGA inside is exported to DUC module and carried out giving DA after Interpolation of signals and digital mixing and convert analog if signal to, through frequency mixing module, becomes launch by transmitting antenna after radiofrequency signal is amplified signal through power amplifier aerial, FPGA is used for carrying out signal sampling rate conversion and signal lag, and the system that is Ams for frame length sent after the time of one frame of time delay to the received signal or N frame.

The frame time length of the communication system of different systems is different, and the time intercropping of time delay changes accordingly.

This employing postpones to forward the implementation method of the system that realizes mobile phone signal shielding, utilize reception antenna to connect aerial signal, after the time of time delay one frame or N frame, by transmitting antenna, send, forward signal is that frame aligns, frequency is identical and modulation technique is identical with normal covering signal.

The invention has the beneficial effects as follows: because recurrent signal is that frame aligns, frequency is identical and modulation technique is identical with normal covering signal, adopt self-interference to make cleverly for the link enhancing technology to jamproof mobile communication all inoperative, the signal that reaches transmission is greater than the object that primary signal can realize effective shielding.Because reception is taken from dual-mode antenna, the signal at the antenna place signal that substantially namely near mobile phone can receive, so the present invention can shield all standard aerial signals that receive, to various standards (GSM, CDMA, WCDMA, TD-SCDMA, TD-LTE, FDD-LTE) the present invention can be suitable for.The realization of native system is simple, and cost is lower, and shield effectiveness is good, can commercialization large-scale popularization use.

Accompanying drawing explanation

Fig. 1 is system schematic of the present invention;

Fig. 2 is the schematic diagram that the present invention forwards after to signal lag one frame;

Embodiment

Below in conjunction with drawings and Examples, the present invention is described further.

Fig. 1 is the schematic diagram that system of the present invention realizes.This employing postpones to forward the system that realizes mobile phone signal shielding, this system comprises reception antenna, transmitting antenna, power amplifier, LNA module, frequency mixing module, analog-to-digital conversion module, D/A converter module and on-site programmable gate array FPGA, receiver: reception antenna receives aerial mobile communication wireless signal, after signal being amplified by LNA module, through frequency mixing module, be downconverted into analog if signal, after sampling becomes digital medium-frequency signal through AD, give FPGA, the DDC module of FPGA inside becomes the digital signal of the low rate of zero intermediate frequency after signal is carried out digital mixing and extracted, then the ram memory cell of giving FPGA inside carries out signal storage, send link: the ram memory cell signal of FPGA inside is exported to DUC module and carried out giving DA after Interpolation of signals and digital mixing and convert analog if signal to, through frequency mixing module, becomes launch by transmitting antenna after radiofrequency signal is amplified signal through power amplifier aerial, FPGA is used for carrying out signal sampling rate conversion and signal lag, and the system that is Ams for frame length sent after the time of one frame of time delay to the received signal or N frame, and the frame time length of the communication system of different systems is different, and the time intercropping of time delay changes accordingly.

As shown in Figure 2, the WCDMA system such as being 10ms for frame length, sends after time delay 10ms to the received signal.

Due to identical with the signal frequency of current base station transmitting, modulating mode (spread spectrum, spreading code and spreading code phase place) identical, mobile phone receives after two kinds of signals (shielded signal and base station signal) are processed simultaneously and is added, as long as the shielded signal of our transmitting be greater than base station signal (for WCDMA system testing proof large with equal 3dB), mobile phone demodulation obtains signal just because the correct demodulation base station signal of the signal that the energy of shielded signal is greater than base station reaches shield effectiveness.

System is to multiple communication standard processing method identical (only need to adjust frame time length), can multisystem integrated.Shielding after only downstream signal time delay being forwarded for frequency division duplex system, and for TDD system, due to time delay one frame, shielded signal uplink and downlink timeslot and base station be strictly to it, thereby shielded later mobile phone, initiatively closes that up transmitting is up can not produce and disturb base station.

All employings be equal to replace or equivalent transformation forms, adopt time delay aerial signal amplification forwarding mobile phone signal shielding scheme and implementation method, all drop on the protection range of requirement of the present invention.

Claims

1. one kind adopts delay to forward the system that realizes mobile phone signal shielding, it is characterized in that: this system comprises reception antenna, transmitting antenna, power amplifier, LNA module, frequency mixing module, analog-to-digital conversion module, D/A converter module and on-site programmable gate array FPGA, receiver: reception antenna receives aerial mobile communication wireless signal, after signal being amplified by LNA module, through frequency mixing module, be downconverted into analog if signal, after sampling becomes digital medium-frequency signal through AD, give FPGA, the DDC module of FPGA inside becomes the digital signal of the low rate of zero intermediate frequency after signal is carried out digital mixing and extracted, then the ram memory cell of giving FPGA inside carries out signal storage, send link: the ram memory cell signal of FPGA inside is exported to DUC module and carried out giving DA after Interpolation of signals and digital mixing and convert analog if signal to, through frequency mixing module, becomes launch by transmitting antenna after radiofrequency signal is amplified signal through power amplifier aerial, FPGA is used for carrying out signal sampling rate conversion and signal lag, and the system that is Ams for frame length sent after the time of one frame of time delay to the received signal or N frame.

2. employing according to claim 1 postpones to forward the system that realizes mobile phone signal shielding, it is characterized in that: the frame time length of the communication system of different systems is different, and the time intercropping of time delay changes accordingly.

3. one kind adopts employing as claimed in claim 1 to postpone the implementation method that forwarding realizes the system of mobile phone signal shielding, it is characterized in that: utilize reception antenna to connect aerial signal, after the time of time delay one frame or N frame, by transmitting antenna, send, forward signal is that frame aligns, frequency is identical and modulation technique is identical with normal covering signal.